QO

100

- U 5 6

87-3571

1987

C . 2

Center for

Radiation

Research

October 1987

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

NBSIR 87-3571

Research Information Center

National Bureau of Standards

Gaithersburg, Maryland 20899

MBS£

Center for

Radiation

Research

Chris E. Kuyatt, Director

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Measurement Laboratory Center for Radiation Research

Gaithersburg, MD 20899

October 1987

U.S. DEPARTMENT OF COMMERCE, C. William Verity, Jr., Secretary

National Bureau of Standards, Ernest Ambler, Director

ABSTRACT

This report summarizes research projects, measurement method development,

calibration and testing, and data evaluation activities that were carried

out during Fiscal Year 1987 in the NBS Center for Radiation Research.

These activities fall in the areas of atomic and plasma radiation,

radiation physics, radiometric physics, radiation sources and

instrumentation, ionizing radiation, and nuclear physics.

Key Words: Atomic radiation, ionizing radiation; measurement support;

nuclear radiation; plasma radiation; radiation

instrumentation, radiation measurements; radiation physics,

radiation sources; radiometric physics.

l
INTRODUCTION

This report is a summary of the technical activities of the NBS

Center for Radiation Research (CRR) for the period October 1, 1986 to

September 3U, 1987. The Center is one of four Centers in the National

Measurement Laboratory.

The Center for Radiation Research develops and maintains the

scientific competences and experimental facilities necessary to provide

the Nation with a central basis for uniform physical measurements

measurement methodology, and measurement services in the areas of near infra-red radiation, optical (visible) radiation, ultraviolet radiation,

and ionizing radiation (x rays, yamma rays, electrons, neutrons,

radi oacti vi ty , etc.); provides government, industry, and the academic

community with essential calibrations for field radiation measurements

needed in such applied areas as nuclear power, liyhtiny, solar

measurements, aerospace, defense, color and appearance, health care,

radiation processing, advanced laser development, and radiation protection

for public safety; carries out research in order to develop improved

radiation standards, new radiation measurement technology, and improved

understandi ny of atomic, molecular, and ionizing radiation processes, and

to elucidate the interaction of radiation and particles (electrons,

neutrons, and ions) with inanimate and biological materials; collects,

compiles, critically evaluates, and supplements the existing atomic,

molecular, and ionizing radiation data bases in order to meet the major

demands of the Nation for such data; and participates in col 1 aborati ve efforts with other NBS centers in the i nterdi sci pi i nary applications of

radi ati on.

The summary of activities is organized into six parts, one for each

of the five Divisions in the Center: Atomic and Plasma Radiation,

Radiation Physics, Radiometric Physics, Radiation Sources and

Instrumentation, and Ioniziny Radiation, and one for the Nuclear Physics

Croup. A major subyroup of the ionizing Radiation Division is the Office

of Radiation Measurement . Each organizational unit tells its own story in

its own way. In general there is an introduction followed by a series of

short reports on current activities, publications during the year, talks

given, committee participation, and professional interactions.

A detailed table of contents has been provided to permit the reader

to find those activities of greatest interest. To obtain more information

about particular work, the reader should address the individual scientists

or their division, c/o Center for Radiation Research, Radiation Physics

Building, C229, National Bureau of Standards, Cai thersburg, MD 20899.
Table of Contents

ABSTRACT i

INTRODUCTION ii

CRR ORGANIZATION CHART vii

ATOMIC AND PLASMA RADIATION - Division 531 1

Atomic Spectroscopy Group 3

Atomic Radiation Data Group 6

Plasma Radiation Group 9

Invited Talks 14

Publications 16

Publications in Preparation 22

Technical & Professional Committee Participation & Leadership .... 24

Major Consulting and Advisory Services 26

Journal Editorships 28

Trips Sponsored by Others 29

Calibration Services Performed 31

Sponsored Seminars and Colloquia 32

RADIATION PHYSICS - Division 533 35

Far Ultraviolet Physics Group 38

Electron Physics Group 45

Photon Physics Group 51

Sponsored Workshops, Conferences, and Symposia 59

Invited Talks 60

Publications 65

Publications in Preparation 69
Technical & Professional Committee Participation & Leadership .... 72

Major Consulting and Advisory Services 75

Journal Editorships 76

Trips Sponsored by Others 77

Calibration Services Performed 79

Sponsored Seminars and Colloquia 80

RADIOMETRIC PHYSICS - Division 534 83

Spectral Radiometry 84

Spectrophotomet ry Group 87

Radiometric Measurement Services Group 90

Invited Talks 95

Publications 96

Publications in Preparation 98

Technical & Professional Committee Participation & Leadership ... 101

Journal Editorships 104

Standards Committee Meetings 105

Major Consulting and Advisory Services 106

Standard Reference Materials 107

Measurement Assurance Services 109

Calibration Services Performed 110

Trips Sponsored by Others Ill

Sponsored Seminars and Colloquia 112

i v
RADIATION SOURCE AND INSTRUMENTATION - Division 535 113

Accelerator Research 113

Linac Operations 121

Radiation Instrumentation 121

Mechanical Instrumentation 126

Invited Talks 127

Publications in Preparation 123

Technical & Professional Committee Participation & Leadership .... 129

Major Consulting and Advisory Services 132

IONIZING RADIATION DIVISION - Division 536 133

Radiation Theory Group 135

Radiation Chemistry & Chemical Dosimetry Group 138

Neutron Measurements & Research Group 144

Neutron Dosimetry Group 152

Radioactivity Group 158

X-Ray Physics Group 163

Dosimetry Group 166

Office of Radiation Measurement 173

Sponsored Workshops, Conferences, and Symposia 179

Invited Talks 180

Publications 185

Publications in Preparation 191

Technical & Professional Committee Participation & Leadership 199

Major Consulting and Advisory Services 210

v
Journal Editorships 220

Trips Sponsored by Others 221

Standard Reference Materials 224

Calibration Services Performed 225

Sponsored Seminars and Colloquia 229

NUCLEAR PHYSICS GROUP - 530.1 231

Sponsored Workshops, Conferences, and Symposia 242

Invited Talks 243

Publications 245

Publications in Preparation 247

Technical & Professional Committee Participation & Leadership 248

Major Consulting and Advisory Services 250

Trips Sponsored by Others 251

Calibration Services Performed 253

Sponsored Seminars 254

LIST OF ACRONYMS 255

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TECHNICAL ACTIVITIES

Division 531, Atomic and Plasma Radiation

The Atomic and Plasma Radiation Division carries out a broad range

of experimental and theoretical research on atomic structure and atomic

radiation in plasmas. The division determines a large variety of atomic

radiation and collision data, encompassing wavelengths of spectral lines;

atomic energy levels; ionization potentials; atomic transition probabilities; plasma line broadening parameters; ionization and excitation cross sections and rate coefficients, and dielectronic rate coefficients. Two

data centers located in the division critically evaluate and compile

atomic energy levels and transition probabilities. The division is also

engaged in research on the interaction of atomic radiation with plasma

environments, and it explores such effects to provide a full fundamental

understanding of atomic processes in plasmas utilized for technological

applications as well as to develop new measurement techniques.

Furthermore, well-defined atomic radiation sources are developed as VUV

radiometric standards or wavelength standards.

These activities support several areas of science and technology.

A part of our work ties into magnetic fusion research, where atomic data

are needed for studies of the effects of heavy ion impurities and where

atomic radiation processes are utilized as non-i nterferi ng plasma probes.

Other areas of direct applications are parts of the Strategic Defense

Initiative (SDI), vacuum ultraviolet and x-ray laser development,

materials processing by plasmas, plasma chemistry, space astronomy and

solar physics. In all these areas, atomic radiation data are one of the

basic ingredients, and plasma measurement techniques utilizing the emitted

radiation are applied. Our vacuum ultraviolet radiometry work is now providing small calibrated radiation source packages to allow radiometric

calibrations on board spacecraft, which are used, for example, on the

space shuttle for accurate monitoring of the solar ultraviolet radiation,

and are part of the space telescope instrumentation.

The division consists of three technical groups: Atomic Spectroscopy, Atomic Radiation Data, and Plasma Radiation. The division

currently has 19 professional physicists, among them 18 Ph.D.s. During

1987 the division has had 10 guest scientists from China (4), Israel (2),

France (1), India (1), Soviet Union (1), and Sweden (1).

Some of our significant accomplishments during the past year are:

• Excitation of spectra of very highly ionized atoms mainly using

the Omega laser at Rochester University; accurate measurements and

identifications have given reference wavelengths and provide

valuable comparison for atomic structure calculations that include

large relativistic and QED contributions.

1
Division 531, Technical Activities (cont'd.)

© Progress in high-precision laser spectroscopy includes wavenumber

measurements with Fabry-Perot wavemeter system at ±1 MHz accuracy

level and construction of atomic-beam apparatus, that contains

large concentration of atoms in metastable states.

® Completion of compilation of critically evaluated atomic

transition probability data for the elements scandium through

nickel, in all stages of ionization, to be published as Vol . Ill

of the series "Atomic Transition Probabilities."

• Calculation of QED corrections to term energies of many-el ectron

atoms and ions.

® Measurement of cavity gain and losses for some C

3+ levels in a theta pinch plasma.

© Characteri zati on of pulsed capillary discharge as irradiance

source for the XUV region.

These and other activities are discussed in the following sections, where

the principal work of the three technical groups during the past year is

descri bed

.

2
Division 531, Technical Activities (cont'd.)

I . Atomic Spectroscopy Group

(a) Highly Ionized Atoms

The energy levels and wavelengths for spectra of highly ionized

atoms are necessary data for modeling and diagnostics of high-temperature

plasmas occuring in tokamaks and other fusi on-research machines, x-ray

laser research, solar flares, etc. These spectra are also of basic

interest for testing atomic calculations including large relativistic and

quantum-field (QED) contributions. We have excited very highly charged

ions in several sources: the highest temperatures were obtained in

plasmas produced by the OMEGA laser at Rochester, and we have also used

plasmas obtained with lasers at Los Alamos and NBS, plasmas generated in

the TEXT tokamak at the University of Texas, and sliding-spark and vacuumspark plasmas at NBS. Our new measurements of 3s-3p, 3p-3d, and 3d-4f

transitions obtained from Na-like ions in such plasmas extend from Cu 18+

to Sn 3 ^". The wavelengths were compared with Dirac-Fock calculations

including transverse Breit and QED contributions. The overall accuracy of

the wavelengths was improved to ±0.007 A by regularizing the small differences between the experimental and calculated wavelengths, and the results

were extended from Ar 7+ to Xe 43+

. Errors as large as 0.05 A in previous

measurements of some of the lines have been corrected in this work. The

wavelengths range from 9 to 713 A and will be useful as standards,

especially in the 50-500 A region (J. Reader, V. Kaufman, J. Sugar, and

collaborators from NRL).

We also measured the 3p 6 3d 9 2 D-3p 5 3d 10 2

P lines in Co-like ions

from Ru 17+ to Au 52+. The experimental wavelengths were again compared

with predictions of relativistic ab initio theoretical calculations, these

comparisons being extended to incTude our previous results for this

sequence up to U 85+

. Chen (LLNL) has recently shown that electron

correlation effects must also be included to obtain calculated wavelengths

in good agreement with our accurate experimental values. A regularizing

procedure similar to that described above reduced the uncertainty of the

wavelengths to ±0.005 A, which makes them useful as reference wavelengths

(8-93A) (J. Reader, N. Acquista, and NRL col 1 aborators )

.

Our most recently completed work includes similar results for

several other i soel ectroni c sequences: Fe-like ions to Gd 38+ and Zn-like

ions (J. Reader and col 1 aborators ) ; Mg -like and Ar-like ions of Cu through

Mo; many Cd-like and In-like ions; as well as various ions of selenium

V. Kaufman and J. Sugar). Detailed comparisons with theoretical

calculations have been carried out for all these spectra.

3
Division 531, Technical Activities (cont'd.)

(b) Laser Spectroscopy: High-Accuracy Measurements and Calculations

of Atomic Structure

A basic objective of our laser spectroscopy program is to test

experimentally the most accurate theoretical calculations for selected

atoms. The development of theoretical methods that treat electroncorrelation, relativistic, and QED energy contributions accurately and

consistently is one of the fundamental problems of current atomic physics.

Helium is of special importance because the el ectron-correl ati on contributions can be calculated to almost arbitrary accuracy in a non-relativistic approximation, and the inclusion of two-electron relativistic and

QED effects is simpler than for atoms having more electrons.

Atomic-Beam Source. We have made good progress in the design

and construction of a "metastable" atomic-beam apparatus for rare gases.

We are testing the vacuum system and metastable-atom source and have begun

assembling parts for the excitation and detection regions. We plan to use this beam source to observe highly excited Rydberg states of helium,

beginning with the 2 *S - n

l P transitions. Accurate wavenumber determinations for this series should allow determination of the 2

X S ionization energy within an error of a few parts in 10 9

. This will permit new tests of the most accurate theoretical calculations in helium including

two-electron QED effects (C. Cromer and C. Sansonetti).

Measurements with Fabry-Perot Wavemeter. Hi gh-accuracy measurements of dye-laser wavelengths are required to realize the full potential

of our metastable beam. We have made extensive tests of the Fabry-Perot

system developed in our laboratory. This system, which is based on computer acquisition of F-P fringe patterns from an array detector, makes

a measurement of any dye-laser wavelength every 1.5 seconds. Using three

different i nterferometer spacer lengths, we have measured more than 40

Doppler-free transitions in molecular iodine. This work has allowed

correction for effects of dispersion of reflection phase-change within

uncertainties smaller than 2 MHz, and we expect to provide a new list of

reference lines in iodine accurate to 1-2 MHz (C. Sansonetti).

Low-Pressure Discharge Source. Development of techniques for

detailed investigations of complex atomic spectra is of interest for basic

atomic physics and for obtaining data needed for laser physics, plasma

physics, astrophysics, etc. We plan to apply state-selective, statelabeling and optical double-resonance techniques to selected complex

atomic spectra. We are investigating el ectri c-di scharge sources in this

connection because they provide both atoms and ions in excited initial

states. We have developed a very low-pressure discharge cell to minimize

collisional transfer of excitation from laser-excited levels to other

4
Division 531, Technical Activities (cont'd.)

levels. Using double-resonance (two-laser) intermodulation optogalvanic

spectroscopy with neon discharges at 10 to 30 mTorr, we have observed

resonances having high si gnal -to-noi se (~ 10 3

) and find almost no transfer

of modulation to neighboring levels (C. Cromer and M.-Q. He).

He! i urn Cal cul ati ons

.

As part of our program on the helium atom,

we combined very accurate variational calculations of Isnd and lsnf term

energies with previously calculated values for the magnetic and other

f i ne-structure interactions to predict nD and nF ionization energies and

fi ne-structure separations (n = 3-8). Comparisons of the nD energies with

other available data gave improved values for the relativistic contributions. The agreement of our calculated nF f i ne-structure separations with

experiment (± 0.1 to ± 1 MHz) is the first confirmation of the Breit finestructure theory for lsnf configurations. (J. Sims, Center for Applied

Mathematics, and W. C. Martin.)

(c) Atomic Energy Levels Data Center

We completed the critical evaluation and compilation of energy

levels for all the molybdenum spectra Mo I through Mo XLII (Mo 41+ ). In

collaboration with a Japanese group, we have also compiled the wavelengths

and energy-levels classifications for all lines of Mo 5+ through Mo 41+

; these spectra are of special interest for fusion-plasma research. Our

similar collaborative work on compiling all lines for the nickel ions Ni 5+

through Ni 27+ was completed and submitted for publication (J. Sugar,

A. Musgrove, W. L. Wiese).

We are now reviewing and compiling energy-levels data for all

the sulfur and copper spectra. We plan to continue our collaboration with

the Japanese group by compiling wavelengths and other data for lines for

copper and chromium in all ionization stages above five-times ionized. We

have almost finished reviewing and compiling wavelengths and energy-levels

classifications for all spectra of scandium as part of our program to

build a more complete data base for atomic spectra (V. Kaufman, J. Sugar,

W . C . Ma rt i n )

.

We plan to publish a fourth supplement to our Bibl iography on Atomic Spectra , covering the period January 1984 through December 1987.

In connection with the 20th General Assembly of the International Astronomical Union, to be held in Baltimore next year, we have submitted a report on recent laboratory research on atomic spectra of interest for

astrophysics. We periodically supply lists of references on atomic

spectral data for fusion-plasma research to be included in bibliographies

issued by the International Atomic Energy Agency (A. Musgrove,

W. C. Martin).

5
Division 531, Technical Activities (cont'd.)

1 1 . Atomic Radiation Data Group

The work of this group is entirely theoretical and consists of two

major areas: (1) theoretical studies of atomic structure and processes,

and (2) critical evaluation and compilation of atomic transition probability and spectral line shape data. The first activity involves the

development of advanced theoretical methods and their implementation to

calculate atomic data. The main areas of activity have been dielectronic

recombination, relativistic quantum mechanics, electron correlation, and

radiative and collisional transition rates. The critical evaluation and

compilation of transition probability and spectral line shape data takes

place in the Data Center on Atomic Transition Probabilities, which also

maintains an up-to-date bibliography of the literature in these fields.

(a) Theoretical Studies

Substantial progress has been made in our capability to calculate relativistic effects in atomic structure. The extension of Lamb

shift calculations for hydrogen-like ions to the n = 3 levels along with a critical study of screening corrections have allowed us to take into

account all the electrons of the atom in estimating Lamb shift corrections

for many-el ectron atoms. The trends of excitation energies in highly

ionized ions of the sodium i soel ectronic sequence and X-ray hole state

transition energies have both been brought into significantly better

agreement with available experimental data than was previously the case.

(Y.-K. Kim and P. J. Mohr)

Our computer codes for relativistic distorted wave calculations

have been rewritten and generalized to handle electron-impact processes

for atoms and ions of arbitrary configuration. Previous versions were

only able to calculate excitation cross sections of alkali-like ions.

Dr. Wen-Jia Qian, a guest scientist from the People's Republic of China,

has begun to participate in the utilization of this program for the

calculation of relativistic electron-atom collision cross sections.

(Y.-K. Kim and W.-J. Qian)

The current phase of our studies of f-value bounding procedures

has ended with the return of Dr. D. Roginsky to Israel. A number of novel

variations of upper and lower bounds theorems have been developed for the

purpose of tightening the bounds, some of them during Dr. Roginsky' s stay

here. However, till now the only applications have been model studies on hydrogen. We therefore carried out numerical calculations on the HartreeFock approximation for the resonance transitions of lithium and sodium.

The purpose was to test the efficacy of the theorems on a many- electron

atom and on a model which is known to produce rather accurate f-values.

The results, not surpri si ngly , were mixed; some procedures held up, some

did not. We were able to calculate a bounds width for lithium of 3%,

6
Division 531, Technical Activities (cont'd.)

which is approximately equal to the known error for the Hartree-Fock

result. (A. Weiss and D. Roginsky)

Our production code for dielectronic recombination rates has

been used to calculate rate coefficients for selected ions in the neon,

nitrogen, carbon, boron and beryllium i soel ectroni c sequences. Parametric

fits have been made to these data and analytic interpolation formulas

developed, which permit interpolation for other ions in these sequences,

and which make the information more easily usable in plasma modeling calculations. All these data have been computed in the single configuration,

LS coupling approximation. Currently, the codes are being modified to

include configuration interaction and intermediate coupling, and the

modification of dielectronic recombination rates by the plasma environment

is being investigated. (L. Roszman)

During the past year, we hosted a number of atomic theorists,

some for an extended period of time, some as regular weekly visitors.

P. J. Mohr (NSF) has spent one day a week, most of this year,

working with Y.-K. Kim on computational aspects of QED problems.

Recently, we were pleased to have Dr. Mohr join us as a full time staff

member. He will be an important participant in the development of better

methods to predict quantum el ectrodynami cal effects in atoms and atomic

i ons

.

M. A. Ali (Howard Univ.) also spends one day a week here,

working with Dr. Kim on relativistic atomic structure calculations for

heavy atoms.

J. P. Desclaux (Grenoble) visited our group for a month to

collaborate with Kim on the improvement of relativistic atomic physics

codes. His trip was sponsored by a grant from NATO.

D. V. I. Roginsky (Hebrew Univ. of Jerusalem) completed an 18-month visit with us, col 1 aborati ng with A. Weiss on f-value bounds

research

.

J. C. Morrison (Univ. of Louisville) spent 10 weeks with us,

collaborating with A. Weiss and M. Suskin in setting up the most recent

version of the multi-configuration Hartree-Fock codes and studying the

mul ti -confi gurati on referent formulation of perturbation theory.

Wen-Jia Qian (Liaoning Univ., Shenyang, China) has recently

joined us for a year

1 s stay to participate in the calculation of

relativistic electron-atom collision cross sections.

7
Division 531, Technical Activities (cont'd.)

L. Woltz (Univ. of Florida) has been with us for the past year,

collaborating with L. Roszman and W. L. Wiese on problems in the theory of

spectral line broadening.

(b) Data Center on Atomic Transition Probabilities

The critical evaluation of atomic transition probability data

for the iron group elements scandium through nickel, in all stages of

ionization, has now been completed. The typesetting and proofreading of

this material preparatory to final publication are now in the final

stages. This has been a major undertaking which has occupied us for a*

number of years now and which represents the third volume of the NBS

transition probability tables. Interest in these data remains high in

both the astrophysics and fusion communities, which has given rise to a continuous influx of new data in the literature. This in turn has

repeatedly slowed the pace of our critical evaluation work as we strived

to maintain the compilation as most complete and up-to-date as possible.

However, we are now past our cut-off point, and we estimate completion

before the end of this calendar year.

The resignation of Dr. Georgia Martin last year was also an important factor in delaying the completion of this compilation, since it

places a heavier burden of evaluation and tabulation on remaining staff.

Thus, W. L. Wiese spent a good fraction of his year in West Germany (as

recipient of the Humboldt Award) with data compilation work for these iron

group elements to accelerate the tabulation process. We also had to

embark on a search for a replacement for Georgia Martin, a process which

was completed last spring with the hiring of Dr. Mark Suskin, a recent

graduate in theoretical atomic physics from the Johns Hopkins University.

Dr. Suskin has been familiarizing himself with the mechanics of Data

Center operations and has recently begun making use of the most recent

version of the Froese-Fi sher/Hi obert mul ti -conf i gurati on Hartree-Fock

computer codes to make f-value calculations for the nitrogen atom.

We continue to monitor the literature, maintaining an up-to-date

bibliography on site. We also continue to supply, in six-month intervals,

bibliographical reference material for inclusion in the "International

Bulletin on Atomic and Molecular Data for Fusion", published by the the

International Atomic Energy Agency. Furthermore, we compile in three-year

intervals all astrophysi cal ly important literature references for the

"Reports on Astronomy" published by the International Astronomical Union.

A new report covering the period mid-1984 to mid-1987 has been prepared

(W. L. Wiese). We have also completed editing a book of spectroscopic

data for the elements titanium, chromium and nickel, which will soon be

published as part of a series of handbooks for fusion researchers by the

Oak Ridge National Laboratory, the so-called 'Red Books' (Editors:

W. L. Wiese and A. Musgrove). This volume contains material largely taken

from existing NSRDS compilations, including energy levels and wavelengths

of spectral lines, assembled in a format convenient for use by fusion

research scientists.

8
Division 531, Technical Activities (cont'd.)

III. Plasma Radiation Group

The plasma measurements program provides valuable data and measurement techniques for plasma diagnostics, mainly for temperature and density

determinations, for VUV source radiometry, and VUV lasing schemes. The

activity in collisional rate coefficients is of critical importance in

plasma modeling, especially for fusion-type plasmas and VUV laser schemes.

The research on line shapes, atomic transition probabilities, and scattering has impact on gain measurements in lasing media as well as direct

bearing on measurements of plasma densities and temperatures of low

temperature plasmas which are widely used for technological applications.

The studies of population inversion in the theta pinch have led to a better understanding of recombination mechanisms for possible VUV laser

schemes. Pulsed plasma source studies have produced promising new VUV

radiometric sources. Our portable radiometric standards have been used

for many spacecraft calibrations and are still in demand for that

purpose.

(a) Collisional Rate Coefficients with the 50 kJ Theta Pinch

Relative excitation rate measurements of N V and 0 VI lines

arising from up to n=5 levels were completed from experiments on the NBS

50 kJ Theta Pinch. These results were compared with theoretical predictions and the agreement between experiment and theory was found to be

within combined uncertainties. These rates are needed for plasma electron

temperature and density determinations and for modeling of edge plasmas in

tokamaks

.

The effect of recombination from He-like ions was observed for

the first time in the temporal evolution of the intensities of transitions

originating from levels of n=4 and n=5 in Li -like ions. A method to

deduce the effective recombination rate coefficient was developed utilizing these observations.

The experimental conditions with an electron density of

lxlO 16 cm-3 and an electron temperature of 15-20 eV in a C^IL plasma

showed a population inversion in the n=4 levels compared with n=3 levels,

and in the n=5 levels compared with n=4 levels in C IV. The population

ratio of the 4 f / 3d was measured to be 10 and that of 5g/4f was measured to

be 1.6 in our 23 cm long plasma column. Using a confocal mirror cavity, a gain of a factor of 12 was measured on the 2530 A line in experiments

conducted in collaboration with a group from Bell Laboratori es . Experiments are underway to further improve the gain (R. Datla, J. Roberts).

9
Division 531, Technical Activities (cont'd.)

(b) Tokamak Spectroscopy

Absolute excitation rate coefficients for Fe XIV and Ni XVI ions

were measured spectroscopically for the first time using the TEXT Tokamak.

Previous measurements for the Cu XVII ion were verified and measurements

were extended to other transition arrays not covered previously. SURF II and branching ratio calibrated spectrometers in the XUV and VUV spectral

region down to 150 A were used to measure absolute spectral line intensities. Computed values of absolute excitation rates in a distorted wave

approximation and Mewe's semi empi ri cal formula were found to be in good

agreement with the experimental values (R. Datla, J. Roberts).

(c) Calculation of Spectral Line Shapes in Plasmas

We have performed line broadening calculations over a wide range

of plasma conditions. The calculations are state-of-the-art in that they

include ion dynamic effects, which can be very large for some plasma con- ditions, and time ordering for electrons, which is also sometimes significant. We have computed profiles and widths for the Balmer alpha transition of neutral hydrogen over the two orders of magnitude in electron

density for which experimental results are available. Excellent agreement

was found over the full range, while discrepancies of factors of 2 to 5 are observed for certain densities if ion dynamics are not included. We

have obtained parallel results for hydrogen-like He+ for conditions at

which experiments are currently being performed. We have also performed

calculations over the full range of radi ator-perturber reduced mass. We

have identified four regions of qualitatively different influence of ion

dynamics on the line profiles, and have derived validity criteria for each

region. We are continuing work on fully quantal "benchmark" calculations

of plasma shifts of hydrogenic lines; the close coupled scattering calculations are completed.

Finally, we have completed an analytic formalism for the broadening of Lyman lines with time ordered ion dynamics included. This is

essentially a generalization of the "unified" theory to include overlapping strong collisions, using a trinary collision model. The formalism

has been coded for the CYBER computer and excellent results obtained for

Lyman alpha. The code is currently being made more efficient so that

higher lying transitions can be computed on the CYBER 205 (D. E. Kelleher,

D. H. Oza, and J. Cooper ( J I LA ))

(d

)

Transfer Standards for VUV

The commercially available Samson source is being tested as a transfer standard for the irradiance calibrations of VUV spectrometers

using the Branching Ratio Technique. The branching line pairs of 2s-3p

10
Division 531, Technical Activities (cont'd.)

and 3 s- 3p transitions of Li-like nitrogen, oxygen and carbon have been

observed. The 3s-3p transitions in these ions are in the wavelength region

greater than 3000 A where intensity standards for calibration exist.

Therefore, VUV instruments can be calibrated at the wavelengths of 2s-3p

transitions using the branching ratio. Presently, experiments are underway to minimize the uncertainty due to self absorption in the 2s-3p transition (J. Roberts, R. Datla, and J. M. Bridges).

( e) Vacuum Ultraviolet Radiometry with Plasmas

Previous to this year we calibrated the irradiance of the Space

Telescope Optical Simulator (STOS), which was then used to calibrate the

Faint Object Spectrograph (FOS), one of the instruments on the Space

Telescope. Upon completion of this calibration, the FOS and the other

instruments were incorporated into the Space Telescope, which is to be

deployed in orbit by the Space Shuttle. We then performed numerous

calibrations of Pt/Cr-Ne and Pt-Ne hollow cathode lamps for the throughput

tests of the Space Telescope with its installed instruments. In addition

to the FOS, the instruments are the high resolution spectrograph , the

wide-field planetary camera, the faint object camera, and the high speed

photometer. The throughput tests turned out to be highly successful and even more useful than projected. In the past year as a check, we have

recalibrated the hollow cathode lamps which we had originally calibrated

for the throughput tests. Also, the data from one of the lamps used in

the STOS for the calibration of the FOS was analyzed and published in

Applied Optics.

The documentation of our calibration program was completed early

this fiscal year and has recently appeared in print as an NBS Special

Publication. This publication will be valuable in delineating our program

for present and future customers. Also, a condensation of this document

will appear in the NBS Journal of Research.

Other notable activities during this fiscal year were our participation in the Eighth Workshop on the Vacuum Ultraviolet Radiometric

Calibration of Space Experiments held in Boulder, CO, March 18 and 19 and

the upgrading and modification of our 3 m monochromator to enable computer

controlled automated operation (J. Klose, J. M. Bridges).

In the past year, progress was made in improving the accuracy of our calibrations. Better accuracy is desired to meet the needs of some

users of our services, especially groups involved in radiometric measurements from spacecraft. Experimental setups were designed and put into

operation which allow rapid comparisons to be made between two sources

running simultaneously. By comparing sources essentially at the same

time, errors from changing detector efficiency or degradation of optical

11
Division 531, Technical Activities (cont'd.)

*

components during a set of measurements are eliminated. With this

improved measurement technique, more accurate comparisons between our radiometric sources are possible, and work is in progress to develop an argon arc model with improved stability. Preliminary results indicate a significant improvement in stability is possible, with fluctuations in the

source output reduced from the few percent level to less than one percent

(J. M. Bridges).

( f ) Stark Broadened Widths and Shifts of Non-hydrogeni c Ion Lines

Experiments are continuing on the widths and shifts of lithiumlike beryllium lines. Beryllium was injected as an impurity into a helium

plasma discharge using a laser blowoff technique. The helium plasma is

well characterized from previous measurements. Side-on measurements of

the pulsed arc source show that within a reasonable time after the firing

of the laser we detect beryllium lines showing the beryllium to be well

distributed and in equilibrium with the basically helium plasma.

A general survey of what beryllium ion lines can be observed in

both the visible and ultraviolet spectral regions has been accomplished.

Two strong visible lines have been selected for further detailed study

since one has an unexpected line shape (a strong asymmetry in the line

with an accompanying forbidden component), and the other is ideal for

detailed width and shift measurements. We have also measured the electron

temperature of the helium plasma. We do this by observing the He II P a line which has been previously calculated to an He-Ne laser i interferometer

for electron density and then observing several 0 II impurity lines which

give the electron temperature using a Boltzmann plot of their relative

intensities. These measurements are done over a range of filling pressures and capacitor charging voltages to give us the electron temperature

over a wide range of densities which is normally used in the experiment.

A new improved multichannel array detector is being incorporated, which will upgrade our capabilities in measuring the various

characteristics of these beryllium ion lines as accurately as possible

(T. Pittman)

.

(g) A wal 1 -stabi 1 i zed arc operating at a temperature of 12500K has

been employed to determine atomic transition probabilities, plasma line

widths (Stark widths) and ion broadening parameters of prominent nitrogen

lines. Due mainly to the application of computerized data acquisition

techniques and precise line profile fittings, accuracy levels of better

than ±10% have been reached (Q. Zhu, W. L. Wiese).

12
Division 531, Technical Activities (cont'd.)

(h) The atomic transition probabilities of neutral argon lines have

been determined many times because of their importance to plasma diagnostic applications. Nevertheless, many discrepancies in the data exist.

Therefore, in collaboration with groups from the West-German Universities

of Kiel and Hannover and the National Solar Observatory, Kitt Peak,

Tucson, a new unified scale for these transition probabilities has been

established. For this joint project, new lifetimes and branching ratios

were determined with high precision techniques, and existing literature

data were critically evaluated and corrected when appropriate. The new scale achieves full consistency between different transition arrays and

agrees with most recent data within ±10% (W. L. Wiese).

13
INVITED TALKS

Division 531, Atomic and Plasma Radiation

Kim, Yong-Ki, "Relativistic Effects in Electron-Ion Collision Cross

Sections," Atomic Physics Seminar, Lawrence Livermore National Laboratory,

October 14, 1986.

Kim, Yong-Ki, "Relativistic Effects in Atoms and Molecules," JILA

Colloquium, December 16, 1986.

Kim, Yong-Ki, Graduate Course in "Atomic Structure Theory," Seoul National

University, July 17 to August 6, 1987.

Kim, Yong-Ki, "Hot Topics in Relativistic Atomic Physics," Seoul National

University, Physics Dept. Colloquium, August 7, 1987.

Martin, W. C., "Energy Levels, Ionization Energies, and Lamb Shifts in

Helium," Symposium on Atomic Spectroscopy and Highly Ionized Atoms,

Hickory Ridge Conference Center, Lisle, IL, August 16-21, 1987.

Reader, Joseph, "Atomic Spectroscopy at NBS," Dept, of Physics Colloquium,

Univ. of Lund, Sweden, June 25, 1987.

Reader, Joseph, "Spectra of Highly Ionized Atoms: Comparisons with

Relativistic Calculations," 1987 Atomic Physics Gordon Research

Conference, Wolfeboro, NH, July 7, 1987.

Reader, Joseph, "Spectroscopy of Highly Charged Ions: How Well Can We

Measure; How Well Can We Calculate?", Symposium of Atomic Spectroscopy and

Highly-Ionized Atoms, Argonne National Laboratory, August 18, 1987.

Sugar, Jack, "NBS Atomic Data Centers: Review of Recent and Imminent

Publications," Atomic Spectroscopy Workshop sponsored by the National

Research Council Committee on Line Spectra, Toronto, Canada, June 19-21,

1987 .

Wiese, W. L., "Atomic Data Evaluation and Compilations at NBS," Meeting of

the Network of Atomic Physics Data Centers, IAEA, Vienna, Austria,

September 9, 1986.

Wiese, W. L., "Some Atomic Physics Issues in Fusion Research," Meeting of

the German Research Society, Munich, West Germany, November 6, 1986.

Wiese, W. L., "Progress and Challenges in the Determination of Atomic

Transition Probabilities," Physics Colloquium, University of Hannover,

West-Germany , November 18, 1986.

14
Division 531,. Invited Talks (cont'd.)

Wiese, W. L., "The Wal 1 -stabi 1 i zed Arc as an Emission Source for Plasma

Spectroscopy," Plasma Physics Seminar, Ruhr University, Bochum,

West-Germany , January 30, 1987.

Wiese, W. L., "Quantitative Data for Visible and Ultraviolet

Spectroscopy," U .S .-Japanese Workshop on Collaborative Work in Fusion

Research, Institute for Plasma Physics, University of Nagoya, Japan, March

20, 1987.

Wiese, W. L., "Plasma Spectroscopy with Steady-State Discharges," Physics

Colloquium, Fudan University, Shanghai, PRC, March 23, 1987.

Wiese, W. L., "Spectral Line Broadening in Plasmas," Physical Society of

Shanghai, PRC, March 25, 1987.

Wiese, W. L., "VUV Spectral Radiometry with Portable Plasma Sources,"

China Institute of Metrology, Hangzhou, PRC, March 27, 1987.

Wiese, W. L., "Spectroscopy of Highly Ionized Atoms," Physics Colloquium,

University of Kassel, West-Germany , May 7, 1987.

Wiese, W. L., "Progress in the Determination of Atomic Transition

Probabilities," Physics Colloquium, Institute of Physics, University of

Zagreb, Yugoslavia, May 28, 1987.

Wiese, W. L., "Line Broadening in Plasmas - Asymmetries Caused by Ion

Broadening," Physics Colloquium, University of Dusseldorf, West-Germany

,

June 5, 1987.

Wiese, W. L., "Progress and Problems in Atomic Lifetime Measurements,"

Physics Colloquium, University of Lund, Sweden, June 22, 1987.

Wiese, W. L., "Status of Atomic Spectroscopy Data for the Plasma Edge."

Specialists Meeting on the Physics of the Plasma Edge, IAEA, Vienna,

Austria, July 9, 1987.

Wiese, W. L., "Some Continuing Puzzles in Atomic Transition Probability

Data," Physics Colloquium, Ruhr-Uni versi ty , Bochum, West-Germany, July 13,

1987.

Wiese, W. L., "Methods of Critical Assessment of Atomic Spectroscopy

Data," Atomic Physics Meeting, Oxford, United Kingdom, August 2, 1987.

15
PUBLICATIONS

Division 531, Atomic and Plasma Radiation

Braun, W. Scheer, M.D. and Kaufman, V., The temperature dependence of

spectral broadening in the Hg (6

1 S 0 “ 6

3 P.) multiplet at high optical

densities, J. Res. Nat. Bur. Stand. 91_, 313 ( 1986).

Bridges, J. M., "NBS Source Standards", Proceedings of 3th Workshop on VUV

Radiometric Calibration of Space Experiments at JILA, Boulder, CO, March

18, 1987.

Bridges, J. M. and Zhu, Q., "Transition Probabilities for Prominent

Visible Lines of N I," Bulletin of Am. Phys. Soc., June 1987.

Callaway, J. and Oza, D. H., Scattering of electrons by atomic hydrogen at

intermediate energies: Total cross-sect i ons from 12 to 54 eV, Phys. Rev.

A 34, 965 (1986).

Callaway J., Unni kri shnan , K. and Oza, D. H., Optical Potential Study of

Electron-Hydrogen Scattering at Intermediate Energies, Phys. Rev. A [in

press - Sept. 87 issue].

Chen, Guoxong and Nee, T.-J., A local measurement of Ba+ density temporal

evolution J. Appl . Phys. iSl, 4707 (1987).

Chen, Guoxong and Nee, Tsu-Jye A., Depolarization of the near-resonance

Rayleigh scattering by barium ions, J. Opt. Soc. Am. B _4, 1303, Aug.

1987 .

Cooper, J. W., Clark, C. W., Cromer, C. L., Lucatorto, T. B., Sonntag, B.

F. and Tomkins, F. S., "Resonant structure in 3p-subshell absorption of

excited and ionized manganese, Phys. Rev. A. 3_5, May 1987.

Datla, R. U . , and Roberts, J. R., The 3 P

1 -

3 p

2 magnetic dipole transition

in the ground configuration of Co XX, J. Opt. Soc. Am. B _4 , 428 (1987).

Datla, R. U . , Roberts, J. R., Rowan, W. L., and Mann, J. B., Excitation

rate coefficient measurements of Cu XIII and Cu XVII ions, Phys. Rev. A

34, 4751 (1986).

Datla, R. IJ . , Roberts, J. R., Silfvast, W. T., and Wood, II, 0. R.,

Population inversions of C IV in a recombining theta-pinch plasma, Opt.

Lett, [in press].

16
Division 531, Publications (cont'd.)

Datla, R. U., Roberts, J. R., and Mann, J. B., Electron-impact excitation

of Ti X, Phys. Rev. A 35, 3849 (1987).

Datla, R., Roberts, J. R., Durst, R. D., Hodge, W. L., Klepper, C. C.,

Rowan, W. L., and Mann, J. B., Measurement of excitation rate coefficients

for Al-like ions: Fe XIV, Ni XVI and Cu XVII, Phys. Rev. A [in press].

Ekberq, J. 0., Feldman, U., Seely, J. F., Reader, J., and Acquista, N.,

3p 6 3d^ - 3p 5 3d 10 transitions of cobaltlike ions from Sr 11+ to U 65+

, J.

Opt. Soc. Am. B [in press],

Feldman, U., Seely, J. F., Brown, C. M., Ekberg, J. 0., Richardson, M.

C., Behring, W. E., and Reader, J., Spectrum and Energy Levels of Br XXV,

Br XXIX, Br XXX, and Br XXXI, J. Opt. Soc. Am. B 3., 1605 ( 1986).

Fernandez, M. T., Cabeza, I., Iglesias, L., Garci a-Ri quel me, 0., Rico, F.

R., and Kaufman, V., Fundamental Configurations in Mo IV Spectrum, Phys.

Scr. 35, 819 (1987).

Hill, W. T., Sugar, J., Lucatorto, T. B., and Cheng, K. T., Analysis of

the 5p

6 - 5p

5 n£ (J=l) Rydberg series in Ba++

, Phys. Rev. A [in press].

Hill III, Wendell T. and Cromer, C. L., Laser-Driven Ionization and

Photoabsorption Spectroscopy of Atomic Ions, in Laser Spectroscopy and

Ideas--The Impact of Arthur Scharlow (Springer-Verl ag, Dec. 1987).

Jones, Douglas W., Pichler, G. and Wiese, W. L., Asymmetries in spectral

lines due to plasma ion broadening: Some unusual cases and a possible

test for plasma homogeneity, Phys. Rev. A 35, 2585 (1987).

Jones, D. W., Wiese, W. L., and Woltz, L. A., Ion Broadening of Ar I Lines

in a Plasma, Phys. Rev. A 34, 450 (1986).

Jup£n, C., Litz£n, U., Kaufman, V., and Sugar, J., Ne-like Ca XIMn XVI 2p 5 3& - 2p 5 4£ transition arrays and energy levels, Phys. Rev. A

35, 116 (1987).

Kaufman, V. and Sugar, J., In I i soel ectronic sequence: Wavelengths and

energy levels for Xe VI through La IX, J. Opt. Soc. Am. B [in press].

Kaufman, V. and Sugar, J., Cd I Isoel ectroni c sequence: Wavelengths and

energy levels for Xe VII through Eu XVI, J. Opt. Soc. Am. B [in press].

Kelleher, 0. E., Dressed Autoionizing States and Population Trapping, in

Interfering Resonances and Stabilized States in the Continuum, p. 41

(1987).

17
Division 531, Publications (cont'd.)

Kelleher, 0. E., Saloman, E. B. and Cooper, J. W., Electric Field Effects

on Structure in the Continuum, in Photons and Continuum States of Atoms

and Molecules , (Springer, 1987) p. 68.

Kelleher, D. E., Saloman, E. B. and Cooper, u.W., Electric Field Effects

on Structure in the Continuum, in Spectral Line Shapes , Vol . 4, edited by

Reginald J. Exton, (A. Deepak Publishing, Hampton, Virginia, 1987),

p. 133.

Kelleher, D. E. and Saloman, E. B., Rydberg states with anisotropic ion

cores: Stark effect, Phys. Rev. A 3_5, 3327 ( 1987 ).

Kim, Yong-Ki and Desclaux, Jean-Paul , Relativistic effects in electronatom collisions (review article for Proceedings of the Symposium on Relativistic Many-Body Problems held in Trieste, I tal y —wi 1 1 be published

in special issues of Physica Scripta).

Kim, Yong-Ki, Relativistic Effects in Electron-Ion Collisions, being

published in Institute of Plasma Physics Report No. IPPJ-AM-47, 1986,

pp. 130-138.

Klose, J. Z. and Bridges, J. M., Radiance of a Pt/Cr-Ne Hollow Cathode

Spectral Line Source (accepted by Applied Optics).

Klose, J. Z., Bridges, J. M., and Ott, W. R., Radiometric Standards in the

Vacuum Ultraviolet, Nat. Bur. Stand. (U.S.) Spec. Publ . 250-3 (June

1987).

Klose, J. Z., Calibration of the Vacuum Space Telescope Optical Simulator

at NBS, Proceedings of the Eighth Workshop on the VUV Calibration of Space

Experiments, Boulder, CO, March 18-19, 1987.

KonjeviC, N. and Pittman, T., Stark broadening of spectral lines of

homologous, doubly ionized inert gases, J. Quant. Spectrosc. Radiat.

Transfer 37 , 311 (1987)

.

Litz£n, 01 f and Reader, Joseph, Spectra and energy levels of ions in the

zinc i soel ectroni c sequence from Rb VIII to Mo XIII, Phys. Rev. A [in

press]

.

Martin, W. C., Improved 4 HeI lsn£ ionization energy, energy levels, and

Lamb shifts for lsns and lsnp terms, Phys. Rev. A ^6_ (Oct. 1987).

Mishin, V. I., Lombardi, G. G., Cooper, J. W., and Kelleher, 0. E.,

Effects of very low electric fields on narrow autoionizing states in

gadolinium, Phys. Rev. A 35, 664 (1987).

18
Division 531, Publications (cont'd.)

Mohr, Peter J., Status of Precision QED in Light and Heavy Atoms, in

Physics of Strong Fields , ed. Walter Greiner (Plenum Publishing

Corporation, 1987).

Mohr, Peter J., Quantum Electrodynamics Calculations, in The Spectrum of

Atomic Hydrogen: Advances, ed . G. Series (World Scientific Publishing Co.

Pte. Ltd., 1987).

Nee, Tsu-Jye A. and Chen, Guoxong, Opacity Effects on Near-ResonanceRayleigh Scattering in a a Barium Plasma, J. Quant. Spectrosc. Radiat.

Transfer 37_, 425 ( 1987).

Oza, Dipak H., Greene, Ronald L., and Kelleher, 0. E.. Col 1 i sional

broadening of the Balmer alpha transition of H and He^ in plasmas,

Phys. Rev. A [in press].

Nee, T.-.J., Calculation of helium plasma satellites in turbulent plasmas,

J. Quant. Spectrosc. Radiat. Transfer [in press],

Oza, Dipak H. and Callaway, J., Numerical Solution of the Schroedinger

Equation with a Non-local Exchange Kernel, Journal of Computational

Physics 68, 89-103 (1987).

Oza, Dipak H. and Callaway, J., Optical Potential Approach for Scattering

of Electrons by Ions, in Proceedings of the Third International Conference

on Radiative Properties of Hot Dense Matter III , eds. B. Rozsnyai , et al . (World Scientific, 1987), pp. 84-104.

Oza, Dipak H., F- and G-wave phase shifts and resonances for electron

scattering by He+

, Phys. Rev. A _35, 4430 (1987).

Oza, D., Greene, R. L. and Kelleher, D. E., The Stark Broadening of Balmer

Lines in C+5

, with Ion Dynamics Included, in Spectral Lines Shapes , Vol . 4

edited by Reginald J. Exton, (A. Deepak Publishing, Hampton, Virginia,

1987) p. 201.

Oza, D. H., Greene, R. L., and Kelleher, D. E., Stark broadening of H and

H

3 of C+5

, Phys. Rev. A 34 , 4519 (1986).

a

Oza, D. H., Autoionisation states (3£3£‘) of helium-like nitrogen ion, J.

Phys. B: At. Mol. Phys. 20, L13 (1987).

Pittman, T. L. and Kelleher, D. E., Widths and Shifts of Be Ion Lines, in

Spectral Line Shapes , Vol. 4, edited by Reginald J. Exton, (A. Deepak

Publishing, Hampton, Virginia, 1987) p. 43.

19
Division 531, Publications (cont'd.)

Pittman, T. L. and KonjeviC, N., Experimental Study of Stark Broadened

N II Lines from States of High Orbital Angular Momentum, J. Quant.

Spectrosc. Radiat. Transfer _36, 289 (1986).

Reader, J., Brown, C. M., Ekberg, J. 0., Seely, J. F., Feldman, U., and

Behring, W. E., 2s 2 2p 5 - 2s2p 6 transitions in fluorinelike ions from Zr 31+

to Sn 41+

, J . Opt. Soc. Am. B 3, 1609 (1986).

Reader, J., Accurate energies for the 4p 5 5s5p 4 So /2 and 4p 5 5s4d 4 P 5/2

levels of neutral rubidium (Rb I), Phys. Rev. A §6_, 415 (-July 1987;.

Reader, J., Kaufman, V., and Sugar, «]., Ekberg, J. 0., Feldman, U., Brown,

C.M., Seely, J. F. and Rowan, W. L., 3s-3p, 3p-3d, and 3d-4f transitions

of sodiumlike ions, J. Opt. Soc. Am. B [in press].

Roberts, J. R., Pittman, T. L., Sugar, J. and Kaufman, V., Magnetic-dipole

wavelength measurements in the n=3 configurations of highly ionized Cu,

Zn, Ga, As, Kr, and Y, Phys. Rev. A 3_5, 2591 ( 1987).

Roszman, L. J., Dielectronic recombination rates for some ions of the

lithium i soel ectroni c sequence, Phys. Rev. A 35, 2122 (1987).

Roszman, L. .]., Dielectronic recombination rate coefficients for ions of

the oxygen i soel ectroni c sequence, Phys. Rev. A 3_5, 3368 (1987).

Roszman, L. J., Di el ectroni c-recombi nati on rate coefficients for ions of

the fluorine i soel ectroni c sequence, Phys. Rev. A 35, 2138 (1987).

Seely, J. F., Ekberg, J. 0., Brown, C. M., Feldman, U., Behring, W. E.,

Reader, J., and Richardson, M. C., Laser-produced spectra and QED effects

for Fe-, Co-, Cu-, and Zn-like ions of Au, Pb, Bi , Th, and U, Phys. Rev.

Lett. _57, 2924 (1986) .

Shirai, T., Ishii, K., Sugar, J., Mori, K, Nakai , Y., and Ozawa, K.,

Spectral Data for Highly Ionized Molybdenum, Mo VI-Mo XL II, «J . Phys. Chem.

Ref. Data 16, 327 (1987).

Shirai, T., Mori, K., Sugar, J., Wiese, W. L., Nakai, Y., and Ozawa, K.,

Spectral Data and Grotrian Diagrams for Highly Ionized Nickel, Ni IX--

Ni XXVIII, At. Data [in press].

Sugar, J. and Kaufman, V., The Mg-like spectrum of Cu XVIII, J. Opt. Soc.

Am. B 3, 1612 (1986)

.

Sugar, J and Kaufman, V., Wavelengths and Energy Levels of Zn XII to

Zn XX, Phys. Scripta 34, 797 (1986).

20
Division 531, Publications (cont'd.)

Sugar, J., Kaufman, V., and Rowan, W. L., Resonance transitions in the

Mg I and Ar I i soel ectronic sequences from Cu through Mo, J. Opt. Soc.

Am. B [in press].

Sugar, J. and Kaufman, V., Additions and revisions to the levels of

Mg- like Cu XVIII and Zn XIX, J. Opt. Soc. Am. [in press].

Sugar, J., Kaufman, V., and Rowan, W. L., Spectra of Se XVI to Se XXIV

observed in a tokamak plasma, J. Opt. Soc. Am. B [in press].

Veza, D. and Sansonetti , C. J., Ionization of Lithium Vapor by CW Quasiresonant Laser Radiation, in Spectral Line Shapes , Vol . 4, (A. Deepak

Publishing, Hampton, Virginia, 1987), p. 259.

Weber, K.-H. and Sansonetti, Craig J., Accurate energies of nS, nP, nO,

nF , and nG levels of neutral cesium, Phys. Rev. A 3_5, 4650 (1937).

Wiese, W. L., Transition Probabilities (Atomic Physics), in Encycl opedi

a

of Physical Science and Technology, Vol. 14, (Academic Press, New York,

1987), p. 59.

Wiese, W. L., Progress and Challenges in the Determination of Atomic

Transition Probabilities, Physica Scripta^, 846 (1987).

Wiese, W. L. and Jones, Douglas W., Ion Broadening of Heavy Element Lines

in Plasmas, in Spectral Line Shapes , Vol. 4, edited by Reginald J. Exton

(A. Deepak Publishing, Hampton, Virginia, 1987), p. 3-21.

Wiese, W. L., Improvements in Transition Probability Data, in Highlights

of Astronomy , Vol. 7 (Reidel Publishing Co., Dordrecht, Hoi 1 and , 1986 )

.

Wiese, W. L., The atomic transition probabilities of argon--A continuing

challenge to plasma spectroscopy, J. Quant. Spectrosc. Radiat. Transfer

[in press],

Woltz, L. A., Quasi-Static Ion Broadening of Isolated Spectral Lines, J.

Quant. Spectrosc. Radiat. Transfer ]36_, 547 (1986).

21
PUBLICATIONS IN PREPARATION

Division 531, Atomic and Plasma Radiation

Brewer, L. R., Buchinger, F., Ligare, M., and Kelleher, 0. E., ResonanceEnhanced Multiphoton Ionization of Atomic Hydrogen.

Clark, Charles W., and Kelleher, D. E., Quadrupole Moments and Tensor

Polarizabilities from Fine Structure Splittings of Non-Penetrating

Orbi tal s

.

Datla, R. and Kunze, H.-J., Electron impact excitation and recombination

into excited states of lithium-like ions, Phys. Rev. A (submitted).

Datla, R. U., Eshhar, S. and Roberts, J. R., Excited level populations in

C IV in a recombining 6-pinch plasma (in preparat i on )

.

Kelleher, D. E., Oza, D. H., Greene, R. L., Cooper, J., An Overview of the

Ion Dynamic Effect in Line Broadening, and a Generalization of the Unified

Theory, in preparation for J. Quant. Spectrosc. Radiat. Transfer.

Iglesias, L., Cabeza, M. I., Rico, F., and Kaufman, V., Fundamental

configurations of doubly-ionized molybdenum (Mo III) (submitted to

Physi ca Seri pta )

.

Kaufman, V., Sugar, J., and Joshi, Y. N., Wavelengths and energy levels of

I V and I VI (submitted to J. Opt. Soc. Am. B).

Klose, Jules Z., Bridges, J. Mervin, and Ott, William R., Radiometric

Calibrations of Portable Sources in the Vacuum Ultraviolet (in

preparati on )

.

Martin, G. A., Fuhr, J. R., Wiese, W. L., and Weiss, A. W., Atomic

Transition Probabilities, Vol . Ill, Scandium through Nickel--A critical

data compilation (to be submitted to J. Phys. Chem. Ref. Data Supplement

Seri es )

.

Martin, W. C., Atomic spectra and wavelength standards, to be published in

Trans. Inti. Astr. Union XX (1988).

Oza, Dipak, Greene, R. !_., and Kelleher, D. E., Dependence of the

plasma-broadened profiles of hydrogen lines of reduced mass, temperature,

and density, submitted to Phys. Rev. A.

Reader, J., Ekberg, J. 0., and Feldman, U., 3p 6 3d 8 - 3p 5 3d 9 transitions in

Fe-like ions from Ru 18+ to Gd 38+

, J. Opt. Soc. Am. B (in preparat i on )

.

22
Division 531, Publications in Preparation (cont'd.)

Roginsky, D. V. I., e-tight upper bounds to expectation values (in

preparation)

.

Roginsky, D.V. I. and Weiss, A. W., The calculation of tighter error

bounds for theoretical atomic oscillator strengths (in preparation).

Roszman, L. J., The dielectronic recombination rates for ions of the

nitrogen i soel ectroni c sequence (in preparation)

.

Roszman, L. J., The influence of ground configuration in metastable states

upon the dielectronic recombination of impurity ions in moderate density

plasmas (in preparation).

Roszman, L. J., The dielecronic recombination rates for ions of the boron

and oxygen isoelecronic sequences (in preparati on )

.

Sims, James S. and Martin, W. C., Variational calculations for 4 He I: improved energies for singlet and triplet n D and n F levels (n=3-8)

(submitted to Phys. Rev. A).

Sugar, Jack, MBS Atomic Data Centers: Review of Recent and Imminent

Publications (submitted to Spectrochim. Acta).

Veza, Damir and Sansonetti , Craig J., Ionization of Lithium Vapor by CW

Quasi resonant Laser Light (in preparation)

.

Wiese, W. L., Atomic Transition Probabilities, submitted to Reports on Astronomy , Intern. Astron. Union.

Wiese, W. L., Critical Assessment of Atomic Spectroscopy Data (in

preparation )

.

Wiese, W. L. and Musgrove, A. (Editors), Spectroscopic Data Tables for Ti , Cr, and Ni , Vol . 7 of Atomi c-Qata-for-Fusi on Series, to be published by

Oak Ridge National Laboratory.

Zhu, Q., Bridges, J. M., and Wiese, W. L., Oscillator Strength

Measurements for Prominent Spectral Lines of Atomic Nitrogen (to be

submitted to Phys. Rev.).

23
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 531, Atomic and Plasma Radiation Division

Daniel E. Kelleher

Member, International Organizing Committee of the Conference on Spectral Line Shapes.

Yong-Ki Kim

Member of Program Committee, APS Topical Conference on High

Temperature Plasmas.

William C . Marti

n

Chairman, Working Group on Atomic Spectra, International

Astronomical Union.

Member, IAEA Network of Atomic Data Centers for Fusion.

James R. Roberts

Member of TEXT Users Organization.

Jack Sugar

Member, OSA Fellows and Honorary Members Committee.

Member, NAS/NRC Committee on Line Spectra of the Elements - Atomic Spectroscopy.

Mark Suskin

Member, NAS/NRC Committee on Line Spectra of the Elements - Atomic Spectroscopy.

Wolfgang L. Wiese

Member of Organizing Committee, International Astronomical Union,

Commission on Fundamental Spectroscopic Data.

Chairman, Working Group on Atomic Transition Probabilities, International Astronomical Union, Commission 14.

Member, IAEA network of Atomic Data Centers for Fusion.

24
Division 531, Technical and Professional Committee Participation and

Leadership (cont'd.)

Wolfgang L. Wiese

Co-Chairman, U. S. -Japan Workshop on “Assessment of Spectroscopic Data

for Density and Temperature Measurements," March 1987, Nagoya, Japan.

(U.S. -Japan Cooperative Fusion Program)

25
MAJOR CONSULTING AND ADVISORY SERVICES

Division 531, Atomic and Plasma Radiation

1. The Data Centers on Atomic Energy Levels and Transition Probabilities

routinely fill requests for atomic data or literature information

submitted by scientists in a wide range of research areas. The

requests average about 30 per month. Periodically, special reports

are prepared for particular user groups. Thus, W. C. Martin and

W. L. Wiese have written updates on atomic data of interest for the

astrophysi cal community for the Transactions of the International

Union (IAU), covering the three year period September 1984 through

August 1987, and give review reports at the General Assemblies of the

International Astronomical Union. J. R. Fuhr and A. Robey submit

literature reference lists every six months to the International

Atomic Energy Agency (IAEA) for inclusion in their semiannual

Bulletin of Atomic Data for Fusion.

2. Y.-K. Kim serves as a consultant to the A Division of the Lawrence

Livermore Laboratory on x-ray laser development.

3. J. Z. Klose performed numerous tests and calibrations of four Pt-Ne

hollow cathode lamps as part of contract work with Goddard Space

Flight Center for the Space Telescope. His work involved close

consultation with personnel from the Space Telescope Science

Institute.

4. W. C. Martin and J. Reader consult and advise NASA scientists and

other astronomers on standard wavelengths for calibration of the

High-Resolution Spectrograph for the Space Telescope.

5. J. Reader continues to consult with members of the x-ray laser

program at Lawrence Livermore National Laboratory about the spectra

of highly ionized atoms in 1 aser-produced plasmas and the wavelength

calibration of such spectra.

6. J. R. Roberts serves as a member of the TEXT Users Organization

(TUG). TEXT stands for Texas Experimental Tokamak and is a national

plasma users facility.

7. J. R. Roberts consulted with members of Bell Labs on population

inversion experiments in C+3 on the N8S theta pinch.

8. L. J. Roszman advises and consults with the Impurity Transport

Modeling Group of the Princeton Plasma Physics Laboratory on electron-ion collision processes and other atomic data as well

as the modeling of low density plasmas.

26
Division 531, Major Consulting and Advisory Services (cont'd.)

9. J. Sugar and W. L. Wiese consulted and advised the Japan Atomic

Energy Research Institute (JAERI) on the compilation of spectral

1 i nes

.

27
JOURNAL EDITORSHIPS

Division 531, Atomic and Plasma Radiation

W. C. Martin, Co-Feature Editor for Journal of the Optical Society of

America B, Special Issue for September 1988, "Atomic Spectroscopy in the

Twentieth Century."

J. Reader, Editor, Line Spectra of the Elements, Handbook of Chemistry and

Physics , CRC Press.

W. L. Wiese, Associate Editor, Journal of Quantitative Spectroscopy and

Radiative Transfer.

28
TRIPS SPONSORED BY OTHERS

Division 531, Atomic and Plasma Radiation

D. Kelleher was invited and gave a talk at the Conference on Interfering

Resonances and Stabilized States in the Continuum, held in Paris, France,

April 6-8, 1987. Most of his airfare was paid by the Conference.

D. Kelleher was invited and gave a talk at the Spectral Line Formation in

Plasmas under Extreme or Unusual Conditions Workshop, held in Nice,

France, August 31 through September 4, 1987. Per diem expenses were paid

by the National Science Foundation.

Yong-Ki Kim was invited by the Univ. of Puerto Rico to explain relativistic atomic physics to their Chemical Physics Program participants. Most

of the expenses were paid by the University (March 1987).

Yong-Ki Kim served as a session chairman at the Gordon Conference on Atomic Physics, Wolfeboro, New Hampshire. All expenses were paid by the

Conference (July 1987).

Yong-Ki Kim gave a summer graduate course on atomic physics at Seoul

National University (Korea). All expenses were paid by the University

(July-August 1987).

W. Martin attended and presented a paper at the Symposium on Atomic

Spectroscopy and Highly-Ionized Atoms, Lisle, Illinois. Room and board

were provided by the conference (August 1987).

J. Reader worked at the Univ. of Lund, Sweden on the i nterpretati on of

spectroscopic data for highly ionized Zn-like and Fe-like ions. All

expenses including airfare and per diem were paid by the Univ. of Lund

(June 1987) .

J. Reader attended and presented a paper at the Gordon Conference on Atomic Physics, Wolfeboro, New Hampshire. Registration fee and per diem

were paid by the Gordon Research Conference (July 1987).

J. Reader attended and presented a paper at the Symposium on Atomic

Spectroscopy and Hi ghly- 1 on i zed Atoms, Lisle, Illinois. Room and board

were provided by the conference (August 1987).

C. Sansonetti attended and presented a paper at the Symposium on Atomic

Spectroscopy and Highly-Ionized Atoms, Lisle, Illinois. Room and board

were provided by the conference (August 1987).

29
Division 531, Trips Sponsored by Others (cont'd.)

J. Sugar attended and presented a paper at the Symposium on Atomic

Spectroscopy and Highly-Ionized Atoms, Lisle, Illinois. Room and board

were provided by the conference (August 1987).

W. L. Wiese spent one year at the Ruhr-Uni versi ty , Bochum, West-Germany as recipient of the U.S. Senior Scientist Award of the Alexander von Humboldt

Foundation. Air fare to Bochum, attendance of two meetings at RottachEgern (March 11-13, 1987) and at Bonn (July 6-7, 1987) convened by the

Humbol dt-Foundati on , and attendance of an Atomic Physics Workshop at

Oxford, (August 1-2, 1987) were paid by the Humbol dt-Foundati on

.

30
CALIBRATION SERVICES PERFORMED

Division 531, Atomic and Plasma Radiation

No. of

Type of Service Customer SP 2 50 Tests Income

Hoi 1 ow Cathode

Lamp

Goddard Space Flight

Center

Contract 4 $36 .3k

Deuteri urn Lamp Goddard Space Flight

Center

40030S 3 4.5k

Argon Mini -Arc Ball Aerospace

Systems Division

Contract 1 3k

Deuterium Lamp University of Colorado 40030S 1 1.5k

Deuteri urn Lamp Naval Research

Laboratory

40030S 1 lk

31
SPONSORED SEMINARS AND COLLOQUIA

Division 531, Atomic and Plasma Radiation

Bart Cardon, MIT/Lincoln Laboratory, "Atomic Transition Probabilities,",

August 25, 1986.

William Deuchars, University of Strathclyde, Glasgow, Scotland, "ThetaPinch Research at the University of St rathclyde ," September 22, 1986.

Tricia Reeves, University of Kansas, Manhattan, Kansas, "Theoretical

Problems in Atomic Data," October 20, 1986.

D. B. Boercker, Lawrence Livermore National Laboratory, "Diffusion and Ion

Dynamic Effects on Lyman-a Lines in Dense Plasmas," November 10, 1986.

S. Bliman, Centre d'Etudes Nucl£aires de Grenoble, France, "Highly

Charged Ions: A New Spectroscopy," November 13, 1986.

Steven Alston, JILA, "Vibrational Excitation in Electron-Molecule Collisions: Towards an ab initio Treatment," November 20, 1986.

Stephen M. Younger, Lawrence Livermore National Laboratory, "Giant

Resonances in El ectron- Impact Ionization," December 5, 1986.

Dennis L. Matthews, Lawrence Livermore National Laboratory, "Livermore

Soft X-ray Laser Program," December 10, 1986.

Paul Indelicato, Curie Institute, Paris, "Relativistic Correlation in

He-Like Ions, December 11, 1986.

John Morrison, University of Louisville, "Numerical Mul ti -Ref erent

Perturbation Calculations for Atoms and Diatomic Molecules,"

March 5, 1987.

Dan V. I. Roginsky, Hebrew University of Jerusalem, "Calculations of

Tighter Error Bounds on Atomic Oscillator Strengths," March 13, 1987.

Karl Welge, Universitat Bielefeld, West Germany, "Highly Excited Atoms

in Strong Magnetic Fields," April 28, 1987.

Walter R. Johnson, University of Notre Dame, "Problems in Relativistic

Many-Body Perturbation Calculations," May 27, 1987.

Vander Mullen, Efndhoven University, The Netherlands, "Plasma

Spectroscopy," July 2, 1987.

32
Division 531, Sponsored Seminars and Colloquia (cont'd.)

Keishi Ishii, Kyoto University, Kyoto, Japan, "The Cobalt Isoel ectroni

c

Sequence," July 18, 1986.

Peter Hagel stein, Lawrence Livermore National Laboratory, "Relativistic

Atomic Physics Calculations for Model Making,", August 6, 1986.

Indrek Martinson, University of Lund, Sweden, "Recent Advances in Lifetime

Measurements for Multiply Ionized Atoms," August 22, 1986.

33
.
TECHNICAL ACTIVITIES

Division 533, Radiation Physics

The Radiation Physics Division focuses on measurement programs relating to the use of electron, laser, ultraviolet, and soft x-ray radiation

in the energy range from about 5 eV (250 nm) to 500 eV (2.5 nm).

In support of this mission, radiation standards and advanced measurement techniques are developed. Through our standards program, the

Division provides the central national basis for the measurement of far

ultraviolet and soft x-ray radiation. The NBS synchrotron radiation

facility and a detector calibration facility based upon wel 1 -characteri zed

photoionization chambers serve as national radiation standards. Measurement services are available for the calibration of the quantum efficiency

of UV photodiodes and the spectral responsivity of vacuum ultraviolet

spectrometer systems.

Through our electron measurements program, new types of electron

sources and detectors are developed to investigate the properties of

matter on an atomic scale. For example, specially designed spin-polarized

electron sources and detectors are used to determine fundamental atomic

scattering properties and to measure surface magnetism. An electron

tunneling device is being developed to provide "images" of surfaces on an atomic scale and to study relationships between macroscopic material

properties and surface microstructure.

With the goals of improving standards and understanding the fundamental physical phenomena upon which they are based, the Division also

conducts theoretical and experimental research on the electronic structure

of atomic and molecular systems, the interaction of the systems with

photon and electrons, and radiation deposition and energy transfer

processes. Theories are developed for the scattering and transport of

electrons in materials of fundamental and technological interest. New

techniques and instrumentation are developed to study radiative reactions

with matter, including photoexcitation and photoionization processes and

non-linear effects in intense laser fields. Studies are underway to

investigate to what extent the properties and behavior of atomic systems

can be manipulated by measuring and controlling atomic and molecular

states in their local environment.

The Division has two major research facilities, a dedicated synchrotron ultraviolet radiation facility ( SURF -II) and a polarized electron

research facility.

SURF-II is a dedicated synchrotron radiation facility, consisting of

a 300 MeV electron storage ring, a 10 MeV microtron injector, and associated synchrotron radiation beamlines. It produces radiation in a

35
Division 533, Technical Activities (cont'd)

narrow, intense, highly polarized beam with a continuous and accurately

known spectrum from the infrared, through the visible and the far ultraviolet, and into the soft x-ray region. SURF-II is unique among synchrotron light sources by virtue of its uniform and precisely known circular

orbit. This allows accurate determination of all the spectral and geomet

rical properties of the radiation and hence its use as an absolute radiometric standard.

This facility serves staff from our own Division, users from other

NBS Divisions, and outside users in radiometric standards and calibration

work, optical physics research, surface science, biochemistry, spectroscopy, and other research areas utilizing far ultraviolet radiation. It

helps to fill a growing demand for radiation in the ultraviolet and soft

x-ray region of the electromagnetic spectrum. Of the 11 light ports at

SURF, 6 are now instrumented for user applications and for calibration of

optical instruments and transfer standard photodiodes. Some of these

ports are shared by more than one experimental station. Three of the

remaining ports are utilized for beam current monitoring, electron counting, and machine diagnostics. Most experiments and calibrations can run simultaneously, unless they require special beam parameters.

The polarized electron scattering facility is used to produce and

measure beams of spin polarized electrons and is available for collaborative research by NBS and outside scientists in areas of mutual interest

on a time-available basis. Three separate, ultra-high vacuum instruments

are available. The polarized electron beams have currents in excess of 1 yA, with an optically reversible polarization at energies less than 1 keV

and with an energy resolution of *0.15 eV.

These electrons are used to probe spin dependent scattering interactions between polarized electrons and surfaces or polarized electrons

and atoms. The el ectron-surface scattering capability can be used to

determine surface structure or study surface magnetic phenomena and their

dependence on temperature, composition, adsorption, etc. The electronatom scattering capability can be used to probe spin-orbit and exchange

interactions in electron scattering and to completely determine the param

eters of a selected collision process.

In relatively new research directions, several innovative electron

measurement techniques pioneered at NBS are being further developed in

cooperative programs with industry to study the atomic and magnetic micro

structure of advanced materials. Magnetic microstructure can be measured

with a spatial resolution approaching 100 Angstroms (0.01 microns) by a technique called Scanning Electron Microscopy with Polarization Analysis

(SEMPA). An ultrahigh vacuum scanning tunneling microscope has also been

constructed to apply the phenomenon of surf ace-vacuum-surf ace electron

tunneling to investigations on an atomic scale of the nucleation and

growth of thin films on clean metallic and semiconductor surfaces.

36
Division staff are also collaborating on two projects at the National

Synchrotron Light Source (NSLS) facility at Brookhaven. The first

involves radiation probing of exotic materials with soft x-rays. With

colleagues from the U. of Tennessee and Oak Ridge National Labs, we are studying core-hole excitation and soft x-ray fluorescence in solid

materials of fundamental and industrial significance such as GaAs, quasicrystals, and high Tc superconductors. This is being done using an IR-100

award-winning, high sensitivity, soft x-ray emission spectrometer with an efficiency 1000 to 10,000 higher than conventional spectrometers in the

energy range 20 eV to 1 keV.

In the second project. Division staff are part of a consortium of 11

principal investigators from 8 major laboratories representing industry,

universities, and government. This "Materials Research Group", funded

principally by NSF, is preparing to study surface magnetism using spin

polarized photoemission techniques on materials prepared with molecular

beam epitaxy methods. This work will be done on an undulator beamline at

NSLS.

As can be seen in the following sections, the Division staff has been

active in publishing research papers, providing calibration services,

presenting invited talks, sponsoring conferences, providing consultation

services, and participating in technical and professional committees. We

have also been very active in technical collaborations within NBS and with

universities, industry, and other government agencies. Some highlights of

the past year include:

1. Cooperative agreements were made with Eastman Kodak Corporation and

Control Data Corporation to initiate joint research on the NBS-SEMPA

"magnetic microscope" to determine the magnetic mi crostructure of

thin film magnetic storage devices with sub-micron resolution.

2. Atomic resolution was demonstrated on the NBS scanning tunneling

microscope. An area 200 angstroms x 150 angstroms on a (111) crystal

surface of silicon was measured with a lateral resolution of 5 angstroms and a vertical resolution of 0.1 angstroms.

3. Analysis of el ectron-scatteri ng data resulted in a new classification

scheme for doubly-excited states of negative ions and in the predic - tion of possible bound states of alkali-earth negative ions such as Sr- and Ba~

.

4. The NBS Synchrotron Ultraviolet Radiation Facility ( SURF -II) set a new record of 221 mA for maximum stored current , 10% higher than the

previous record. At the same time, the lifetime of a stored beam

under high current conditions was improved about a factor of 6, the

half life being about 1 3/4 hours for a 200 mA stored current.

5. A new soft x-ray measurement program was implemented at BrookhavenNSLS in collaboration with the U. of Tennessee and Oak Ridge National

37
Lab. Measurements utilizing a state-of-the-art soft x-ray emission

spectrometer were made to study the properties of technologically

significant materials such as GaAlAs, Al 6 Mn icosahedral quasicrystals, dilute magnesium and aluminum alloys, solid krypton

"bubbles" in A1 foil, and high Tc superconductors

.

6. High Tc superconductors were studied using synchrotron radiation at

N6S-SURF and Brookhaven-NSLS . At SURF, several experiments were

made, both by our own staff and users from the NBS Surface Science

Division, utilizing photoemission and total electron yield methods to

investigate the electronic structure and energy bands of the

compounds. At NSLS, the NBS/U. Tennesee/ORNL soft x-ray spectrometer

was used to measure local density of states both above and below Tc.

7. The optical isotope shifts for the geologically interesting pair

10 Be: 9 Be in the X S and *D Rydberg series have been measured for the

first time by resonance ionization mass spectrometry (RIMS). The

measurements were performed on samples of less than 10 ng of 10 Be,

demonstrating the ultrasensitive capability of the RIMS technique.

The goal of the program is to exploit enhanced isotopic selectivity

in RIMS and develop ultrasensitive isotope abundance measurement

capabi 1 i ti es

.

8. An x-ray data-eval uati on project was completed , in collaboration with

the Ionizing Radiation Division (536), providing x-ray attenuation

coefficients for all elements Z=1 to 92 in the energy range from 100

eV to 100 keV. This x-ray attenuation information is used in the

areas of medical therapy and diagnosis, industrial radiometric

gauging and control, materials analysis and modification, and in a broad range of other existing and emerging technologies vital to

health care, industrial productivity, and national defense.

9. Twenty major visiting scientist collaborations were active in FY87:

three in the Far UV Physics Group; eight in the Electron Physics

Group; and nine in the Photon Physics Group.

FAR UV PHYSICS GROUP

The Far UV Physics Group is characteri zed by the development of

radiometric techniques and standards for far ultraviolet radiation and by

research on measurement methods utilizing far ultraviolet radiation. The

NBS electron storage ring, SURF -II, is operated for radiometric research,

for calibration of spectrometer systems and transfer standard detectors,

and as a source of V UV/soft x-ray radiation for user-groups within NBS and

outside. Additionally, off-SURF experimental research and development in

radiometry is carried out, and transfer standard detectors are calibrated

and supplied in the wavelength region 4-250 nm.

38
Division 533, Technical Activities (cont'd)

Far UV Detector Calibrations (L.R. Canfield and N. Swanson)

The far ultraviolet detector radiometry program continues to calibrate photodiodes from the soft x-ray region to the near ultraviolet,

5-254 nm. We also provide a service for recal i brati ng photodiodes

returned by outside users. Since this program began in 197U, several

hundred calibrated detectors have been shipped, and recal i brati ons have

been performed on over 100 detectors. During FY 87, 21 new or recalibrated photodiodes were processed.

Windowless photodiodes for the spectral region 5-121.6 nm are fabricated in-house, and working standards of this type are calibrated directly

using rare gas photoi oni zation chambers. At wavelengths beyond the range

of this direct technique, a special thermopile is used to extend the ionization chamber calibrations to longer wavelengths. The thermopile then serves as a secondary standard with which in-house, commercially-supplied,

windowed photodiodes are calibrated. Transfer standards are then prepared

for outside users by intercomparison calibrations with the working standards. These transfer standards are of the NBS-constructed windowless

type for the short wavelength region, or the commercially-supplied, MgF 2

- windowed photodiodes for the 116.4-253.7 nm spectral region. At SURF, the

windowless photodiodes are calibrated in the spectral region 5-50 nm. (see Detector Calibration Beamline). All other calibrations of transfer

standard photodiodes are carried out using laboratory light sources.

We are currently designing an experimental arrangement which will

allow SURF-II to be the absolute standard for detector calibrations from

90-300 nm, i .e. eliminate our dependence on thermopile measurements having

quite poor si gnal -to-noi se . We hope to begin developing this new capability in FY 88.

Complete documentation of the far ultraviolet detector calibration

program has recently been published as an NBS Special Publication

(SP250-2).

SURF II Operations (L. Hughey, R. Madden, and W. Wooden)

The performance of SURF II continues to improve. The average beam

current over the past year is about 90 mA, while the average over the last

six months is closer to 130 mA. A new record beam of 221 mA was recorded

during this period. In addition to this, the beam lifetime at high energy

has been improved. SURF II has also operated quite reliably this year.

Beam was provided to users 94.57, of the scheduled beam time (nine hours/

day; 4 days/week) in FY 87.

A number of improvements made at SURF have been responsible for the

higher current and lifetime performance. Vacuum improvements, particularly in the transport line connecting the injector to the storage ring,

39
Division 533, Technical Activities (cont'd)

resulted in lower ring pressure during injection. This improves the lifetime of the beam at injection and during the early part of the ramp to

high energy. Another injection improvement was to optimize the height and

duration of the high current pulse which "bumps" the electron beam immediately after injection, allowing it to be captured in a stable orbit.

Another improvement was to re-adjust the magnetic field radial

gradient program to acnieve the largest possible radial zone having a field index of 0.59 at each magnetic field strength throughout the ramp

from injection to full energy. This was a change in acceleration philosophy that resulted in fewer lost electrons during the ramp phase.

Finally, a new, constant current filament power supply in the microtron

brought about a significant stabilization of the microtron output allowing

better fine tuning of all injection parameters. These things in concert

are responsible for the significant increase in accelerated current in

recent months.

Other improvements have led to increased lifetime of the beam at full

energy. The dynamic range of the main rf power supply was increased

allowing the maximum rf voltage available at the cavity to be increased; a power splitting coaxial attenuator was installed in the rf feed-line

between the final output amplifier and the rf cavity which stopped the

electron beam from "talking" to the power amplifier; and a phase-shi f ter

was added to this same rf feed-line to allow adjustments of the effective

length of the feed-line. These changes have increased the applied rf

power and have given us new tools to use in stabilizing resonant behavior

of the beam. Now when the magnetic field gradient and rf power and phase

are properly tuned, increased lifetime at full energy is achieved.

Operations staffing at SURF II remains a critical issue. After a long period of recruitment, an electronics engineer was finally hired

in January 1987 to fill the vacancy created by the leaving of the SURF

engineer in February 1986. Unfortunately, another opportunity lured this

new person away six weeks later. We are once again recruiting a replacement. As an additional hardship, the SURF operator/technician retired in

February 1987. However, in this case we were fortunate to quickly find a replacement. Thus, we are squeaking through this difficult period, but

will be relieved when we are able to hire an electronics engineer to take

some of the pressure off our two SURF operations staff members.

SURF -II User Programs (R. Madden)

SURF II was utilized by a variety of N8S and outside users in FY 87

for spectrometer and detector calibrations and for research in surface

science, atomic and molecular physics, and UV and soft x-ray optical

physics. The heaviest use was seen on the Surface Science beamline, Bl-1,

and the Spectrometer Calibration beamline, BL-2, followed closely by

activity on the Angle-Resolved Photoelectron Spectroscopy (AR p ES)

40
Division 533, Technical Activities (cont'd)

beamline, BL-5, and the Detector Calibration beamline, 3L-9. Steady

progress in commissioning the High Resolution Spectrometer beamline, BL-3,

has also been made, and some lesser activity and considerable upgrading

has occurred on the Optical Properties of Materials beamline, BL-8 . The

following paragraphs give more detail on the programs at each of these

experimental stations.

A. Surface Science Beamline, BL-1 (R. Kurtz, T. Madey, and R.

Stockbauer, all from NBS Center for Chemical Physics)

We have supported at SURF - 1 1 the establishment by the NBS Surface

Science Division of an experimental capability to study adsorbed molecules

on surfaces. These studies use several SURF-II monochromators and an ultrahigh vacuum system. Photon stimulated desorption (PSD) of ions is

being studied to understand desorption mechanisms and energetics. Ion

desorption mechanisms for ionically and covalently bonded adsorbates are investigated. Variable wavelength ultraviolet photoemission spectroscopy

(UPS) is also utilized to study the electronic structure of metals,

oxides, and chemical species adsorbed on these materials.

One of the techniques developed by this group is the measurement of

electron attenuation lengths through molecular films. By measuring the

decrease of a substrate photoemission peak as a molecular film is con- densed and varying the photon energy, the attenuation length can be mea- sured as a function of electron energy. These are the first measurements

of their kind in the 20-200 eV energy range and are important in modeling

the effects of ionizing radiation on materials and tissue.

The most exciting work this year was the study of the new, high temperature superconductors. Using variable wavelength photoemission, this

group, in collaboration with a group from the Naval Research Laboratory,

was able to investigate the electronic structure of Ba^YCugOy above and

below its superconducting critical temperature (Tc = 92K). These results

showed that the mechanism for superconductivity in the material did not

involve a large change in the electron energy states. This group is now concentrating on the electronic structure and surface chemistry of a variety of high Tc materials.

Work is also continuing on the effects on molecular adsorption of

surface defects in Ti

0

2

• This is an important catalytic material and a model compound for the theory of ion desorption.

A new ellipsoidal mi rror analyzer (EMA) is being readied for installation on the Surface Science beamline. This is a unique instrument, with

only one other operational in the United States. It is capable of measuring kinetic energy and angular distributions simultaneously. It will be

used for angular resolved photoemission and ion desorption measurements.

A He-cooled sample stage, a side sample preparation chamber, and a sample

41
Division 533, Technical Activities (cont'd)

transport mechanism are being constructed to produce single crystal thin

films of the high Tc superconductors and of semiconductors. When the EMA

is installed on 8L-1, the present instrument will be moved to BL-8 to

continue the electron attenuation length measurements.

B. Spectrometer Calibrations Beamline, BL-2 (M. Furst and T. Hall)

During FY 87 there were 10 user groups who used the SURF II spectrometer calibration facility over a period of 24 weeks. Since the photon

flux from the electron storage ring can be calculated from precisely mea- sured parameters, the synchrotron radiation is used as a radiometric standard to characterize absolute instrument response over a range of wavelengths from 4-400 nm. Users were from NASA/Goddard Space Flight Center,

Univ. of Texas, North Carolina State University, LASP/Univ. of Colorado,

Lawrence Livermore Labs, Air Force Weapons Laboratory, Naval Research

Laboratory, and NBS. NASA continues to help support the facility.

There were several new user groups at the facility. One of the new users was a group from the Air Force Weapons Laboratory, who calibrated a spectrometer to be used to measure radiation from neutral particle beam

bombardment of various materials. Another new user group was the University of Texas at Austin Fusion Research Center, who calibrated a spatial

imaging vacuum monochromator. A group from Lawrence Livermore Laboratory

was also new to the facility. They calibrated a spectrograph used for

Tokamak plasma diagnostics.

Improvements to the large vacuum chamber for spectometer calibrations

are continuing. The chamber provides a vacuum to simulate upper atmospheric conditions for spectrometer calibrations. A new computer has been

acquired as a part of a dedicated control system for the vacuum chamber.

The new computer system will have a much shorter response time when it is

interfaced with user systems. Also, a class 10,000 clean room was com- pleted for users of the vacuum chamber. At the 11.5 meter calibration

gimbal, upgraded motor controllers have been installed to facilitate user

operation of the gimbal system.

C. Ultra High Resolution Spectrometer Beamline for Atomic and Molecular

Physics, BL-3 (M. Ginter, D. Ginter, and J. Proctor, all from the

University of Maryland)

The work on a new beamline for a very high resolution, 6.65m normal

incidence monochromator is continuing at SURF- II. Researchers from the U.

of Maryland and the NRL are the principal investigators on this project,

with partial support from the NSF . The goal of this project is to carry

out research on the dynamics of energy transfer in atoms and molecules

with an energy resolution that is a factor of ten better than photometric

instruments currently in service at synchrotron radiation facilities. In

a collaborative effort, a similar instrument has been installed and

42
Division 533, Technical Activities (cont'd)

converted to photometric studies at the KEK Photon Factory in Japan.

These instruments will cover the 30-200 nm spectral range with resolving

powers of 2 x 10 5

. In addition, our instrument will provide highly

polarized radiation to study atomic and molecular systems (polarization > 98% for wavelengths >60 nm)

.

The high resolution spectrometer was brought into near final focus in

a series of tests conducted in Summer 37, and the components were prepared

for connection to the SURF beamline. Absorption of SURF-II radiation by

argon will be used for final spectral line focus tests. The first experiment will be the Stark effect in parahydrogen . This work will investigate

the effects of an electric field upon predissociating and autoionizing

states of molecular hydrogen. These measurements will be carried out by a visiting scientist with the Photon Physics Group of the Radiation Physics

Division in collaboration with the University of Maryland team.

D. Angle-Resolved Photoelectron Spectroscopy Beamline for Molecular and

Chemical Physics, BL-5 (T. Ferrett, J. Hardis, A. Parr, and S. Southworth

,

all from Div. 534)

In this research program, a high resolution angle-resolved photoelectron spectrometer is used on the high flux, normal -incidence 2m mono- chromator at SURF to study photoionization processes in atoms and molecules. Wavelength dependent measurements of the photoelectron intensities, branching ratios, and angular distributions are compared with

correspondi ng theoretical calculations in order to develop basic understanding of resonant processes such as those due to autoionization and

shape resonances. The high resolution and high sensitivity capabilities

of the instrumentation are used to study vi brational ly dependent effects

and provide a sensitive set of experimental results that challenge the

development of the theory of resonant processes in molecules. In addition, the measurements are applicable to phenomena involving the

interaction of radiation with atoms and molecules such as occur in the

upper atmosphere and astrophysi cal systems.

The instrumentation was substantially improved during the year. The

channeltron photoelectron detectors were replaced with position sensitive

detectors which allow a range of kinetic energies (approximately 0.5 eV)

to be measured simultaneously. The data collection system is under

computer control and makes use of a unique set of programs to efficiently

store and display the photoelectron spectra as they are recorded. Newly

designed components for the gas nozzle, electrostatic shielding, and

photon beam intensity and polarization analysis were also installed. Data

analysis has been greatly improved with the addition of a powerful microcomputer, graphics devices, and automation software which allow data

analysis to be done concurrently with the data collection.

43
Division 533, Technical Activities (cont'd)

We have completed studies on H

2 and NO. Angular distribution

measurements on H

2 were combined with correspondi ng measurements made

independently at Daresbury Laboratory. The measurements confirmed a small

but significant difference with theoretical calculations and imply that an additional interaction needs to be accounted for in the theory. The NO

measurements showed strong, non-Franck-Condon effects over a wide energy

range and have motivated the development of a theoretical model in which a shape resonance, valence excitation, and Rydberg excitation are combined

into a complex autoionizing state.

Additional studies were made on CO, C0 2 , and N

2 0. Detailed oscillatory structure was measured in the photoelectron parameters of CO and is

providing new information on electronic autoionization processes in this

system. The measurements are being used to critically evaluate new theoretical methods under development. An extensive set of measurements

made on C0 2 were used to characterize the effects of vibronic coupling in

this system. This study of nonadiabatic interactions adds a new level of

detail to the understanding of molecular photoionization processes. The

measurements on N

20 characterized non-Franck-Condon effects arising from a shape resonance in a tri atomic molecule and will be compared with theoretical calculations in progress.

E. Optical Properties of Materials Beamline, BL-8 : (R. Keski-kuha, GSFC;

D. Husk, U. Virginia; and S. Ebner, Div. 534)

This experimental station has a 2.2m grazing incidence monochromator

and an experimental chamber outfitted with a ref 1 ectometer for studying

reflectance as a function of angle of incidence. It has been used by

scientists from NASA/Goddard for the study of reflectance of substrate

materials for XUV optical systems and for the evaluation of multilayer

structures made at Goddard and also provided by Dr. Troy Barbee of

Lawrence Livermore Laboratori es . The system was also used by scientists

from the U. of Virginia to study the linearity of response of phosphors

excited by XUV radiation.

A number of improvements of this experimental station have been

undertaken this year. A new sample manipulator and ion pump were provided

for the experimental chamber, and a gate valve for the monochromator . A new viewport for the entrance slit and a new monochromator drive system

are also being designed.

F. Detector Calibration Beamline, BL-9 (L.R. Canfield)

The new detector calibration facility at SURF -II, commissioned last

year, has been refined and is routinely producing outgoing calibrations in

the range 5-50 nm as part of our transfer standard detector program (see

Far UV Detector Calibrations).

44
Division 533, Technical Activities (cont'd)

This facility has also recently been used to perform total photoemission measurements of high temperature superconducting materials in a collaboration with other groups from NBS, the U. of Tennessee, and abroad.

A number of composition and production parameters were varied in bariumyi ttri um-copper-oxide samples prepared at NBS and were studied at SURF in

the region 5-55 nm. The spectra are dominated by the large resonance due

to the d+f transitions in barium but also show structure due to copper 3p

excitations near 77 eV which may contain valency information.

In addition, a recent modification to this facility has enabled the

measurement of the optical properties of alkali nitrates and nitrites in

collaboration with Oak Ridge National Laboratory. These samples are being

prepared in thin film form on plastic substrates and studied in transmission. Other groups have expressed an interest in doing collaborative work

using this new capability, including an interest by fusion diagnosticians

to develop energy selective detectors by proper choice of photoemi ssi ve surface and accompanying filter.

ELECTRON PHYSICS GROUP

The Electron Physics Group has ongoing research efforts in electron

collision physics including el ectron-surface interactions, surface

magnetism, electron interaction theory, electron polarization phenomena,

electron-atom collisions, and electron optics and instrumentation. The

wide applicability of electron-based measurement technologies allows us to

contribute to the solution of many diverse scientific and technological

probl ems

.

This year, we have made very significant advances in our

electron-atom collision experiments. Our spin dependent scattering

measurements provide so much detail and control of parameters as to exceed

the capability of all current theoretical models. In particular, our superelastic measurements require a new theoretical formalism to describe

the results. This new theoretical framework was also developed by us in

conjunction with the experiments.

We have continued to study interfacial phenomena. As col 1 aborators

in a national effort, centered at the Brookhaven NSLS, we have begun

experiments aimed at determining the spin dependent band structure of a new class of magnetic materials we will create in situ by molecular beam

epitaxy.

We have continued to increase and focus our efforts toward the study

of microscopic phenomena and their influence on the macroscopic properties

of surfaces. A major emphasis is on magnetic phenomena and structure. We

have improved our instrumentation by adding a scanning Auger microprobe

facility to increase our capabilities in the study of magnetic micro45
Division 533, Technical Activities (cont'd)

structure. We have also brought on-line an ultrahigh vacuum scanning

tunneling microscope and obtained atomic spatial resolution for the first

time. Additionally, most of our experiments are being adapted to the use

of the technique of molecular beam epitaxy to grow thin overlayer films,

permitting us to study interfacial phenomena.

Electron - Atom Collision Studies (M.H. Kelley and J ,J . McClelland)

Our purpose is to study, in as complete a manner as possible, the

interactions between electrons and atoms in low energy collisions. We

employ optical state preparation techniques to prepare beams of electrons

and atoms in well defined quantum states and perform scattering measurements to determine the effect of atomic state preparation on the spin

polarized incident electrons. When the atoms are optically-pumped, they

are prepared in selected states of spin and orbital angular momentum. The

measurement of the spin dependent effects in the collision provides direct

information about spin dependent interactions, such as the exchange or the

spin-orbit interaction, and consequently provides substantially more

information than is available in conventional differential cross section

measurements

.

The elastic measurements were performed at an incident electron

energy of 54.4 eV and at scattering angles in the range from 20° to 135°.

Most surprising was that for even a light target such as sodium, the spinorbit interaction played a significant role in the scattering, producing a spin dependence with a magnitude comparable to that due to exchange.

Current state-of-the-art theoretical calculations, which include exchange

but not the spin-orbit interaction, cannot reproduce our measurements of

either th.e exchange or the spin-orbit spin dependences, indicating that

further theoretical work is necessary.

In addition to the experimental studies of superelastic scattering in

sodium, we have developed a theoretical framework with which to describe

our results. In this framework we treat the electrons as scattering into one of two independent channels in which the spins of an incident electron

and atom couple to form either a singlet or triplet composite spin state.

Because the spin-orbit interaction is negligible for the inelastic collisions, this composite spin is conserved in the collision. From our measurements, we determine the ratio between the cross sections for

triplet versus singlet scattering, and determine the orbital angular

momentum imparted to the atom in collisions via either channel. Comparison with theory shows that, while the best available calculations are in

substantial agreement with our measurements, there are important disagreements which point out the shortcomings of the theoretical models.

Our current efforts are directed at extending the energy range in

which these measurements are possible. Our aim is to provide measurements

of spin dependances for both elastic and superelastic scattering. This

46
Division 533, Technical Activities (cont'd)

provides theoreticians very detailed information about both of the

dominant channels for electron scattering, and hence serves as an important benchmark for evaluting calculations.

Magnetic Microstructure Research (J. Unguris and R..J. Celotta)

Recently we have emphasized research investigating sub-micron

magnetic structures using Scanning Electron Microscopy with Polarization

Analysis (SEMPA). The SEMPA technique was developed at NBS and basically

involves the combination of an ultrahigh vacuum scanning electron microscope (SEM) with detectors that measure the spin polarization of the

secondary electrons. When a magnetic sample is scanned by the SEM, the

secondary electrons that are emitted retain the spin orientation that they

had in the solid and therefore are directly related to the magnetization

in the region probed by the incident electron beam. In practice this

means that magnetic structures can be resolved with a spatial resolution

of about 10 nm (0.01 microns), which is the highest resolution available

of any technique for looking at magnetic mi crostructure in reflection. In

addition, because the escape depth of the secondary electrons is approximately 2 nm, SEMPA is an ideal probe of surface and thin film magnetism.

We have recently exploited the surface sensitivity of SEMPA to study

the magnetic structures of ultra-thin Fe films that were epitaxially grown

on Ag and Cu crystals. Because the lattice structure of the thin film is

strongly affected by the substrate, the thin film magnetic properties can differ radically from those of bulk Fe. By adding Fe evaporation sources

to our SEMPA apparatus, we were able to observe how the magnetic structure

evolved as the film thickness changed. Magnetic domain structures could

be observed with as little as three monolayers of Fe present. This work

was done in col 1 aborati on with the Naval Research Lab.

In addition to this fundamental scientific research, we have also

continued collaborating with private industry to use SEMPA to investigate

more applied problems. For example, we worked with researchers from

Eastman Kodak Corporation to study the magnetic properties of new materials for thin film magnetic recording heads.

We are also close to completing construction of a new SEMPA facility

which will be centered about a scanning Auger microprobe. The Auger

microprobe will provide us with a way of determining elemental composition

with about the same spatial resolution and from the same area as the

magnetic and topographic images. This microscope also features improved

Au film polarization detectors and an enhanced image processing system to

speed up data acquisition and analysis.

We have established joint research efforts with industry, other

government laboratories, and universities. We have received a multitude

of samples from major corporations interested in exploring the applicabil47
Division 533, Technical Activities (cont'd)

ity of this new technique to outstanding scientific and technological

problems of concern. We expect these collaborative efforts to be scientifically fruitful, intellectually stimulating, and mutually beneficial.

Scanning Tunneling Microscopy (R. Dragoset, R. Young, S. Mielczarek, and

D. Pierce)

As part of our shift in emphasis toward the physics of

microstructures, we constructed and began operating a scanning tunneling

microscope to improve our understanding of the fundamental atomic

processes involved in the nucleation and growth of thin films on clean

metallic and semiconductor surfaces. We have successfully operated the

instrument in air, scanning gold and pyrolytic graphite surfaces, and we have measured the regular structure of a mechanically fabricated

diffraction grating. While working in a high vacuum environment, we studied the result of the diamond-turning process used to fabricate

extremely smooth mirrors. We have completed the installation of this

system in a standard ultrahigh vacuum surface analysis chamber. In addition to scanning tunneling microscopy, this chamber allows LEED

measurements, Auger spectroscopy, ion-sputtering, and sample installation,

heating, cooling, and cleaning. The control of sample cleanliness and

preparation available to us in this new system has recently permitted us to obtain topographic maps with atomic resolution of a Si ( 1 1 1 ) crystal

.

They clearly show the 7x7 reconstruct!' on

.

Now that we have an atomic resolution instrument on-line in a UHV

system, our primary interest is the characteri zat i on of thin-film growth

structures. Our initial plans include observing surface changes after

sub-monol ayer deposition of an evaporate on a Si (111) crystal surface. We

will attempt to perforin evaporation in situ in order to scan the same area

of the surface before and after evaporation. We hope to correlate changes

in surface structure after evaporation with the character of the surface

before deposition (e.g. defects).

Polarized Photoemission Studies of Magnetic Systems (R. Celotta and

D. Pierce)

Two years ago we began plans to collaborate with AT&T Bell

Laboratories and Brookhaven National Laboratory to employ spin-polarized,

angle-resolved photoemission to study surface magnetism. This effort has

been greatly expanded in scope by the addition of a large number of

prominent col 1 aborators to form a Materials Research Group (MRG). The

NSF-supported MRG consists of eleven principal investigators from the

following institutions: AT&T Bell Labs, NSLS-Brookhaven National

Laboratory, Argonne National Laboratory, Northwestern U., Rice U., IJ. of

Texas at Austin, Naval Research Laboratory, U. of California at Irvine,

and our own Group at NBS.

48
Division 533, Technical Activities (cont'd)

The focus of the effort will be to study both bulk materials and

epitaxial ferromagnetic mono- , bi - , tri- and multi-layer materials.

Investigations will include ground state magnetic properties, testing

local density theory predictions, surface magnetic critical phenomena,

spin-dependent photo-excitation, and energy- and wave-vector- resolved

electron spectroscopy. Because of the increasing importance of interfaces

and multilayered structures, the experimental station will include a molecular beam epitaxy apparatus for fabricating unique magnetic

multilayered structures.

A component of this research will be aimed at improving the photon

flux available from the U05 beam port on the NSLS x-ray storage ring. Our

MRG has been designated as an insertion device team and will be installing

a new undulator to provide a greatly enhanced photon flux for use in

spin-polarized photoemission experiments. We have begun the initial

experiments at NSLS using an existing experimental chamber and undulator.

A molecular beam epitaxy system is being installed now, and contracts are being finalized for a new undulator and optical monochromator system.

This effort in understanding exotic magnetic structures will

complement our effort in magnetic microstructure (SEMPA) and physical and

electronic mi crostructure (STM) and greatly enhance our ability to

understand the macroscopic physical properties of matter through study of

their microscopic structure.

Spin Polarized Inverse Photoemission (L. Klebanoff, R. Jones, D. Pierce)

Studies of ferromagnetic metal surfaces using the spin polarized

electron source developed in this group have continued productively over

the last year. By using our polarized electron gun to observe the effects

of the exchange interaction, we are able to measure the local net

alignment of spins in the surface of a ferromagnet. The short mean free

paths for elastically scattered electrons make this technique extremely

surface sensitive, unlike neutron scattering which is used to study bulk

magnetic phenomena. In the past several years we have focused on a spin

polarized inverse photoemission (SPIPES) technique to study some transition metal surfaces.

Inverse photoemission complements photoemission studies by yielding

energy and momentum resolved information about the unoccupied band

structure at the surface. An electron incident upon the sample can undergo a radiative transition and become bound in a vacant orbital of the

solid. The flux of 9.7 eV photons emitted from the sample is measured as

a function of the energy, angle of incidence, and spin of the electrons.

Since the energy, momentum, and spin are conserved, the final state is

well defined. Because of its spin selectivity, SPIPES is applicable to a large number of areas of current interest in ferromagnetic materials.

49
Division 533, Technical Activities (cont'd)

In the past year, we completed and submitted for publication a SPIPES

investigation of the clean Ni(001) surface and the c(2x2) absorption

systems 0/ Ni ( 001 ) and S/ Ni ( 001 ) • For clean Ni(001), we found a minorityspin character for the unoccupied 3d band, but an essentially non-maynetic

character for the Ni 4sp band. These spin-dependent results confirm

previous spectral assignments made for Ni(001). No spin dependence of the

Ni(001) image potential surface state was found.

Our investigations of Ni(001) chemisorption yielded surprising

results. No evidence was found for a C (2x2 )

, oxygen-i nduced antibonding

. This finding is in direct

theoretical predictions. The

state at the Surface Brillouin zone center,

contradiction with published experiments and

chemisorbed oxygen does not significantly alter the intrinsic magnetization of the observed mi nori ty-spi n 3d spectral peak. Chemisorbed sulfur

produced qualitatively different results. The presence of a c(2x2) sulfur

overlayer produces a small intensity enhancement at the Ni 3d IP peak, and

reduces the observed spin dependence of the peak by four-fold. These

variations suggest the possible existence of a sulfur-induced unoccupied

state of majority spin character just above the Fermi level at . Such a state would play a central role in the mechanism by which sulfur destroys

surface magnetism.

We are currently investigating the electronic and magnetic properties

of ultra-thin epitaxial metallic films deposited on metallic substrates

with SPIPES. The first thin film systems under study, monolayer and

multilayer cobalt yrown in situ on situ on Cu(lll), have already yielded

interested results. We have measured the energies of the unoccupied

minority and majority spin cobalt d bands as well as a surface electronic

state in cobalt films ranging from 0.8 to 9 monolayers. Changes in both

the spin character and energy of the d band features are directly related

to film thickness. These observations may lead to significant conclusions

about the relationship between the electronic structure of a metallic

monolayer film, which is a quasi two dimensional system, and the electronic structure of the correspondi ng three dimensional bulk metal.

Electron Theory (D. Penn)

A new, general formula was proposed for determining electron inelastic mean free paths (IMFPs) for 200-2000 eV electrons in solids. The new formula is based on separate IMFP calculations for 27 elements and 4

compounds using a previously developed algorithm. This formula is

believed useful for determining the IMFP dependence on electron energy for

a given material and the materi al -dependence for a given energy. The new formula should also be a reasonable guide to electron attenuation lengths

that have been difficult to determine with the needed accuracy.

Also studied was the process of Auger decay in the interaction of

metastable helium with metal surfaces. When metastable helium atoms

50
Division 533, Technical Activities (cont'd)

approach the surface of a metal, an Auger decay can take place in which a metal electron falls into an empty Is state of helium and a second electron (the Auger electron) is ejected. Measurements of the total number

of Auger electrons ejected from nickel for opposite spin-polarizations of

metastable helium show a difference (normalized) that increases from 0 to

10% as the kinetic energy increases. We have formulated a theory for this

asymmetry. In contrast to the standard interpretation, we find the

sp-electrons to be of crucial importance. Whereas the d-electrons carry

the main magnetic moment, the sp-electrons have the largest overlap with

the helium.

Finally, the interaction between two test charges in a solid was studied. This interaction can be described in terms of a total dielectric

function that includes electronic and lattice polarization. Stability

requirements place restrictions on the dielectric function. These

restri cti ons , which have previously been determined for the case of a uniform media, have been generalized to the inhomogeneous case. Some

implications for superconductivity have been investigated. A total

dielectric function for the electron-lattice system was derived in the

mean field approximation, and it was shown that the resulting phonon modes

are determined by the usual dynamical matrix.

PHOTON PHYSICS GROUP

The Photon Physics Group investigates the interaction of electromagnetic fields on atoms and molecules in various environments in support of

radiation measurements and standards programs important to N3S and the

outside technical community. This work includes theoretical and experimental studies on the electronic structure of atomic and molecular systems

in field free environments and in strong external fields. The group has

specialized in ionization phenomena and in nonlinear or multiphoton laseratom interactions. Studies are currently focused on molecular excitation

dynamics, shell contraction in atoms, multiphoton transitions, atoms in

high electric and magnetic fields, and the structure of highly excited

atoms. Collaborative work is directed toward ultrasensitive analysis

through resonant multiphoton ionization, the measurement of picosecond VUV

pulses by nonlinear cross correlation techniques, and the identification

of highly excited atomic states suitable for a soft x-ray laser. For many

of the activities, synchrotron radiation from NBS-SURF-II or BrookhavenNSLS is used as a source of tunable vacuum ultraviolet and soft x-ray

radi ati on

.

Ultrasensitive Trace Analysis (T. Lucatorto and C. Clark)

This is a collaborative effort with the Mass Spectrometry Group in

the MBS Center for Analytical Chemistry having the goal of developing a resonance ionization mass spectrometric (RIMS) capability with sub part51
Division 533, Technical Activities (cont'd)

per-billion isotopic abundance sensitivity. Present thermal ionization

mass spectrometers have an ultimate isotopic abundance sensitivity of

about one part in 10 7

. By putting isotopic selectivity into the resonance

ionization step, we hope to improve the overall sensitivity by three to

five orders of magnitude.

Because of the lack of cw lasers capable of producing significant

intensities in the ultraviolet, most RIMS applications have employed

pulsed lasers. Our RIMS studies have used special narrow bandwidth pulsed

lasers to perform isotopically selective ionization. Preliminary results

with the isotope pair 10 Be: 9 Be show laser selectivities in excess of

3000:1, which would, in principle, increase the overall isotopic abundance

sensitivity from 1 : 10 7 to 1 : 3x 10 1

0

. However, due to the poor duty factor

of the pulsed laser (roughly 1 : 1

0

5

) , the sample utilization efficiency is

very low, with the result that sensitivities of only 1 : 10 7 are attainable

with practical samples.

The problem of poor sample utilization efficiency is perhaps the

single most troublesome limitation for RIMS. To attack this problem, we have begun studies on pulsed laser desorption as a method of atomization

that is matched to the duty cycle of the ionization laser. Preliminary

results show that this technique can produce significant enhancements in

efficiencies for relatively volatile elements such as Fe, but only

produces marginal improvements for the more refractory elements such as Ta and 0s. Three mechanisms limiting the effectiveness of the laser

desorption technique are laser plasma formation, thermally induced exfoliation, and molecular binding. The pulsed laser desorption method is being

modified to the pulsed laser evaporation of a thin film in an attempt to

reduce the effects of these mechanisms.

In another effort done in collaboration with the Radiometric Physics

Division (534), we are pursuing the development of a novel "storage ring" mass spectrometer for krypton isotopic abundance analysis in the sub-partper-trillion range. The storage ring concept utilizes a combination of

selective laser excitation and resonant charge exchange to recirculate a krypton ion beam along a set of prescribed orbits in a racetrack configuration. By combining the selectivity inherent in the laser excitation, the

charge exchange, and the magnetic orbit filtering, this method should

provide abundance sensitivities much higher than any of the presently

available techniques.

Resonance Ionization Mass Spectrometry Data Service (E. Saloman)

The techniques of Resonance Ionization Spectroscopy (RIS) and Resonance Ionization Mass Spectroscopy (RIMS) have demonstrated high elemental

sensitivity and the potential for almost 100% efficiency. They should

become most valuable tools for analytical chemistry. For these techniques

to meet their potential, they must be made available to practicing analyt52
Division 533, Technical Activities (cont'd)

ical chemists. Presently much of the information needed to apply RIS and

RIMS is scattered in several atomic data bases, which generally contain

much more information than the chemists would need. Our goal is to

provide a handbook to supply the RIS schemes and atomic data that would

allow the techniques to be applied to analytical needs without a major

literature study in advance for each element to be measured.

This kind of data has been collected at NBS for seven decades. It is

the objective of this project to organize the available data and supplement it with calculations where gaps exist to provide the needed information to permit the application of RIS and RIMS to routine use in analytical chemistry. Initial funding has been obtained and appropriate data

sheets are being developed in collaboration with the RIS - RIMS community,

including the Institute for Resonance Ionization Spectroscopy at the

University of Tennessee.

Soft X-ray Emission Spectroscopy Using Synchrotron Light Excitation

(D.L. Ederer)

Soft x-ray fluorescence can provide important information about the

electronic states of solid state materials. Fluorescence measurements can

be used to study the properties of alloys, impurities, clusters, surface

layers, organics, and other fragile compounds. A novel, high sensitivity

soft x-ray spectrometer especially designed for fluorescence measurements

has been in operation at the NSLS for over a year now and is the proud

accomplishment of a joint NBS-Uni versi ty of Tennessee-Oak Ridge National

Laboratory collaboration. This experiment has proved to be one of the

best instruments in the world for soft x-ray fluorescence measurements.

The unique capabilities of the instrument has attracted a number of

col 1 aborators including scientists at the University of Utah, the

University of Hawaii, the University of Connecticut, the University of

Uppsala, AT&T Bell Laboratories, and NBS colleagues from the Institute of

Materials Science and Engineering and the Institute for Computer Science

and Technology. Through collaboration with our IMSE colleagues, we have

studied the electronic structure of the icosahedral phase of an aluminum

manganese alloy, as well as the electronic structure of the Ba 2 YCu 3 0 7 _5

superconducting ceramics. This last area of research has been included as part of the scientific case for a DoC initiative on high temperature

superconductors. A few of the highlights of this program are:

a) High Tc Superconductors:

The p-type density of states peak about 4 eV below the Fermi

energy at all four different atomic sites. We confirm that copper

has a valence of +2, and there is no change in the electronic

structure as the temperature is changed from room temperature to

below Tc.

53
Division 533, Technical Activities (cont'd)

b) Quasi crystal s

:

Several calculations predict an enhancement in the density of

states near the Fermi energy. We observe a diminution in the

density of states at the Fermi energy. One calculation predicts a rather large chemical shift in the Fermi energy as the symmetry

changes from octagonal to icosahedral. We observe no significant

chemical shift. In fact the major change observed in the spectrum

is due to the alloying process rather than the phase change.

c) Al-GaAs and GaAs-P Semiconductor Compounds:

This collaboration with AT&T Bell Labs yielded the chemical shift

as a function of aluminum concentration, which follows the change

in the width of the band gap obtained from optical measurements.

The slope of the chemical shift changes at the concentration where

the alloy switches from an indirect to a direct semiconductor.

During the next year we will be continuing our studies of the high

temperature superconductors and commence studies on implanted species

of importance to the semiconductor industry. A new monochromator will be

added to the i nstrumentat i on to allow for narrow band irradiation. We

will also study radiation damage in the alkali halides, important window

materials used in UV lasers.

Polarized Fluorescence Studies (D.L. Ederer)

A series of studies done in collaboration with the University of

Maryland and the University of Central Florida has been carried out at

SURF using the polarization of the synchrotron radiation beam as a probe

of molecular and atomic photoionization dynamics. In helium we made the

first measurements of the angular distribution of the 304 A radiation

following photoionization. This distribution reflects the alignment of

the ion with the electron in a 2p orbital. The alignment is related to

the ratio of the photoionization cross section to final continuum states

of d symmetry to the total cross section for ionization and excitation of

the electron to a 2p orbital. The measurements were in good agreement

with close coupling calculations and complemented other experiments that

measure the correlation among the electrons in this fundamental two

electron system. The results were published in Phys. Rev. Letters.

We have made measurements on the alignment of 0

2+ for two different

ionization channels. We have observed that the A state channel of the ion

exhibits pronounced structure which correlates well with the known positions of autoionizing Rydberg states, whereas the polarization signal in

the b channel of the ion has broad and less prominent features. A paper

on this subject has been accepted for publication in the Journal of

Chemical Physics.

54
Division 533, Technical Activities (cont'd)

Photoabsorption of Laser-Ionized Species (T. Lucatorto and C. Clark).

Our group has a unique capability to measure the VUV photoabsorption

(between 8 nm and 65 nm) of laser-excited and laser-ionized atoms. The

I R- 100 award-winning instrumentation includes a state-of-the-art, VUV

spectrometer with a 1024 channel photoelectric detector, a 20 ns pulsed

VUV source, several pulsed tunable dye lasers, a high temperature (up to

2500°C) heat-pipe oven, and a mode-locked laser capable of powers of 0.3

GW for durations as short as 30 ps.

Photoabsorption studies of laser-excited and laser-ionized atoms have

uncovered the dramatic effects of relatively small changes in electron

screening on orbital collapse. During the last year we completed an analysis of the 5p-photoabsorpti on of Ba++ and performed a preliminary analysis of the 3p photoabsorption of Mn(3d 5 4s 2 6 S), Mn (3d 5 4s4p 8 P), and

Mn+ (3d 5 4s 7 S) in collaboration with visiting scientists.

The objective of the research on Mn(Z=25) is to explain why the 3p

photoabsorption of Cr(3d 5 4s 7 S) with Z=24, which displays a wel 1 -devel oped

Rydberg series, differs so dramatically from the analogous photoabsorption

in Mn and other neighboring elements which have a single broad resonance

and several much weaker features. It is hoped that by obtaining a detailed spectrum of Mn + (3d 5 4s 7 S) , which is i soel ectroni c to the Cr, we may provide a key element in finding the explanation for the puzzling

difference between Cr and the other transition metals. Obviously the

difference in screening between the Mn+ and Cr systems has a crucial

influence on the structure of the 3d 5 - and 3d 6 - based configurations which

play a central role in the 3p photoabsorption spectra. A theoretical

effort is being pursued in parallel to the experimental work.

This work is a collaboration with the Atomic and Plasma Radiation

Division

.

Development of a Measurement Program to use the Time Structure of the

Electron Beam at SURF (D.L. Ederer)

A new class of experiments are being planned for SURF which will

utilize both lasers and synchrotron radiation. Synchrotron radiation is a source of pulsed VUV radiation that can be used to produce excitation

leading to chemical reactions. By probing a sample of excited molecules

undergoing a reaction with a laser-locked to the storage ring radio frequency, we may obtain detailed information on the dynamics of the chemical

reaction. The mode locked ND:YAG laser with the doubler and Q switch has

arrived and will eventually be installed on the SURF Storage Ring.

55
Division 533, Technical Activities (cont'd)

During the waitiny time for the laser arrival, we have been exploring

some potential new directions for the pump-probe program through a collaborative research program at AT&T Bell Laboratori es . At Bell Labs a subpicosecond laser is used to produce a plasma rich in XUV radiation which

is then monochromat i zed . A portion of the laser beam is combined with the

monochromatic XUV beam to conduct purnp-probe experiments. The goal of

this work is to make a VUV- visible cross correlation on core excitons in

al kal i -hal i des which will allow sub-picosecond measurements of VUV pulses.

Our long-term collaboration to study 1 aser-prepared states with the

University de Paris-Sud in Orsay, France, is winding down. Measurements

of the partial photoionization cross section from the 5d metastable state

in barium vapor were published in Phys. Rev. Letters. In this work, we showed that inner core correlations between the 5d electron and the

electrons in the 4d sub shell were responsible for structure in the 5d

photoi oni zati on cross section. A review of photoionization from excited

states, co-authored by D. Ederer and F. Wuilleumier, will be published

early in 1983 as a book chapter in Advances in Atomic and Molecular

Physics entitled "Photoionization and Col 1 isional Ionization of Laser

Excited Atoms Using Synchrotron Radiation."

Atomic and Molecular Theory (C.W. Clark)

Theoretical work in the Photon Physics Group continued its focus on problems of core- and multiply-excited states. The main accomplishments

of the past year in this area were:

1) Conclusion of the analysis of isotope shifts in the l S and X D series

of 9 Be and 10 Be;

2) Identification of the principal features in 3p photoabsorption by

Mn+

;

3) Systematic classification of low energy p-wave shape resonances in

electron-atom scattering;

4) Completion of a comparative study of photoabsorption and electron

energy loss spectroscopy of metallic Ce near the 4p excitation

threshol d;

5) Work on the development of a general computer code for computation of

two-photon transition probabilities; and

6) Formulation of a procedure for the computation of high-order multiphoton processes in atomic hydrogen by a Sturmian functions approach.

56
Division 533, Technical Activities (cont'd)

In addition, a project to investigate certain radiative corrections

to the energy levels of high-Z ions was started. Other theoretical work

was done during this period to directly assist experimental efforts in the

group:

1) Analysis of soft x-ray fluorescence spectra and total photoemission

yield spectra of new high-Tc superconducting compounds;

2) Participation in the proposal and design of an experiment to measure

the Stark effect in para rl 2 ; and

3) Proposals for new atomic physics experiments on the RIMS apparatus.

This work was done in collaboration with guest scientists from the

University of Delaware, the Australian National University, and the Royal

Holloway & Bedford New Colleges.

X-Ray Attenuation Cross Sections (E. Saloman)

A comparison has been carried out, in both tabular and graphical

form, over the energy range 0.1-100 keV between the National Bureau of

Standards' data base of experimental attenuation coefficients (total

absorption cross sections) and cross sections obtained using two widely

used sets of absorption cross section values: the semi -empi ri cal set of

recommended values produced by Henke et al . and a theoretical set of

recommended values calculated by Scofield (and extended at our request

down to 0.1 keV). We also evaluated whether Scofield's calculation should

be subject to a renormal i zati on from a Hartree-Sl ater to a Hartree-Fock

atomic model and determined that the experimental data tend to argue

against such renormalization.

A bibliography of the NBS data base has been produced in conjunction

with this comparison. The results of this work were issued as NBS

Internal Reports 86-3431 and 86-3461. A compilation of experimental and

theoretical x-ray attenuation coefficients for this energy range has been

prepared in collaboration with H. Scofield of Lawrence Livermore National

Laboratory. It is expected to be published early next year.

This work is a collaboration with the Ionizing Radiation Division.

Relativistic Mul ti -Conf i gurati on Calculation of Atomic Properties ( E . Saloman)

Relativistic mul ti -conf i gurati on Dirac-Fock methods have been applied

to the calculation of atomic and ionic energies and transition probabilities. The initial study being carried out is an investigation of the

energies and oscillator strengths in the ground state configuration of the

sulfur i soel ectroni c sequence. Results have been obtained already for 31

57
Division 533, Technical Activities (cont'd)

members. They demonstrate strikiny effects in the f-values correspondi ny

to atomic numbers where different conf i yurati ons become important. Calculation of the rest of the members of this sequence will take place next

year.

This work is a collaboration with the Atomic and Plasma Radiation

Division

.

Electric Field Effects (E. Saloman)

This proyram studies the effect of electric fields on the absorption

cross sections and autoionization rates of atoms and molecules. We have

investiyated the effect of electric fields on autoioniziny Ba states using

multi-color, multi-photon laser excitation. We have completed a theoretical and experimental investigation of the Stark effect on Rydberg states

with anisotropic ion cores. The results of this investigation have been

published in Physical Review. Further work on this project has been

temporarily suspended.

This work is a collaboration with the Atomic and Plasma Radiation

Division.

58
SPONSORED WORKSHOPS, CONFERENCES, AND SYMPOSIA

Division 533, Radiation Physics

C.W. Clark organized a meeting on the Atomic Physics of Beryllium, NBS,

December 12, 1986.

C. W. Clark organized and chaired the Symposium on Formation and Decay of

Multiply Excited States, IV International Conference on Multiphoton

Processes, Boulder, CO, July 15, 1987.

R.P. Madden organized, jointly with J I LA and Ball Research Corporation,

the 8th Workshop on the Vacuum Ultraviolet Radiometric Calibration of

Space Experiments, Boulder, CO, March 18-19, 1987.

D. T. Pierce organized and chaired the Symposium on Magnetic

Mi crostruct ure, Conference on Magnetism and Magnetic Materials, Baltimore,

MD, November 18, 1986.

59
INVITED TALKS

Division 533, Radiation Physics

1 . Celott a, R.J.,

SEMPA," Physics

1986.

2. Celott a. R.J.,

Meet i ng of the

1986.

3. Celotta, R.J.,

Co 1 loqui urn, 3M

4. Celott a, R.J.,

Using Sc anni nq

"New Ways of Observing Mi crostructure:

Colloquium, City College of New York,

The STM and

NY, November 5,

"Polarized Electron Microscopy of Magnetic Surfaces,"

American Vacuum Society, Minneapolis, MN, November 11,

"Polarized Electron Microscopy of Magnetic Surfaces,"

Corporation, Minneapolis, MN, November 12, 1986.

"Magnetic Mi crostructure of Amorphous Alloys Studied

Electron Microscopy with Polarization Analysis," 31st

Conf. on Magnetism and Magnetic Materials, Baltimore, MD, November 17

1986.

5. Celotta, R.J., "New Directions in Electron Microscopy," Philosophical

Society of Washington, Cosmos Club, Washington, D.C., December 5,

1986.

6. Celotta, R.J., "Scanninq Electron Microscopy with Polarization

Analysis," Colloquium, Chemistry Dept., University of Maryland,

Colleqe Park, MD, February 27, 1987.

7. Celotta, R.J., "Scanning Tunneling and Scanninq Polarization

Microscopy," Physics Colloquium, Johns Hopkins University, Baltimore,

MD, April' 2, 1987.

8. Celotta, R.J., "Scanning Electron Microscopy with Polarization

Analysis-SEMPA," Electron Microscopy Society of America, Annual

Meeting, Baltimore, MD, August 5, 1987.

9. Celotta, R.J., "Scanning Electron Microscopy with Polarization

Analysis: Studies of Magnetic Microstructure, " American Vacuum

Society, Annual Meeting, Anaheim, CA, November 2, 1987.

10. Clark, C.W., "Excited States of Atoms and Negative Ions," Atomic

Physics Colloquium, University of Virginia, Charlottesville, VA,

November 12, 1986.

11. Clark, C.W., "Doubly-Excited States of Negative Ions," Physics

Colloquium, College of William and Mary, Wi 1 1 i amsburq, VA, February

13, 1987.

60
Division 533, Invited Talks (cont'd)

12. Clark, C.W. "Atomic Negative Ion Resonances," International

Conference on the Physics of Electronic and Atomic Collisions,

Brighton, England, July 27, 1987.

13. Clark, C.W. "Summary Remarks," Atomic Spectra and Collisions in

External Fields, Royal Holloway and Bedford New College, Egham,

England, July 31, 1987.

14. Clark, C.W., "Theory of Highly Excited Atoms in Electric and Magnetic

Fields," Symposium on Atomic Spectroscopy and Highly Ionized Atoms,

Hickory Ridge Conference Center, Lisle, IL, August 17, 1987.

15. Dragoset, R.A., "Scanning Tunneling Microscopy of a Diamond-turned

Surface and a Grating Replica," SPIE Conference on Metrology: Figure

and Finish, Los Angeles, CA, January 15, 1987.

16. Ederer, D.L., "X-Ray Fluorescence in Dilute Alloys," Workshop on New

Directions in Soft X-Ray Near Threshold Phenomena, Monterey, CA,

March 3, 1987.

17. Ederer, D.L., "X-Ray Fluorescence in Low Z Metals," University of

Maryland Baltimore County, Baltimore, MD, March 15, 1987.

18. Ederer, D.L., "Pump and Probe Experiments with Lasers and Synchrotron," Brookhaven National Laboratory, Islip, NY, July 14, 1987.

19. Ferrett, T.A., "Shake-up, Shake-off, and Shape Resonances in Near

Threshold Photoemission," Workshop on New Directions in Soft X-ray

Near-Threshold Phenomena, Pacific Grove, CA, March 2, 1987.

20. Ferrett, T.A., "High-resolution Photoelectron Spectroscopy of Gaseous

CO and C0

2 Using Synchrotron Radiation," Daresbury Laboratory,

Warrington, England, September 1, 1987.

21. Ferrett, T.A., "High-resolution Photoelectron Spectroscopy of Gaseous

CO and C0

2 Using Synchrotron Radiation," National Research Council

Laboratory, Frascati, Italy, September 8, 1987.

22. Hughey, L.R., "Radiometry Using Synchrotron Radiation at NBS-SURF,"

Council for Optical Radiation Measurements, NBS, Gait hersburg, MD,

May 28, 1987.

23. Johnson, B.C., "Transition Probabilities for Astrophys i cal Plasmas,"

Carneqie Institute of Washinqton, Washinqton, DC, April 11, 1987.

24. Johnson, B.C., "Experimental Study of Laser-Induced Collisions," Rice

University, Houston, TX, November 17, 1986.

61
Division 533, Invited Talks (cont'd)

25. Johnson, B.C., "Kinetics of Associative Ionization in Heteronuc 1 ear Collisions," Meeting of the Division of the Atomic, Molecular, and

Optical Physics of the American Physical Society, Cambridge, MA, May

18, 1987.

26. Lucatorto, T.B., "Ultrasensitive Isotopic Analysis With RIMS: Application to 10 Be: 9 Be," Twenty-ninth ONRL-DoE Conference on Analytical

Chemistry in Energy Technology, Knoxville, TN, October 1, 1986.

27. Lucatorto, T.B., "Resonance Ionization Mass Spectrometry for Longlived Radionuclide Assay," Thirty-second Annual Conference on Bioassay Analytical and Environmental Radiochemistry, NBS, October 22,

1986.

28. Madden, R.P., "UV Radiometric Calibration of Space Experiments at

NBS-SURF II," Symposium on Solar Irradiance Measurements, Vancouver,

Canada, August 21, 1987.

29. Madden, R.P., "By What Means Can Better Flux Calibrations Be

Achieved," Eighth Workshop on the VIJV Radiometric Calibration of

Space Experiments, JILA/NBS, Boulder, CO, March 19, 1987.

30. Madden, R.P., "SURF II Performance and Research Activities," Synchrotron Radiation Instrumentation Conference, University of Wisconsin,

Madison, WI, June 22, 1987.

31. Ott, W.R., "UV and Soft X-ray Measurements Services", Region 3 Local

Chapter of the National Conference of Standards Labor ator i es,

Lexington Park, MD, January 21, 1987.

32. Ott, W.R., "Radiation Standards and Calibrations: Documentation

Available from NBS," Workshop and Symposium on Innovation: Key to the

Future, National Conference of Standards Laboratories, Denver, CO,

July 14, 1987.

33. Ott, W.R., "UV and Soft X-Ray Measurement Services at NBS," Workshop

and Symposium on Innovation: Key to the Future, National Conference

of Standards Labor at or i es , Denver, CO, July 16, 1987.

34. Ott, W.R., "Industri al ly-Signif icant NBS Developments in the Physical

Sciences," Government/ Industry Technology Transfer Conference,

Nashville, TN, August 7, 1987.

35. Penn, D.R., "Electronic Structure and Theory of Superconductivity,"

NBS, Boulder, CO, July 16, 1987.

62
Division 533. Invited Talks (cont'd)

36.

37.

38.

39.

40

41.

42.

43.

44.

45.

46.

47.

Pierce, D.T., "Scanning Electron Microscopy with Polarization

Analysis: High Resolution Images of Mannetic Microstructure, " 5th

Pfefferkorn Conference on Physical Aspects of Microscopic

Character i zat ion of Materials, Bruggen, Germany, October 10, 1986.

Pierce, D.T., "The Ga-As Polarized Electron . Source and Its

Application," Perkin-Elmer Corporation, February 23, 1987.

Pierce, D.T., "Scanning Electron Microscopy with Polarization

Analysis," IBM Research Labs, Zurich, Switzerland, April 6, 1987.

Pierce, D.T., "SEMPA: High Resolution Imaqing of

Maqnetizat ion," Eidgenossische Technische Hochschule, Zurich,

Switzerland, April 8, 1987.

Pierce, D.T., "Experimental Study of Surface Magnetism with Polarized

Electrons," 9th European Conference on Surface Science, Lucern,

Switzerland, April 15, 1987.

Pierce, D.T., "Electron Spin Polarization Analyzers for Use With

Synchrotron Radiation," 5th National Conference on Synchrotron

Radiation Instrumentation, Madison, WI, June 22, 1987.

Pierce, D.T., "Polarized Electron Microscopy," Adriatic Research

Conference on Scanning Tunneling Microscopy, Trieste, July 29, 1987.

Pierce, D.T., "Experimental Studies of Surface and Thin Film

Magnetism with Polarized Electrons," Sandia National Laboratory

Seminar, Albuquerque, NM, September 8, 1987.

Unguris, J., "Imaging Magnetic Microstruct ures Using Scanning

Electron Microscopy with Polarization Analysis," Seminar, Physical

Electronics, Eden Prairie, MN, July 11, 1986.

Unguris, J., "Investigations of Maqnetic Microstruct ures Using

Scanninq Electron Microscopy with Polarization Analysis (SEMPA),"

Gordon Conference on Electron Spectroscopy, Wolfeboro, NH, July 17,

1986.

Unguris, J., "Microscopy with Spin Polarized Electrons,"

Inter/Mi cro-86, Chicago, IL, July 22, 1986.

Unguris, J., "Spin Polarized Electron Studies of Magnetic Materials,"

Physics Colloquium, University of Maine, Orano, Maine, November 4,

1986.

63
Division 533, Invited Talks (cont'd)

48. Unguris, J., "Scanning Electron Microscopy with Spin Polarized

Electrons", 31st Conference on Maqnetism and Maqnetic Materials,

Baltimore, MD, November 18, 1986.

49. Unquris, J., "Maqnetic Mi crostruct ure Imaqinq usinq Scanning Electron

Microscopy with Polarization Analysis", Microbeam Analysis Society

Meeting, Kona, HI, July 16, 1987.

64
PUBLICATIONS

Division 533, Radiation Physics

Callcott, T.A., Tsang, K.L., Zhang, C.H., Ederer, D.L., and Arakawa, E.T.,

A High Efficiency Soft X-ray Emission Spectrometer for use with Synchrotron Radiation Excitation, Rev. Sci. Instrum. _57, 2680 (1986).

Canfield, L.R., New Far Ultraviolet Detector Calibration Facility at NBS,

Appl . Opt. 26, 3831 (1987)

.

Canfield, L.R. and Swanson, N., NBS Measurement Services: Far Ultraviolet

Detector Standards, NBS SP 250-2 (June 1987).

Canfield, L.R. and Swanson, N., Far Ultraviolet Detector Standards, NBS

J. of Res. 92, 97 (1987)

.

Celotta, R.J. and Pierce, D.T., Polarized Electron Probes of Magnetic

Surfaces, Science, 234, 333 (1986)

Celotta, R.J., Hembree, G.G., Unquris, J. and Pierce, D.T., Maqnetic

Microstructure Imaqing by Secondary Electron Spin Polarization Analysis,

Proc. of the Electron Microscopy Society of America, San Francisco Press,

634 (1986)

Celotta, R.J., Unquris, J., Hembree, G.G., Pierce, D.T., and Aroca, C.,

Maqnetic Mi crostructure of Amorphous Alloys Studied Using Scanning

Electron Microscopy with Polarization Analysis", Proceedings 31st

Conference on Magnetism and Magnetic Materials, 3217 (1986).

Celotta, R.J., Skold, K., Price, D.L. and Levine, J., Methods of

Experimental Physics, _23, Neutron Scattering, Part A, Academic Press,

1986.

Celotta, R.J., Hembree, G.G., Unguris, J. and Pierce, D.T., Scanning

Electron Microscopy with Polarization Analysis: High Resolution Images of

Maqnetic Microstructure, Scanning Microscopy Supplement 1, 229 (1987).

Clark, C.W., Term dependence in the Hartree-Fock Approximation for Heavy

Atoms, Phys. Rev. A 15, 4865 (1987).

Clark, C.W. and Lucatorto, T.B., Giant Resonances in the Transition

Regions of the Periodic Table, Giant Resonances in Atoms, Molecules, and

Solids , J.P. Connerade, J.M. Esteva, and G.C. Karnatok eds . , (Plenum

Publishing, 1987) p. 137.

Clark, C.W., Regularities of Neqative Ion Resonances, J. Opt. Soc Am. B,

4, 815 (1987)

.

65
Division 533, Publications (cont'd)

Cooper, J.W., Clark, C.W., Cromer, C.L., Lucatorto, T.B., Sonntag, B.F.,

and Tomkins, F.S., Resonant Structure in 3p Subshell Absorption, Phys.

Rev. 35, 3970 (1987).

Ferrett, T.A., Heimann, P.A., Kerkhoff, H.G., Becker, U., Lindle, D.W. , and Shirley, D.A., Photoelectron Asymmetry Parameter for the S 2p Level of

S0

?

, Chem. Phys. Lett. 138 , 607 (1987).

Ferrett, T.A., Pi ancastel 1

i , M.N., Lindle, D.W., Heimann, P.A., Shirley,

D.A., Resonance Effects in the Inner-Valence Levels of SF in the

Photon-enerq.y Ranqe 52-72 eV, Chem. Phys. Lett. 134 , 146 (1987).

Hill, W.H., Sugar, J., Chenq, K.T., and Lucatorto, T.B., Analysis of the

5p6 +5p5 n£(J=l) Rydberq Series in Ba++

, Phys. Rev. A 36_, 1200 (1987).

Hubbell, J.H., Gerstenberq, H.M., and Saloman, E.B., Biblioqraphy of

Photon Total Cross Section (Attenuation Coefficient) Measurements 10 eV to

13.5 GeV, NBS IR 86-3461 (July 1986).

Johnson, B.C., Smith, P.L., and Parkinson, W.H, Transition Probability of

the A1 II 2669 Anqstroms Intersystem Line, Astrophysical Journal 308, 1013

(1986).

Kelleher, D.E., and Saloman, E.B., Rydberq States with Anistropic Ion

Cores: Stark Effect, Phys. Rev. A _35, 3327 (1987).

Keller, J.W., Ederer, D.L., and Hill, W. Ill, Polarized Fluorescence from

the A and B States on 02+, J. Chem. Phys. 87_, 3299 (1987)

Kelley, M.H., Hertel, I.V. and McClelland, J.J., Analysis of Collisional

Alignment and Orientation Studied by Scattering of Spin-Polarized

Electrons from Laser Excited Atoms, Z. Phys. D 6, 163 (1987).

Kelley, M.H., McClelland, J.J. and Celotta, R.J., Elastic Scattering of

Spin-polarized Electrons from Spin-polarized Na Atoms, Proceedings ICPEAC

XV, 150 (1987).

Kelley, M.H., Hertel, I.V. and McClelland, J.J., Analysis of Collisional

Orientation and Aliqnment Studies Usinq Spin-Polarized Electrons and Laser

Excited Atoms, Proceedings ICPEAC XV, 151 (1987).

Kelley, M.H., McClelland, J.J. and Celotta, R.J., Superelastic Scattering

of Spin-Polarized Electrons from Optically Pumped Sodium, Proceedings

ICPEAC XV, 152 (1987).

Klose, J.Z., Bridges, J.M., and Ott, W.R., NBS Measurements Services:

Radiometric Standards in the Vacuum Ultraviolet, NBS SP250-3, June, 1987.

66
Division 533, Publications (cont.)

Kostkowski, H.J., Lean, J.L., Saunders, R.D., and Huqhey, L.R., Comparison

of the NBS-SURF and Tungsten Lamp Ultraviolet Irradiance Standards, Appl.

Opt, 25, 3297 (1986).

Lindle, D.W., Ferrett, T.A., Heimann, P.A., and Shirley, D.A., A Complete

Photoemission Study of the He ls2 -->3s3p Autoionizing Resonance, Phys.

Rev. A 2112 (1987).

Lindle, D.W., Heimann, P.A., Ferrett, T.A., and Shirley, D.A., Helium

Photoelectron Satellites: Low-energy Behavior of the n=3-5 Lines, Phys.

Rev. A 35, 1128 (1987).

Lindle, D.W., Heimann, P.A., Ferrett, T.A., Pi ancaste 1 1 i , M.N., and

Shirley, D.A., A Photoemission Study of Kr 3d-->np Autoionizing

Resonances, Phys. Rev. A _35_, 4605 (1987).

Lucatorto, T.B., Of What Use is Basic Research, Wavelength , Newsletter for

Candela Laser Corporation, Vol 4, #2 (1987).

McClelland, J.J., Kelley, M.H. and Celotta, R.J., Spin-Orbit and Exchange

Effects in Elastic Scattering of Spin-Polarized Electrons from Spin-Polarized Na Atoms, Phys. Rev. Lett. _58, 2198 (1987).

McClelland, J.J. and Waclawski, B.J., Mott Scattering Measurements of the

Spin Polarization of the NBS GaAs Electron Source, NBS Internal Report,

April, 1987.

McClelland, J.J., Kelley, M.H. and Celotta, R.J., Large-Angle Superelastic

Electron Scattering from Na(3P), J. Phys. B20, L385 (1987).

Pi ancastel 1 i , M.N., Lindle, D.W., Ferrett, T.A., and Shirley, D.A., The

Relationship Between Shape Resonances and Bond Lengths, J. Chem. Phys. _86_,

2765 (1987).

Poliakoff, E.D., Dehmer, J.L., Parr, A.C., and Leroi, G.E., Fluorescence

Polarization Studies of Autoionization in CS9

, J. Chem. Phvs 86, 2557

(1987).

Saloman, E.B. and Hubbell, U.H., Critical Analysis of Soft X-ray Cross

Section Data, Nucl. Instr. and Meth. A 255 , 38 (1987).

Saloman, E.B. and Hubbell, J.H., X-ray Attenuation Coefficients (Total

Cross Sections): Comparison of the Experimental Data Base with the Recommended Values of Henke and the Theoretical Values of Scofield for Enerqies

Between 0.1-100 KeV, NBS IR 86-3431 (July 1986).

67
Division 533, Publications (cont.)

Southworth, S.H., Parr, A.C., Hardis, J.E., Dehmer, J.L., and Holland,

D.M.P., Calibration of a Monochromator/Spectrometer System for the

Measurement of Photoelectron Angular Distributions and Branching Ratios,

Nucl. Instr. and Meth. A 246 , 782 (1986).

Travis, J.C., Fassett, J.D., and Lucatorto, T.B., Resonance Ionization

Mass Spectroscopy, RIS 86 , G.S. Hurst ed., Inst. Phys. Conf. Ser. No. 84

(Inst, of Physics 1986 )

.

Tsang, K.L., Zhang, C.H., Callcott, T.A., Ederer, D.L., and Arakawa, E.T.,

Fluorescent Emission Spectra of Lithium Fluoride With Use of Synchrotron

Radiation, Phys. Rev. B 35_, 8374 (1987).

Unguris, J., Hembree, G.G., Celotta, R.J. and Pierce, D.T., Summary

Abstract: Scanning Electron Microscope with Polarization Analysis Studies

of Magnetic Materials, J. Vac. Sci. Technol. A 5, 1976 (1987).

68
PUBLICATIONS IN PREPARATION

Division 533, Radiation Physics Division

Callcott, T.A., Tsang, K.L., Zhang, C.H., Ederer, O.L., and Arakawa, E.T. , Soft X-Ray Emission Spectra and the Bonding of Aluminum (to be published,

J. De Physique).

Callcott, T.A., Tsang, K.L., Zhang, C.H., Ederer, D.L., and Arakawa, E.T. , Area Detectors for X-Ray Spectroscopy (submitted, Nucl. Inst. & Meth.).

Celotta, R.J., Unguris, J. and Pierce, D.T., Scanning Electron Microscopy

with Polarization Analyses - SEMPA (to be published, Proc. Electron

Microscopy Society of America, 1987).

Celotta, R.J., Unguris, J. and Pierce, D.T., Summary Abstract: SEM

Polarization Analysis: Studies of Magnetic Microstructure (to be

published, J. Vac. Sci. Technol.).

Celotta, R.U., Advances in Microscopy: Scanning Tunneling and Electron

Polarization Microscopy, Applied Surface Science (in press).

Dragoset, R.A. and Vorburger, T.V., Scanning Tunneling Microscopy of a Diamond-turned Surface and A Grating Replica (to be published, SPIE

Conference Proceed'1 ngs , 1987).

Ederer, D.L., Schaeffer, R., Tsang, K.L., Zhang, C.H., Callcott, T.A., and

Arakawa, E.T., Electronic Structure of the Icosahedral and Other Phases of

Aluminum-Manganese Alloys Studied by Soft X-Ray Emission Spectroscopy

( i n preparati on)

.

Ferrett, T.A., Lindle, D.W. Heimann, P.A., Brewer, W.D., Becker, U. , Kerkhoff, H.G., and Shirley, D.A., Lithium Is Mainline and Satellite

Photoemission: Resonant and Nonresonant Behavior, (to be published, Phys.

Rev. A).

Ferrett, T.A., Schmidt, V., Roy, P., Parr, A.C., Hardis, J.E., and Dehmer,

J.L., Vi brati onal ly-resol ved Photoemission Cross Sections and Asymmetry

Parameters for the X, K, ft, and ft. States of C0

2 + (in preparation).

Heimann, P.A., Lindle, D.W., Ferrett, T.A., Liu, S.H., Medhurst, L.J.

,

Pi ancastel 1 i , M.N, Shirley, D.A., Becker, U. , Kerkhoff, H.G., Langer, B. , Szostak, D., Wehlitz, R., Shake-off on Inner-shell Resonances of Ar, Kr,

and Xe, (to be published, J. Phys. B).

Jimenez-Mi er , J., Caldwell, C.D., and Ederer, D.L., Oscillator Strength

Distribution of Fluorescence from Photoionization Produced He+(n=2) (in

preparation)

.

69
Division 533, Publications in Preparation (cont'd)

Jones, R.K., Klebanoff, L.E., Pierce, D.T. and Celotta, R.J., SpinResolved Inverse Photoemission Study of Ni(001) and its Chemisorption (to

be published, Phys. Rev. B.).

Jones, R.K., Klebanoff, L.E., Pierce, D.T. and Celotta, R.J., Spin

Resolved Inverse Photoemission of Ultra-thin Epitaxial Cobalt Films on Cu ( 111) (in preparati on)

.

Lucatorto, T.B., Hutchinson, J.M.R, and Whitaker, T.J., Exploiting the

Optical Isotope Shift for Ultrasensitive Isotopic Analysis with Lasers,

Proc. of the 1986 Annual Meeting of the American Nuclear Society (Reno,

NV, June 1986) (to be published).

Matthew, J.A.D., Netzer, F.P., Clark, C.W., and Morar, J.F., Giant 4p

Quadrupole Resonances in the Rare Earths (to be published, Europhysics

Letters)

.

McClelland, J., Scholten, R.E., Kelley, M.H. and Celotta, R.J., Spin Sensitivity of a Channel Electron Multiplier (submitted. Rev. Sci. Instr.).

Parr, A.C., Southworth, S.H., and Dehmer, J.L., Shape Resonance Effects in

Photoionization of NO (in preparat i on)

.

Parr, A.C, Hardis, J.E., Southworth, S.H., Feigerle, C.S., Ferrett, T.A. , Holland, D.M.P., Quinn, F.M., Dobson, B.R., West, J.B., Marr, G.V., and

Dehmer, J.L., Vi brati onal ly Resolved Photoelectron Angular Distributions

for H

2 in the Range 17 eV < hu < 39 eV (submitted, Phys. Rev. A).

Penn, D.R., Tanuma, S., and Powell, C.J., Inelastic Mean Free Paths;

Energy and Material Dependence (in preparat i on)

.

Penn, D.R., Allen, P., and Cohen, M. , Total Dielectric Function: Algebraic

Sign, Electron-Lattice Response, and Superconductivity (submitted, Phys.

Rev)

.

Penn, D.R., Ape 1

1 , P., and Monreal, R. Spin Polarization of Secondary

Electrons in Metastable Helium-Nickel Interactions (in preparati on)

.

Pierce, D.T., Hembree, G.G., Unguris, J. and Celotta, R.J., SEMPA: High

Resolution Image of Magnetic Mi crost ructure (to be published, Scanning

Electron Microscopy, 1987).

Pierce, D.T., Experimental Studies of Surface Magnetism with Polarized

Electrons (to be published. Surface Science).

Pierce, D.T., Celotta, R.J., Kelley, M.H. and Unguris, J., Electron Sp s n Polarization Analyzers for Use with Synchrotron Radiation (to be published, Nucl. Instr. Meth).

70
Division 533, Publications in Progress (cont'd)

Roy, P., Ferrett, T.A., Schmidt, V., Parr, A.C., Southworth, S.H., Hardis,

J.E., Bartlett, R., Trela, W. , and Dehrner, J.L., A Study of Vibronic

Coupling in the C State of C0

2 + (to be published, J. de Physique).

Roy, P., Ferrett, T.A., Schmidt, V., Parr, A.C., Southworth, S.H., Hardis,

J.E., Bartlett, R., Trela, W., and Dehrner, J.L., A Dynamical Study of

Vibronic Coupling: the Z State of C0

2 + (in preparati on)

.

Tsang, K.L., Zhang, C.H., Callcott, T.A., Canfield, L.R., Blendall, J.

,

Ederer, D.L., Clark, C.W., Wassdahl, N., Rubensson, J.E., Bray, G. , B.C.,

Nordgren, J., Martensson, N., Nyholm, R., and Cramm, S., Soft X-ray

Absorption and Emission Spectra and the Electronic Structure of

Ba

2 YCu

3 0

? _ x Superconductor, Proc. of the 14th International Conference on X-rays and Inner Shell Processes (to be published, J. de Physique).

Tsang, K.L., Zhang, C.H., Callcott, T.A., Canfield, L.R., Blendall, J. , Ederer, D.L., Clark, C.W., Wassdahl, N., Rubensson, J.E., Bray, G. , B.C.,

Nordgren, J., Martensson, N., Nyholm, R., and Cramm, S., Soft X-ray

Absorption and Emission Spectra and the Electronic Structure of

Ba

2 YCu

3 0

7

_ x Superconductor (to be published, Phys. Rev B. Rapid

Communi cation)

.

Unguris, J., Celotta, R.J., Pierce, D.T. and Hembree, G.G., Magnetic

Mi crost ructure Imaging using Scanning Electron Microscopy with Polarization Analysis (to be published. Analytical Electron Microscopy, 1987).

Wen, J., Travis, J.C., Lucatorto, T.B., Johnson, B.C., and Clark, C.W.

,

Measurement of Isotope Shifts of Two-Photon Transitions in Beryllium (to

be published, Phys. Rev. A.).

Wuilleumier, F.J., Ederer., D.L., and PicquG, J.L., Photoionization and

Co llisional Ionization of Laser Excited Atoms Using Synchrotron Radiation

(to be published, January 1988, chapter in "Advances in Atomic and

Molecular Physics," Volume 33).

Zhang, C.H., Tsang, K.-L., Callcott, T.A., Ederer, D.L., and Arakawa,

E.T., The A1 L

2 3 and Mg Double Ionization Emission Spectra of Dilute A1

in Mg Alloys (submitted, Phys. Rev. B).

71
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 533, Radiation Physics Division

Robert J. Celotta

Member, General Committee, International Conference on the Physics of

Electronic and Atomic Collisions.

Member, NML EEO Committee, 1986-87.

Charles W. Clark

Member, National Research Council Committee on Line Spectra of the

Elements - Atomic Spectroscopy.

Member, Organizing Committee, IV International Conference on Multiphoton Processes, 1987.

Member, Organizing Committee, 1987 Conference on Atomic Spectra and

Collisions in External Fields.

Thomas B. Lucatorto

Co-chairman, 1989 International Conference on the Physics of Electron

and Atomic Col 1 is ions.

Member, Program Committee, 4th International Symposium on Resonance

Ionization Spectroscopy and its Applications, 1988.

Co-chairman, Local Organizing Committee, 4th International Symposium

on Resonance Ionization Spectroscopy and its Applications, 1988.

Co-chairman, 1987 Workshop on Advanced Laser Techniques in Chemical

An alys i s

.

Robert P. Madden

Chairman, Optical Society of America Nominating Committee.

Member, Calibration and Stability Working Group of the Ozone Trends

Panel

.

Coordinator, International Radiometric Intercomparison of Solar

Irradiance Experiments.

Member, International Committee for the International Conference on Vacuum Ultraviolet Radiation Physics.

72
Division 533, Technical and Professional Committee Participation (cont'd)

Member, Editorial Advisory Board, Optics Communication .

Member, Middle Atmospheric Program International Working Group on Solar Spectral Irradiance Measurements, 1981-1987.

Member, Council of U.S. Synchrotron Radiation Laboratory Directors.

Member, International Committee of the International Conference on X-ray and VUV Synchrotron Radiation Instrumentation.

Member, Advisory Committee for the Laboratory of Laser Energetics,

University of Rochester, Rochester, NY.

Member, Optical Society of America Objectives and Policy Committee.

Member, Synchrotron Radiation Facility Working Group (Department of

Energy)

.

Member, NBS-NML Classification Committee for the NBS Personnel

Demonstration Project.

Stanley R. Mielczarek

Member, NBS Property Review Board.

W i 1 1 i am R . Ot t

Member, International Workinq Group for Middle Atmosphere Proqram on Solar Spectral Irradiance Measurements, 1981-1987.

Member, Local Orqanizing Committee for the 4th International

Symposium on Resonance Ionization Spectroscopy and Its Applications,

1987-88.

Chairman, NBS-CRR Calibrations Advisory Committee, 1985-87.

Chairman, NBS-NML Performance Review Panel, 1986-87.

Member, NBS-NML Classification Committee for the NBS Personnel

Demonstration Project.

Daniel T. Pierce

Member, Editorial board, Review of Scientific Instruments.

Member, Editorial board, Journal of Electron Spectroscopy.

Chairman, 1988 Gordon Conference on Electron Spectroscopy

.

73
Division 533, Technical and Professional Committee Participation (cont'd)

Vice Chairman, Executive Committee, Surface Science Division of

American Vacuum Society, 1987.

Program Chairman, 1987 American Vacuum Society (Surface Science

Division) Meeting in Anaheim.

Member, Organizing Committee, 1987 International Colloquium on Magnetic Films and Surfaces.

Member, Scientific Advisory Committee, 9th European Conference on Surface Science, 1987.

74
MAJOR CONSULTING AND ADVISORY SERVICES

Division 533, Radiation Physics

1. R.J. Celotta and D.T. Pierce consulted on the production and detection

of polarized electrons with researchers from Rrookhaven, AT&T Bell

Labs, Bell Communications Corporation, University of Texas, Princeton,

Kimball Physics Corporation, Rice University, University of Oklahoma,

City Colleqe of New York, MIT, Arqonne National Laboratory, Jet

Propulsion Laboratory, Perkin Elmer Corporation, and the Naval

Research Laboratory.

2. C.W. Clark advised a group at Princeton Plasma Physics Laboratory on atomic physics problems associated with x-ray laser development.

3. D.L. Ederer consulted with Denise Caldwell

Central Florida on angular distribution of

of the University of

fluorescence in helium.

4. D.L. Ederer consulted with Richard Freeman of AT&T Bell Labs on pumpprobe experiments involving lasers and synchrotron radiation.

5. W.R. Ott consulted with scientists

Goddard Space Flight Center on new standards and inflight radiometric

and principal investigators at

possibilities for radiation

calibration of spectrioradiometers

.

6 . W.R. Ott consulted individual ly with industrial scientists

Dupont, 3M, Uniroyal, and about 10 other corporations at a Transfer Conference and discussed cooperative research and

opportunities at NBS.

from

Technology

1 icensing

75
JOURNAL EDITORSHIPS

Division 533, Radiation Physics

R.J. Celotta, Series Editor

C. W. Clark, Topical Editor,

Society of America B.

D. T. Pierce, Editoral Board

D.T. Pierce, Editoral Board

Methods of Experimental Physics.

Atomic Spectroscopy, Journal of the Optical

Review of Scientific Instruments.

Journal of Electron Spectroscopy.

76
TRIPS SPONSORED BY OTHERS

Division 533, Radiation Physics Division

R.J. Celotta presented a talk at a Physics Colloquium, City College of New

York, NY, November 5, 1986.

R.J. Celotta presented a talk at a meeting of the American Vacuum Society,

Minneapolis, MN, November 11, 1986.

C.W. Clark consulted on x-ray laser development at Princeton Plasma

Physics Laboratory, Princeton, NJ, October 15, 1986.

C.W. Clark presented a talk at the University of Virqinia, Charlottesville, VA, November 12, 1986.

C.W. Clark consulted on x-ray laser development at Princeton Plasma

Physics Laboratory, Princeton, NJ, February 6, 1987.

C.W. Clark presented a talk at Colleae of William and Mary, Wi 1 1 i amsburq

,

VA, February 13, 1987.

C.W. Clark consulted on x-ray laser development at Princeton Plasma

Physics Laboratory, Princeton, NJ, April 6, 1987.

C.W. Clark attended and chaired a session at the Gordon Conference on Atomic Physics, Wolfeboro, NH, July 5-11, 1987.

C. W. Clark attended the symposium on Atomic Spectroscopy and Highly

Ionized Fields and presented a talk, Hickory Ridge Conference Center,

Lisle, IL, August 17, 1987.

D. L. Ederer consulted on collaborative physics experiments at the

University of Central Florida, Orlando, FL, October 22, 1986.

D.L. Ederer attended a workshop on New Directions in Soft X-Ray Near

Threshold Phenomena, Monterey, CA, March 1-4, 1987.

T.A. Ferrett presented an invited talk at the Workshop on New Directions

in Soft X-ray Near-Threshold Phenomena, Pacific Grove, CA, March 1987.

B.C. Johnson visited labs and presented a talk at the Weiss School of

Natural Sciences, Houston, TX, November 14, 1986.

D.R. Penn consulted with M. Cohen for a week at Berkeley on Superconductivity, 1J. of CA at Berkeley, Berkeley, CA, May 1987.

D.T. Pierce presented a talk at Perkin Elmer Corp., Minneapolis, MN

,

February 23, 1987.

77
Division 533, Trips Sponsored by Others (cont'd)

D.T. Pierce presented a talk at the Synchrotron Radiation Conference,

Madison, WI , June 25, 1987.

D.T. Pierce attended an abstract selection meeting in Anaheim, June 28-29,

1987.

J. Unquris presented a talk at a Physical Electronics Corp. seminar, Eden

Prairie, MN, 1986.

J. Unguris presented a talk at the Gordon Conference on Electron

Spectroscopy, Wolfeboro, NH, 1986.

J. Unquris presented a talk at Inter/Micro-86, Chicaqo, IL, 1986.

J. Unquris presented a talk at a Physics Colloquium, University of Maine,

Orano, Maine, November 4, 1986.

78
CALIBRATION SERVICES PERFORMED

Division 533, Radiation Physics

Type of Service

Customer

Type*

SP 250

Item No.

Number of

Cal ibrations

or Tests

Far UV radiometric

transfer standard

detectors (photodiode calibrations)

1,4-8 N . A. 21

Spectrometer calibrations using SURF

as an absolute source 5-7 N . A

.

12

Tot al

s

31

^Column 2: 1, calibration labs; 2, hospitals; 3, nuclear energy

establishments; 4, industry; 5, US government labs;

6, DoD labs; 7, universities; 8, foreign governments.

79
SPONSORED SEMINARS AND COLLOQUIA

Division 533, Radiation Physics

Baldwin, Ken, Australian National University, "Emission Spectrum of Helium

Excimers Formed in a Nozzle Beam," April 24, 1987.

Barth, Jochen, BESSY, "Spectroscopic Ellipsometry with Synchrotron Radiation," March 12, 1987.

Blazewicz, Perry, Oak Ridge National Laboratory, "Non-Linear Spectroscopic

Processes in Xenon and Krypton," December 4, 1986.

Brown, Louis, Carnegie Institute of Washington, Department of Terrestrial

Maqnetism, "Geochemical Applications of 10 Be Dating Techniques,

December 12, 1986.

Buncick, Milan, Oak Ridqe University, "Optical Absorbence of Silver

Ellipsoidal Particles," July 30, 1987.

Chanq, Tu Nan, University of Southern California, "Configuration Interaction in Quasi-Two Electron Atoms", May 14, 1987.

Codling, Keith, University of Readinq, "Femtosecond Dynamics of

Multiphoton Multiple Ionization of Molecules Usinq a Picosecond Laser,"

July 31, 1987.

Dietz, Eberhard, Der Johann Wolfgang Goethe Un i vers i fat , "Temperature

Dependent Photoelectron Spectroscopy on 3d Metals," June 15, 1987.

Fairbank, William, Colorado State University, "Fundamental Experiments

Using Lasers and Single Atom Detection," January 22, 1987.

Falco, Charles, University of Arizona, "Metallic Multilayers for X-ray

Optics," November 3, 1986.

Frank, Cal, Cornell University, K-Shell Inelastic X-ray Scattering in

Coincidence with Fluorescence," May 28, 1987.

Huennekens, John, Lehigh University, "Near Infrared Spectra of Alkaline

Molecules," April 16, 1987.

Kerner, Jonathan, Lawrence Berkeley Laboratory, "Absolute Character i zat ion

of Filters, Multilayers, Transmission Gratings, and Photocathodes,"

July 9, 1987.

Klein, Jeffrey, University of Pennsylvania, "Applications of 26 A1 and 10 Be

to Studies of Earth Surface Properties," January 13, 1987.

80
Division 533, Sponsored Seminars and Colloquia (cont'd)

Korevaar, Eric, Western Research Corporation, "Atoms in Crossed Electric

and Magnetic Fields," March 27, 1987.

Li, Jia-Ming, Chinese Academy of Sciences, "Molecular Rydberg States,"

June 30, 1987.

Milchberg, Howard, AT&T Bell Labs, "Studies of Plasmas Produced by

Sub-Picosecond Lasers," December 15, 1986.

Mitroy, James, JILA, "Electron Impact Excitation of Be+

: Status of

Experiment and Extensive Close-Coupling Calculations," December 12, 1986.

O'Neill, David, University of Wisconsin, "Cr/Au 110: Two Dimensional

Electronic Structure of Monolayer and Bi layer Chromium Films,"

March 23, 1987.

O'Mahony, Patrick, University of London, "Rydberg Atoms in Maqnetic

Fields," December 5, 1986.

Schmidt, Volker, Universifat Freiburq, "Important Electron Correlations

in Atomic Physics," April 21, 1987.

Westbrook, Chris, University of Michigan, "Precision Measurements of the

K-rate of Ortho-Positronium," December 29, 1986.

Windt, David L., University of Colorado, "Optical Properties of Materials

in the XUV and Soft X-ray Region," April 28, 1987.

Wunner, Gunther, UniversitHt Tubingen, "Magnetic Rydberg Atoms: A

Gateway to Quantum Chaos," December 10, 1986.

81
'
TECHNICAL ACTIVITIES

Division 534, Radiometric Physics

Introduction

The Radiometric Physics Division (534) of the Center for Radiation

Research is the primary unit within NBS for carrying out the traditional

Bureau role of promoting accurate, meaningful, and compatible optical

radiation measurements in the uv , visible, and ir spectral regions. The

Division:

• develops, improves, and maintains the national standards for

radiation thermometry, spect roradi ometry , photometry, and

spectrophotometry

;

• disseminates these standards by providing measurement services to

customers requiring calibrations of the highest accuracy;

• conducts fundamental and applied research to develop the

scientific basis for future measurement services in optical

radi ometry

.

In pursuing these goals, the Division is actively engaged in collaborative

efforts with industry, other government agencies, uni versi ti tes

,

professional societies, and standards organizations at the national and

international levels.

Fiscal year 1987 was a year of transition for Division 534. The loss

of personnel incurred during FY86 continued with the retirement of V.

Weidner, resignation by R. Schaefer, and termination of G. Jaafari . This

made it necessary to restructure the Division. The former Spectroradiometry and Photodetector Groups were combined into the Spectral

Radiometry Group. Dr. Albert C. Parr, formerly with the Photon Physics

Group of the Radiation Physics Division (533) of CRR, was asked to take

charge of this Group. Six scientists were hired to ensure the

continuation of ongoing work and the implementation of new programs in

advanced radiometry:

Dr. Tricia Ferrett came to the Division as a postdoctoral fellow to work

on the ARPES project at SURF. Several others joined as temporary

employees or guest scientists.

Mr. Stephen C. Ebner

Dr. A. Barry Hi 1 1 ard

Dr. Stephen H. Southworth

Mr. Charles E. Gibson

Dr. Jonathan E. Hardis

Dr. Alan L. Migdall

83
To help in focusing on programmatic responsibilities, to facilitate

technical planning, and to simplify the pri ori ti zati on and allocating of

resources, the activities of the Division were divided into "projects," as listed below. The project leaders who will be in charge of the day-to-day

technical management of these projects are shown in parentheses.

Advanced Radi omet ry (Hardis)

Thermal Radiometry (Saunders)

Photodetector Metrology (Zalewski)

Laser Spectrometry (Migdall)

Facilities Development (Fowler)

Spectrophotometry (Hsia)

Photometric R&D (McSparron)

Radiometric Measurement Services (Walker)

The progress made during the year in each of these eight projects is

detailed in the following reports by the three Group Leaders of the

Di vi si on

.

Spectral Radiometry (A. C. Parr, Group Leader)

This Group is responsible for establishing a solid scientific basis for

optical radiometry. Specifically, the Group:

• performs research leading to new, advanced approaches to

radiometric measurements;

• applies the concepts arising from this research to the development

of specific new measurement methods and standards for optical

radi omet ry;

• extends and improves NBS measurement services in optical

radiometry by extending the range of the parameters calibrated and

by upgrading the equipment and techniques used.

Advanced Radiometry

This effort includes the Kr

+ ion charge exchange light source

development as well as some col 1 aborat i ve projects in the use of

synchrotron radiation. The Kr

+ project entails studying the charge

exchange of a Kr

+ beam with neutral rubidium vapor. After the collision,

the krypton is left in a neutral metastable state which can then be laser

excited. The excited state decays with the emission of two photons, one

on the uv and one on the near ir. Alternatively, the metastable state can

be reionized and the process used as an isotope selective process for mass analysis. The Kr

+ ion source and ion optics have been parameterized and

design considerations for the full project have been formulated. A

postdoctoral scientist who will work exclusively on this project has been

recruited and will join the project in FY-38.

84
Division 534, Technical Activities (cont'd)

The Spectral Radiometry Group has assumed the responsi bl i ty for the

Angle Resolved Photoelectron Spectroscopy (ARPES) experiment at the NBS

synchrotron ultraviolet radiation facility ( SURF- II). This activity,

which was the principal activity for Parr before he joined the Group, is

being funded for the near future to allow for the sensible completion of

the SURF phase of the work. It is expected that this project will evolve

into a collaboration at another synchrotron facility in the next several

years, and correspondingly the emphasis by the Radiometric Physics

Division will decrease. Other new options in radiometry, including the

use of superconductor technology to obtain very sensitive bolometers, are being explored in conjunction with the NBS Boulder labs.

Thermal Radiometry

A first round of direct radiometric measurements of the temperature

of a freezing-gold olackbody work has been completed, and the results have

undergone preliminary analysis. The results indicate agreement with the

accepted value for the freezing point of gold at the 0.1 K level. The

margin of experimental error is, however, consistent with the downward

redefinition, which seems to be the intent of the international

temperature community. We feel that further effort in this project is

warranted, particularly if the temperature region above the melting point

of silver is given to radiometry for temperature scale realization. This

project has taken the lead in developing a program of imaging radiometry.

It is also actively refurnishing the blackbody calibration facilities.

New modern facilities for calibration and research capability will be

completed during the next year or so, which will leave the Group with a much improved posture in its calibration responsibilities. Collaboration

with other Groups in the Division is underway on the development of new optical pyrometry capability. Saunders finished a collaboration with

Bruening on remodeling the lamp spectral flux facility. Incandescent

spectral flux standards have been calibrated, and a new automation of the

facility has been installed. Saunders has also participated in

i ntercompari sons of the argon mini -arc and the NBS storage ring as absolute radiometric sources. These results indicate good overall

agreement between the various radiometric standards maintained by NBS.

Photodetector Metrology

This project has as its principal activity the development of

detector based radiometry in the visible, near uv , and near infrared. The

DRIP calibration program and the various international i ntercompari sons are also a part of the responsi bi 1 i t i es of this project. The first round

of the CIE i ntercompari son is underway, and the international intercomparison for the CCPR has been completed. Zalewski has prepared a draft

publication on this latter effort for publication in the near future.

85
Division 534, Technical Activities (cont'd)

These efforts are part of a long term program in maintaining an international effort in detector based radiometry and in exploring the benefits

and limitations of the procedures which have evolved at NBS over the last

few years

.

In collaboration with Andor (guest scientist), a set of three

photopically corrected detectors has been calibrated against the absolute

detector base. Because of their higher precision and accuracy, detectors

calibrated in this manner could be used to improve the photometry effort

at NBS. These detectors are being i ntercompared with luminous lamp

standards. In a separate collaboration with Eppeldauer (guest scientist),

a very low level detector package with built-in amplifiers has been

constructed and tested. This effort is primarily directed at the near'

infrared region and could offer considerable improvement in NBS

measurement capabilities.

The calibration documentation for the detector calibration services

has been completed and is undergoing final review in preparation for

release and publication. It is anticipated that new services to be

offered as special tests will be developed in the near future. This will

include special calibration of photodiodes outside the DRIP program, as well as perhaps extending the wavelength coverage of the measurements in

the detector program.

Laser Spectrometry

Laser heterodyne technology has been developed which allows for

optical transmission measurements over at least 10 orders of magnitude to

about \% accuracy. This has been demonstrated at the HeNe wavelength and

is now being implemented in the infrared. RF attenuation can be

accurately measured and this precision can transferred to the optical

attenuation within the heterodyne scheme of measurement. The

applicability of this technique in other areas of spectrophotometry is

being explored.

Facilities Development

NBS accepted the responsi bl i ty to develop a national Low Background

Infrared (LBIR) calibration facility, which is funded by DoD. This

facility, which will occupy three lab modules, will be a large

cryogeni cal ly cooled vacuum chamber suitable for calibration of low

background blackbody sources. This facility will be operated by a new employee to the group, Mr. Steve Ebner, who comes with a background in

facilities management and in radiometric calibrations. The cryogenic

system has been installed and tested. The large vacuum chamber has been

designed and bids for its construction are being solicited. The effort by

Fowler in developing water bath blackbodies has had some minor technical

86
Division 534, Technical Activites (cont'd)

difficulties in that the purchased water baths are not regulating temperature to the desired accuracy. A new water bath has been acquired and the

results look promising for a rapid and successful completion of this

project

.

Spectrophotometry (J. J. Hsia, Group Leader)

The Spectrophotometry Group is responsible for the establishment and

dissemination of primary measurement scales for transmission and

reflection spectrophotometry , densitometry, spectrof 1 uori metry , and other

methods for the radiometric characteri zation of optical components and

materials. For these purposes, the Group:

• develops and maintains reference instrumentation for performing

spectrophotometric measurements of the highest accuracy;

• develops methodologies for highly accurate spectrophotometric

measurements

;

• publishes critically evaluated reference data on intrinsic

standards for spectrophotometry

;

• provides transfer standards, measurement quality assurance

programs, and special calibrations as needed to support the

national measurement system for spectrophotometry

.

The FY87 accomplishments of the Group in four key areas are presented

bel ow. Spectrof 1 uori metry

The purpose of this project is to develop measurement methods and

transfer standards to assess the performance of fluorescence spectrometers

used for analytical chemistry, non-destructive testing, and appearance

measurements

.

The first phase is to study sintered mixtures of inorganic phosphors

and polytetraf 1 uoroethyl ene (PTFF) powder with emission spectra in the

blue, green, yellow and orange spectral regions. In addition to previous

investigations of the effects of concentration, excitation wavelength,

irradiation and temperature on the corrected emission spectra, Eckerle has

studied this year the polarization effect, the uniformity of samples, and

the usefulness of the "blank" PTFE sample. Several sets of samples have

been sent out for user comments.

Limits on the polarization effects of the four colored samples have

been established by measuring the four possible combinations of excitation

87
Division 534, Technical Activities (cont'd)

and emission polarization (SP, SS, PS, PP). The uniformity study showed

that only the yellow sample exhibited slight nonuni formi ty in the long

wavelength region. A study of the blank PTFE sample on the reference and

two commercial spectrofl uori meters revealed that this sample can be used

as a diagnostic tool for second order- radi ati on and stray excitation

radiation

.

Dr. Chen of the National Institute of Health and Dr. Williams of the

Perkin Elmer Corporation have commented favorably on the usefulness of

these prototype samples for calibrating spectrofl uori meters . ASTM

subcommittee E13.01 is circulating a set of samples among members to

evaluate their applicability in chemical application. Dr. McKinnon of

the National Physical Laboratory (UK) has indicated that these samples'

would not be suitable as spectral radiance factor standards for the

appearance industry. Other materials are required for this application.

UV-VIS-NIR Spectrometry

Calibration Services

Calibrations, standards, and test methods in the wavelength range

from 200 nm to 2.5 urn are needed by the coating, optics, non-destructive

testing, energy, safety, space, agriculture, appearance, photography,

printing, textile, paint, and chemical industries. In FY87, calibration

services totaling $22K were performed. Barnes provided special

calibrations of spectral transmittance, specular reflectance, diffuse

reflectance, and opacity. Eckerle provided measurement assurance services

for transmittance and retrof I ectance . Two new calibration documents were

publ i shed:

"NBS Measurement Services: Regular Spectral Transmittance," Eckerle,

K.L., Mielenz, K.D., and Weidner, V.R., NBS Special Publication

250-6, July 1987.

"NBS Measurement Services: Spectral Reflectance," Weidner, V.R., and

Hsia, J.J., NBS Special Publication 250-8, July 1987.

Gray Scales

Gray reflectance standards with diffuse surfaces are needed to

calibrate the linearity of spectral ref 1 ectometers by instrument

manufacturers and users. Weidner has produced uniform gray diffusers with

reflectances below 50% by sintering mixtures of PTFE and black powders.

A technical breakthrough in producing uniform gray diffusers with

reflectance above 50% has been achieved by Collins and Barnes. They have

developed a method to prepare finer PTFE powders, and have achieved better

mixing before sintering. In addition, they have found a method of

88
Division 534, Technical Activities (cont'd)

pre-selecting the proper PTFE/black powder ratio to obtain the required

reflectance of the sintered sample.

Automation Conversion

The reference spectrophotometer for reflectance has been the basic

instrument used by NBS to establish U.S. national scales of specular

reflectance, 6°/hemi spheri cal reflectance factor and 45/0° reflectance

factor. The data acquisition and control units of this instrument have

become outdated, and are now being converted to IBM-GPIB systems. Zhu has

completed the software conversion of subroutines to control new stepper

motor drivers, the high voltage power supply, a new relay module, a new lock-in amplifier, and a new digital voltmeter. He has completed the

conversion of all computer programs for measurements. All hardware and

software are now ready for final tests.

Transmission Densitometry

Measurements of transmission density are used for quality control of

photographic and printing products and for non-destructive testing. Fink

has calibrated 360 x-ray step tablets (SRM 1001) and 180 photographic step

tablets (SRM 1008) for the calibration of transmission densitometers in

the transmission density range 0 to 4. He has evaluated bid microcopy

resolution charts for determining the resolving power of photographic

systems. The reference transmission densitometer (Inverse Fourth

Instrument) has been fitted by Fink and Popenoe with a new receiver

consisting of an opal glass, a sample plate with grooves for applying

vacuum or pressure, a small section of glossy-aluminum cone, an averaging

sphere, filters and a photomultiplier. The new receiver was built to

conform to the new ANSI Standard PH2 . 19-1986 .

Infrared Spectrometry

Measurement services in the infrared spectral region are needed by

instrument manufacturing, coating, optical, glass, and DoD related

industries. The purpose of the long-wavelength infrared spectrometry

project is to establish infrared measurement capabilities from 2.5 to

25 urn for transmittance, diffuse reflectance and specular reflectance.

The plan is to develop dual systems with dispersive and Fourier transform

(FT) infrared spect rometers . This year's efforts have concentrated on establishing the infrared transmittance measurement capability with a monochromator-based infrared spectrometer, and on planning the diffuse

reflectance instrumentation.

Lin has completed investigations on linearity and i nterref 1 ecti on . A modified doubl e-aperture method for the linearity determination of the

spectrometer has been developed. Using this new method, linearity

89
Division 534, Technical Activities (cont'd)

measurements have been performed at different wavelengths, slit widths,

and transini ttances

.

Three types of i nterref 1 ect i ons were analyzed and methods of

eliminating them were developed. Sampl e-to-source-to-sampl e interreflections were as large 0.02 or 0.03 transmi ttance units. Sampl e-to-sourceto-reference beam i nterrefl ecti ons were approxi mately 0.001 or 0.002

transmittance units. Blocking optical f i 1 ter-to-sampl e-to-bl ocki ng

optical filter i nterref 1 ecti ons were about 2xl0 -3 of the sample

transmittance. The results after correcting for all i nterref 1 ecti ons with

the sample normal and angled to the beam agreed within 2xl0” 3 transmittance units. This is consistent with theory.

The FTIR-based spectrometer used in the diffuse reflectance mode has

had some operational difficulties due to the geometry of the liquid

nitrogen cooled detector. The liquid N 2 was not adequately contained,

resulting in temperature instability of the HgCdTe detector. The system

is being redesigned to solve the problem and to operate more efficiently.

Bidi recti onal Scattering Distribution Function (BSDF)

The objective of this project is to develop a national facility for

BSDF measurements. This year's effort was to conduct a comprehensive

analysis of the required configuration for such a facility, and to

coordinate a worldwide investigation of BSDF measurements.

The definition, measurement equations and BSDF measurement methods

have been reviewed, and a preliminary plan has been developed. The

mechanical configurations of BSDF facilities in other countries have been

reviewed, including those of the FGR, Italy, Japan, PRC, and USSR. The

dark currents of silicon photodiodes, and the effect of the earth's

magnetic field on photomultiplier response have been studied.

A worldwide investigation of measurements of the reference materials

such as PTFE and BaSO^ powders has been planned by Hsia within CIE

Committee TC2-11 on Goni oref 1 ectometry . He planned and chaired the

session on goni oref 1 ectometry for the ISCC Williamsburg Conference, and

advised Daoust of the Rochester Institute of Technology on instrumentation

and measurements of goni oref 1 ecti on properties of PTFE and BaSO^ powders.

Radiometric Measurement Services Group (0. A. McSparron)

The Group maintains the national scales for radiance temperature,

spectral radiance, spectral irradiance, luminous intensity, luminous flux

and color temperature. Access to these scales is provided through 29

specific calibration services performed on a routine basis. Research and

development projects are undertaken to extend and improve these scales.

90
Division 534, Technical Activities (cont'd)

Activities such as intercomparisons (domestic and international),

measurement assurance programs, intermediate laboratory support programs,

consultations, special calibrations, and ad hoc experiments are undertaken

to insure that measurements made in laboratories outside NBS have

acceptable levels of accuracy.

Overall, the past year has been one of consolidation for the Group.

Several projects begun in previous years have been completed.

Substantial progress has been made in modernizing the calibration

facilities. Direct calibration billings increased by 9.5% and directly

funded calibration work for other government agencies increased by 20%

from last year's depressed level. The combined effect was an overall

increase of 11%.

Oocumentati on

The Group's contribution to the NBS-wide project to provide full

documentation of all routine calibration services was completed. The

documents prepared address the quantities measured, services offered,

equipment and procedures used, and particular attention was paid to the

preparation of complete uncertainty statements. Four documents were

produced by the Group and published in the NBS Special Publication 250

seri es

:

Calibration Services

Spectral Radiance

Radiance Temperature

Photometry

Spectral Irradiance

Authors

Walker, Saunders and

Hattenburg

Waters, Walker, and

Hattenburg

Booker and McSparron

Walker, Saunders, Jackson

and McSparron

Publ i cati on

SP250-1

SP250-7

SP250-15

SP2 50-20

Three companion articles describing the scientific basis for these

calibrations have been prepared for publication in the NBS Journal of

Research (radiance temperature and spectral irradiance) or Metrologia

(spectral radi ance)

.

Spectroradi ometri c Measurement Services

Pyrometric Calibration Facility

Waters continued the development of the new photoelectric pyrometer

for performing radiance temperature calibrations. This instrument, which

91
Division 534, Technical Activities (cont'd)

employs refractive optics, an extended-red photomultiplier detector, and

interference filters to restrict the bandpass to about 1 nm, was used to

calibrate 25 tungsten strip lamps, 5 visual pyrometers, and 2 sets of

absorbing glass filters. The gold point heat-pipe blackbody was compared

with the reference datum maintained on the extremely stable, Quinn-Lee,

vacuum tungsten lamp. A difference of about 0.5 K was observed and this

difference will be investigated in the coming year. Considerable thought

and effort were expended in developing a specification for a variable

temperature blackbody to be incorporated in this facility. At present,

visible and infrared pyrometers must be calibrated on the Facility for

Automatic Spectroradi ometric Calibrations (FASCAL). These FASCAL

measurements are severely limited by the small opening (2 mm diameter) in

the FASCAL blackbody. In order to acquire some hands-on experience with

measurement problems associated with infrared pyrometers, Walker performed

two special calibrations on FASCAL. The first involved the calibration of

three silicon-cell based infrared pyrometers, and the results were limited

by the small target area available. The second involved the evaluation of

a commercial variable temperature blackbody. This test blackbody was determined to be unsuitable because of its limited temperature range (1000

to 1500 K) and long stabilization times (approximately 90 minutes after a temperature change of 50 K). A specification for a blackbody with a temperature range from 1000 K to 2500 K and a 25 nm diameter opening was developed. Delivery is expected in November 1987.

FASCAL

The shifting of the bulk of the pyrometric calibration load to the

new pyrometer allowed time for the first steps in FASCAL moderi zati on

.

Walker, Jackson, and Gibson converted the instrument control and data

reduction programs to 16-bit, PC-family machines. Plans have been

developed to replace the 15-year old interface system with modern GPIB

components. Popenoe has developed plans to provide the facility with a ceiling mounted lamp station that will allow source-to-recei ver distances

ranging up to 3 m. Implementation of these improvements is expected in

the coining year.

Spectral Irradiance Intercompari son

At the October 1986 Consultative Committee on Photometry and

Radiometry (CCPR) meeting, it was decided to conduct an intercomparison of

national scales of spectral irradiance. The work is to be completed

before the next CCPR meeting in the fall of 1990. NBS will serve as the

pilot lab for this intercomparison. Participating national laboratories

will obtain lamps from the National Physical Laboratory (UK), measure

them, send them to NBS for comparison measurements, and then remeasure

the lamps. Preliminary work at NBS is now underway. It is expected that

NBS will perform the comparison measurements in the fall of 1988.

92
Division 534, Technical Activities (cont'd)

Photometry

International Intercompari sons

The international i ntercompari son of national photometric units,

begun under the auspices of the CCPR

reported at the October 1986 meeting

summarized as follows:

Number of participating national

1 aboratori es

:

Average quotient of 13 1 PM value

(cd or 1 m) to values obtained

by participating laboratories:

Standard deviation of quotients:

Quotient of B I PM and NBS values:

in 1982, was completed. Results were

CCPR. The results may be

Candela Lumen

1 5 1

1

0.990 1.007

0.77% 0 . 58%

0.98 5 0.997

The spread in the candela and lumen values reported by the different

national laboratories was slightly better than in previous intercomparisons. Because of the much wider range of techniques now used for

realizing photometric scales, the results were viewed as giving

confidence to the new definition of the photometric base unit. From the

above table it can be seen that the ratios of the NBS luminous intensity

and luminous flux values to the world mean were 0.990/0.985 = 1.005 and

1.007/0.997 = 1.010 respectively. These differences fall well within the

quoted uncertainties of 1.0% and 1.4%, respecti vely , for routine NBS

calibrations. Nevertheless, research will be undertaken to investigate

these observed differences. It should be noted that the i ntercompari son showed the NBS candela and lumen to be consistent with each other to

0.5%.

Calibration Facilities Upgrade

Booker, Breski, and Wilkinson have continued the program to replace

obsolescent photometric calibration facilities with a modern photometric

bench. The bench is now nearing completion and routine operations are expected to begin in the fall of 1987. Andor characterized four

photopi cal ly-corrected silicon cells on the Division's detector spectral

response instrument and spectrophotometers . The first use of these cells

was a comparison of the detector-based scale they incorporated with the

bl ackbody-based scale incorporated by working-lamp photometric standards.

93
Division 534, Technical Activities (cont'd)

The observed agreement was better than 0.5%. This very encouraging result

will greatly facilitate an orderly revision of the routine photometric

calibration procedures to incorporate the new cells.

Spectral Flux Standards

The program to provide the U.S. lighting industry with

geometri cal ly-total , spectral flux standards reached a major milestone

with the issuance of the incandescent lamp standards. The overall program

involves NBS calibrating one incandescent lamp type and one

non-i ncandescent lamp type for issuance to secondary labs and major U.S.

lamp manufacturers. From these lamps, industry will derive spectral and

photometric standards for all types of high-intensity discharge lamps.

The work is coordinated through the Lamp Testing Engineer's Conference

(LTEC). NBS will oversee the results through a secondary lab support

program. During the past year, Bruening, He, and Saunders completed the

spectral distribution measurements on the incandescent lamps. Jackson,

Walker, and Gibson performed spectral irradiance measurement on FASCAL

which completed the incandescent lamp calibration. Bruening and Saunders

have begun the characteri zation of the high pressure sodium lamps (HPS)

selected by He as suitable for calibration. Issuance of these HPS lamps

is expected in the December 1987/January 1988 period.

94
INVITED TALKS

Division 534, Radiometric Physics

Bruening, Robert, "The National Capital Section of the Optical Society of

America 1962-1987, Historical Notes," National Capital Section of the

Optical Society of America, Arlington, VA, March 21, 1987.

Hsia, J.J., "National Scales of Spectrometry in the U.S.," CORM/USVG

Conference, Oxford, England, September 13-23, 1986.

McSparron, Donald, "NBS Radiometric Measurement Services," NCSL Region 8

Meeting, Lexington Park, MD, Jan. 21, 1987.

McSparron, Donald, "Radiation Thermometry Calibration Program at NBS,"

NASA Noncontact Temperature Measurement Workshop, NASA Headquarters

,

Washington, D.C., April 30, 1987.

McSparron, Donald, "Photometric Standards," Council for Optical Radiation

Measurements - Gaithersburg, MD, May 28, 1987.

Mielenz, Klaus, "Fluorescence Spectrometry in Analytical Chemistry and

Color Science," CORM/UVSG Conference, Oxford, England, September 13-23,

1986.

Mielenz, Klaus, "Intrinsic Standards in Spectrophotometry," 1987 NCSL

Conference, Denver, CO, July 12-16, 1987.

Mielenz, Klaus, "Radiometric Measurement Services at NBS," 1987 NCSL

Conference, Denver, CO, July 12-16, 1987

Parr, Albert, "Radiometric Intercompari son using Synchrotron Radiation,"

1987 NCSL Conference, Denver, CO, July 12-16, 1987.

Parr, Albert, "Future Directions in Molecular Photoionization Using

Synchrotron Radiation," Workshop on New Direction in Soft-x-ray Near

Threshold Phenomena, Asilomar, CA, March, 1987.

Parr, Albert, Progress Report on LBIR Facility, SDC, Huntsville, ALA,

Apri 1 , 1987

.

Parr, Albert, "LBIR Facility at NBS," Report to Calibration Review

Committee, Hanscom AFB, May, 1987.

Saunders, Robert, "Goldpoint Freezing Point Determination," IMEKO TC-2

Meeting, Braunschweig, Germany, September 14, 1987.

Schaefer, A.R. and Fox, N.P., "Tunable Dye Laser Spectrometry," CORM/UVSG

Conference, Oxford, England, September 13-23, 1986.

95
PUBLICATIONS

Division 534, Radiometric Physics

Booker, R. L. and McSparron, 0. A., NBS Measurement Services: Photometric

Calibrations NBS Special Publication SP 250-15.

Bruening, R. J., Spectral Irradiance Scales Based on Filtered Absolute

Silicon Photodetectors, Applied Optics, Vol . 26, March 15, 1987.

Eckerle, K. L., Mielenz, K. L., and Weidner, V. R., NBS Measurement

Services: Regular Spectral Transmittance, NBS Special Publication 250-6,

July 1987.

Parr, A. C., Polikoff, E., Qehrner, J. L., and Leroi , G. E., Fluorescence

Polarization Studies in Autoionization in CS 2 , J. Chem Phys., 86, 2557

(March, 1987)

Pi ancastel 1

i , M.N., Lindle, D.W., Ferrett, T.A., and Shirley, D.A., Reply

to Comment on The Relationship Between Shape Resonances and Bond Lengths,

J. Chem. Phys. 87_, 3255 ( 1987).

Southworth, S. H., Parr, A. C., Hardis, J. E., Channel Coupling and Shape

Resonance Effects in the Photoelectron Angular Distributions of the 3 o^ L and 2c" 1 Channels of N 2 , Phys. Rev. A, _33 , 1020, (February, 1987).

Tibbits, T. W., McSparron, D. A., and Krizek, D. T., Spectral Effects on the Use of Photon Flux Sensors for Measurement of Photosynthetic Photon

Flux in Controlled Environments, Biotronics, Vol. 15, 1986.

Walker, J. H., Saunders, R. 0., and Hattenburg, A. T., The NBS Scale of

Spectral Radiance, Metrologia, Fall, 1987.

Walker, J. H., Saunders, R. 0., and Hattenburg, A. T., NBS Measurement

Services: Spectral Radiance Calibrations, NBS Special Publication

SP 250-1, January 1987.

Walker, J. H., Saunders, R. 0., Jackson, J. K., and McSparron, 0. A., NBS

Measurement Services: Spectral Irradiance Calibrations, NBS Special

Publication SP 250-20, October 1987.

Waters, W. R., Walker, J. H., and Hattenburg, A. T., NBS Measurement

Services: Radiance Temperature Calibrations, NBS Special Publication SP

250-7, October 1987.

96
Division 534, Radiometric Physics (Publications Continued)

Waters, W. R., Walker, J. H., and Hattenbury, A. T., The N8S Scale of

Radiance Temperature, Journal of Research of the National Bureau of

Standards, Vol . 92, No. 1, January-February 1987.

Weidner, V. R., Barnes, P. Y., and Eckerle, K. L., A Wavelength Standard

for the Near Infrared Based on the Reflectance of Rare-Earth Oxides, NBS

J. Res. 91_ ( 5), 243, (Sept. -Oct., 1986).

Weidner, V. R. and Hsia, J. J., NBS Measurement Services: Spectral

Reflectance, NBS Special Publication SP 250-8 (July 1987).

Weidner, V.R., Hsia, J. J., and Eckerle, K. L., Exploratory Research in

Reflectance and Fluorescence Standards at the National Bureau of

Standards, Optics News, 12_ (11), 18-20, (Nov. 1986).

Zalewski, E. F., The NBS Photodetector Spectral Response Calibration

Transfer Program, NBS Special Publication SP 250-18.

97
PUBLICATIONS IN PREPARATION

Division 534, Radiometric Physics

Becker, U. Langer, B., Kerkhoff, H.G., Kupsch, M., Szostak, D., Wehlitz,

R., Heimann, P.A., Liu, S.H., Lindle, D.W., Ferrett, T.A., and Shirley,

D.A., Observation of Many New Argon Valence Satellites Near Threshold (to

be published, Phys. Rev. Lett).

Dehmer, J. L., Dill, D. and Parr, A. C., "Shape Resonances in Molecular

Fields," to be published in Fundamental Processes of Atomic Dynamics

Geist, J. and Mi gda 11, A. L., "Analytic representation of the silicon

absorption coefficient in the intermediate and high energy indirect gap

region, to be published.

Dehmer, J.L., Dehmer, P., Parr, A.C, Hardis, J.E., Southworth, S.H., and

Ferrett, T.A., Resonant Photoionization in the X State of CO in the

Photon-energy Range 17-20 eV (in preparati on )

.

Dehmer, J.L., Parr, A.C., Roy, P. Hardis, J.E., and Ferrett, T.A., Triply

Differential Photoelectron Spectroscopy of Autoionization in the X and A

States of Co Between 17 and 20 eV (in preparation).

Ferrett, T.A., Lindle, D.W., Heimann, P.A., Pi ancastel 1 i , M.N., Kobrin,

P.H., Kerkhoff, H.G., Becker, U.E., Brewer, W.D., and Shirley, D.A.,

Shape-resonant and Many-el ect ron Effects in the S 2p Photoionization of

SF 6 (in preparati on ) .

Ferrett, T.A., Pi ancastel 1

i , M.N., Lindle, D.W., Heimann, P.A., and

Shirley, D.A., Si 2p and 2s Resonant Excitation and Photoionization of

S i

F

4 (in preparation).

Ferrett, T.A., Dehmer, J.L., Hardis, J.E., and Parr, A.C.,

Vibrati onal ly-resol ved Study of the A State of N

2 0 in the Range

17.4<hv<26.0 eV (in preparati on )

.

He, M.G. and Bruening, R.J., "Study of the Stability of High Pressure

Sodium Discharge Lamps for Use as Standards of Geornetri cal ly Total

Luminous Flux", to be published as an NBS Technical Note.

Hsia, J.J., "National Scales of Spectrometry in the U.S.," to be published

in Symposium on Advances in Standards and Methodology in Spectrometry

,

Oxford, UK.

98
Lean, J., Saunders, R. and VanHoosier, M., "Linearity Studies of UV

Photodetectors" , to be published in Proc. of UV Workshop.

Lindle, D.W. and Ferrett, T.A., Resonant Interaction Between Correlation

Satellites and Double Ionization (in preparation).

Lindle, D.W., Heimann, P.A., Ferrett, T.A., Pi ancastel 1 i , M.N., and

Shirley, D.A., Photoemission from Xe in the Vicinity of the 4d Copper

Minimum (to be published, Phys. Rev. A).

McSparron, D.A., Radiation Thermometry Calibration Program at NBS, NASA

Conference Publication.

Mielenz, K.D., "Fluorescence Spectrometry in Analytical Chemistry and

Color Science," to be published in Symposium on Advances in Standards and

Methodology in Spectrometry.

Mielenz, K. D., "International Intercompari sons of Photometric Base

Units", to be published in J. Res. NBS.

Mielenz, K.D. and Hsia, J .J . "Measurement of Light and Radiation," CIE

Division 2 Summary Report for 1983-1987.

Ohno, Y., and McSparron, D. A., "Realization of a Total Flux Scale from

the Spectral Irradiance Standard", To be published in Applied Optics.

Parr, A. C., Hardis, J. E., Southworth, S. H., Feigerle, C. S., Ferrett,

T. A., Holland, D. M. P., Quinn, F. M., Dobson, B. R., West, J. B., Marr,

G. V., and Dehmer, J. L., "Vi brati onal ly Resolved Photoelectron Angular

Distributions for H 2 in the Range 17eV < hv < 39 eV", WERB approved for

publication in Phys.

Rev. A.

Parr, A. C., Southworth, S.H., Hardis, J. E. and Dehmer, J. L., "Resonance

Structure in the Vi brati ona 1 ly Resolved Photoelectron Branching Ratios and

Angular Distributions of the 2tt _1 Channel of NO", WERB approved for

publication in J. Chem. Phys.

Pi ancastel 1

i , M.N., Ferrett, T.A., Lindle, D.W., Medhurst, L.J., Heimann,

P.A., Liu, S.H., and Shirley, D.A., Resonant Processes Above the C Is

Ionization Threshold in Benzene and Ethylene (in preparati on )

.

Saunders, R. D., "Comparison of the NBS SURF and Argon Mini-Arc Inachinice

Standard at 2124 to be published in Applied Optics.

Saunders, R., "Roughened Quartz Surfaces and Teflon as Small Angle

Diffusers and Depolarizers Between 200 and 400 nm, to be published in

Applied Optics.

99
Schaefer, A.R. and Fox, N.P., "Tunable Dye Laser Spectrometry ," to be

published in Symposium on Advances in Standards and Methodology in

Spectrometry

.

Thomas, 0. and Zalewski, E., "CCPR Detector Intercompari son ," to be

published in Metrolgia.

Walker, J. H., Saunders, R. 0., Jackson, J. K., McSparron, D. A. "The NBS

Scale of Spectral Irradiance," to be published in Journal of Research of

the National Bureau of Standards.

Zalewski, E.F. and Thomas, D.B., An Intercompari son of Absolute Detector

Response Measurements at 633 and 488 nm.

100
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 534, Radiometric Physics

Robert Booker

Member, U.S. National Committee of the CIE

Robert J. Bruening

Past President, National Capital Section of the Optical Society of

Ameri ca

Julius Cohen

Member, ASTM E-07 Committee on Nondestructive Testing, Section

E-07.10.04 on Infrared Methods.

Member, ASTM E710.04 Other NOT Methods (infrared)

Kenneth L. Eckerle

Member, ASTM E- 13 Committee on Molecular Spectroscopy, Subcommittee

E-I3.03 on Infrared Spectroscopy, Subcommittee E-13.01 on Ultraviolet

and Visible Spectroscopy , Subcommittee E- 13 .06 on Luminescence.

Laurence E. Fink

Alternate, ANSI PH2 on Photographic Sensitometry and PH2-28 on Densitometry

Jack J. Hsia

Director, Inter Society Color Council.

Associate Director and Secretary, CIE Division 2, Physical

Measurement of Light and Radiation.

Chairman, CIE TC 2-11 Technical Committee on Goni ophotometry

.

Member, U.S. National Committee of the CIE.

NBS Representative, ANSI PH2, Photographic Sensitometry, PH2-28,

Densi tometry

.

Member, ASTM D- 1 .26 Subcommittee, Optical Properties of Paint,

Varnish, Lacquer and Related Products.

101
Division 534, Technical and Professional Committee Participation and

Leadership (cont'd)

Jack J. Hsia (Cont'd)

Member, ASTM E- 12 Committee, Appearance of Materials

(Spectrophotometry , Colorimetry and Geometric Properties).

Member, ASTM E- 13 Committee, Molecular Spectroscopy; Subcommittee

E-13.01, Ultraviolet and Visible Spectroscopy; E- 13 .03 , Infrared

Spectroscopy, and E-13.06, Molecular Luminescence.

Member, ASTM E-07.03, Task Group for Fluorescent Penetrant

Measurement Standards.

Secretary, CORM/NBS Task Force on Spectrophotometry.

Donald A. McSparron

Member, ANSI Z311, Photobi ol ogi cal Safety of Lamps and Lighting

Systems

.

Member, Illuminating Engineering Society (IES), Testing Procedures

Commi ttee

.

Member, Lamp Testing Engineers' Conference.

Klaus D. Mielenz

Secretary, U.S. National Committee of the CIE.

Director, CIE Division 2, Physical Measurement of Light and

Radi ati on

.

Member, ASTM E- 13 Committee, Molecular Spectroscopy; Subcommittee

E-13.06, Molecular Luminescence.

Member, IES Subcommittee C 0 1 2 , Nomenclature.

Vice Chairman, CORM Task Force on Spect rophotomet ry

.

Member, OSA International Affairs Committee.

Albert Parr

Member, Queen Match Calibration Review for SDC

.

Member, Organizing Committee, National Synchrotron Instrumentation

Conference.

102
Division 534, Technical and Professional Committee Participation and

Leadership (cont'd)

Albert Parr (Cont'd)

Member, Organizing Committee, Local Co-chairman Chemical Low-Level

Light Detector Conference

Robert D. Saunders, Jr.

Member, ANSI Z311, Photobiol ogi cal Safety of Lamps and Lighting

Systems

.

Member, IES Photobiology Committee.

Member, CIE TC2-05, Distribution Temperature.

A. Russell Schaefer

Member, CIE TC2-06, Absolute Spectral Responsi vi ty

.

Douglas B. Thomas

Member, ASTM E44, Solar Energy Conversion.

Willi am R. Waters

Member, ASTM E-20, Temperature Measurement.

Edward F. Zalewski

Chairman, CIE TC2-06, Absolute Spectral Responsi vi ty

.

Member, U.S. National Committee of the CIE.

103
JOURNAL EDITORI ALSHIP

Division b34, Radiometric Physics

Alman, D. H., Hsia, J. J., and Johnson, N. L. (Program Committee),

Appearance, 1987 Williamsburg Conference Proceedings, Inter-Society Color

Council, Feb. 8-11, 1987.

104
STANDARDS COMMITTEE MEETINGS

Division 534, Radiometric Physics

ASTM Committee E12 Meeting, NBS, May 26-27, 1987.

CORM Annual Meeting, NBS, May 28-29, 1987.

LTEC , NBS, May 27, 1987.

105
MAJOR CONSULTING AND ADVISORY SERVICES

Division 534, Radiometric Physics

R. L. Booker and D. A. McSparron provided consultation to respresentati ves

of Minolta Corporation on luminance standards and measurements.

R. L. Booker provided consultation to the FAA on the conspicuous daytime

marking of tall towers.

J. J. Hsia provided consultation to H. Heydt and C. Peterson of General

Electric in Lanham, Maryland, on using pressed PTFE and black powder to

normalize signals from area array detectors.

J. J. Hsia provided consultation to Roy Berns of the Rochester Institute

of Technology on goni oref 1 ectomet ry

.

J. J. Hsia provided consultation to L. Lewellen of Newark Air Force

Research Laboratory on infrared transmi ttance measurement.

K. L. Eckerle provided consultation to J. Seely of Reflexite Company on retrorefl ectance calibration.

K. L. Eckerle provided consultation to B. Brekke of the Norwegian Research

Institute of Electricity Supply on retroref 1 ecti on instrumentation.

K. L. Eckerle provided consultation to P. Armatis of Lawrence Livermore

Laboratory on spectrophotometri c measurement methods.

D. A. McSparron provided consultation to B. Guenther of NASA on spectral

radiance and spectral irradiance calibration problems.

0. A. McSparron attended the Annual Laboratory Review of NAVY Metrology

Research and Development Requirements meeting at Corona, California, and

provided consultation on the status and future directions of the NBS

infrared standards program.

J. H. Walker and W. R. Waters provided consultation to R. Holman of

Corning Glass Company on the calibration of infrared pyrometers and

bl ackbodi es

.

E. F. Zalewski and D. A. McSparron provided consultation to representati ve

of the Army Night Vision Laboratory on low light level uv irradiance and

detector responsi vi tiy calibrations.

106
STANDARD REFERENCE MATERIALS

Division 534, Radiometric Physics

1. SRM 1001, X-Ray Film Step Tablet

For calibration of optical densitometers and similar equipment used

in the photographic, graphic arts, and x-ray fields. Certified for

optical densities from 0 to 4.

2. SRM 1008, Photographic Step Tablets

For calibration of optical densitometers and similar equipment used

in the photographic and graphic arts fields. Certified for optical

densities from 0 to 4.

3. SRM 1010a, Microscopy Resolution Tests Charts

For determining the resolving power of microscopy systems.

4. SRM 2061, Reflection Step Tablets

For calibration of reflection densitometers and similar equipment

used in the photographic and graphic arts fields. Certified for

optical densities from 0 to 2.

5. SRM 2019 and 2020, White Ceramic Tile for Di recti onal -Hemi spheri cal

Reflectance from 350 to 2500 nm. SRM 2021 and 2022, Black Porcelain

Enamel for Directional- Hemispherical Reflectance from 280 to 2500

nm. SRM 2015 and 2016, White Opal Glass for DirectionalHemi spheri cal Reflectance from 400 to 7 50 nm.

For use in calibrating the reflectance scale of an integrating sphere

ref 1 ectometer

.

6. SRM 2003b, First Surface Aluminum Mirror for Specular Reflectance

from 250 to 2500 nm. SRM 2011, First Surface Gold Mirror for

Specular Reflectance from 600 to 2500 nm. SRM 2023, 2024, and 2025

Second Surface Aluminum Mirror for Specular Reflectance from 250 to

2 500 nm.

For use in calibrating the photometric scale of specular

ref 1 ectometers

.

7.

SRM 2009, 2010, 2013, 2014 Di dymi um-Oxide Glass, Wavelength Standards

between 400 and 760 nm.

107
Division 534, Standard Reference Materials (cont'd)

8. SRM 2034 Holinium oxide in Perchloric Acid Solution as Wavelength

Standards between 241 and 640 nm.

9. SRM 1920 Near Infrared Reflectance Wavelength Standards from 740-2000

nm.

108
MEASUREMENT ASSURANCE SERVICES

Division 534, Radiometric Physics

1. Transmittance MAP Service

Provides a means for a laboratory to assess the accuracy of its

spectral transmittance measurement capabilities from 92 % to 0.1% in

the visible region.

2. Retrorefl ectance MAP Service for Coefficient of Luminous Intensity

Provides a means for a laboratory to assess the accuracy of its

coefficient of luminous intensity measurement capabilities for bead

sheeting and prismatic cube-corner retroref 1 ectors and to assess the

conformance to the spectral specification of its

retroref 1 ectometers

.

109
Type of Service

Pyrometry

Spectroradiometry

Photometry

Spectrophotometry

CALIBRATION SERVICES PERFORMED

Division 534, Radiometric Physics

Number of

Customer SP250 tests

3501 OC thru 35070S 27

Defense & Aerospace 18

Instrument & Cal labs 3

Foreign 1 Electrical & Materials 5

3901 OC thru 39070S 45

Defense & Aerospace 18

Instrueinent & Cal labs 11 Lighting & Photography 8

Foreign 2

Electrical & Materials 6

3701 OC thru 37180S 24

Defense & Aerospace 7 Instrument & Cal labs 3

Lighting & Photography 9

Foreign 2

Electrical & Materials 3

3801 OC thru 38100S 22

Defense & Aerospace 3

Instrument & Cal labs 10

Foreign 1 Electrical & Materials 8

118

110
TRIPS SPONSORED BY OTHERS

Division 534, Radiometric Physics

J.J. Hsia, Laboratory Visit to the Optical

Metrology, partially sponsored by Protocol

Chinese State Bureau of Metrology, Beijing,

Division, National

Agreement between

May 26-28, 1987.

Ill

Institute of

NBS and the
SPONSORED SEMINARS AND COLLOJUIA

Division 534, Radiometric Physics

J. Cohen, HDL Seminar on Automated Laser Inspection System (6/17/87)

Dr. W. Erb, PTB, Germany, "Goni oref 1 ectometry and Ref 1 ectomet ry" , Dr. W.

Czepluch, BAM, Germany, "Photometric Characteri sti cs of Materials and

Measurements of Gloss", Radiometric Physics Division Seminar, February 5,

1987 .

Dr. S. Shaefer, Carnegi e-Me 1 1 on University, Pittsburgh, "Computer Vision

and the Optics of Materials", Radiometric Physics Division and Robot

Systems Division Joint Seminar, March 19, 1987.

Dr. L. Shirley, Institute of Optics, University of Rochester,

"Characteri zation of Transmission Diffusers - Theory and Experiment",

Radiometric Physics Division, March 27, 1987.

Prof. U. Oppenheim, Israel, "Infrared Ref 1 ectomet ry and Radiometry in the

Techni on-Israel Institute of Technology", Radiometric Physics Division,

April 23, 1987.

112
TECHNICAL ACTIVITIES

Division 535, Radiation Source and Instrumentation

ACCELERATOR RESEARCH

CW Racetrack Microtron Project (P.H. Debenham)

The joint NBS-Los Alamos project, "Research on CW Electron Accelerators Using Room-Temperature RF Structures," has been funded by the DoE

Division of Nuclear Physics for the past eight years. The goal is to

develop technology for room temperature, cw electron accel erators. To

meet this goal we have been designing, constructing and testing a 185 MeV,

500 uA cw racetrack microtron (RTM). The RTM, which is shown in Fig. 1,

is approximately 85% complete. The success of the project is reflected in

its many technical contributions. These include: a reliable, room- temperature, rf accelerating structure with a high cw accelerating gradient; a 100 keV beam chopping and bunching system; a high-quality 5 MeV

injector; microtron end magnets with excellent field uniformity; and simple, precise, beam profile scanners.

Late in 1986 the DoE Division of Nuclear Physics announced it had

decided to phase out support of the project in FY87 and not provide funds

for completion of the 185 MeV RTM. The decision was based on the judgment

that although the accelerator and nuclear physics research that could be

done with the full RTM are valuable, they do not justify the projected

completion cost. A major factor was DoE's prior decision to use superconducting (cryogenic) rather than room- temperature rf structures in its premier new accelerator for nuclear physics, CEBAF. DoE emphasized the high

quality of the RTM project staff and expressed satisfaction with their

performance.

DoE has provided funds through mid-FY 1988 for measuring the emittance of the 5 MeV injector and for evaluating the performance of the rf

power distribution system with full power to all four linac sections.

This requires completion of the RTM to the point where beam from the injector can be accelerated to 17 MeV in one pass through the RTM linac,

deflected through 180 degrees by one end magnet for momentum analysis, and

stopped in a temporary beam stop between the end magnets. We have made

good progress towards these goals in FY 1 987.

In October and November, 1 986 the 65 kV klystron power supply was restored to operation with a redesigned variable transformer stage. (The new design was discussed in last year's report.) Simultaneously, the

water system which cools the high power rf distribution waveguide was upgraded for better reliability, and a large filter was added to the

facility cooling water system. The RTM linac and associated rf power

distribution and vacuum systems were connected to the control system at

this time.

113
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114
Division 535, Technical Activities (cont'd.)

From December, 1 986 to May, 1 987 we operated the injector in order to

measure its beam parameters. We first tested the performance of our beam

profile scanners with the 5 MeV beam. Detailed results may be found in

Reference 1. Good performance was achieved with both pulsed and cw beams

after eliminating several noise sources. We were able to measure cw beam

widths as small as 50 ym fwhm, the design value of position resolution.

The beam scanners were then used to measure the transverse emittance and

energy spread at beam currents between 150 yA and 600 yA and energies from

4 MeV to 5.5 MeV. This work is described in Reference 2. The results are spectacular. The measured, normalized emittance was between 0.3 ym and

0.9 ym over this range of current and energy, with an average of 0.6 ym.

This is almost an order of magnitude improvement over our design value of

5 ym. The measured energy spread was 5 keV, and indirect measurements

indicated a longitudinal emittance of no more than 5 keV«degrees, considerably better than our design value of 20 keV»degrees. A final determination of longitudinal emittance will be made during the next period of

operation early in 1 988.

RF power was applied to the RTM linac for the first time in March.

In two weeks of operation the linac was rf-condi tioned to 50% of maximum

voltage. Stability of the rf field strength and phase was measured and

found to be better than ± 0.05% and ± 0.2°, respectively, in all four

linac sections. Field and phase variations of up to ± 0.2% and ± 1.4° are tolerable. These results were reported at the 1 987 Particle Accelerator

Conference (PAC) in March. 3 We had resumed rf-condi ti oni ng the RTM linac

in July, after completing the injector beam measurements, when the new variable transformer stage of the klystron power supply failed after 600

accumulated hours of operation. The failure was apparently caused by

defective insulation in the bucking transformer. The manufacturer has

^.1. Cutler, J.C. Owen, and J.K. Whittaker, Performance of Wire Scanner

Beam Profile Monitors to Determine the Emittance and Position of High

Power CW Electron Beams of the NBS-Los Alamos Racetrack Microtron, to be

published in the Proceedings of the 1 987 Particle Accelerator Conference,

Washington, DC, March 16-19, 1987.

2 M.A. Wilson, R.L. Ayres, R.I. Cutler, P.H. Debenham, E.R. Lindstrom,

D.L. Mohr, S. Penner, J.E. Rose, L.M. Young, and J. Stovall, Performance

of the 5 MeV Injector for the NBS-Los Alamos Racetrack Microtron, to be

published in the Proceedings of the 1 987 Particle Accelerator Conference,

Washington, DC, March 16-19, 1987.

3 R.I. Cutler and L.M. Young, Performance of the High Power RF System of

the NBS-Los Alamos Racetrack Microtron, to be published in the Proceedings of the 1 987 Particle Accelerator Conference, Washington, DC, March

16-19, 1987.

115
Division 535, Technical Activities (cont'd.)

rewound and tested the transformer, and will reinstall the variable transformer at NBS the first week of October. We plan to finish conditioning

the RTM 1 i nac in October.

A total of 17 magnets, including one quadrupole design and seven different dipole designs, will be used to transport the 5 MeV beam from

the injector to the RTM for single-pass acceleration. By April, 1987

these magnets had all been assembled, field-mapped, and shown to meet all

specifications. We reported many of these results at the 1 987 RAC. 4 * 5 Following completion of injector beam measurements in May, we removed the

temporary 45 degree beam stop and began assembling the 5 MeV transport and

RTM axis beam lines. Currently all 5 MeV transport beamline magnets have

been installed, and installation of the axis beamline is under way. We

expect to complete installation of these beamlines in November, connect

them to the control system in December, and begin accelerating beam with

the RTM linac in January, 1 988.

Free Electron Laser Facility (S. Penner)

A. Background

A study was initiated in FY 1986 to investigate the suitability of

the NBS RTM as the electron beam source for a free electron laser (FEL).

The study was funded by the Office of Naval Research, and performed in

collaboration with Drs. Phillip Sprangle and Cha-mei Tang of the Naval

Research Laboratory (NRL). Based on this design study, we submitted a response to an announcement by the Strategic Defense Initiative Office

(SDIO) for funding facilities for performing research in biomedical and

materials sciences applications of FELs. The proposal, developed jointly

by NBS and NRL, requests $4.9 million from SDIO over three years. NBS

would, in addition, supply a new laboratory building, three staff scientists salaries, RTM operation as needed to test and calibrate the FEL, and some general purpose equipment. The new laboratory, a 2000 ft 2 building

located above the existing linac facility, would house the experiments

using the FEL radiation. Since it would be shielded from the underground

space containing the RTM and FEL, there would be no significant background

4 P.H. Debenham, S.S. Bruce, S. Penner, and M.A. Wilson, The Injection

Chicane of the NBS-Los Alamos Racetrack Microtron, to be published in the

Proceedings of the 1 987 Particle Accelerator Conference, Washington, DC,

March 16-19, 1987.

5 M.A. Wilson, P.H. Debenham, S. Penner, and S.S. Bruce, Orbit Reversing

Magnets for the NBS-Los Alamos Racetrack Microtron, to be published in

the Proceedings of the 1 987 Particle Accelerator Conference, Washington,

DC, March 16-19, 1987.

116
Division 535, Technical Activities (cont'd.)

radiation from the RTM (or linac) in this area. We proposed that the FEL

radiation be used by NBS staff and external collaborators for programs in

atomic physics, molecular spectroscopy, biophysics, surface sciences, and

FEL technology. Outside users from such institutions as the Uniformed

Services University of the Health Sciences (USUHS) and Electro-Optics

Branch of the Center for Devices and Radiological Health of the FDA have

expressed interest and enthusiasm for using the facility for biomedical

research applications.

Our proposal was one of nine submitted in October 1986, in response

to the announcement, and one of two selected for funding by the Office of

Naval Research (ONR), which manages the Medical /Materi al s FEL program for

SDIO. A contract for developing the facility has been negotiated with

ONR, and the first increment of funding received in April 1987. We started design work for the FEL immediately upon receiving funding, using staff

of the RTM project, while we began recruiting for the additional staff

needed for the FEL development. We have already hired one new physicist

for the project (Carol Johnson, formerly an NBS Postdoc with Tom Lucatorto

of Di vi sion 533)

.

B. FEL Fundamental s

An FEL extracts energy from an electron beam in the form of a coherent beam of nearly monochromatic radiation. The principle of operation is as follows: A relativistic electron beam is passed through a "wiggler,"

wherein an array of permanent magnets produces a periodic strong trans- verse magnetic field. The electron beam emits synchrotron radiation in a narrow cone centered on its direction of propagation through the wiggler

due to the transverse oscillations of the electrons in the magnetic field.

Synchrotron radiation from successive periods of the wiggler will be co- herent when the wavelength, X, of the radiation satisfies the relationshi p

X

X2y

^2 0 + K

2

),

where X wis the wiggler period, y is the electron energy in units of electron rest energy, and K is the "wiggler parameter" which is proportional

to the strength of the magnetic field and is typically of order unity.

The "spontaneous, coherent" radiation is reflected back through the wiggler by a mirror, then reflected again to copropagate with the electron

beam. Beam electrons are bunched at the optical wavelength by the electromagnetic fields of the radiation, and thus emit still more radiation.

(In a quantum mechanical analysis of the process, additional coherent

radiation is stimulated by the presence of the original radiation, hence

the use of the term laser in describing the device.) In travelling once through the wiggler, the radiation field is amplified with some "gain,"

the necessary energy being extracted from the electron beam. If the gain

117
Division 535, Technical Ac ti v i ti e s (cont'd.)

per pass is greater than the sum of all losses per pass, the radiation

will build up on successive passes until saturated equilibrium occurs.

Losses are due to mirror reflectivity, diffraction effects, and the "outcoupling" of some of the radiation for external use.

The expected small energy spread, emittance, and beam stability of

the RTM are very important factors in FEL performance. The operating

energy range of the RTM is suitable for producing radiation in the wavelength range of about 0.25 pm to 10 ym spanning the range from the near

UV, through the visible and near IR. The emitted light is extremely intense (hundreds of watts, time averaged, for a 1 00 kW electron beam) and

nearly 100% spatially coherent. The light beam has the same time structure as the electron beam, i.e. pulse lengths of a few picoseconds, and

its frequency bandwidth should be just the transform limit of the pulse

length (<0.1% in the visible region). In addition to the fundamental

laser radiation, significant amounts of spontaneous coherent radiation are emitted at the odd harmonics of the fundamental. For some applications,

useful amounts of radiation would be available at wavelengths of order

30 nm. The combination of high power, easy tuneability over a very large

range, spatial coherence, reasonably small bandwidth and a continuous

train of very short pulses makes an FEL an extremely useful tool for a very wide variety of applications including photochemistry, surface

science, atomic and molecular physics, and biophysics.

The ONR-funded feasibility study showed that the gain of an FEL based

on the design peak current of the RTM would be marginal (i.e. 1-3 percent

per pass) even with a very long, precise, and expensive wiggler. The

problem is the relatively small peak current of the CW microtron, 140 mA,

limited by the available RF power at design beam energy. We examined the

possibility of increasing the peak current by recapturing some of the

electron energy in the RTM by beam recirculation. This proved not to be

useful because of the small longitudinal phase space acceptance of the RTM

(compared to the degraded longitudinal emittance of the beam which has

generated laser light). We next considered enhancing the peak current

without increasing the average current by injecting electrons during only

a fraction of the RF cycles, i.e. by not filling every RF "bucket." For

example, if we fill only one bucket in 32, the average current is within

the power limit for peak current up to 3.4 A. With peak currents in ex- cess of 2 A, the FEL single-pass (small signal) gain is in the range 8-30%

with a 3.6 m long wiggler, having a 2.8 cm period for wavelengths in the

range 0.2 - 2 ym. For longer wavelengths, a shorter wiggler is used.

There are several possible methods for generating the required pulses of

electrons for subharmonic injection. The method which appears most

attractive is to use a short-pulse mode-locked laser operating at a subharmonic of the RF frequency to produce electrons by photoemission from a suitable cathode material.

118
Division 535, Technical Activities (cont'd.)

C. Progress

In the first five months of the FEL project, we have progressed

rapidly in designing the facility. Major areas of work are the wiggler,

optical cavity, injector modification, electron beam transport, and building modification. Progress to date is described below.

1. Wi ggl er

Our detailed design of the wiggler began with a very fruitful

two-day visit to NBS by Klaus Hal bach of Lawrence Berkel ey Laboratory. We also visited FEL laboratories and prospective commercial

wiggler vendors throughout the country.

The final version of the wiggler technical specifications was delivered to the Contracting Specialist along with a purchase requisition and related documents on June 8, approximately seven weeks

ahead of schedul e.

On July 14, the Acquisition Plan for the wiggler was sent to

DoC. The Plan was approved on July 29. The Request for Proposals

(RFP) was issued in mid August. We are hoping to award a contract

for the wiggler in January, 1988 for delivery and acceptance by

October 1989.

2. Optical Cavity

The optical cavity of the FEL encloses the "gain medium" within

the wiggler. The round-trip transit time of the cavity must be precisely commensurate with the electron beam repetition period. We

have chosen a cavity length of 8.06 m, correspond!* ng to a round-trip

transit time of 128 RF periods. This permits an electron beam period

equal to the RF period divided any power of two, which is a highly

flexible and easily realizable condition. The nominal electron beam

period is 32 RF periods, corresponding to a beam repetition frequency

of 74.375 MHz.

A calculation has been performed to predict the FEL power output

as a function of wavelength for the baseline case where the photocathode pulse frequency is 74.375 MHz. These calculations indicate

that an FEL average power exceeding 50 watts can be achieved at the

fundamental frequency for all wavelengths between 0.2 and 10 pm,

assuming a peak electron beam current of 2 A and a pulse length of

3 pS. These power levels should be regarded as minimum capabilities.

Significantly 1 arger power output can be obtained by some or all of

the following possibilities: (1) doubling or quadrupling the photocathode pulse frequency, (2) increasing the electron beam current

119
Division 535, Technical Activities (cont'd.)

and/or pulse length, (3) tapering the wiggler, (4) increasing the

outcoupling above the 3% assumed in the calculations.

The cavity mirrors will be multi-layer dielectrics in order to

minimize cavity losses and thermal damage to the mirrors. The limited bandwidth of these mirrors will be the determining factor in the

range of rapid tuneability of the FEL. Diffraction losses have been

estimated to be of order 10~ 4 over most of the FEL tuning range,

increasing to a maximum of 0.6% at 10 pm, due to the aperture of the

wiggler vacuum chamber.

Outcoupling from the cavity will be through the downstream

mirror. The preferred method is a parti al 1 y-transmi tti ng (~3%)

mirror, but a small-bore on-axis hole coupler will be used when far

UV output i s desi red .

3.

Injector Modifications

We are proceeding with the development of a photocathode injector system after determining that this offers both cost and performance advantages over a thermionic gun subharmonic injector. A commercially available mode-locked laser system will illuminate a suitable photoemitter (probably cesium-antimony). We will receive

assistance in gun design from SLAC personnel, and will have the advice and collaboration of a group at LANL who have developed a system

whose performance exceeds our requirements.

4. Electron Beam Transport

Physics design of the electron beam transport system has been

completed. The emittance of the RTM electron beam is expected to be

small enough that the beam envelope is entirely within the optical

mode profile in the wiggler for maximum electron-photon coupling.

The acceptance of the beam transport channel, including the wiggler

vacuum chamber is large enough that the defining aperture of the

system is the linac section of the RTM. After traversing the wiggler, the electron beam will be deflected by a dumping magnet into a shielded beam dump to minimize radiation damage effects to the wiggler and optical components.

5. Building Modification

A preliminary design of the new 2000 ft2 research area has been

completed. Cost estimates by the NBS Plant Division are in agreement

with our earl ier estimates. They are proceeding with detailed architec tural /engi neeri ng design and specifications with the goal of beginning construction in the spring of 1988.

120
Division 535, Technical Activities (cont'd.)

D. Schedule and Program

The RTM construction is scheduled to be completed in November

1988, and the FEL facility in March 1990. Contacts with prospective

users of the facility, both within and outside of NBS are being made,

with the goal of having a strong user organization in place before

completion of the facility.

LINAC OPERATIONS (J. Broberg)

The NBS Electron Linac was designed in 1960 with maximum flexibility

in order to support a wide variety of program activities of interest to

NBS. Due to the changes in program direction, the Linac has been used

mostly for neutron cross section standards and radiography. We also have

supplied beam to a group from the Naval Surface Weapons Center for transition radiation studies.

The Linac Operations staff, in spite of its small size, continues to

achieve a highly commendable operating efficiency as described below. The

staff operates and maintains the facility as well as designs, constructs,

and installs new equipment to improve operations and extend the capability

of the Linac and the beam handling system. The Mechanical Instrumentation

Group within the Division provides help by maintaining the integrity of

the vacuum and cooling systems of both the Linac and beam handling system

as well as designing, constructing, and installing mechanical components.

All of the beam time, except for 94 hours, used by the Naval Surface

Weapons Center, was run for the Neutron group. We have supplied 1475.5

hours of actual beam time to the Neutron group (for a total of 1569.5

hours) at an efficiency approaching 99%. The unscheduled maintenance was

19 hours of air conditioning outage and 8 hours of Linac down time.

The RTM-FEL is operational to the extent that testing is now necessary. Since the 60 degree water cooling system will not permit both the

Linac and the RTM-FEL to operate simultaneously, their operations must be

scheduled jointly. The long range plan is to operate the Linac approximately 1/3 of the time and RTM-FEL 2/3 of the time. With our operational

staffing and assuming at least 80% efficiency of operation this should

give us about 1200 hours of Linac time and about 2400 hours of RTM-FEL

time per year.

RADIATION INSTRUMENTATION

Electronic Instrumentation Maintenance and Construction (J.K. Whittaker,

J. Oven)

Electronics instrumentation maintenance and construction for the

experimental programs of the Center for Radiation Research is a continuing

responsibility of the Radiation Instrumentation Group in the Division.

121
Division 535. Technical Activities (cont'd.)

Due to a long lasting shortage of technicians (we have two) in the Group

we have had to confine Group activities to the construction of instrumentation not otherwise available. Repair and maintenance is limited to

instrumentation produced in our laboratory and to specialized items such

as accel erators. This year 51 instruments and pieces of equipment have

been constructed and 48 repaired.

Instrumentation Design and Construction (J.K. Whittaker, N.D. Wilkin,

A. B. Marella, J.C. Owen, L.A. Shuman)

Design and construction of experimental and system data acquisition

and control instrumentation is a continuing and important element of the

Radiation Instrumentation Group activities. This year the Electron

Physics Group has been given priority support for their efforts in constructing a scanning tunneling electron microscope (STM) and building

accessory equipment for a scanning electron microscope. For the STM not

only was severe electronic noise problems solved but a new and stable

servo positioning system was constructed enabling the Electron Physics

Group to obtain stable pictures of a surface. Other examples of instrumentation design for this year include: instrumentation for the Regional

Calibration centers; an automatic computer-control 1 ed sample changer;

interlock systems; automatic control and data acquisition systems for the

300 kV and 100 kV X-ray machines (X-ray standards); detector electronics,

wire-scanner amplifiers, radiation monitors, counting system, microcalorimetry temperature controller, and neutron dosimetry instruments.

Instrumentation Support for Physics and Chemistry Projects (J.K.

Whittaker, N.D. Wilkin, A.B. Marella)

Consulting and systems instrumentation assistance has been provided

to scientists in programs relating to neutron physics, electron physics,

pulse radiolysis (both CRR and CAC), X-ray dosimetry, radiation chemistry,

analytical chemistry, physical chemistry, reactor radiation, vacuum ultraviolet physics, RTM construction, nuclear physics and the CRR Center

Office.

A new HP 350C computer has been received and will be set up for

computer-aided design and computer-aided engineering purposes as soon as the software can be obtained. Software for these operations is expensive

and will have to be installed slowly due to lack of funds. The effective

payback period for CAD and CAE systems is very short due to greatly improved productivity but this does not make funding any easier. The system

is compatible with presently installed systems of lesser capability and we look forward in the future to being able to synthesize and simulate both

digital and analog systems.

The wire-chamber detector for electron physics has been completed but

has yet to be tested (due to technician labor shortage). High voltage

tests have been successful and the gas handling components are on hand.

122
Division 535, Technical Activities (cont'd.)

Consultation by the Group expert staff continues to be important to

CRR and many other centers in NBS. The cooperative program with the

Center for Chemical Physics relating to pulse radiolysis and Van de Graaff

accelerator operations has entered its initial phase very successfully.

Of particular importance is the cooperative program with the Harry Diamond

Laboratories in programs relating to fuze measurement instrumentation and

other subjects which continue outstandingly well.

Computer Systems (N.D. Wilkin, A.B. Marella)

Some 35 computer systems, mainly Hewlett-Packard and PC types have

been installed this year together with numerous types of software including several CAD systems. The bookkeeping operations of the Group have

just been computerized on a database system, thus enabling the Group to

keep track of its many operations in construction, repair and maintenance. Guest Sci enti sts

This year we have been fortunate to welcome Mr. Danny Tirosh from the

Nuclear Research Center, Negev, Israel. Mr. Tirosh is the Head of the

Environmental Engineering and Electronics Division at that Laboratory and

initially he will be designing and constructing analog electronics data

acquisition apparatus for pulse radiolysis experiments. In addition Mr.

Li -chun Dai, a final year student at the University of Maryland will be

with us until next June.

Radiation Instrumentation Standards (L. Costrell)

The Division provides national leadership in the standardization of

nuclear instrumentation. The standards work falls into three categories

as follows: (a) National Voluntary Standards - The Division plays an active role in the development and processing of Standards of the Institute of Electrical and Electronic Engineers (IEEE) and the American

National Standards Institute (ANSI) and participates in the associated

policy boards. L. Costrell serves as Chairman of ANSI Committee N42 on Radiation Instruments and as Secretary of the IEEE Nuclear Instruments and

Detectors Committee. In these capacities he has processed a considerable

number of ANSI and IEEE standards, serves on the ANSI Nuclear Standards

Board, and is a member of its Planning Committee.

(b) NIM Committee Standards - This involves development and maintenance of instrument standards, in cooperation with the National Laboratories, primarily for use in nuclear applications. NBS has the management

responsibility for this work, with L. Costrell serving as Chairman of the

NIM Committee. The Nuclear Instrumentation Module (NIM) system has been

adopted nearly universally in the U.S. and a continuous coordination

effort is required, involving contact with numerous laboratories and manu123
Division 535, Technical Activities (cont'd.)

facturers. Similar management, direction and maintenance services are provided in the U.S. with regard to the international CAMAC (Computer

Automated Measurement and Control) system that is utilized in the National

Laboratories and in a large number of other laboratories and installations

throughout the world. A third system for which the Division has similar

responsibility is the FASTBUS high speed modular data acquisition system

for high energy physics and other applications. The FASTBUS development

has been a major effort with commercial equipment now available and systems in operation or in preparation in numerous laboratories in the U.S.,

Europe, and Japan.

The preparation of reports for the above systems involves a number of

individuals and 1 aboratories. Coordination and processing, as well as writing of some sections, is handled by the National Bureau of Standards.

The documents are usually issued as Reports of the Department of Energy

and then processed as Standards of the Institute of Electrical and Electronics Engineers (IEEE), the American National Standards Institute

(ANSI), and the International Electrotechnical Commission (IEC).

The Nuclear Instrument Module (NIM) system 1 ’ 2 has had a phenomenal

acceptance in laboratories and industry throughout the world. There is a continuous coordination requirement involving contact with numerous laboratories and manufac turers and the resolution of questions that arise. In order to allow and encourage exploitation of technological development

without impairing compatibility and i nterchangeabil i ty , continued vigilance and direction is essential and is provided. The shift from discrete

components to integrated circuits and the increasing use of computers and

mic roprocessors necessitates continued accommodation to those devices.

Work is proceeding on updating the NIM standard in the light of recent

developments and practice. Also, the division continues to provide information regarding the CAMAC standards. 3

The FASTBUS standard, previously issued as a Department of Energy

Report, 4 has been updated and issued as a standard of the Institute of

1 "Standard Nuclear Instrument Modules," AEC (now DOE) Report TID-20893

(Rev 4), July 1 974 (currently under revision).

2 "Standard NIM Digital Bus (NIM/GPIB)," Department of Energy Report

DOE/ ER -01 73, August 1 983.

3 CAMAC Instrumentation and Interface Standards, IEEE Publication SH08482,

Library of Congress Catalog No. 81 85060 (ANSI/IEEE Stds 583, 595, 596,

675, 683, 726, 758).

4 "FASTBUS Modular High Speed Data Acquisition and Control System," DOE

Report DOE/ ER -01 89 , December 1 983.

124
Division 535, Technical Activities (cont'd.)

Electrical and Electronics Engineers (IEEE) and the American National

Standards Institute (ANSI). 5 It has also been approved as an international standard of the IEC, to be issued as IEC Publication 935. 6

The software standard, "FASTBUS Standard Routines" dated March 1987

has been issued as DOE Report D0E/ER-0325. 7

The NIM and CAMAC standard instrumentation projects have resulted in

a savings of at least 1.9 billion 1 982 dollars according to a study conducted for the Department of Energy by a firm of economics consultants. 8 The study report states that the 1.9 billion dollars is considered to be a minimum figure conservati vel y arrived at on the basis of available data.

1.7 billion dollars is attributed to the NIM system initiated by the

Center for Radiation Research 9 and the balance of 200 million dollars to

the CAMAC instrumentation system developed by the ESONE Committee of

European Laboratories with the active collaboration of the U.S. NIM

Committee and the CRR. The report adds: "The benefits were estimated

only if they could be documented from the literature or telephone contacts. There are a number of other direct and indirect benefits associated with the use of CAMAC and NIM interfaces which were not considered in

this analysis because no measurable data were available." The total

worldwide savings can be reasonably projected to be double the U.S sav- ings.

(c) International Electrotechnical Commission - L. Costrell serves

as Technical Advisor to the U.S. National Committee of the IEC for IEC

Committee TC45 on Nuclear Instruments. He serves as Chief U.S. Delegate

to TC45, as Chairman of the Working Group on Detectors and as a member of

the working groups on Interchangeability and on Terminology. Numerous IEC

draft documents were prepared and reviewed resulting in a number that were

5 "FASTBUS Modular High Speed Data Acquisition and Control System,"

ANSI/IEEE Std 960-1 986.

6 "FASTBUS Modular High Speed Data Acquisition System," International

Electrotechnical Commission Publication 935 (to be published).

7 "FASTBUS Standard Routines," Department of Energy Report D0E/ER-0325,

March 1987.

8 "Benefit Analysis of Selected Accomplishments of DOE 1 s Office of Health

and Environmental Research," Final Report RR-166, November 29, 1 982,

Ecosometric s, Inc. (M. Lago, M.J. Ram sd ell, S.F. Knapp, S.I. Siddique,

Bethesda, MD.)

9 "Standard Modules for Nuclear Instrumentation," NBS Report 8137,

December 5, 1 963, L. Costrell.

125
Division 535, Technical Activities (cont'd.)

published and others that are to be published. These include documents

that are technically identical to the NIM, CAMAC and FASTBUS standards. 1 * 2 ,3 ,5 Similarly, the international standard on test procedures for germanium semiconductor detectors is to be technically identical

to ANSI/IEEE Std 325.

MECHANICAL INSTRUMENTATION

Mechanical Instrumentation Services (D. Mohr)

Mechanical instrumentation services were provided for the Center for

Radiation Research in connection with its particle accelerators and experimental programs. The services provided consisted of design and construction of new equipment and facilities as well as maintenance and modification of existing equipment to improve performance and reliability.

Instrumentation Design and Construction (D. Mohr)

Design and construction of mechanical devices is an ongoing and

important element of the mechanical instrumentation group activities.

Examples of these devices built this year are: nonmagnetic, high vacuum

chambers for the RTM end magnets and for the small dipole magnets on the

RTM injection system and main accelerator axis; support structures and

precision optical alignment fixtures for various RTM dipole magnets.

The single CAD/CAM workstation is operational and has allowed us to

design the magnet chambers much more cost effectively. Two additional

units are currently on order and will, when operational, help us to

achieve the extremely tight mechanical design schedules of both the RTM

and the FEL.

Installation and Maintenance of Facilities (D. Mohr)

Another major element of our activities is installation and maintenance of major facilities. Examples this year are: installation and

alignment to ±.001" of six RTM dipole magnets; a 500 gpm cooling water

filtration system; rebuilt vacuum pumps for SURF, Linac and the 3 MeV Van

de Graaff; maintained the mechanical and vacuum equipment on the linac to

allow in excess of 90% beam efficiency.

The group staff continues to provide consultation service to other

groups in CRR and other NBS organizations. The staff is also consulted by

people outside NBS who build and operate accelerators worldwide.

126
INVITED TALKS

Division 535, Radiation Source and Instrumentation

Debenham, P.H., "Ultrasensitive Laser Isotope Analysis in an Ion Storage

Ring," Ninth Conference on the Application of Accelerators in Research and

Industry, North Texas State University, Denton, TX, November 12, 1986.

Penner, S., "RF Linac Based Free Electron Lasers," 1 987 Particle

Accelerator Conference, Washington, DC, March 16, 1 987.

Penner, S., "NBS Free Electron Laser Facility," NBS Special Seminar,

Gaithersburg, MD, June 15, 1987.

Penner, S., "NBS/NRL Free Electron Laser Facility," Ninth International

Free Electron Laser Conference, Williamsburg, VA, September 16, 1987.

127
PUBLICATIONS IN PREPARATION

Division 535, Radiation Source and Instrumentation

Cutler, R.I., Owen, J.C., and Whittaker, J.K., Performance of Wire Scanner

Beam Profile Monitors to Determine the Emittance and Position of High

Power CW Electron Beams of the NBS-Los Alamos Racetrack Microtron, to be

published in the Proceedings of the 1987 Particle Accelerator Conference,

Washington, DC, March 16-19, 1987.

Cutler, R.I., and Young, L.M., Performance of the High Power RF System of

the NBS-Los Alamos Racetrack Microtron, to be published in the Proceedings

of the 1987 Particle Accelerator Conference, Washington, DC, March 16-19,

1987.

Debenham, P.H., Bruce, S.S., Penner, S., and Wilson, M.A., The Injection

Chicane of the NBS-Los Alamos Racetrack Microtron, to be published in the

Proceedings of the 1987 Particle Accelerator Conference, Washington, DC,

March 16-19, 1987.

Penner, S., RF Linac Based Free Electron Lasers, to be published in the

Proceedings of the 1987 Particle Accelerator Conference, Washington, DC,

March 16-19, 1987.

Tang, C.M., Sprangle, P., Penner, S. and Maruyarna, X.K., Analysis of FEL

Performance Utilizing the National Bureau of Standards' (NBS) CW

Microtron, to be published in the Proceedings of the 1987 Particle

Accelerator Conference, Washington, DC, March 16-19, 1987.

Wilkin, N.D., Downing, G., and Whittaker, J.K., Alpha Particle Detector

Using RAM Cell Upset (in preparat i on )

.

Wilson, M.A., Ayres, R.L., Cutler, R.I., Debenham, P.H., Lindstrom, E.R.,

Mohr, D.L., Penner, S., Rose, -J.E., Young, L.M., and Stovall, J.,

Performance of the 5 MeV Injector for the NBS-Los Alamos Racetrack

Microtron, to be published in the Proceedings of the 1987 Particle

Accelerator Conference, Washington, DC, March 16-19, 1987.

Wilson, M.A., Debenham,

Magnets for the NBS-Los

Proceedings of the 198/

March 16-19, 1987.

P.H., Penner, S., and Bruce, S.S., Orbit Reversing

Alamos Racetrack Microtron, to be published in the

Particle Accelerator Conference, Washington, DC,

128
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 535, Radiation Source and Instrumentation

Robert L. Ayres

Member, ANSI Technical Committee N42.2 on Procedural Standards for

Calibration of Detectors for Radioactive Materials

Member, IEEE PI 01 4/ VMEbu s Standard Committee

Member, NBS RIF Assignment Panel

Member, Science and Technical Pool, Science Panel, Committee on Interagency Radiation Research and Policy Coordination (CIRRPC)

U.S. Representative, Life Sciences Working Group of the International

Committee for Radionuclide Metrology

Louis Costrell

Chairman, ANSI Technical Committee N42, Nuclear Instruments

Chairman, DoE National Instrumentation Methods (NIM) Committee

Chairman, IEC/TC45 Working Group-9 on Radiation Detectors

Chief U.S. Delegate, International Electrotechnical Commission (IEC),

Technical Committee on Nuclear Instruments (IEC/TC45)

Member, ANSI Technical Committee N41, Controls, Instrumentation, and

Electrical Systems for Nuclear Power Generating Stations

Member, IEC/TC45 Working Group-1 on Classification and Terminology

Member, IEC/TC45 Working Group-3 on Interchangeability

Member, 1 987 Particle Accelerator Conference Organizing Committee

Member, U.S. National Committee of International Electrotechnical

Commission (IEC)

Secretary, Institute of Electrical and Electronics Engineers Nuclear

Instruments and Detectors Committee of IEEE Nuclear and Plasma

Sciences Society (IEEE/NPSS)

Technical Advisor, U.S. National Committee of IEC

129
Division 535, Technical and Professional Committee Participation and

Leadership (cont'd.)

Roy I. Cutler

Assistant Arrangements Chairman and Treasurer, 1987 Particle

Accelerator Conference

Philip H. Debenham

Technical Consultant, DoE CEBAF Review Committee

Member, NSF Small Business Innovation Research Review Panel

Member, 1 987 Particle Accelerator Conference Program Committee

Eric R. Lindstrom

Editor, Proceedings of the 1 987 Particle Accelerator Conference

Samuel Penner

Chairman, 1 987 Particle Accelerator Conference

Member, GBFEL/TAG

Jul i an K. Whi ttaker

Member, ASTM Committee D-22 on Methods of Sampling and Analysis of

Atmospheres

Member, DoC Industry and Trade Administration, Electronic Instrumentation Technical Advisory Committee

Neil D. Wi 1 ki

n

Member, Editing Committee for IEEE Nuclear and Space Radiation

Effects Conference Publication

Member, Electronics Storeroom Committee, NBS

Senior Member, Institute of Electrical and Electronics Engineers

130
Division 535, Technical and Professional Committee Participation and

Leadership (cont'd.)

Mark A. Wil son

Member, Organizing Committee for Heavy Ion Fusion Symposium,

Washington, DC, May 27-29, 1 986

131
MAJOR CONSULTING AND ADVISORY SERVICES

Division 535, Radiation Source and Instrumentation

1. R. Ayres serves as a member of the U.S. Pharmacopoeia Convention

Advisory Panel to the Subcommittee on Radiopharmaceuticals.

2. S. Penner and M. Wilson continue to provide Accelerator Technology

and Assessment and Oversight for DARPA.

3. S. Penner serves as a consul tant to the U.S. Army Strategic Defense

Command on particle accelerator issues related to programs in Free

Electron Lasers and Neutral Particle Beam Weapons.

4. N. Wilkin serves as consultant on microcomputers and semiconductor

radiation hardness testing to Harry Diamond Laboratories.

5. N. Wilkin serves as consultant on mic rocomputer control of fuze

instrumentation for Harry Diamond Laboratori es

.

132
TECHNICAL ACTIVITIES

Division 536, Ionizing Radiation

The functions of the Ionizing Radiation Division are summarized in

the following table:

o Provides primary national standards, dosimetry methods, measurement

services, and basic data for applications of ionizing radiation (x

rays, gamma rays, electrons, neutrons, and radi oac ti vi ty , etc.) in such

areas as:

- Radiation protection of workers and the general public

- Radiation therapy and diagnosis

- Nucl ear med ici ne

- Radiography

- Industrial radiation processing

- Nucl ear energy

- National defense

- Environmental protection

9 Conducts theoretical and experimental research on the fundamental

physical and chemical interactions of ionizing radiation with matter to

provide the competence for:

- Developing improved understanding of the physical stage of the

interaction of ionizing radiation with matter.

- Developing an understanding of basic mechanisms involved in

radiation-induced chemical transformati ons and the parameters that

influence the yields of short-lived intermediates, final chemical

products, and biological effects

- Developing improved methods for radiation measurement, dosimetry,

and radiography

- Developing improved primary ionizing radiation standards

- Producing highly accurate standard reference data for ionizing

radiation or radioactive materials

© Provides essential standards and measurement support services to the

National Measurement Support System for Ionizing Radiation that

provides calibrations and measurement quality assurance services to:

- Medicine

Industry

- States

- Other Federal Agencies

• Develops and operates wel 1 -charac teri zed sources of electrons, photons,

and neutrons to provide:

133
Division 536, Technical Activities (cont'd.)

- Primary radiation standards and fields

- Wei 1 -charac teri zed beams of radiation for research on radiation

interactions and for measurement methods development.

The group structure of the Ionizing Radiation Division was changed October

1, 1987 to establish the Office of Radiation Measuremen t as a separate

group, rather than attached to the Division Office. The current group

structure is:

Ionizing Radiation Division (R. S. Caswell)

Radiation Theory (M. J. Berger)

Radiation Chemistry & Chemical Dosimetry (M. G. Simic)

Neutron Measurements & Research (0. A. Wasson)

Neutron Dosimetry (J. A. Grundl ) Radioactivity (D. D. Hoppes)

X-ray Physics (J. W. Motz)

Dosimetry (R. Loevinger)

Office of Radiation Measurement (E. H. Eisenhower).

Dr. Loevinger has requested that he be relieved of his Group Leader duties

to return to research. It is expected that a new group leader will be

identified shortly.

Some of the major thrusts of the Ionizing Radiation Division for FY-1988

are:

(1) Research leading to a scientific basis for predicting, measuring, and

modifying ionizing radiation effects in chemical and biological

systems;

(2) Improving NBS radiation facilities for providing radiation beams and

measurement instrumentation to characterize both the short-lived

intermediates and the end products of radiolysis induced by ionizing

radi ati ons

;

(3) Designing, construction, and funding of a high-energy electron and

photon dosimetry facility on the race-track microtron;

(4) Advancing the science of state-of-the-art, real-time x-ray

radiography

;

(5) Dissemination of newly-developed ionizing radiation standards and

improvement of the accuracy of present standards;

(6) Identification of organizations in the private, state, and federal

sectors to construct and operate secondary calibration laboratories

for important radiation measurements; and

134
Division 536, Technical Activities (cont'd.)

(7) Identification of technical or industrial organizations to manage

accreditation programs for each of the three sectors of secondary

1 aboratories.

I . Radiation Theory Group

Cross Sections: Photons (M. J. Berger, J. H. Hubbel 1 , E. B. Saloman,

& H. M. Gerstenberg)

® A data base and computer program have been developed which can be

used to calculate, with a personal computer, photon cross sections for

scattering, photoelectric absorption and pair production, in any element,

compound or mixture, at energies from 1 keV to 100 GeV. This work has

been described in report NBSIR-87359.

© Extensive comparisons have been made of all available experimental,

recommended and theoretical photon attenuation coefficients (total cross

sections) in the energy region 100 eV to 100 keV. A paper on this work

has been published as an NBSIR report, and has since been thoroughly

revised and accepted for publication in Atomic and Nuclear Data Tables.

This paper will also include a comprehensive bibliography, with references

to approximately 20,000 data points from several hundred publications.

© A complete set of Photonuclear Data-Abstrac t Sheets has been

published as a fifteen volume work and distributed to 45 research and

educational institutions throughout the world. These abstract sheets

cover most classes of experimental nuclear data leading to information of

the electromagnetic matrix elements between the ground and excited states

of a given nucleus. The set, containing nearly 7200 abstract sheets and

covering 89 chemical elements from hydrogen through americium, represents

a 27-year history of the study of electromagnetic interactions.

Cross Sections: Electrons (M. J. Berger, S. M. Seltzer, & Ruqing Wang)

© Cross sections for emission of bremsstrahl ung by electrons (differential in the energy of the emitted photons) from recently published tables

by the group have been organized on a computer-readabl e data file,

presently stored on the CYBER 855. This file contains cross sections for

all elements, Z=1 to 100, for energies from 1 keV to 10 GeV. Work is in

progress to download and organize these data for storage on use on a personal computer.

© Systematic calculations were made of the cross section for the

elastic scattering of electrons by atoms. These were done by a partial wave expansion, involving the numerical solution of the Dirac equation.

The potential used was derived from relativistic Hartree-Fock wave functions. Scattering cross sections (at 65 deflection angles, for 11

135
Division 536, Technical Activities (cont'd.)

electron energies from 1 keV to 1024 keV) have been obtained for all

elements with atomic numbers Z=1 to 100. For several elements, such cross

sections have also been calculated with Thomas-Fermi potentials, and with

solid state potentials from the muffin-tin model.

® The new elastic scattering cross sections have been used as input for

improved calculations of angul ar multiple scattering according to the

Goud smi t-Saund erson method, and results have been obtained which are more

accurate at low energies than the standard multiple-scattering theory of

Mol iere. Preliminary results of this work were presented by R. Wang

(guest scientist from PRC) at the March meeting of APS.

Cross Sections: Neutrons (J. J. Coyne & E. J. Axton)

o Substantial progress has been made in the analysis and critical

evaluation of the cross sections for the nuclear interactions between

neutrons and carbon nuclei, and this information is being incorporated

into more accurate calculations of kerma factors. An internal report on the nuclear-physics aspects of this work has been prepared, and an improved kerma tabulation is in progress.

Radiation Protection (M. J. Berger, S. M. Seltzer, C. M. Eisenhauer, & G. Barnea)

o A paper has been published in the Journal of Spacecraft and Rockets

in which calculations are reported pertaining to the shielding of space

vehicles against electrons, and in particular, secondary bremsstrahl ung

originating within the shield. These calculations were done for radiation

environments in typical shuttle and geosynchronous orbits. It was demonstrated that considerably improved shielding can be obtained through the

replacement of an aluminum shield by a composite shield of the same total

mass thickness with an inner lining of lead.

o A final report was prepared for the Federal Emergency Management

Agency (FEMA) describing engineering methods and computer codes for

predicting the protection provided by various kinds of buildings against

initial gamma rays and neutrons from nuclear weapons. This report is the

culmination of a 15-year research program that has been a part of a 30-

year contract with FEMA and its predecessor agencies concerned with Civil

Defense.

Dosimetry (M. J. Berger, S. M. Seltzer, & C. M. Eisenhauer)

© Work has been completed and published on the deposition of energy by

electrons and photons in multi-layer targets consisting of several

adjacent slabs of different materials. Results were calculated with the

NBS transport program ZTRAN for electron beams with energies from 0.4 to

136
Division 536, Technical Activities (cont'd.)

60 MeV, for bremsstrahl ung beams with endpoint energies from 2 to 20 MeV,

and for 60 Co gamma-ray beams. Various comparisons indicate good agreement

with experiments.

• An analysis has been carried out of the radiation exposure from 125 I seeds used in brachytherapy , this analysis confirmed a suspected 6-8

percent error in the NBS calibration procedure, due to the presence of

secondary Ti x rays. An appropriate correction factor has been

i ndicated

.

© Monte Carlo calculations were made of silicon detector response

functions required by the CRR Dosimetry group in the course of their work

on the calibration of beta-particle detectors.

© Monte Carlo calculations have been made of the effect of air scatter

on neutron fluence from Cf, moderated Cf, Am-Be and Am-B neutron sources.

These results have been applied to the calibration of neutron personnel

protection instruments, and a method has been derived for estimating air

scatter effects for other neutron sources with different spectra.

© As a contribution to the planning of NASA's Mars Observer Mission,

the response function of large high-purity germanium detectors was calculated for gamma rays with energies from 100 keV to 20 MeV, as a function

of the direction of incidence of the radiation. Methods for space shielding calculations developed at NBS were presented in an invited talk at a LBL/D0E/NASA Workshop on High-Energy Accelerator and Space Radiation.

Mic rodosi metry (J. J. Coyne, R. S. Caswell , & H. M. Gerstenberg)

© Mic rodosimetric event-size distributions have been calculated for

four different neutron spectra using the analytical method developed at

NBS. The source spectra treated included a 252 Cf source, a source with a large component of energetic neutrons (energies up to 16.9 MeV, and

sources of neutrons from a pulsed thermal reactor with and without a lead

shield. These calculations were carried out in support of the radiobiological research program at the Armed Forces Radiobiology Research

Insti tute.

© Work has been initiated on developing a "standard version" of the

analytical code for calculating neutron-induced event-size spectra. This

version will be sufficiently documented so that it can easily be used by

outside users familiar with the microdosimetry.

© The investigation of alpha-particle event-size spectra resulting from

neutron interactions has advanced to the point where the use of the newlyevaluated carbon cross sections, together with the angular di stribution' of

137
Division 536, Technical Activities (cont'd.)

alpha particles from the 12 C(n,n')3a reaction gives reasonable agreement

between experiment and theory. However, there are still some questions

about the results at 19 MeV which remain to be resolved.

Transport Theory (M. J. Berger & S. M. Sel tzer)

© Significant improvements have been made in the all-purpose NBS

electron-photon Monte Carlo program ETRAN. These include an improved

sampling for energy-loss straggling, the i ncorporati on of more accurate

stopping powers, bremsstrahl ung cross sections and elastic scattering

cross sections. Thereby the agreement of calculated electron penetration

data with experiments was significantly improved.

© A cross section data base and Monte Carlo model have been developed

for calculating the energy-loss straggling of electrons in water, at

energies up to 1 MeV. Whereas the conventional theories of Landau,

Vavilov and B1 unck-Lei segang are applicable only for sufficiently long

pathlengths, the new Monte Carlo method is applicable to arbitrarily short

pathlengths, and has been developed with a view towards applications in

mic rodosimetry where targets of dimensions of 1 micron or smaller are of

i nterest.

II. Radiation Chemistry and Chemical Dosimetry Group

The program deal s with kinetic and mechanistic aspects of radiation

effects from model chemical to biological systems and their applications

to radiation processing, radiation protection, radiation biology, radiation therapy, and physiology. It is based on the measurement of free

radical i ntermed i ates and final products. In addition, these measurements

are used for the development of chemical dosimeters, dosimetry of damage,

and post-i rrad iation dosimetry ( sel f dosimetry )

.

A. Radiation Chemi stry (M. G. Simic, D. S. Bergtold, L. R. Karam,

E. P. L. Hunter, M. Al-Sheikhly, M. F. Desrosiers, & E. A. Thompson)

Radiation effects are studied from the initial physical interaction

o

f radiation and matter to the final biological end points from a kinetic

and mechanistic point of view at a molecular level. The properties (spectral, acid-base, redox, reactivity), and reactions of generated free

radicals are studied by pulse radiolysis and ESR. Stable products resulting from free radical reactions are studied by various analytical techniques (HPLC, GC/MS, spectroscopy, etc). Bio-effects are investigated by

suitable biochemical techniques (ultracentrifugation, el ec trophoresi s

,

chromatography , etc.).

138
Division 536, Technical Activities (cont'd.)

The emphasis of research is on the mechanisms of radiation damage to

bio-systems and the repair of damage. Specifically, DNA, proteins, lipids

and their subcomponents are used as model systems for the study of

radiation-induced damage. The interactions of sulfhydryls and antioxidants with free radicals on damaged biomolecules are studied in order to

understand the mechanisms of chemical repair.

DNA (L. R. Karam, D. S. Bergtold, S. Jovanovic, & M. G. Simic)

The research has been focused predominately on the mechanisms of DNA

base damage, crosslinking of DNA with proteins, and measurement of the

resulting products. The mechanisms and consequences of crosslinking,

however, are not yet understood because of the lack of measurement methodologies. The measurement of products of DNA damage (e.g., thymine glycol,

8-hydroxy-guani ne, etc.) is utilized for the development of postirradiation biochemical and biological dosimetry (e.g., in urine).

Irradiation parameters (dose, dose rate, temperature, state, 02 , etc.) are

of critical importance since the effects of radiation can be qualitatively

and quantitatively altered by them. The effects of quality of radiation

(LET) are not investigated at present. However, the study of the effects

of 1 ow-energy protons and a-particles, as well as high-energy high-Z

nuclei (BEVALAC), are in the planning stages.

This research is expected to have an impact in radiation biology,

radiation therapy of cancer, cancer etiology, risk assessment, and radiation protection. Specifically, the conducted research is relevant to:

assessment of damage from low-LET radiations (y and x rays, electrons) vs. a-particles (e.g., radon), and development of standards for individual

biological sensitivity to radiation. Unique facilities and expertise at

NBS, suitable conditions for the development of assays and standards,

provide new approaches in the study of the mechanisms of the biological

effects of radiation.

Thymine glycol, 8-hyd roxyguani ne and their nucleosides were separated

and identified in urine by GC/MS by using preseparati on techniques. The

redox potentials of guanine and 8-hyd roxyguani ne were determined (0.95 and

0.28 V), indicating the charge transfer in a DNA-hi stone complex takes

place from DNA to protein and not the other way around. These measurements are crucial for the understanding of the mechanisms of the direct

effect of radiation.

Proteins and Amino Acids (L. R. Karam, M. F. Desrosiers, E. P. L. Hunter,

& M. G. Simic)

The research has been focused predominantly on the hyd roxyl ation of

aromatic amino acids and dimer formation induced by radiation. The

measurement methodologies for hydroxyl ated products (e.g., o-Tyr) and

dimers have to be developed for ppb quantities in the presence of large

139
Division 536, Technical Activities (cont'd.)

numbers of other products, amino acids, and other physiological subcomponents. This research is relevant for safety assessment of irradiated

foods and the development of post irradiation dosimetry. The PID of meat

is important for quality control and regulatory (imports-exports)

proc edures.

A differential spec trofl uorimetric method was developed for the

measurements of radiation induced tyrosine dimers. It was shown that

phenoxy radicals do not react with oxygen at a measurable rate

k < 10 -3 M

-1

s -1

) and that crosslinking can take place in the presence of

oxygen as well as via interaction of two phenoxy radicals. The developed

mechanisms may serve as a general model for crosslinking of proteins.

Li pids (M. Al-Sheikhly, M. H. Hussmann, & M. G. Simic)

Mechanisms of radiation induced autoxidation of lipids are being

studied by pulse radiolysis and oxygen uptake (utilizing oxygen electrode)

in aqueous solutions. Since irradiation of aqueous solutions provides a definable number of initial reactive species, it is possible to measure

accurately the length of chain reactions. Pulse radiolysis measurements

provide kinetic and spectroscopic parameters of the relevant lipid

transients, and the reactions which lead to product formation.

Autoxidation of lipids is relevant for cancer promotion, meat irradiation processing, and the storage of foods. Pulse radiolysis measurements

in model systems have been conducted in order to provide important kinetic

information such as reaction rate constants, for the reaction of oxygen

and lipid radicals, which have been lacking until now. Rod-shaped micelles of linoleic acid have been developed as a model

for the studies of autoxidation and antioxidants under simplified membrane

condi ti ons. Antioxidants and Sulfhydryls (E. P. L. Hunter, S. Jovanovic, M.

Al-Sheikhly, M. F. Desrosiers, & M. G. Simic)

The kinetic and mechanistic features of natural and man-made antioxidants are not fully understood. Pulse radiolysis measurements provide

important features (kinetic parameters, redox potentials) for the selection of the most suitable antioxidants for a particular system. The

experiments conducted are geared toward acquisition of such predictability. The emphasis is on phenolic and heterocyclic antioxidants and

their reactions with DNA, protein, and lipid radicals.

Antioxidants and sulfhydryls act as radioprotec tors and anticarcinogens and in both cases the mechanism of action is not understood. The

impact of this work is also of significance in food preservation, and

human physiology. NBS is the only institution in the U. S. dealing with

140
Division 536, Technical Activities (cont'd.)

the kinetic aspects of antioxidants. The redox potential of vitamin E was determined (E = 0.48V), providing thermoki netic support for restitution

of consumed vitamin E molecules by various physiological antioxidants.

Efficiency of bilirubin and vitamin E as antioxidants was compared in

model micelles (rod-shaped) and the efficiency of bilirubin was found to

exceed that of vitamin E. This raises a question of the actual physiological role of bilirubin.

8-hydroxy-guani ne was found to be an excellent antioxidant for

processes in aqueous media.

B. Chemical Dosimetry (W. L. McLaughlin, M. Desrosiers, M. Al-Sheikhly,

M. Farahani, M. Khan, M. H. Hussmann, W.-Z. Ba, J-H Liang, and H.

A. El-Azez)

Research on the mechanistic behavior of both inorganic and organic

chemical systems suitable for dosimetry has isolated several promising new systems: (1) An improved and more sensitive dichromate solution; (2) a new form of radiochromic solution having a response over a broad range of

absorbed doses; (3) a new fluorescence dosimeter based on substituted

phenylcarboxyl ic acids; (4) several forms of optical waveguide dosimeters;

(5) several solid-phase chemical dosimeters (plastics, glasses, and

crystalline systems). The first two in this group are being designed as SRM's for various industrial applications of ionizing radiation. The

other three are for routine dosimetry and for quality assurance in various

applications of current interest: clinical and diagnostic medicine,

agriculture, electronics, materials, environmental technology, space and

defense, industry, and radiation protection.

Steady-State Dosimetry (W. L. McLaughlin, M. Al-Sheikhly M. Farahani,

M. Khan, W.-Z. Ba, J-H. Liang, M. H. Hussmann, & A. El-Azez)

Radiation chemistry studies of the reduction of hexavalent di chromate

to the chromic ion in acidic aqueous solution have shown this system to be

exceptionally accurate and reproducible for reference dosimetry. Similar

to the Fricke dosimeter (dose range 10-400 Gy), it gives an unusually

precise and stable system which can be used in a higher dose range (100 to

4000 Gy) for i ntercornpari son studies and for calibration of working dosimeters in industrial and food applications. Another promising reference

aqueous dosimeter for doses lower than the Fricke dosimeter range (0.1-10

Gy) for medical and biological applications has been developed in this

research effort. It consists of aryl carboxyl i c acid solutions which are analyzed by a spectrof 1 uorimeter in terms of photostimul ated fluorescence

signals due to radiation-induced hydroxyl substitutions on the phenyl

groups. These systems are also linear, stable, and reproducible for QA

purposes and i ntercornpari son studies. In addition to these liquid-phase

dosimeters, several new forms of solid dosimeter have been designed, based

141
Division 536, Technical Activities (cont'd.)

on very thin coated films, thicker plastic films, crystalline solid-state

systems, and glasses. There is now a family of highly practical and

inexpensive dosimeter devices for industrial use, to enable radiation

processing industries to measure on a routine basis doses over very broad

ranges (10-10 9 Gy). The thin-film devices are also being used for mapping

and imaging of dose distribution.

Real-Time Dosimetry (W. L. McLaughlin, M. Al-Sheikhly, & M. H. Hussmann)

Pulse radiolysis studies have revealed the response mechanisms of

both dichromate and radiochromic dosimeter systems. The dichromate

dosimeter, if properly designed, can be used without dose-rate dependence

for both photons and electrons over a wide range of radiation intensities.

The same is true for the radiochromic solutions, and in fact, it has been

shown recently that, in liquid- or gel -core sensors, these serve as optical waveguide dosimeters for real-time measurements for diagnostic and

clinical radiology. They are also being designed and used by DoD for

personnel dosimetry of mixed radiation fields. Real-time dosimeters are being investigated for telemetering purpose, in particular, certain solidstate devices whose radiation-induced signals can readily be transmitted

remotel y

.

Chemical Dosimetry Mechanisms (W. L. McLaughlin, M. G. Simic,

M. Al-Sheikhly, M. Khan, A M. Desrosiers)

Chemical dosimeters developed at NBS are subjected to rigorous experimental and theoretical investigation, in order to unravel their

radiation-chemical response mechanisms. Kinetic studies by pulse radiolysis have recently supplied hidden answers to the behavior of both dichromate and radiochromic radiation dosimetry systems, and have thus offered

convenient means of enhancing the performance of these sensors as practical dosimeters. For example, the dichromate dosimeter has been made

more sensitive by nearly an order of magnitude; new radiochromic dyes have

been designed for greater accuracy, reproducibility, and long-term

stability. These efforts are now being extended to other chemical

dosimeters, such as photol umi nescent solutions and free-radical systems.

High-Dose Calorimeters (W. L. McLaughlin J. C. Humphreys, S. R. Domen, & W-Z Ba)

At present there exists no primary standard for high-dose dosimetry.

There are, however, new demands from industry for such a standard, as the use of industrial electron accelerators expands rapidly, and as quality

control on assembly lines depends more and more on traceability to such

standards. Calorimeters especially suited for standardization and calibration of dosimeters used at large radiation doses and dose rates are being designed and built at NBS for both electron beams and large radionuclide gamma-ray sources. These NBS designs are also being adapted by

142
Division 536, Technical Activities (cont'd.)

other National Laboratories in the UK, Denmark, Canada, and the Federal

Republic of Germany. International i ntercompari sons of these standards

are now being carried out on an annual basis, as a means of developing

recognized primary standards for the quantities absorbed dose and dose

rate delivered at high f! uence rates in industrial radiation processing.

C. Post Irradiation Dosimetry (PIP) . (L. R. Karam, D. S. Bergtold,

M. F. Desrosiers, E. A. Thompson, & M. G. Simic)

There are numerous instances when the knowledge of the delivered

radiation dose is required either immediately or long after the exposure.

For example, proof that suspected foods have or have not been irradiated

is required by food processors and wholesalers for purposes of regulation

of imports/exports. Reliable measurements which can indicate that irradiated foods have not received radiation dose in excess of the legal limits

are needed by regul atory agencies.

Accidental exposure of personnel to radiation has occurred in some cases without an adequate on-line dosimeter being present, accentuating

the need for the development of novel concepts in real-time dosimetry and

PID for such c i rcumstances.

Measurements of the total energy delivered (J) to a patient in radiation therapy would be useful information to a therapist. So would be the

dose received by the NASA personnel exposed to cosmic showers and solar

flares in space. The possible presence of unique radiolytic products,

URPs, or specific markers, in the urine of irradiated patients or personnel in space (e.g. thymine glycol, 5-hydroxymethyl uracil, etc.) is under

i nvesti gation.

The discovery of o-Tyr in irradiated chicken meat may be utilized for

the development of suitable PID for meats. Analytical procedures and a separation methodology have been developed for determination of o-Tyr in

irradiated and noni rrad i ated chicken-breast meat. No measurable ( <0 .

1

ppm) quantities of o-Tyr were found in noni rrad i ated meats, while in

irradiated samples a linear yield-dose relationship was found. Carbon

tetrachl oride (fat extraction solvent) was found to induce o-Tyr in

irradiated and noni rrad i ated meat. However, even under those circumstances no o-Tyr was found in the water-insoluble fraction (~75 percent of

protein) after water extraction.

Electron spin resonance (ESR) measurements of irradiated bones (pork

and chicken) exhi bi t I i near signal -dose rel ationshi ps. The ESR signal in

uni rrad i ated bone was different from the rad i ation-i nduced signal. The

signal intensity persists for months, making this approach an ideal one

for determination whether meat (with bones) has been irradiated.

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Division 536, Technical Activities (cont'd.)

Thermoluminescence and 1 yol umi nesc ence methodologies for PID are under development as a counterpart of ESR measurements, since photoncounting could be a much more sensitive technique than electron spin

measurements.

III. Neutron Measurements and Research Group

This group is concerned with measurements of neutron interactions

which depend strongly on the neutrons' energy. The interactions require

neutron spectroscopic capability from 0.005 eV to 50 MeV--over ten decades

of energy. The largest program is devoted to a continuing international

effort to push the accuracy of reference neutron cross sections into the

±1 percent (1 SD) range. Although the group has made signi ficant contributions to this effort, much work remains in selected neutron energy

regions to achieve this important goal. This activity, which is jointly

supported by the U.S. Department of Energy and N8S, includes both an extensive experimental effort as well as coordination of the evaluation of

the neutron cross section standards for the United States. These

standards form the basis for nearly all neutron nuclear data since these

data are measured relative to the standards. Hence they supply large

leverage since an improvement in the accuracy of the standards will

improve the accuracy of the entire data base without an extensive

remeasurement effort. Other programs are concerned with the development

and exploration of analytical techniques based on the unique features of

the neutron's interaction with matter. Both the standards and analytical

studies require a significant component of fundamental neutron research.

The group possesses the unique combination of highly trained technical

staff and research facilities to continue to produce significant leadership in these areas. The NBS facilities used are the 100-MeV linac

dedicated pulsed neutron source, 3-MV positive ion electrostatic accelerator, 100 keV neutron generator, and nuclear research reactor. In response

to requests from other programs within NBS, a 6-MeV y-ray radiation

facility and a Rutherford Bac ksc atteri ng Analyzer for surface studies have

been implemented at the positive-ion accelerator. A technical description

of the group's activities and significance of its success in completing

projects follows.

235 U(n,f) Cross Section from 0.02 to 1000 Electron Volts (R. A. Schrack)

The Neutron Measurements and Research Group has undertaken a measurement of the shape of the neutron induced fission cross section from .02 to

1000 eV where there have been large discrepancies (on the order of 7 percent) in the reported values of these integrals. This measurement is

being undertaken to help resolve the current discrepancies in this

important cross section standard.

144
Division 536, Technical Activities (cont'd.)

The past year was devoted to diagnostic tests to improve the accelerator operation and data-acqui si ti on electronics. The data obtained after

these diagnostic efforts are in good agreement with the most recent work.

A final evaluation of these results will produce a cross section which

will satisfy the accuracy request in this energy region.

Measurements of the 235 U(n,f) Cross Section in the MeV Energy Region

(A. D. Carlson, 0. A. Wasson; P. W. Li sowski , LANL; J. L. Ullmann, LANL ; & N. W. Hill , ORNL)

Significant progress has been made in the fission measurement program

initiated at the Los Alamos National Laboratory (LANL) facilities. This

program was begun in an effort to improve the accuracy and range of the

235 U(n,f) cross section standard. The neutron flux is being measured with

the NBS annular proton telescope. The fission detector is a LANL fission

chamber with fission foils prepared at Oak Ridge National Laboratory

(ORNL). The multi foil capability of this chamber is being utilized to

provide redundancy of measurements and to provide fission cross section

measurements of other actinides.

The cross section measurement work began late last year when the new

WNR Target 4 facility became operational. This facility is capable of

producing the very intense beams of high energy neutrons required for this

measurement. The detectors were set up at the 20 m flight path end

station. During the brief period before the LAMPF/WNR cycle came to an end, experimental tests, diagnostic studies and some preliminary fission

cross section results were obtained in the 3-30 MeV neutron energy range.

Measurements have never been made before of this cross section in the

higher energy region.

Plans have been made to continue the measurement program at the

beginning of the WNR cycle. The longer period of time available for

measurements this year should allow comprehensive background investigations, diagnostic tests, and a considerable improvement in the counting

stati Stic s. Absolute Measurements of the 235 U(n,f) Cross Section for Neutron Energies

from 0.3 to 3 MeV~ (A. D. Carlson, J. W. Behrens, R. G. Johnson, &

G. F. Cooper)

The measurements of this cross section have been made at the NBS

neutron time-of-fl ight facility. The neutron flux was measured at the 200

m end station with the NBS Black Neutron Detector. The 235 U fission reaction rate was determined with a fission chamber located on the same beam

line at 69 m from the neutron producing target. The cross sections from

this measurement have been finalized and made available along with extensive correlation and uncertainty information for use in the ENDF/B-VI

145
Division 536, Technical Activities (cont'd.)

standards evaluation. The numerical data are available from the National

Nuclear Data Center at Brookhaven National Laboratory. A paper describing

this work is being prepared for journal publication.

ncation of the Dual Thin Scinti

U(n,f) Cross Section Measurement

A. D. Carlson, & 0. A. Wasson)

The 235 U(n,f) cross section ha

neutron energy range using the dual

flux monitor. Final results of the

analysis have been obtained and are

publ ication.

lator Neutron Flux Monitor in a (M. S. Dias, R. G. Johnson,

, been measured over the 1.0 to 6.0 MeV

thin scintillator (DTS) detector as a measurement along with a full error

in the process of being submitted for

Charac teri zati on of the Moderating Neutron Detector (J. B. Czirr,

G. Jensen, R. G. Johnson, A. D. Carlson, & 0. A. Wasson)

An innovative series of neutron detectors has been developed at MESA

Services International by Dr. J. B. Czirr. In collaboration with Drs.

Czirr and Jensen (Brigham Young University), the Neutron Research and

Measurement Group are conducting measurements to help characterize this

detec tor.

The detector consists of 2 to 9 sheets of 6 Li-enriched glass scintillator. (Each sheet is 10-cm square and 0.5-mm thick.) The ^ Li - gl ass scintillators are surrounded by a neu tron-moderati ng liquid and viewed by

two photomultiplier tubes. With five pieces of glass the efficiency drops

from 75% to 32% over the 1-eV to 1-MeV range. The timing resolution over

this same energy range is 8.1 to 4.0 ps.

At the NBS Neutron Time-of-Fl i ght Facility (NT0FF) a shape measurement of the efficiency for neutron energies from 100 eV to 30 keV has been

performed. The measured efficiency will then be compared to the predictions of a Monte Carlo code.

Development of the NBS 3 He/Xe Gas Scintillation Counter (J. W. Behrens,

Hongchang Ma , & 0. A. Wasson)

3 He/Xe gas scintillation counters have been designed, built, and

tested at the NBS for measuring the neutron energy range from 1 keV to 3

MeV. Great effort was concentrated on improving the detector design to

optimize ultraviolet-light production in xenon, wavelength shifting in

di phenyl stil bene, and light collection in the photomultipliers, since the

main component affecting energy resolution was photon statistics. The

goal was to improve the resolution of the 3 He(n,p)T pulse-height distribution so that it could be easily separated from most of the 3 He recoil

events. Two detector designs have been built and tested using a 238 Pu

146
Division 536, Technical Activities (cont'd.)

alpha-particle source, thermal -neutron beam from the NBS reactor, and

white-neutron spectrum from the NBS dedicated pulsed neutron source. The

progress of our work has been reported in recent ANS and APS meetings.

We are pleased to report that our goal has been reached. We now have a detector which can be used in experiments to measure the 3 He(n,p)T cross

section and has great promise as a flux monitor in future standards

measurements. We have prepared a paper summarizing our design studies and

will be submitting it for publication in Nuclear Instruments and Methods.

Measurement of the 3 He(n,p)T Cross Section from 1 eV to 750 keV

(J. W, Behrens, A. D. Carlson, & H. Ma)

Having designed, built, and tested a

3 He/Xe gas scintillation counter

which has an energy resolution of 17% (FWHM) for the 3 He(n,p)T reaction

and with which we can separate out most of the 3 He recoil events, we decided to use the detector to measure the 3 He(n,p)T cross section. Our

first measurements utilized the 10 B(n,a) reaction as the reference

standard. The energy range of interest was from 1 eV to 750 keV and the

NBS linac was chosen to produce the neutrons. Data have been taken using

our two-detector, two-parameter data taking system. We measured neutron

backgrounds with gold, sodium, and aluminum filters. These data are presently being analyzed.

Detectors for Neutron Scattering in the eV Region (R. G. Johnson)

Over the last few years the Neutron Measurements and Research Group

has carried out a modest program in detector development for low energy

neutron scattering. Neutron scattering is one of the primary tools in

condensed-matter studies. With the advent of accel erator-based neutron

sources the possibility of extending this technique to higher energies was perceived. However, in moving to higher energies the traditional detectors and instruments used in condensed-matter studies are inappropriate.

An opportunity for this group to use its experience in neutron measurements over a very wide range of energies was foreseen.

Recently the results of this detector development were accepted for

publication. In this report two detectors for one of the principal

general methods to extend the neutron- sea tteri ng technique to the eV

region are described and tested. The general method uses low energy

neutron resonances to define one energy in the scattering process. The

other energy can be measured by time-of-fl ight. The particular method

studied here would be applied to the so-called Resonance Detector

Spectrometer (RDS) where the nuclear resonance defines the energy after

scattering (indirect geometry).

147
Division 536, Technical Activities (cont'd.)

Mul ti -Particl e Accel erator for Neutron and High-LET Radiation Research

(R. G. Johnson)

A final report on a linear induction accelerator for neutron and

high-LET radiation has recently been published. This preliminary design

study was originally performed as part of the analysis of neutron and

high-LET radiation research program at NBS conducted by the Center for

Radiation Research staff. The accelerator design study was later updated

to include the most recent advances in technology for induction linacs.

Data Acquisition System (R. G. Johnson, G. E. Cooper, & R. A. Schrack)

Funds from the NBS capi tal -equi pment fund were obtained in F

Y -87 to

complete the purchase of computers for replacement of those in our data

acquisition systems. Although limited funds were available, the rapid

improvement in the price-performance ratio has permitted us to implement

our ambitious plan made several years ago. This final purchase did

require a change in vendors but virtually no change in computer

a re hi tec ture.

Two MZ9400 computers were obtained from MIZAR, Inc. These computers

use the VME bus and the Motorola MC68020 mic roprocessor. The basic

machine contains 1-Mbyte of memory, a 1.2-Mbyte 5-1/4-in floppy disk, and

a 20-Mbyte hard disk. The 0S-9/68k operating system is being used. The

computers were enhanced by a 4-Mbyte memory board and a CAMAC-VME interface board. In addition, two AST Research Inc. Premium/286 computers were purchased to be intelligent terminals for the MIZAR computers. The

Premium/286 which is a PC-AT clone will allow us to use the vast pool of

software available for personal computers.

The Charles River Data Systems UV2403FT computer (previously

purchased) which is also based on a VME and MC68020 architecture will be

used for data analysis and storage. This computer with its 1 arger harddisk capacity (105-Mbyte), better input/ output capability (9-track tape

drive, laser-jet printer, etc.), and superior multiuser operating system

is ideally suited for that role. To fully implement that use we need to

acquire a high-speed local area network (LAN).

Continued Development of a 2.5 MeV Neutron Source for Standard Cross

Section Measurements (K. C. Duval 1 ) Development of a 2.5 MeV neutron source using the D(d,n) 3 He reaction

and the time-correl ated associated particle (TCAP) method continues. The

100 k V, 0.5 mA ion generator is in place and operating according to the

required specifications. A magnetic quadrupole doublet and a magnetic

dipole X-Y steerer have been installed on the beam line. The components

are effective in focusing and steering the deuteron beam. A beam spot

size of 3 mm diameter has been attained with nearly two hundred microamps

148
Division 536, Technical Activities (cont'd.)

of beam on target. Water cooling is being used to maintain the target

heating and outgassing to a reasonable level. In addition to the vac ion

main vacuum pump, a turbomol ec ul ar pump has been installed near the target

to provide increased target pumping. Isolation gate valves are used to

separate the target vacuum from the main accelerator vacuum. The nearly

10' neutrons/ sec D-D source yield is produced from the commercially

obtained titanium deuteride targets. The deuteron beam characteristics

and the neutron source yield are sufficient for use with TCAP to measure

standard neutron cross sections. An article describing the development of

the standard 2.5 MeV neutron source has recently been published in Nuclear

Instruments and Methods.

Dual Thin Sc i nti 1 1 ator Devel opment in the Sum Coincidence Mode (K. C.

Duval 1 & R. G. Johnson)

The Dual Thin Scintillator (DTS) is a unique detector that is continually being developed here at the NBS for neutron flux and spectrum

measurements in the 1 to 15 MeV energy range. The detector consists of

two thin, back to back, plastic scintillators that are optically separated

and independently coupled to photomultiplier tubes. Current interest is

focused on the development of the detector in the sum coincidence mode of

operation which produces a peaked rather than a rectangular spectrum. The

peaked energy distribution provides improvement for neutron flux and spectrum measurements.

For absolute neutron flux measurements, the peaked response function

will produce more accurate results due to reduced sensitivity to electronic gain instabilities and computational uncertainties. For spectral

determinations with spectrum unfolding analyses, the peaked response functions should provide an improvement in unfolded results because of the

increased correlation with the initial neutron energy spectrum. As a result of the added effect due to multiple scattering on the detector

efficiency at low neutron energies, the DTS detector in the sum coincidence mode fulfills the desired requirements for use with spectrum unfolding analyses.

A Study of Fission Cross-Section Systematics (J. W. Behrens)

A publication has been completed giving the results from a study of

fission cross-section systematics. Future studies will examine the

thorium and protactinium isotopes and will extend into the transplutonium

mass region.

149
Division 536, Technical Activities (cont'd.)

Util ization of the NB5 Dual Thin Scintillator Neutron Detector for

Activation Cross Section Measurements (K. Zasdny, G. F. Knoll, U. of

Michigan; R. G. Johnson, K. C. Duvall, & 0. A. Wasson)

The value of the Dual Thin Scintillator Neutron Detector for precise

neutron fluence measurements in the 1-15 MeV energy region continues to be

recognized by other 1 abora tori es. This detector is being used to determine the neutron fluence incident on the samples for new 14 MeV neutron

activation cross section measurements at the 125 keV neutron generator

facility at the University of Michigan. Previous measurements were compared to a commonly used 56 Fe(n,p) reference cross section. These new measurements will combine these techniques and further reduce the systematic errors which will produce more accurate cross sections. These cross

sections are applied in many areas of neutron dosimetry and spectral

measurement.

Development of a Method for the Dosimetry of High Energy Photon Fields by

Nal Spectrometry (K. C. Duvall, S. M. Seltzer, C. G. Soares, & B. W.

Rust)

A method for the dosimetry of high energy monoenergetic photon fields

by analysis of 3-inch x 3-inch Nal pulse height data has been developed.

This approach uses calculated Nal detector response functions that have

been shown to be reasonably accurate up to 20 MeV. A least-squares fit of

the appropriate response functions to a selected region of the data determines the primary high-energy photon fluence. The air kerma delivery at a reference position in the photon field is calculated from the high-energy

photon fluence. The primary high-energy photon contribution to the detector response is then removed from the data and the remaining distribution

of lower-energy photon contamination is evaluated by spectrum unfolding

analyses. The method is applied to Nal measurements at the nearlymonoenergetic 6 to 7 MeV photon source developed at the National Bureau of

Standards (NBS) for radiation protection i nstrument cal ibration.

The ENDF/B-VI Neutron Cross Section Standards Evaluations (A. D. Carlson,

W. P. Poenitz, ANL ; G. M. Hale, LANL ; & R. W. Peelle, ORNL)

The evaluation cycle has been started for the sixth version of the

U.S. Evaluated Nuclear Data File, ENDF/B. The individual evaluations are

all critically dependent on the new evaluations of the neutron cross

section standards. The standard evaluation process for this new version

is more thorough and logically consistent than that used in earlier

versions. The primary effort is focused on a simultaneous evaluation

using generalized least squares, R-matrix evaluations and a procedure for

combining the results of these evaluations. The simultaneous evaluation

is important to this process since ratio measurements in addition to shape

and absolute determinations are treated properly. Correlations within and

150
Division 536, Technical Activities (cont'd.)

among experimental data sets are also taken into account. Also the output

results from the thermal constants evaluation by Axton, including the

associated vari ance-covari ance matrix, has been used as input for this

evaluation. The R-matrix evaluations provide a method which allows

charged-particl e measurements involving the same compound nuclei ( 7 Li and

U B) to be included in the evaluation process. These evaluations also

provide a smooth meaningful expression for the energy dependence of the

cross sections. Independent data bases are used in the simultaneous and

R-matrix evaluations. The combining procedure is used to combine the

information obtained from these analyses in a proper way to form the final

evaluation and its vari ance-covari ance matrix. The standards being

evaluated are 6 Li(n,t), 10 B(n,a 1 ),

10 B(n,a), 197 Au(n,y), and 235 U(n,f).

Evaluations for the important reactions 238 U(n,y), 238 U(n,f), and

239 Pu(n,f) are also being performed. The new R-matrix evaluation of the

hydrogen scattering cross section by Dodder and Hale has already been

accepted as the hydrogen standard for ENDF/B-VI.

The standards evaluation effort required for this project has turned

out to be more substantial than we had originally expected. A total of seven cycles of this evaluation process have been performed in order to

implement various improvements, changes, and checks into the procedure.

This work is now entering its final phase. The last combining procedure run and the smoothing of the capture and fission data which were

performed in July should yield the final cross section values.

Fifty Years with Nuclear Fission, a Conference (J. W. Behrens, A. D.

Carl son , & 0. A. Wa sson)

The NBS will host a topical conference entitled, "Fifty Years with

Nuclear Fission" from April 26-28, 1989. Joining the NBS as co-sponsors

are the American Chemical Society's Division of Nuclear Chemistry and

Technology, the American Nuclear Society, and the American Physical

Society's Division of Nuclear Physics. Professors John Archibald Wheeler

and Edoardo Amaldi will serve as Honorary Co-Chairman. The conference

will be dedicated to the memory of Niels Bohr and Enrico Fermi.

The conference's program committee met on April 22, 1987 to decide on tentative general topics and to nominate members to the advisory committee. The general topics chosen were, 1) The History of Fission, 2)

Fission-Theory, 3) Fission-Experiment, 4) Fission-Applied Data, 5)

Applications Utilizing Fission, and 6) The Impact on Society of the

Discovery of Nuclear Fission. A postcard announcement was distributed to

1600 individuals, worldwide, on the mailing list from the 1985 Santa Fe

Conference. A second announcement including a call for contributed papers

will be sent out in early 1988. We presently estimate that the conference

will be attended by 400-500 participants.

151
Division 536, Technical Activities (cont'd.)

IV. Neutron Dosimetry Group

This group is engaged in the development and the application of wel 1 - charac teri zed neutron fields as permanent irradiation facilities for

neutron dosimetry standardization, for neutron detector development and

calibrations, and for reaction cross section measurements. Strong interactions with outside organizations, both in the federal and private

sectors, are important programmatic elements.

Neutron Personnel Dosimetry (R. Schwartz, E. Boswell, & C. Eisenhauer)

Activities carried on under this heading include use of the NBS

standard neutron fields for routine calibrations of health physics instrumentation, for development and testing of new types of instrumentation,

and for quality control of production instruments. In the area of dosimetry, methods research, a tissue equivalent proportional counter system

(TEPC) is under development to determine neutron dose as a function of

energy deposi ted

.

1. Cal i brati on service . Required documentation for the calibration

service has been completed. Approximately 55 health physics instruments

were calibrated this year. Most of these were for nuclear power plants

and the armed forces. A remotely operated detector positioner has been

installed that adds convenience, improves accuracy and speeds up data

taki ng.

2. Performance test of a new type of remmeter . The French Atomic

Energy Commission (Commissariat a L'Energie Atomique) have developed a new remmeter, an unusual event, intended to be more accurate and easier to use than current instruments. At their request, definitive performance tests

were performed at NBS. Since the instrument is designed to take account

of scattered neutrons, it was necessary to correct for room scatter in our calibration facility in order properly to interpret the data. Results

indicate that the new remmeter gives accurate results when used as

i n tended

.

3. I ntercompari sons . Calibration intercomparisons were undertaken

with the University of Arkansas Southwest Radiation Calibration Center,

and with the Battel le Pacific Northwest Laboratory. Agreement in both

cases was within ±5 percent. An i ntercompari son involving NPL (Great

Britain), PTB (Germany), and CEA (France) is in full swing.

4. Purity of the filtered beams . In response to questions concerning the purity of the NBS 2 keV filtered beam, the neutron spectrum was carefully remeasured using a He-3 spectrometer with a new low-noise preamplifier and pile-up rejection circuitry. Newly observed lines between

70 keV and 550 keV amount to only about 2 percent of the primary 2 keV

152
Division 536, Technical Activities (cont'd.)

line. The pulse height spectrum shows that by far the cleanest 2 keV beam

at any reactor facility in the world is at NBS. The 144 keV beam also has

been improved recently by increasing the amount of Ti in the filter.

5. Quality assurance and type testing . The filtered neutron beams

together with the beam at the thermal column, continue to be used for

testing radiation protection instrumentation. Included this year were quality control measurements on neutron area monitors for the Naval

Surface Weapons Center, dosimeter irradiations as part of the Department

of Energy Laboratory Accreditation Program (DOELAP), and testing of a new type of neutron detector developed at the Chalk River Laboratories. The

latter testing, done in collaborations with several other laboratories in

the United States and England, forms the basis for a paper to be given at

the Sixth Symposium on Neutron Dosimetry to be held in Neuherberg,

Germany, in October, 1987.

6. Tissue equivalent proportional counter (TEPC) development . New

data taking equipment has been tested and computer programs rewritten as appropriate. Work has begun on definitive measurements in NBS reference

neutron fields (e.g., bare and moderated californium, filtered beams),

which will then be compared with calculation.

7. Figuring out what we're doing . The combination of facility

improvements and the coming on-line this year of the MCNP (Monte Carlo)

code, made it possible to begin a more detailed study, both experimental

and theoretically, of the problem of room scattered neutrons. A clearer

understanding of the physics of this aggravating problem is emerging.

Dosimetry for Material Performance Assessment (E. D. McGarry, G. Lamaze,

& J. Grundl

)

Exposure to neutrons can cause critical performance degradation in

materials as different as a silicon wafer and an 8 inch thick plate of

steel. Dosimetry methods for assessing the degradation of materials in

high-intensity neutron fields are equally diverse. The Neutron Dosimetry

Group provides some form of measurement assurance, standardization,

methods development, and/or advice for nearly all of the approaches to

materials neutron dosimetry pursued in the United States. Because of

assorted commercial interests, foreign involvement is also a strong

component of this activity.

1. Neptunium neutron fluence standard . For the first time an Np

fluence standard was prepared with sufficient activation to allow the

30-year 137 Cs activity generated by the Np fission reaction to be calibrated for dosimetry. The Np fission detector is a uniquely effective

threshold detector for establishing a neutron exposure component below

1 MeV, and the 137 Cs fission product activity is especially useful for

monitoring long term exposures.

153
Division 536, Technical Activities (cont'd.)

2. Masses of ultralight fissionable deposits . In many applications

solid state track recorders require fissionable deposits of very low mass

as for example in the monitoring of 18-month-long power reactor fuel

cycles. A cooperation has begun with Westinghouse Corp. to provide mass

assay of deposits of three fissionable isotopes in the picogram and subprogram range. The accuracy goal is a few percent! The quantity measured is the total number of fissions which take place in the SSTR deposit

during a high fluence thermal or fission spectrum irradiation. The final

mass is established relative to FIMS, the NBS set of Fissionable Isotope

Mass Standards.

3. Development of the SPAD Code Procedure . An NBS procedure for

deriving neutron exposure parameters from threshold detector measurements

was described in a paper presented in June at the Sixth ASTM/EURATOM

Reactor Dosimetry Symposium. The derivation focuses on individual

detector results and the option of a coarse group spectrum adjustment when

observed detector responses are in modest disagreement with those

predicted by an a priori calculation. The procedure is epecially appropriate for threshold detector measurements that have limited information

and/or are benchmark referenced.

4. Application of the SPAD procedure . Activation dosimetry experiments have been evaluated with the SPAD Code for the NESSUS reference

neutron field at Winfrith, England and for a heavy section steel testing

irradiation facility operated by the MEA Corp. at the Univ. of Buffalo.

The NESSUS evaluation is part of a more extensive measurement intercomparison of calibration methods in the U. K. and the U. S.

5. Pulsed reactor dosimetry . The Nuclear Effects Laboratory at the

White Sands Missile Range has requested help in developing an in-house

active fission rate measurement capability connected to NBS standard

neutron fields. Plans have been formulated for initial on-site measurements in early FY-88. Fission rate measurements at this laboratory are

used to establish neutron dose for electronic components exposed to leakage neutrons from the White Sands fast burst reactor.

Neutron Source Strength Calibration Facility (E. D. Ms Garry &

E. Boswel 1 )

NBS provides routine calibration of neutron source emission rates.

Source strengths are calibrated against the National Standard radiumberyllium photoneutron source, NBS-1, to an accuracy of about 1.2 percent

by the manganous sulfate bath technique.

1. Cal i brati on service . A total of 15 neutron sources were

calibrated for seven U. S. laboratories and installations. This is a threefold increase in source calibrations over last year.

154
Division 536, Technical Activities (cont'd.)

2. Calibration document . The document SP250-18 describing the NBS

neutron source calibration facility was completed and published after much

unavoidabl e travail . Benchmark Neutron Field Facilities and Fission Rate Measurement Capability

(E. Boswell, D. Gilliam, J. Grundl , G. Lamaze, & E. D. M: Garry)

The foundation of the Neutron Dosimetry Group's service to nuclear

technology are the wel 1 -spec i fi ed neutron fields that are maintained as permanent irradiation facilities. Ten separate irradiation sites at NBS

provide certified fluences of thermal neutrons (beam or isotropic), of

keV neutrons (filtered beams), of sub-MeV distributions (ISNF and the D

2 0

Moderated Cf Fission Source), or of pure fission spectrum neutrons (Cf or 235 U with fluence rates of up to 4 x 10 10 n/cm 2 s). Complementing the

neutron fields, but with independent applications of its own, is the NBS

fission rate measurement capability. At the center of this capability

are the NBS set of fissionable isotope mass standard (FIMS) and the double

fission chambers in which they are used. Passive and active neutron

detectors of all kinds are exposed in these neutron fields for calibration, for measurement assurance projects, for cross section measurements,

and for development of new measurement techniques.

1. Facility improvements

© An in-depth review and reworking of the calibration base for the 235 U cavity fission source has begun. The complicated path by which the

absolute fission neutron fluence rate is established will be set out

more explicitly and calculations of irradiation fluences will be

handled with computerized spread sheets.

© A new method for monitoring ISNF irradiation fluences has been

perfected. It involves neutron fluence transfer from the Cf fission

source via fission product activation counting of 23 5 U.

© The calibration documents SP250-13 covering activation foil irradiations at the Cf fission neutron Irradiation Facility and SP250-14 for

activation foil irradiations at the 235 U Cavity Fission Source were completed and published.

2. Ion chamber testing at 14 MeV . The NBS double fission chamber

was used to establish 14 MeV fluence rates for performance test of tissueequivalent ion chambers. The project is supported by the National Cancer

Institute. Early on, an unexpected discrepancy of 15 percent arose

between the ion chamber response and that of the fission chamber.

Subsequent measurements with a threshold fission reaction (Np) revealed

an unsuspected contamination of the 14 MeV fluence by d-D neutrons.

Re-analysis with the contamination included resulted in agreement to

±1.1 percent.

155
Division 536, Technical Activities (cont'd.)

3. Fission chamber monitors . Enlarged versions of the NBS double

fission chamber were designed and constructed for use as the primary monitor for exposure rooms at the AFRRI Triga reactor in Bethesda. This new monitoring scheme, which replaces existing ion chambers, will provide an unambiguous response to neutrons in the MeV range for biological specimen

irradiations at high fluence rates.

4. Benchmark measurement for criticality safety . The outcome of a series of meetings initiated by managers of the nuclear criticality safety

program at DOE is a proposal to create a neutron field at NBS which would

benchmark nuclear criticality calculations, especially those which involve

fissile materials in water. Initial measurements would establish fission

detector responses to the leakage spectrum from various sized water

spheres driven by Cf fission sources. As benchmark data for the indefinite future the emphasis will be on accurate definition of geometry and

materials in the benchmark, high quality scattering corrections for the

fission chamber, and good documentation.

Integral Cross Section Measurements (D. Gilliam, J. Grundl , G. Lamaze & E. D. McGarry)

The standard and reference neutron fields, together with the fission

rate measurement capability and the nearby facilities of the Radioactivity

Group, conspire to make NBS an excellent place to measure absolute

reac ti on-rate cross sections. As a base program this activity has been

pursued for a long time generating influential data for reactor physics as

well as neutron dosimetry.

1. Nb ( n , n

1 ) for high-fluence materials neutron dosimetry . The NBS

cavity fission source was the site for a DOE sponsored, mul til aboratory

cross section measurement that included substantial international participation. Nb is an up and coming dosimetry detector with a 16 year halflife that is attractive for long term sub-MeV neutron exposure monitoring,

but not so attractive for differential cross section measurements. Hence,

for this detector, a fission-spectrum-averaged cross section is of particul ar importance. The results of this work were reported at the Sixth

ASTM/EURATOM Reactor Dosimetry Symposium in June, 1987.

2. Photofission for correcting fission detector responses . The

problem of photofission interference in fission detectors has been around

for a long time. To check existing corrections, photofission cross

sections in four fissionable isotopes were measured in the new neutron

driven gamma ray source designed and constructed by the Neutron Dosimetry

Group in cooperation with the SCK/CEN laboratory in Belgium. For these

measurements the source was operated first with a cadmium and then with

an iron converter. The data obtained will be used to validate and/or

adjust calculated correction methods, notable those developed by

156
Division 536, Technical Activities (cont'd.)

C. Ei senhauer at NBS. The measurements were carried out in a cooperation

headed by Prof. T. Williamson of the Univ. of Virginia and were reported

by him at the ASTM/EURATOM Reactor Dosimetry Symposium in June.

3. Capture reactions in ISNF . Two carefully planned irradiations

of 20 activation detectors were carried out in the Intermedi ate-Energy

Neutron Field (ISNF). The purpose was to extend previous capture cross

section measurements to include Na, Ag, and Sc, ail important reactions

for reactor physics applications. Major measurement issues were the

perfection of a new method of neutron fluence transfer and corrections

for resonance self-absorption. Executing and documenting the irradiations

was largely done under contract by a reti red group member.

4. Dosimetry reactions in the Cf fission spectrum . Some twelve

irradiations have been performed over the last two years at the Cf Fission

Neutron Irradiation Facility with the goal of measuring reaction cross

sections for nine neutron dosimetry reactions. Absolute neutron fluences

were established for each irradiation in analyses completed this year.

Preliminary cross sections have been derived for most of the reactions.

This activity is carried out with the help of the Radioactivity Section.

Special projects (all group members).

The unique irradiation facilities and measurement capabil i ties in

the Neutron Dosimetry Group coupled with the wide range of institutional

involvements c harac teri Stic of neutron dosimetry in practice continues to

bring on small worthwhile projects and unavoidable responsibilities.

1. Neutron lifetime experiment . In the measurement proposed by the

NBS Quantum Metrology Group, the Neutron Dosimetry Group will determine

the average linear density of neutron beam downstream from an electromagnetic proton trap. Preliminary experiments carried out this year

explored the possibility of using a 10 B(n,a,y) coincidence technique for

absolute thermal neutron counting. More than promising results were

obtained and reported in a paper to be published in the Journal of

Radioanalytical Chemistry. A visiting scientist from the Univ. of Sussex

in England participated in this work.

2. Public knowledge and radiation emergencies . Committee 63 on Radiation Exposure in a Nuclear Emergency, constituted by the NCRP some years ago, recently created a task group to develop guidelines for improving public knowledge about radiation exposure in order to enhance public

response during a major radiation emergency. The initial assignment for

the Neutron Dosimetry Group appointee to this task group is to identify

the pathways by which the public receives information and forms a point of

view regarding the hazard of nuclear radiation before and during such an emergency

.

157
Division 536, Technical Activities (cont'd.)

3.

LiF Chips for megagray gamma dosimetry . The new Li F Chip dosimeter (see Tech. Act. -86) has been tested for neutron sensitivity this year

by exposure in the 235 U Cavity Fission Source. In the course of this work

a new color center was explored and the sensitivity of the dosimeter was extended to the 10 MGy range. In a typical application the correction for

neutron response will be 15 to 20 percent. Special Li F -gl ass encapsulation for the dosimeters are being fabricated prior to shipment to Babcock

& Wilcock Co. who have supported this R&D effort. The calibration work

has been done in cooperation with the X-ray Physics Group and the results

were presented at the ASTM/EURATOM Reactor Dosimetry Symposium in June

1987.

4. Sixth ASTM/EURATOM Reactor Dosimetry Symposium on Reactor

Dosimetry . The sixth symposium in this biennial series was held this

1 ast June in the U. S. and two group members were strongly involved in

preparing and running what has become a rather large international

gatheri ng

.

5. Nuclear energy exhibit at the National Atomic Museum . The

exhibit will focus on the realities of nuclear energy through audio/visual

displays and operating devices including the Smithsonian Replica of the

Lady Godiva Reactor, a nuclear historic landmark. Our cooperation with

the NAM this year concentrated on the preparation of demonstration

lectures designed to challenge viewers interests and perception.

V. Radioactivity Group

Introducti on

Several long-standing problems were addressed this year. A significant international calibration discrepancy was resolved and methods for

assuring the international acceptability of calibration sources were proposed through BIPM and ICRM. A new Research Associate program was established to test measuring abilities in the radiochemistry department

of nuclear power plants, and provide a coherent measurement assurance

program for commercial suppliers of calibration sources and services.

More automated data-processi ng and certi ficate-generati on programs were developed for calibration services and SRMs. New techniques were investigated and applied. Some of these topics are discussed in the sections

that follow. Three significant conferences or workshops were organized.

Program for the Nuclear Power Industry

In response to industry requests, a new program has been organized in

cooperation with the U. S. Council for Energy Awareness (CEA). This program, with an additional CEA (formerly AIF) Research Associate now working

at NBS, supplies six types of test samples annually to nucl ear-power-pl ant

radiochemi stry departments as blinds. Activity values measured in the

158
Division 536, Technical Activities (cont'd.)

plants, or by service companies, are compared with the NBS values and a certificate of traceability issued. If measurement results are significantly discrepant, assistance is offered in resolving the difficulty.

Another important aspect of the cooperation is a measurement assurance program for the companies supplying calibration sources to the power

plants. In addition to measuring any of the six blind samples supplied

each year which are pertinent to calibration sources which they supply,

the companies submit a variety of calibrated samples to NBS for verification. The company facilities and procedures will be checked to see if

they follow the guidelines being established internationally by the ICRM,

with considerable Group input.

At present the program involves 12 utilities (with over 30 existing

nuclear power plants), three companies supplying most of the commercial

calibration sources, and (directly) one of the major organizations supply

ing measurement services.

L arge-Area R ad i

o

ac ti vi ty S ource Measu r ements (J. M . R. Hutchinson &

S. J. Bright)

A counting system for 238 Pu and 239 Pu x-ray measurements of large

area sources was designed and constructed. Its charac teri Stic s are being

examined and a computer program to be used in the calibration of largearea sources has been developed. This system and the two alpha-particle

measurement systems will be used in a traceability program with the

central U.S. Air Force calibration laboratory.

After the completion of the planning and investigative phase of the

alpha measurements traceability program in FY 1986, two 1 arge-area propor

tional counters, approximately 14-in by 10-in, have been constructed for

the purpose of calibrating large-area surface-moni tori ng standards to be

used by the U.S. Air Force in its programs for battlefield monitoring of

plutonium. Sources of plutonium on large-area mounts were also construct

ed and calibrated and issued to the Air Force.

One of the counting systems uses an i nternal - source proportional

counter and the other measures sources external to the counting volume

through a thin aluminized mylar window. The "internal" system is used to

measure sources in the lower activity ranges. These calibrated sources

are then used to establish the efficiency of the "external" counter which

is used to measure higher activity sources.

Radon Measurements System (J. M. R. Hutchinson & S. J. Bright)

An updated radon measurements system with four pulse-ionization

chambers and two Lucas cells has been designed. Parts have been ordered.

159
Division 536, Technical Activities (cont'd.)

In addition, as a result of reports of a discrepancy in radon calibrations

of major laboratories in the U.S., NBS has initiated an i ntercompari son in

a collaboration with these laboratories aimed at resolving this

di screpancy

.

Comparison of 2QI T1 Activity Measurements (B. M. Coursey,

A. T. Hirshfeld, & D. D. Hoppes)

Until the past year there were significant discrepancies (up to 7%)

in international activity calibrations for 73-hour-half-life 2 0

1

T1 , the

radionuclide most used in cardiac imaging. There were consequences for

international trade, and for patient dose and image quality for material

from different suppliers.

The NBS calibration had been established over 10 years ago, using

coincidences between the Auger electrons and x rays from the electroncapture decay detected in a pressurized proportional counter and the subsequent gamma rays selected with a Nal(Tl) spec trometer . The ratio of the

coincidence rate to the gamma-ray rate was a measure of the detection

efficiency in the proportional counter for a given pulse-height discriminator setting, and this setting was varied to generate points for an extrapolation of the proportional counter rate to 100 percent efficiency.

There are several complications in applying this established

technique to 201 T1. The gamma-ray probability is low (about 10 percent),

two strong x rays detected simultaneously can sum to about the gamma-ray

energy, electron capture in the atomic M shell produces pulses near the

detection limit, and corrections must be made for impurities which are always present.

These impurities also make routine measurements with simple instruments such as medical dose calibrators less accurate. For that reason,

most radiopharmaceutical manufac turers use gamma-ray spectrometry with

efficiency-calibrated systems for analyses. Unfortunately, current

tabulations of nuclear data list an old value for the probability of the

main gamma-ray which is some six percent different from the present NBS

value, although the same authors later published a number in much better

agreement.

Concurrent measurements on samples from a common solution at NBS,

NPL, and PTB in 1986 showed excellent agreement (<1% difference) with the

original NBS activity calibration, as preserved on our reference ionization chambers. A measurement of the gamma-ray probability per decay was also made at NBS, with a careful consideration of uncertainties. The

value of 0.0988 ± 0.008 (combined uncertainty as an approximation to one standard deviation) was submitted to the comparison organizer at NPL for

publication in a joint report.

160
Division 536, Technical Activities (cont'd.)

SRM 4354 (K. G. W. Inn & F. J. Schima)

A new natural -matrix envi ronmental -1 evel radioactivity Standard

Reference Material (SRM 4354) was issued. The freshwater-1 ake sediment

(Gyttja), very rich in organic matter (- 50% wt) , was certified for ten

radionuclides. The SRM is intended for use in tests of measurements of

environmental radioactivity contained in similar matrices or evaluating

analytical methods, or as a generally available calibrated "real" sample

matrix in i nterl abora tory comparisons.

Tritium Measurements (F. J. Schima and M. P. Unterweger)

The Group internal gas counters were used to calibrate several

submitted samples of tritium. Activity levels ranged from 1 pCi mL _1 to

5 yCi mL -1

. Uranium in Human Bone Ash (K. G. W. Inn)

NBS participated in an i nterl aboratory comparison for the determination of low levels of uranium in ashed human bone. The i ntercompari son was organized by the Environmental Measurements Laboratory (DoE). The

results of the i ntercompari son indicated some serious differences between

the laboratories and may indicate a need for future development of an SRM.

Xenon-Isomer Spectrometer (A. T. Hirshfeld, D. D. Hoppes, & F. J. Schima)

The xenon-isomer detector system, using conversi on-el ec tron

spectrometry of low-activity samples condensed on cooled silicon

detectors, is being redesigned with experimental 1 arge-area implanted

detectors in direct contact with a thermal conductor. This arrangement

should avoid thermal contact problems that arose with previous lowbackground ring-mounted detectors, while increasing the transmission of

gamma rays used to assay other xenon radionuclides.

Low-level Radioactivity Study of Calcium Fluoride Dosimetry Materials

(B. M. Coursey, K. G. W. Inn, & F. J. Schima)

NBS studied the low-level radioactivity content in calcium fluoride

dosimetry materials for the U.S. Naval Sea Systems Command. The purpose

of the study was to help them determine if there was excessive radionuclide content in dosimetry materials which may have caused high blank

values. The measurements indicated that the radioactivity content did not

account for the high blanks for the calcium fluoride materials.

161
Division 536, Technical .Activities (cont'd.)

Multilevel Anticoincidence System Design (L. L. Lucas)

The relevance of the new IEEE 488.2 standard to the design of 1 aboratory instrumentation was investigated, with a survey of present commercial

use of the 488 bus. It was suggested that experience gained in the application to anticoincidence and control -system design be used to produce an engineers' guide to aid others in the applying of the standard.

Cl osed-vessel Microwave Dissolution of Environmental Samples (K. 6. W.

Inn & S. J. Bright)

Because previous studies indicated open-vessel acid dissolutions of,

environmental samples were unreliable, an investigation was initiated to

investigate closed-vessel microwave dissolution techniques. The development of a reliable dissolution method is critical for all future

envi ronmental -1 evel radioactivity SRM efforts. Preliminary results are very encouraging.

Comprehensive Data Management (M. P. Unterweger)

A dBase III program was developed to enable final calibration reports

and SRM certificates to be generated from initial data with a minimum of

operator manipulation and hand entry. The program will also lead to realtime updating of SRM inventories, with eventual interfacing to the Health

Physics inventory data base.

Calibration of Germanium Spectrometry Systems (D. D. Hoppes, P. A. Hodge

& F. J. Schima)

In order to prepare for the reissue of SRMs 4275 and 4276, the longlived mixture of 125 Sb, 154 Eu, and 155 Eu popular for the calibration of

germanium spectrometry systems, three Group spec trometers are being recalibrated with radionuclides for which gamma-ray emission rates can be

established independent of past spectrometry measurements. Many of these

radionuclides are short-lived but are available with activity calibrations

through the NBS-CEA nuclear medicine program once a year.

Propagation of NBS Radioactivity Calibrations (J. M. Calhoun, B. M.

Coursey, & P. A. Hodge)

Traditionally, the basic calibration established at NBS for each

radionuclide is supplied to U.S. users through Standard Reference

Materials, with a variety of forms and activity levels available to suit

particular needs. Calibration services and special measurements are a useful supplement for cases where demand does not warrant SRM production.

162
Division 536, Technical Activities (cont'd.)

However, programs developed in recent years have increased confidence

in the calibrations of commercial suppliers; accurate data have been

developed which allow good activity measurements with gamma-ray spectrometers for which efficiency-energy relations have been established with

unique long-lived mixed-radionuclide SRMs; and techniques have been

developed for sufficiently accurate measurement of many radionuclides with

commercial liquid- scintillation counters and NBS tritium SRMs.

These factors, coupled with SRM prices that have been increased in an effort to support a greater fraction of the cost of the variety of basic

calibration and analysis techniques required, have led to gradual small

reductions in SRM sales and less general use of the calibration services.

However, there has been a correspond]' ng increase in the traceability

tests, especially through the new nucl ear-power-pl ant program.

In the period August 1, 1986 to July 31, 1987, the following actions

supplied NBS cal ibrations to users:

Total radioactivity SRMs distributed 792

Short-lived SRMs supplied under the USCEA(AIF)

program for nuclear medicine 202

Scheduled calibrations 24

Special measurements 36

Traceability tests for FDA,

NRC, and commercial firms 145

VI. X-Ray Physics Group

Performance Evaluations of DoD Radiological Inspection Systems (20 KeV to

16 MeV) (Jul ian H. Sparrow)

At the request of the Navy Department, this program carries out the

following tasks:

1) Measure and calibrate, every 12 to 18 months, the x-ray outputs

of approximately ten 16 MeV Linear Accelerators used for radiological

inspection systems by DoD and their contractors;

2) Propose radiological procedures to determine image quality

achieved during production and refitting inspection of missiles;

approximately every 6 to 12 months, perform an on-site audit of the

radiological image quality achieved at the various DoD facilities and

product manufac turers ; participate in the development of radiological

163
Division 636, Technical Activities (cont'd.)

penet rameters which are used as imaye quality indicators; and participate in new desiyn of a test specimen used to evaluate both imaye

quality and system performance for hiyh eneryy CT radioloyical

inspection systems;

3) Assist in the inteyration of old and new radioloyical methods,

(film, real-time, and tomoyraphy ) , so that imaye quality is adequate

for routine inspections; and

4) Propose radioyraphic equipment which can be used at the DoD

facilities and vendors to monitor the x-ray beam eneryy fluence and

beam position; and assist in the implementation of that equipment.

4-MeV Electron Van de Uraaff Accelerator (C. E. Dick)

Use of the 4 MeV electron Van de Uraaff accelerator has increased

with the applications of the pulsed beams to studies in pulsed radiolysis

and chemical kinetics. At the present, experiments are underway to determine the radiation chemistry associated with acid rain. In addition, the

dc electron beams are beiny used to examine the response of beta particle

detectors in standardized electron fields. Improvements to the facility

are continuiny with the construction of a double sector non-di spersi ve bendiny maynet system. This system will provide additional beam ports for

experimental proyrams while preserviny the pulse shape and beam position

for the pulsed electron beams. At present, the final components of this

system are under construction and installation will beyin shortly.

Diyital Eneryy Subtraction for Biomaterials (C. E. Dick)

The proyram to investiyate the efficacy of digital subtraction irnayiny is well underway. With the definition of the x-ray beams to be used

and the implementation of a new PC based imaye storaye and retrieval

system, irnayes of a diyital subtraction anyioyraphy (DSA) phantom are beiny recorded. This phantom which contains material that emulates soft

tissue, bone, and arterial blood vessels will be imayed with various

eneryy x-ray beams and the resultiny video irnayes from a 9-inch imaye

intensifier system will be analyzed usiny various imaye analysis and

manipulation alyorithms.

Pnotostiinul abl e Phosphors (C. E. Dick)

A proyram is beiny implemented to investiyate the properties of a new class of x-ray imayiny medium, photostimul ab le phosphors. These phosphors

have the property of storiny the x-ray imaye information in deep traps in

the phosphor material and then releasiny the trapped charye when stimulated with infrared radiation. Experiments are currently in the formative

stayes to investiyate the physical properties of these materials, includiny the x-ray interaction efficiency, the prompt eneryy release, the

164
Division 536, Technical Activities (cont'd.)

delayed fluorescence, and the resolution of the systems. In addition,

Monte Carlo calculations are underway to investigate some of these

phenomena.

Portable Dental X-Ray Imaging Systems (J. H. Sparrow, M. R. McClelland,

J. W. Motz)

The X-Ray Physics Group has completed prototypes of portable, dental

x-ray imaging systems for field use by the U.S. Army. The smallest prototype, which weighs approximately 16 pounds, is an analog imaging system

consisting of a carrying case with a six pound, 55 kilovolt x-ray source,

batteries, and self-developing dental x-ray films. A second prototype,

which weights approximately 45 pounds, is a non-film system consisting of

a carrying case with a real-time intra-oral x-ray image sensor, a framegrabber, a monitor, and the x-ray source described above. This second

system may be used either in an analog or digital format, and images may

be instantly displayed on the monitor or stored on tape, floppy disks, or different types of solid-state memories. Future efforts in the program

will be directed toward improvements in the x-ray intra-oral image sensor,

in the portable x-ray source, and in the image storage and display

equi pment.

Dosimetry of High-Energy Electron Beams (J. C. Humphreys)

A new project was initiated to explore various techniques for measuring absorbed dose, dose rate, and electron energy in a 25-40 MeV highintensity electron beam at the White Sands Missile Range (NM) linac. This

accelerator facility is utilized essentially 24 hours a day for hardness

testing of electronic semiconductor devices by DoD contractors. Because

of discrepancies of dosimetry results from internal White Sands measurements, NBS was asked to develop new methods for the measurement of the

linac electron beam charac ten Stic s. One possible design approach is the use of a multiple foil -array calorimeter with a total thickness greater

than the electron range. The temperatures of all foils would be measured

as a function of time after irradiation by a single pulse of electrons by

means of a fast scan multiplex data acquisition system. Thus, the entire

electron depth-dose profile would be determined by dynamically, yielding

both total absorbed dose and dose rate. The extrapolated range could then

be used to calculate the maximum electron energy. Development of such

portable calorimeter systems will enable NBS to provide routine on-site

calibration of industrial electron beam facilities. They will eventually

enable NBS to provide routine calibration irradiations of customer's

dosimeters with electron beams when such facilities become available at

NBS.

165
Division 536, Technical Activities (cont'd.)

High-Dose Radiation Calibration Services (J. C. Humphreys)

Documentation of these services has been developed which describes in

detail the various services available for the standardization of high

absorbed dose measurements of ionizing radiation (photons and electrons

only). The first internal report was published in October, 1986, and

described the irradiation facilities employed, the dosimeter handling and

analysis procedures and the assignment of uncertainties to all aspects of

the services. Final revisions of this documentation are nearly complete

and the published SP250 document should be available for public distribution shortly.

Industrial Radiology (R. C. Placious)

There is an ongoing program in the X-Ray Physics Group in standards

and methods for industrial radiology. These programs include (e.g.)

Standards for Quantitative Evaluation of X-Ray Image Quality at Very Low

and Very High Energies, Charac teri zati on of X-Ray Sources - Kilovoltage

and Unsharpness and Standards for Radiographic Film Processing and Storage

Of Radiographic Film. Some of this work is collaborative with industrial

laboratory based investigators.

Another effort relates to developing a long range program plan for

meeting some of the measurement needs of industrial users of real time

radiological systems engaged in the inspection of a large variety of

industrial materials and components. To this end, a workshop was organized and convened in April 1987 to discuss the NBS role.

VII. Dosimetry Group

Use of ionizing radiation is becoming ever more widespread in modern

society. The exposure of humans can be purposive (medical) or incidental

(occupational), but both require close control to ensure that the radiation is efficacious in the one case, and harmless in the other. Such

control can only be achieved with reliable measurement. With the

increased use and the improved knowledge of radiation effects, the need

for more accurate measurement is constantly increasing. The measurement

of ionizing radiation for the purpose of controlling a radiation effect

falls in the field of radiation dosimetry. The Dosimetry Group has the

responsi bil i ty for providing an up-to-date basis for reliable measurement

in dosimetry of ionizing radiation, principally in medicine and radiation

protection. This program involves: (1) establishment and maintenance of

the national primary dosimetry standards; (2) dissemination of the units

established by those standards by means of calibration services and

measurement quality assurance programs; (3) research in measurement technology as necessary for any part of the program; and (4) participation in

the relevant national and international activities of the community of

radiation users.

166
Division 536, Technical Activities (cont'd.)

X-ray and Gamma-ray Calibration and Measurement-Assurance Services (J. T.

Weaver, P. J. Lamperti, & E. L. Bright)

Calibration services for x-ray and gamma-ray measuring instruments

continues at approximately the same rate as last year. The number of TLD

badge irradiations has increased by a factor of two this fiscal year.

Measurement-assurance tests have been carried out with the five AAPM

therapy-level accredited calibration laboratories, with Battel le Pacific

Northwest Laboratories, Richland, WA and with the Department of Energy

Laboratory, Idaho Falls, ID. Satisfactory agreement was obtained with

these -1 abora tori es , although a small systematic difference was uncovered

with the AAPM 1 aboratories , which has not yet been satisfactorily

explained. In these measurement-assurance tests, the test equipment is

shipped to the participating laboratory, calibrated by the participant,

then returned to NBS for final calibration. Traceability to NBS is maintained by such a measurement test, without the necessity of returning the

local standard to NBS, unless the results of the measurement-assurance

test show it to be necessary.

The Navy thermoluminescence dosimetry (TLD) measurement-assurance

program, sponsored by the Naval Sea Systems Command, continues. NBS

receives boxes of 15 TLDs from the Naval Surface Weapons Center and irradiates 12 of them to known exposures with 137 Cs gamma rays. The boxes are dispatched to designated Naval units for readout, the results of which are returned to NBS for data reduction and comparison to NBS exposures. The

results are sent to the sponsoring agency, who schedules a retest or

rec al i brati on for any TLD readout instruments that indicate exposures that

differ from the NBS exposure by more than 13 percent. About 285 such

boxes, containing 3420 exposed dosimeters, were dispatched during FY87.

It is estimated at the time of writing that 14 brachytherapy sources

(small -size gamma-ray sources used in medicine and industry) will have

been calibrated during FY87.

The documentation of the NBS calibration procedures for x-ray and

gamma-ray measuring instruments, and also the documentation of the NBS

calibration procedures, equipment, standards and history for the brachytherapy sources, have been through the appropriate review and are in the

final stages of revision. About 100 copies of the above two documents

were made available for internal (NBS) use. Final publication will be in

the NBS Special Publication 250 series.

The Hewlett-Packard data-acqui si ti on system used with the x-ray and

gamma-ray instrument calibration ranges is obsolete and no longer supported, and a breakdown would interrupt the calibration services. As a result, work is underway to interface the DEC 1123 minicomputer with a current-model HP 3497A data-acqui si tion system using an IEEE-488 bus

167
Division 536, Technical Activities (cont'd.)

connection instead of a serial input. The DEC 1123 would then be used to

control essentially all aspects of the instrument calibration.

Another round of in-house capacitor comparisons has taken place,

utilizing four capacitors recently calibrated by the capacitance group at

NBS. These in-house comparisons have been improved by the interfacing of

a computer with a precision power supply and a precision digital voltmeter. The new technique provides superior statistical results and to a large degree eliminates human bias. Recalibration of the laboratory working standard barometer, and comparison of that with other laboratory

barometers, has been completed.

Assistance in use of the 60 Co and 137 Cs gamma-ray ranges was provided

to the Environmental Measurement Laboratory of the Department of Energy,

New York, NY for their special international i ntercompari son of TLDs.

Assistance was also provided to the X-Ray Physics Group and a guest

scientist from Israel for their study of the intensifying effects of

metallic screens in industrial radiography. Increased heavy use for radiation chemistry by other NBS groups continues on the vertical gamma-ray

ranges.

High-Energy Electron and Photon Measurement-Assurance Services

(C. G. Soares & E. L. Bright)

Users of medical linear accelerators for cancer teletherapy need

assurance that their machines are delivering the required radiation

dosage. To meet this need, NBS offers a measurement-assurance service

that involves mailing to the users passive dosimeters to be irradiated in

a prescribed geometry and returned to NBS for evaluation of the absorbed

dose delivered. For this service, ferrous-ferric (Fricke) dosimeters are

used at present. There were four mailings of Fricke dosimeters in FY87,

involving 62 sets of participants. Two batches of dosimeters were

prepared. In principle, each dosimeter can be used as many times as it

takes to accumulate 200 to 300 Gy (20 to 30 krad). In order to conserve

time, and thus cost to the participants, the tests are administered simultaneously to as many participants as the batch size permits. To help in

preparing summary reports and identifying trends, the test results from

the entire 20-year history of the service have been entered into a data

base.

Documentation of the NBS procedures for the Fricke measurementassurance service is complete and in the process of being published.

Standard Monoenergetic Electron Beams (C. G. Soares)

NBS has been requested by the radiation protection community to

establish standards for and assist in the development of methods of

measuring the beta-particle radiation fields that are found in nuclear

168
Division 536, Technical Activities (cont'd.)

power installations. Beta-particle detection instrumentation is currently

being calibrated at NBS usiny only broad-spec trum radionuclide sources. In order to determine, in detail, instrument response as a function of energy

NBS has developed a set of accel era tor- produced nearly monoenergetic electron beams. The beam monitoring and control system described in the

previous year's annual report has been completed. Test results indicate

that its use has reduced the random uncertainties in i nstrument-response

measurements from the previously unacceptable 10-15 percent to an acceptable level of less than 5 percent. The system's flexibility was demonstrated when a need for radiation-processi ng dose levels (10 kGy, 1 Mrad) was expressed. By moving the monitors away from the beam axis, it was possible to monitor dose rates of 10 Gy/s, showing that a seven-decade

dynamic range in dose-rate monitoring is possible with the system. Using

this modified arrangement, high-dose irradiations were performed for

Humphreys and McLaughlin of the X-Ray Physics and Radiation Chemi stry

Groups as well as for an outside user who paid for the service.

Beta-particle Source Calibration and Associated Measurement-Assurance

Services (J. S. Pruitt)

The NBS extrapolation chamber has been used to calibrate four

ophthalmic applicators for absorbed dose to water at the applicator

surface. Each calibration was accompanied by qual i ty-assurance measurements with the NBS applicator SN0258. The quality-assurance parameter is

the position of the high-voltage electrode obtained by extrapolating to zero air gap the measurements made at air gaps between 0.5 mm and 2.5 mm.

Since February of 1986, when qual i ty-assurance measurements were begun,

that position has varied by no more than 0.02 mm. In June of 1987, the source alignment mechanism was improved so that the variation of the highvoltage electrode position is expected to be even smaller in the future.

The PTW extrapolation chambers have been used for a variety of purposes, including cal ibration-at-a-di stance of sources owned by several

different customers. The first of these was a physically large source (44

cm x 44 cm x 7 cm) made from the dried coolant of a reactor at the Palo

Verde Nuclear Generating Station in Arizona. Preliminary investigations

in Arizona had shown that the principal beta-particle-emitting radionuclide was 124 Sb, which has a half-life of about 60 hours. Measurements

of dose rate were made over a period of about two weeks at several positions near the source and at several absorber depths.

A plaque source of "Tc was calibrated at distances of 0.5 cm, 4 cm,

and 10 cm. More recently, calibration of a complete set of AmershainBuchler beta-particle sources has been undertaken. This set of four

sources consists of the same radionuclides as the NBS set, two of

90$ r + 90y s arK| one edC h 0 f

204-jq ancj i47pm> These were calibrated at the

normal distances, the first three at a distance of 30 cm and the 147 Pm source at 20 cm.

169
Division 536, Technical Activities (cont'd.)

All of the source c al i brati ons-at-a-d i stance consist of current

measurements with a PTW extrapolation chamber, and are corrected for

perturba ti ons caused by the presence of the chamber, as well as for variations from reference conditions of time, altitude, and humidity. Most of

the eight chamber corrections have been well documented for the AmershamBuchler set of sources at the standard source distances, but considerable

time was spent determining the proper corrections for "Tc at the

distances used. (For the 124 Sb source, the dose rates were never larger

than 10 yGy/h (1 mrad/h) and the standard deviations ranged from 4% to

30%, too large to warrant investigating the exact size of corrections that

are normally no larger than 1%.).

The PTW extrapolation chambers have been used in a program to determine chamber side-scatter corrections for the three Amersham-Buchl er radionuclides at nonstandard distances. For 204 T1 and 147 Pm, the result

to date is verification of the published data at the standard distances,

but for 90 Sr +

90 Y, measurements have been completed for five distances

between 20 cm and 40 cm, showing that the correction varies from 0.45 to

0.29% per mm of air gap over that range.

When the Amersham-Buc hi er sources were delivered to N6S in January

1983, they had been calibrated in terms of absorbed dose to tissue at the

tissue surface, by the Physikalish Technische Bundesanstal t (PTB) of

Braunschweig, W. Germany. The fully corrected NBS surface calibrations of

these sources agree with the PTB calibrations within 4% for 147 Pm, 2% for

204 T1 , and 1% for 90 Sr +

90 Y.

Measurements with the 147 Pm source have shown that, during normal operation, the retracted shutter intercepts part of the beta-particle beam

during irradiation, even though it lies about 1 cm outside of the

truncated cone connecting source and chamber. This is caused by excessive,

air scatter, which makes the beam barrel -shaped rather than conical. When

the shutter is completely removed, the field is flat over an 8-cm diameter

at a distance of 20 cm. When the shutter is in place, but retracted to

one side, the dose rate varies by 5% across that central 8-cm area. Absorbed dose calorimetry (S. R. Domen)

Medical and industrial applications of ionizing radiation are quantified in terms of the physical quantity absorbed dose, which is the energy

absorbed per unit mass in the material of interest. The calorimeter,

which measures absorbed energy in terms of the temperature rise, is the

logical standard of absorbed dose. NBS has developed a series of calorimeters as part of a program to develop reliable national measurement

standards for absorbed dose. One of these NBS cal orimeters, the water

calorimeter, which measures the temperature rise due to radiation directly

in water, has aroused much interest, and has been studied in a number of

170
Division 536, Technical Activities (cont'd.)

standards laboratories and universities. One of the persistent problems,

which has not received adequate attention, is the effect of convection on

the accuracy of temperature readings by the tiny thermistors. An experiment was devised to study this phenomenon using controlled flow past

thermistors operated at various power levels. The results of this experiment will allow operation of water calorimeters under efficient conditions

and without loss of accuracy, when convection is present. A report of the

work is in preparation.

Preliminary tests of a calorimeter made of A-150 plastic (a tissue

substitute) have shown adequate behavior except for thermal drifts apparently caused by contact potentials at the connectors. Connectors with

gold-plated contacts are being prepared. The completed calorimeter will

be tested in the NBS 60 Co beam for comparison of calorimeter and

ionization-chamber measurements. A similar comparison will be made at

another institution using a beam of 15-MeV neutrons.

Dosimetry of High-Energy Photon and Electron Beams (L. J. Goodman, C. G.

Soares, & R. Loevinger)

It is important to test the adequacy of current clinical protocols to

provide accurate photon and electron dosimetry for applications to highenergy cancer therapy. These tests would compare measurements made with

ionization chambers calibrated according to prescribed protocols to

measurements performed with an absorbed-dose calorimeter. We propose to use the electron beam of the NBS racetrack microtron to produce collimated

beams of high-energy protons and electrons, which will simulate those

applied clinically to treat cancer.

A separate beam line will be used to transport the electron beam to a transmission window from which it will enter a target, filter, and collimator assembly. The electron beam current and energy required will range

from about 180 yA at 5 MeV to about 1 yA at 35 MeV. The apparatus which

has thus far been designed and constructed includes the target, filter,

and collimator assembly, a special alignment and support table for this

assembly, and a rolling table with a remote-control 1 ed translation platform for positioning the phantoms and dosimeters. Several of the beamline components have been ordered. Funding is being sought to purchase a water phantom with a three-dimension, remote-controlled translation system

and its computer for control and data analysis, to purchase the remaining

beam-line apparatus, and to install the equipment in a shielded room adjacent to the accelerator.

171
Division 536, Technical Activities (cont'd.)

Development of Dosimetry Standards for Neutron Therapy (L. J. Goodman,

D. M. Gilliam, S. R. Domen, J. J. Coyne, & R. S. Caswel 1 ) Neutron radiation therapy is being clinically tested at several

cancer treatment centers in the United States and at other centers worldwide. To facilitate the exchange of clinical information between treatment centers, it is essential that the U.S. neutron dosimetry standards be

accurate and consistent with the international standards system. The

dosimetry program, sponsored by the National Cancer Institute, aims at

improving the accuracy and consistency of absorbed-dose measurements for

neutron therapy by developing national dosimetry standards and providing

improved data on neutron interactions in tissue and tissue-like materials.

NBS will provide these standards as it has provided and continues to

provide similar standards for photons and electrons.

Tissue-equivalent ionization chambers, in combination with lowneutron-sensitivity gamma-ray dosimeters, are accepted as the most

reliable instruments for clinical neutron dosimetry. We have under study

such a system of instrumentation. Its accuracy will be assessed by

comparing it to other instruments of the same type and of different types.

Thus far, the NBS ionization chambers have been compared to a similar set

of dosimeters from the Bureau International des Poids et Mesures and to

instruments of other national standards 1 aboratories. At NBS we have also

favorably compared the ionization chamber dosimetry method of measuring

neutron kerma to a determination of this quantity made from measurements

of neutron fluence combined with calculated kerma factors. This latter

comparison will be repeated using monoenergetic 15-MeV neutrons, an energy

more appropriate for developing a neutron standard. A comparison between

the ionization chamber method and a tissue-equivalent calorimeter is also

planned using the intense 15-MeV neutron beam available at a remote site.

Agreement between the three independent methods and with the measurements

of other standards laboratories will assure the accuracy and consistency

of the U.S. dosimetry standards for neutron therapy.

Theoretical support for the experimental standards program is aimed

at improving the physical data and correction factors needed to interpret

the physical measurements. These data and factors include the mean energy

required to produce an ion pair, kerma factors, and mass stopping powers.

Reactor Dosimetry and Consultation at AFRRI (L. J. Goodman,

R. B. Schwartz, E. D. ft Garry, D. M. Gilliam, & C. M. Eisenhauer)

Work performed under this contract with the Armed Forces Radiobiology

Research Institute (AFRRI) aims to improve the accuracy and long-term

consistency of neutron and gamma-ray dosimetry at the AFRRI research

reactor by consultations with a group of NBS scientists and by providing

specific dosimetry services. This effort is needed to support the radiobiological studies at AFRRI because of the relatively frequent (approxi172
Division 536, Technical Activities (cont'd.)

mately 2-year) turnover of scientific military personnel at AFRRI. It is

essential that accurate dosimetry methods support the radiobiological

experiments in order to relate this research to similar work at other

1 aboratories.

During the past year we have designed and installed a 252 Cf radiation

source housed in a special shield for use in checking the large variety of

ionization chambers at AFRRI for proper operation. This source, which

emits neutrons by spontaneous fission, is necessary to test the neutron

response of the dosimeters used at the AFRRI reactor. Benchmark measurements of the AFRRI ionization chambers have begun and will be continued

after needed modifications to the check-source cask have been completed.

An improved monitoring system for the radiation fields produced in

the reactor exposure rooms has been designed. The fission chambers needed

to implement this system were designed, constructed, and installed.

Testing and calibration of these chambers is in progress.

To verify the accuracy of the AFRRI reactor dosimetry, and as a training exercise for new military dosimetrists at AFRRI, a comparison of

neutron and gamma-ray dosimetry in free air and in two sizes of monkey

phantoms was carried out. This work compared the instruments, measurement

techniques, and calculation procedures of the NBS and AFRRI scientists.

VIII. Office of Radiation Measurement

The function of the Office of Radiation Measurement is to promote the

dissemination to federal, state, and local radiation control programs, and

to the medical, industrial, and defense communities, of the measurement

standards and technology required for reliable measurement of ionizing

radiation. The Office assists the technical organizational components of

the Ionizing Radiation Division in monitoring the radiation measurement

needs of these national user groups, and in activities undertaken to meet

national needs. The latter include methods for improving the consistency

of field measurements with the national physical measurement standards,

through a national system of secondary standards 1 aboratori es. The Office

maintains liaison with organizations that conduct measurement-intensive

programs in the areas of radiation safety, energy, health, and environmental contamination. Examples are the Nuclear Regulatory Commission,

Department of Energy, Food and Drug Administration, Environmental

Protection Agency, Health Physics Society, and the Conference of Radiation

Control Program Directors. The Office participates in collaborative

programs with these organizations to satisfy specific measurement quality

assurance requi rements.

173
Division 536, Technical Activities (cont'd.)

Radon (R. Col 1 6 & J. M. R. Hutchinson)

The Office continued to collaborate with members of the Radioactivity

Group on projects that include upgrading and replacement of the primary

radon measurement system; continuing work on developing a transfer standard for radon flux density measurements; new calibrations of a Nal(TJl)

detector system for direct assay of radon samples contained in spherical

glass ampoules; and measurement intercomparisons with laboratories that

maintain an independent radon calibration capability.

Work on replacing the old primary radon measurement system has

started. Based on our specifications, four new pulse ionization chambers'

are being custom-built by Reuter-Stokes. All ancillary electronics for

power and signal processing and a computer for the system are being

assembled. The extensive gas handling and purification manifold was designed, and construction will begin shortly. The construction and

initial calibrations of the system will be completed in 12 to 18 months.

The Office provides oversight for the project to develop a large

surface area flux density standard. A 40-cm prototype is fully operational. Preliminary calibrations for the constrai ned flux density have been

completed; and the efficacy of performing a direct calibration for the

unconstrai ned flux density was demonstrated. The latter is an unexpected

significant technical achievement since it will allow use of the standard

without having to rely on the adequacy of a diffusion model for the

standard. Confirmatory calibrations under both constrained and unconstrained conditions continue.

A NaI(T£) well counter was cross calibrated against the primary radon

measurement system. This detector used in conjunction with spherical

glass ampoules was shown to be very reproducible and fairly independent of

geometry. It has a wide dynamic range and can be used for radon samples

from the picocurie level to a 100 nCi level. This system was used for a recent measurement intercompari son of all laboratories within the U.S.

that maintain an independent calibration capability.

Measurement Uncertainties (R. Col 16)

Significant progress on developing an international guidance document

for the treatment and reporting of measurement uncertainties was made in

the past year under the leadership of a member of the Office. The document is being developed by a joint international working group which

represents the International Standardization Organization, the

International Electrotechnical Commission, the International Bureau of

Weights and Measures, and the International Organization of Legal

Metrology. A first draft was completed in June, and presently is under

revision. The next version will be completed in the next few months and

then distributed to a larger audience for comment.

174
Division 536, Technical Activities (cont'd.)

Input and views of the US industrial metrology community are being

sought through an ad hoc advisory group of nearly 70 members. An all -day

meeting of this group was held at NBS to keep the US industry aware of the

international activities, as well as to encourage their participation in

the development and dissemination of the final guidance document.

Private-Sector Calibration Laboratories (E. H. Eisenhower, C. G. Jones, & H. T. Heaton)

In July 1987 the Executive Board of the Health Physics Society (HPS)

gave final approval to the policy, procedures, and criteria that will be

used in a program for accreditation of laboratories that calibrate ionizing radiation survey instruments. This program is an outgrowth of a workshop held by NBS in 1984. Since then the Office and the HPS collaboratively developed the criteria to be used for evaluation of candidate

1 aboratories. NBS is represented on the HPS Operations Group that is

responsible for carrying out the policies and procedures of the program,

including a review of quality assurance procedures used by candidate

laboratories and an on-site assessment of each laboratory. The Office

will conduct periodic proficiency tests of candidate and accredited 1 aboratories, beginning in early 1988. The entire program will be selfsupporting through fees paid by accredited 1 aboratories. It will initially be limited to x and gamma radiations, but is expected to expand to

other radiations in the future.

With the increasing number of secondary 1 aboratories , it will be

necessary to use the same instrument for testing the proficiency of

several laboratories without recalibration by NBS. Thus the Office is

developing procedures to monitor continued proper operation of the test

instrument before sending it to the next participant. This includes

developing quality control procedures for all NBS equipment used to monitor the test instrument.

The Office in cooperation with the Radiation Measurements Committee

of the CRCPD is revising the "Directory of Commercial Calibration Services

for Ionizing Radiation Survey Instruments". As part of the revision, the

results from a questionnaire were entered into data base files suitable

for analysis with DBASE. This allows specific searches of the services

offered by the calibration companies. The proposed final draft is awaiting any editorial changes by the Radiation Measurements Committee.

Federally-Owned Calibration Laboratories (E. H. Eisenhower & C. G. Jones)

In December 1986 representati ves of various federal departments and

agencies met at NBS to discuss the possibility of developing a program

that would lead to formal recognition of the competence of federally-owned

calibration laboratories. It was unanimously agreed that development

175
Division 536, Technical Activities (cont'd.)

should proceed, and that performance criteria should be prepared for a broad range of calibrations (i.e., survey instruments, x-ray diagnostic

instruments, dosimeter i rradiations, and source calibrations). A first

draft of those criteria was subsequently developed for secondary laboratories, and is now being refined. It is planned that criteria for

tertiary laboratories will be developed in the near future. Various

possibilities for formal recognition have been considered, including

accreditation under the NBS National Voluntary Laboratory Accreditation

Program (NVLAP). The Office is coordinating program development, leading

the preparation of criteria, will conduct proficiency tests, and will

participate in on-site evaluation of candidate secondary laboratories. . Departments and agencies actively involved are DOE, DOD, FDA, and FEMA,

represented by a total of 21 individuals from 18 laboratories.

State-Operated Calibration Laboratories (H. T. Heaton & E. H.

Ei senhower

)

The Office is continuing to provide technical assistance to five

state-operated calibration labs (IL, SC, WA, CA, and AR ) . These labs

provide calibrations of instruments used for diagnostic x-ray machine

compliance measurements and for x-ray and gamma-ray radiation protection

measurements. The lab in Springfield, IL continues to be accredited by

the Conference of Radiation Control Program Directors (CRCPD) for both

x-ray and gamma-ray calibrations. The lab in Seattle, WA is accredited by

the CRCPD for gamma-ray calibrations. Their x-ray machine and gamma

sources have been installed on a turntable mechanism to allow any of the

radiation sources to be used with the calibration bench. They are presently making the preliminary measurements necessary to characterize

the x-ray equipment. The lab in Columbia, SC has completed their protocol

for x-ray calibrations and is awaiting an on-site visit from the CRCPD as

the last step before accreditation. The lab in Sacramento, CA has been

simultaneously developing their x-ray and gamma-ray facilities. Emphasis

is now being placed on the x-ray facility. The measurements necessary to

characterize this equipment are nearly complete and the first draft of the

lab protocol for x rays has been written. The lab in Fayetteville, AR

continues to place major emphasis on neutron calibrations. Both bare and

moderated Cf sources are available at both high- and low-level calibration

facilities. This lab recently participated in a performance test using an instrument as the transfer standard. The results of the test showed an unexpectedly large deviation at the high-level facility. Further investigations attribute this deviation to a scatter problem. The results show

the importance of performance tests to help a lab discover unsuspected

problems in their calibration procedures.

176
Division 536, Technical Activities (cont'd.)

Instrument Calibration Computer Code (H. T. Heaton)

The computer code used to assist the state-sector labs in their

instrument calibrations and routine in-house QC programs has been field

tested for the past year by the CA lab. Their suggested changes are being

incorporated into the code. At the same time the code is being rewritten

from an interactive BASIC to a compiled BASIC. Also additional subroutines are being written to include more QC programs for the equipment used

in the calibration and for calibrating more types of instruments. The

code is specifically geared to the equipment common to the state-sector

labs and, in fact, the CA 1 ab is developing their protocol around the

computer code. Once all the state labs are using this code, it will be

much easier to monitor the problems in lab performance by having them

transmit the files containing their QC data for evaluation by Office

personnel. Finally, the code is being extended to include the procedures

necessary for the Office to monitor the instrument used to test the * secondary level 1 aboratories.

Fixed-Geometry Radiation Source-Detector System (C. G. Jones)

To allow laboratories that calibrate portable ionizing radiation

detection instruments to conduct proficiency tests, routine quality

control, and calibrations with greater efficiency, a prototype of a source/detector system is being designed and developed. This type of

system will ultimately be used in secondary laboratories for routine testing of the laboratory's demonstrated proficiency in calibrating radiation

protection instrumentation. This device, or jig, will be used to maintain

mechanically the correct position between the survey instrument being

calibrated and the radiation source being used for such calibrations. One

type of source/detector system that has been designed would enable the

interchange of radioactive sources within the jig to allow the user to

calibrate and test survey instruments for different radiation types,

energies, and intensities. This system is being designed to assure that

it will have the broadest potential range of uses and therefore maximum

util i ty

.

Environmental Dosimetry (H. T. Heaton, J. T. Weaver, & C. G. Soares)

This is a joint program between NBS and personnel from the DOE

Environmental Measurements Laboratory (EML) to determine potential effects

of the type of radiation used to calibrate environmental dosimeters. In the past EML has conducted 8 international intercomparisons of environmental dosimeters in which the participants sent in dosimeters to be exposed

to a known amount of radiation in a laboratory setting. EML has consistently found that those participants who use Cs to calibrate their readout

unit have a systematically lower result than those who use Co for their

calibration. This difference is independent of the type of radiation used

177
Division 536, Technical Activities (cont'd.)

in the EML lab to irradiate the dosimeters (Co, Cs, and Ra). This difference is just statistically significant and, if it really exists, there are potential implications for all dosimetry applications. To investigate

this effect, a special i ntercompari son was arranged in which the dosimeters will be irradiated to known amounts of radiation in Cs and Co beams.

The irradiations at NBS and EML have been completed and the dosimeters

returned to the participants for their readout. In addition to the i rra- diations done at NBS, and to act as a control, NBS submitted dosimeters as

a participant. These will be read out by our Dosimetry Group.

178
SPONSORED WORKSHOPS, CONFERENCES AND SYMPOSIA

Division b36. Ionizing Radiation

P. Cerutti , Chairman, M. G. Simic, 0. F. Nyyaard, Co-Chairmen, Second

Conference on Anti carci noyenesi s and Radiation Protection, Gai thersburg,

MD, March 9-12, 1987.

J. F. Weiss, Chairman, M. G. Simic, Co-Chairman, Perspective in Radioprotection, Bethesda, MD, March 13-14, 1987.

M. G. Simic, Chairman, C. von Sonntag, and J. F. Ward, Co-chairmen, 4th

International Congress on Oxygen Radicals, La Jolla, CA, June 27-July 4,

1987.

J. M. Calhoun and B. M. Coursey planned and conducted a workshop on "Design and Calibration of Ionization Chambers for use in Nuclear

Medicine" which was sponsored by the NBS Radioactivity Group, the

International Committee for Radionuclide Metrology, and the Center for

Devices, U.S. Food and Drug Administration, on November 19-20, 1986. This

workshop provided a forum for the designers of these chambers, pharmaceutical suppliers, commercial source manufacturers , and representati ves from

national standards laboratories, to discuss methods of improving the

accuracy of assays made in hospitals.

J. M. R. Hutchinson and the Low-level Techniques Group of the

International Committee for Radionuclide Metrology (ICRM) organized a two

and one-half day symposium, with Hutchinson as chairman, in Wurenlingen,

Switzerland on June 10 to 12, 1987. The symposium provided a forum for

the exchange of information regarding the current status of five areas of

concern to scientists in the field of low-level radionuclide metrology:

standards, quality control, regulatory concern, applications, and techniques. The meeting was hosted by the Swiss Federal Institute for Reactor

Safety. Thirty-nine papers were presented. The proceedings will be

published in Environment International.

K. G. W. Inn organized and conducted the 32nd Annual Conference on Bioassay, Analytical and Environmental Radiochemistry, at NBS, October 21-

23, 1986. The purpose of this conference was to bring toyether researchers and analysts from government, the pri vate-sector , the nuclear power

industry, contractors, and academia to openly and frankly discuss new,

improved, or even problem analytical methods, and to interpret subsequent

data and evaluate health and environmental implications. The scope of the

conference included in-vivo and in-vitro bioassay, analytical method

development, distribution and partition of radionuclides in the environment, and modeling and health significance of radionuclide pathways to

humans

.

179
INVITED TALKS

Division 536, Ionizing Radiation

Berger, M. J. and Seltzer, S. M., A series of lectures for the course

“Monte Carlo Transport of Electrons and Photons Below 50 MeV,"

International School of Radiation Damage and Protection at the Ettore

Majorana Center for Scientific Culture, Erice, Sicily, September 24 - October 3, 1987.

Bergtold, D. S., Alessio, H., Cutler, R. G., and Simic, M. G., “Measurement of Biomarkers for DNA Damage by GC/MS," Fourth International Congress

on Oxygen Radicals, LaJolla, CA, June 27-July 4, 1987.

Bergtold, D. S., "The Oxygen Effect in Radiation Biology," Fourth

International Congress on Oxygen Radicals, LaJolla, CA, June 27-July 4,

1987.

Calhoun, J. M., " NBS Measurements of Sample Geometry Effects on Ionization

Chamber Calibrations," ANS Winter Meeting, Washington, DC, November 18,

1986.

Caswell, R. S., "Neutron Dosimetry and Mic rodosimetry , Theory and Experiment," Institute of Atomic Energy, Beijing, China, June 6, 1987.

Caswell, R. S., "Neutron Energy Deposition in Biological Materials,"

Institute of Atomic Energy, Beijing, China, June 9, 1987.

Caswell, R. S., "Research and Standards Program of the Ionizing Radiation

Division of the National Bureau of Standards," Institute of Atomic Energy,

Beijing, China, June 9, 1987.

Caswell, R. S., "Neutron Dosimetry and Mic rodosimetry , Theory and Experiment," National Institute of Metrology, Beijing, China, June 10, 1987.

Caswell, R. S., "Research and Standards Program of the Ionizing Radiation

Division of the National Bureau of Standards," National Institute of

Metrology, Beijing, China, June 1 0, 1 987.

Caswell, R. S., "Research and Standards Program of the Ionizing Radiation

Division of the National Bureau of Standards," Beijing Oniversity,

Beijing, China, June 11, 1987.

Caswell, R. S., "Neutron Energy Deposition in Biological Materials,"

Research Institute of Xian Petroleum Exploration Instrument Complex, Xian,

China, June 16, 1987.

180
Division 536, Invited Talks (cont'd.)

Caswell, R. S., "Research and Standards Program of the Ionizing Radiation

Division of the National Bureau of Standards," Research Institute of Xian

Petroleum Exploration Instrument Complex, Xian, China, June 16, 1987.

Caswell, R. S., "Research and Standards Program of the Ionizing Radiation

Division of the National Bureau of Standards," Fudan University, Shanghai,

China, June 18, 1987.

Caswell, R. S., "Neutron Dosimetry and Microdosimetry, Theory and Experiment," Fudan University, Shanghai, China, June 18, 1987.

Col 16, R., "Measurement Uncertainties," Analytical Chemistry Seminar, NBS,

April 21, 1987.

Coll 6, R., "Measurement Uncertainties: Converging on an International

Consensus," Measurement Science Conference, Irvine, CA, January 29, 1987.

Domen, S. R., "Development, Investigation, and Status of an Absorbed Dose

Water Cal orimeter , " Conference on Application of Accelerators in Research

and Industry, Denton, TX, November 10-12, 1986.

Eisenhower, E. H. (with R. Col 16 and H. T. Heaton), "National Measurement

Quality Assurance Programs," 32nd Annual Conference on Bioassay, Analytical, and Environmental Radiochemistry, NBS, October 21, 1986.

Eisenhower, E. H., "Measurement Quality Assurance," 25th Hanford Life

Sciences Symposium, Richland, WA, October 21, 1986.

Eisenhower, E. H., "Status and Plans for a National System of Secondary

Calibration Laboratories," Department of Energy Workshop on Instrument and

Dosimeter Calibrations, Richland, WA, October 24, 1986.

Eisenhower, E. H., "Measurement Quality Assurance and Laboratory Accreditation for Ionizing Radiation," Region 3 Meeting of the National

Conference of Standards Laboratori es , Lexington Park, MD, January 21,

1987.

Eisenhower, E. H., "Measurement Quality Assurance through a National

System of Secondary Laboratories," Workshop and Symposium of the National

Conference of Standards Laboratories, Denver, CO, July 14, 1987.

Eisenhower, E. H.,

Assurance," Health

1987.

"The Role of Traceability in Measurement Quality

Physics Society Summer School, Pocatello, ID, July 16,

Heaton, II, H. T.,

Laboratories," HPS

July 14, 1987.

"Controlling the Calibration Process at Secondary Level

Summer School at Idaho State University, Pocatello, ID,

181
Division 536, Invited Talks (cont'd.)

Hoppes, D. D., "Ionizing Radiation Measurement Services at NBS," National

Conference of Standards Laboratories Workshop and Symposium, Denver, CO,

July 16, 1987.

Hubbell, J. H., "Industrial, Agricultural, and Medical Applications of

Radiation Metrology: Current Status and Prospects for the 1990's," 6th

Pacific Basin Nuclear Conference, Beijing, PRC, September 9, 1987.

Hubbell, J. H., "Survey of Photon Attenuation Coefficient Data 10 eV to

100 GeV and the Major Individual Processes for Interaction of Photon with

Atoms," Institute of Applied Physics and Computational Mathematics,

Beijing, PRC, September 10, 1987.

Humphreys, J. C., "ASTM Dosimetry Activities: A Progress Report," 6th‘

International Meeting on Radiation Processing, Ottawa, Canada, May 31 - June 5, 1987.

Jovanovic, S. V., and Simic, M. G., "Redox Properties of Oxy and Antioxidant Radicals," 4th International Congress on Oxygen Radicals, LaJolla,

CA, June 27-July 4, 1987.

Karam, L. R., "Radiation-Induced Cross-links in Biological Model Systems

(DNA and proteins)," 8th International Congress of Radiation Research,

Edinburgh, UK, July 15-19, 1987.

Karam, L. R., "Alcohol and Free Radicals," 1st Congress of the European

Society for Biomedical Research on Alcoholism, Paris, France, September

18-19, 1987.

Lucas, L. L., "Uncertainties Associated With the Calibration and Use of

NBS Pressurized 4tty Ionization Chamber A," American Nuclear Society Winter

Meeting, Washington Sheraton, Washington, DC, November 18, 1986.

McLaughlin, W. L., "Radiation Dosimetry," International Conference on Sterility Assurance, Travenol Laboratories, Round Lake, IL, September 17,

1986.

McLaughlin, W. L., "Radiation Sterility Assurance," International

Conference on Sterility Assurance, Travenol Laboratori es , Round Lake, IL,

September 18, 1986.

McLaughlin, W. L., "NBS Reference Standards and Traceability of High-Dose

Measurements in Electron Beams," IAEA Consultants Meeting on Electron

High-Dose Intercompari son. International Atomic Energy Agency, Vienna,

Austria, October 30, 1986.

182
Division 536, Invited Talks (cont'd.)

McLaughlin, W. L., "Dosimetry in the Radiation Treatment of Foods," World

Health Organization Working Group on Health Impact and Control Methods of

Irradiated Foods, Gesellschaft fUr Strahlen-und Umwel tforschung

,

Neuherberg, MUnchen, Federal Republic of Germany, November 18, 1986.

McLaughlin, W. L., "Electron Beam Dosimetry," 3M Seminar, 3M ECC Products

Laboratory, Burlington, MA, November 20, 1986.

McLaughlin, W. L., "Electron Beam Dosimetry With Thin Films," Seminar, GAF

Chemicals Corporation, Wayne, NJ, December 9, 1986.

McLaughlin, W. L., "Calibration of Thin-Film Dosimeters in Electron Beams

by Cal orimetry ," Accelerator Department Seminar, Ri s0 National

Laboratory, Roskilde, Denmark., November 11, 1987.

McLaughlin, W. L., "Dosimetry System," Irradiation Sterilization Seminar,

IOTECH, Inc., Thornton, CO, January 27, 1987.

McLaughlin, W. L., "Optical Waveguide Dosimetry," FEMA Special Facility

Seminar, February 23, 1987.

McLaughlin, W. L., "Chemical Dosimetry," Committee on Interagency

Radiation Research and Policy Coordination, Gaithersburg, MD, April 28,

1987.

McLaughlin, W. L., "Radiation Dosimetry for Sterility Control of

Pharmaceuticals," National Cancer Institute Seminar, Ft. Detrick, MD,

May 7, 1987.

McLaughlin, W. L., "Radiation Effects on Microbes and Natural Products,"

NIH, National Cancer Institute, Bethesda, MD, May 11, 1987.

McLaughlin, W. L., "A Thin-Film Recording Medium for Use in Food Irradiation," 6th International Meeting on Radiation Processing, Ottawa, Canada,

June 2, 1987.

McLaughlin, W. L., "Cellulose Diacetate Film Dosimeter," 6th International

Meeting on Radiation Processing, Ottawa, Canada, June 3, 1987.

McLaughlin, W. L., " Rad i oc hromic Dosimetry for Validation and Commissioning of Industrial Radiation Processes," 6th International Meeting on Radiation Processing, Ottawa, Canada, June 4, 1987.

Placious, R. C., "A Look at the Long Term Role for the National Bureau of

Standards in Real Time Radiology Standards," ASNT Topical Conference

Automating and Advancing Radiographic NDG, Wilmington, DE, August 11,

1987.

183
Division 536, Invited Talks (cont'd.)

Seltzer, S. M., " El ec tron-Breinsstrahl ung Space Shielding Calculations,"

LBL/DOE/NASA Workshop on High Energy Accelerator and Space Radiation,

Berkeley, CA (February 17-19, 1987).

Schrack, Roald A., "NBS Research on Resonance Neutron Radiography,"

Workshop on Neutron Resonance Radiography, Los Alamos, NM, July 27-29,

1987.

Simic, M. G., " Autoxidation of Linoleic Acid and Its Prevention by Antioxidants," University of California, Berkeley, CA, November 12, 1986.

Simic, M. G., "Mechanisms of Free Radical Damage to DNA Bases," Stanford

University, Stanford, CA, November 13, 1986.

Simic, M. G., "Mechanisms of Repair of Free Radicals by Sulfhydryls and

Implications for Radiation Protection," University of California, San

Francisco, CA, November 14, 1986.

Simic, M. G., "Chemistry of Irradiated Foods," CIRRPC, Washington, DC,

December 1, 1986.

Simic, M. G., "Free Radical Mechanisms of DNA Damage," Center for Devices

and Radiobiological Health, FDA, Rockville, MD, January 9, 1987.

Simic, M. G., "Repair Mechanisms of DNA Damaged by Free Radicals,"

Pharmacology Dept., University of Southern California, Los Angeles, CA,

February 19, 1987.

Simic, M. G., "Electron vs. H-atom Transfer in Chemical Repair," 2nd

International Conference on Anticarcinogenesis & Radiation Protection,

Gaithersburg, MD, March 8-12, 1987.

Simic, M. G., "Mechanisms of Anticarcinogenesis," American Industrial

Health Council, Washington, DC, March 25, 1987.

Simic, M. G., "Chemistry of Irradiated Food," American Institute of

Physics Annual Meeting, April 21, 1987.

Simic, M. G., "Post-i rradiation Dosimetry," CIRRPC, Gai thersburg, MD,

April 28, 1987.

Simic, M. G. and Jovanovic, S. V., "Interaction of Vitamin E and Physiological Antioxidants," 4th International Congress on Oxygen Radicals, La

Jolla, Ca, June 27-July 4, 1987.

Unterweger, M., "Ionization Chambers in the National Bureau of Standards

Radioactivity Group," ANS Winter Meeting, Washington, DC, November 11,

1986.

184
PUBLICATIONS

Division 536, Ionizing Radiation

Abdel -Rahim, F., Eid, S. A., Souka, N., and McLaughlin, W. L., The

Radiolysis of Bromophenol Blue In Aqueous Solutions, Radiat. Phys. Chem.

27, 211-217 (1986).

Barnea, G. and Dick, C. E. , Coupled Electron/Photon Monte Carlo Calculations of X-Ray Scattering with Applications in Industrial Radiography, NDT

International _20_, 111 (1987).

Barnea, G. , Berger, M. J. , and Seltzer, S. M., Optimization Study of

Electron Bremsstrahl ung Shielding for Manned Spacecraft, J. Spacecraft 24,

158-161 (1987).

Behrens, James W., Ma , Hongchang, and Wasson, Oren A., Advances in the Use

of 3 He in a Gas Scintillation Counter, Trans. Am. Nucl . Soc . 5_3, 163

(1986).

Berger, M. J. and Hubbell, J. H. , XCOM: Photon Cross Sections on a Personal Computer, NBSIR 87-3597 (1987).

Calhoun, J. M., Paras, P., Comer, F. D., Coursey, B. M., and Golas, D. B.,

Evaluation of Radionuclide Dose-Cal i brator Measurements, Trans. Am. Nucl.

Soc. 53, 18 (1986)

.

Calhoun, J. M. , Radioactivity Calibrations with the NBS "4tt" Gamma

Ionization Chamber and other NBS Radioactivity Calibrations Capabilities,

NBS SP250-10 (1987).

Calhoun, M., Golas, D. B., and Harris, S. , Effects of Varying Geometry on Dose Calibrator Response: Cobalt-57 Techneti um-99m, J. Nucl. Med. 28^, No.

9, 1478 (1987).

Calhoun, J. M., NBS Measurements of Sample Geometry Effects on Ionization

Chamber Calibrations, Trans. Am. Nucl. Soc. _53, 21 (1986).

Carlson, A. D., Wasson, 0. A., Li sowski , P. W., Ullmann, J. L., and Hill,

N. W., Measurements of the 235 U(n,f) Cross Section in the MeV Energy

Region, Bull. Am. Phys. Soc. _32> 1035 (1987).

Caswell, R. S., Coyne, J. J., Gerstenberg, H. H., and Schwartz, R. B.,

Refinement of Neutron Energy Deposition and Microdosimetry Calculations,

Proceedings of the International Conference on Fast Neutron Physics , Dubrovnik, Yugoslavia, 122-134 (1986).

185
Division 536, Publications (cont'd.)

Chang, C., Sei czer, S. M., and Wilson, J. W., Effects of Backing Plates on

the Electron Exposure of Thin Polymer Films, NASA Technical Memorandum

88995 (1986).

Col 16, R., and Karp, P., Measurement Uncertainties: Report of an International Working Group Meeting, NBS J. Res. _92_, 243-244 (1987).

Coursey, B. M., Hoppes, D. D., Schima, F. J., and Unterweger, M. P., The

Standardi zati on of Samarium-153, Int. J. Appl . Radiat. Isot. _38, No. 1,

31 -34 (1987).

Creagh, D. C., and Hubbell, J. H. , Problems Associated with the

Measurement of X-Ray Attenuation Coefficients. I. Silicon. Report on the

International Union of Crystal 1 ography X-Ray Attenuation Project, Acta . Cryst. A43, 102-112 (1987).

Domen, S. R., Advances in Cal orimetry for Radiation Dosimetry, The

Dosimetry of Ionizing Radiation , Vol . II, K. R. Kase, B. E. Bjarngard, and

F. H. Attix, eds., Academic Press (1987)

Domen, S. R. and Ba, W.-Z., Polystyrene Absorbed-Dose Rate Calorimeter,

Nucl . Instr . Meth. Phys. Res. B24/25 , 1054-1057 (1987).

Domen, S. R., Comment on "Convection Currents in a Water Cal orimeter"

,

Phys. Med. Biol. 31, 1166-1168 (1986).

Dooley, M., Goodman, L. J., Zeman, G. H., Schwartz, R. 8., Eisenhauer,

C. M. and Blake, P. K. , Ionization Chamber Intercomparisons in Mixed

Neutron and Gamma Ray Radiation Fields by National Bureau of Standards and

Armed Forces Radiobiology Research Institute, AFFRI TR86-3 (1986).

Duvall, K. C., Development of a Standard 2.5-MeV Neutron Source, Nucl.

Instrum. Meth. Phys. Res. B24/25 , 893-896 (1987).

Eisenhauer, C. M., and Spencer, L. V., Approximate Procedures for

Calculating Protection from Initial Nuclear Radiation from Weapons, NBSIR

87-35U7 (1987).

Eisenhower, E. H. , Measurement Quality Assurance through a National System

of Secondary Laboratories, Proceedings of the Workshop and Symposium of

the National Conference of Standards Laboratories (1987).

Eisenhower, E. H., The Role of Traceability in Measurement Quality

Assurance, Syllabus of the Health Physics Society Summer School (1987).

Eisenhower, E. H., Glossary of Terms and Definitions for Radiographic

Testing, Military Standard 369 (1987).

186
Division 536, Publications (cont'd.)

Heaton, II, H. T., Controlling the Calibration Process at Secondary Level

Laboratories" , Proceedings of 10th Annual Health Physics Society Summer

School (1987).

Hoppes, D. D. , Coursey, B. M., Schima, F. J., and Yang, D. , National

Bureau of Standards Decay-Scheme Investigations of Stronti um-82-

Rubidium-82, Appl . Radiat. Isot. _38, No. 1, 195-203 (1987).

Hoppes, D. D., NBS Ioni zi ng-Rad i a ti on Measurement Services, Proc. of 1987

NCSL Conf. (1987).

Hubbell, J. H. , Gerstenberg, H. M., and Salamon, E. B., Bibliography of

Photon Total Cross Section (Attenuation Coefficient) Measurements 10 eV to

13.5 GeV, NBSIR 86-3461 (1986).

Hubbell, J. H., Invited book review of The Dosimetry of Ionizing Radiation

(Kase, Bjarngard and Attix, eds., Academic Press 1985), in Appl. Radiat.

Isot. 38, 77 (1987).

Hutchinson, J. M. R., Mullen, P. A., and Colle, R., The NBS Radon-i n-wa ter

Standard Generator, Nucl . Inst, and Meth. in Phys. Res. A247, 385-389,

1986.

Hutchinson, J. M. R., Inn, K. G. W., Parks, J. E., Beekman, D. W., Spaar,

T. M., and Fairbank, W. M., Investigation of Matrix Effects and Isotope

Dilution in SIRIS Measurement of Uranium in Soils, Nucl. Instr. and Meth.

in Phys. Res. B26, 578-584, (1987).

Johnson, Ronald G. , Mul ti -Particl e Accelerator for Neutron and High-LET

Radiation Research, Proceedings of the IAEA Advisory Group Meeting on Properties of Neutron Sources, held in Leningrad, USSR, June 9-13, 1986,

IAEA-TECD0C-410, Properties of Neutron Sources , pp. 29-35, Publ . by IAEA,

Vienna (1987).

Jovanovic, S. V., and Simic, M. G. , Mechanism of OH Radical Reaction with

Thymine and Uracil Derivatives, J. Am. Chem. Soc . 108, 5968-5972 (1986).

Kalla, S. L., Conde, S., and Hubbell, J. H., Some Results on Generalized

Elliptic-Type Integrals, Applicable Anal y si s _22 273-287 (1986).

Kronenberg, S., McLaughlin, W. L., and Seibentritt, Jr., C. R.,

Radiological Instrument, US Patent No. 4,631,414 (1986).

Kronenberg, S., McLaughlin, W. L., and Siebentritt, C. R., Radiochromic

Waveguides for Gamma and Fast Neutron Dosimetry, Proceedings of Meeting of

NATO Panel VIII Meeting (1986).

187
Division 536, Publications (cont'd.)

Kronenberg, S., McLaughlin, W. L. and Siebentritt, C. R., TissueEquivalent Radiochromic Waveguide Dosimeters for X-and Gamma Rays and Fast

Neutrons, Nuclear Tracks 12, 561-564 (1986).

Lett, J. T., Keng, P. C., and Bergtold, D. S., Effects of Heavy Ions on Rabbit Tissues: Induction of UNA Strand Breaks in Retinal Photoreceptor

Cells by High Doses of Radiation, Radiation and Environmental Biophysics

26, 23-26 (1986).

Li sowski , P. W., Ullmann, J. L. , Balestrini, S. B., Carlson, A. D.

,

Wasson, 0. A., and Hill, N. W., Neutron Induced Fission Cross Section

Ratios for 235 *238^ ancj 2 3 7 |\|p f rom i 4 qq me v, Bull. Am. Phys. Soc . 3_2>

1035 (1987).

Loevinger, R. , Budinger, T. F., and Watson, E. , MIRD Primer for Absorbed

Dose Cal cul ati ons , The Society of Nuclear Medicine, New York (1987).

Ma, Hongchang, Behrens, J. W., and Wasson, 0. A., Optimization of Light

Production and Collection for the NBS 3 He Gas Scintillation Counter, Bull.

Amer. Phys. Soc. 32., 1045 (1987).

McDonald, J. C. , and Domen, S. R., A-150 Plastic Radiometric Calorimeter

for Charged Particles and Other Radiations, Nucl . Instr. Meth. Phys. Res.,

A252 , 35-40 (1986).

McLaughlin, W. L. , Comprehensive Dosimetry for Food Irradiation,

Proceedings Health Impact and Control Methods of Irradiated Foods,

WH0/BGA/GSF, Published by World Health Organization, Geneva (1986).

McLaughlin, W. L., Book Review: Safety and Wholesomeness of Irradiated

Foods, Int. J. Radiat. Biol. _50_, 753-754 (1986).

Nath, R., Anderson, L., Jones, D., Ling, C., Loevinger, R.,

Williamson, J. , and Hanson, W., Specification of Brachytherapy Source

Strength — A Report of Task Group 32, Published for the AAPM by the

American Institute of Physics (1987).

Placious, R. C., Eitzen, D. G., Swartzend ruber, L. D., and Mordfin, L.,

Nondestructive Evaluation of Monolithic Transportation Casks for Spent

Nuclear Fuel, Sandia National Laboratories Report, SAND 86-7158 (1987).

Pruitt, J. S., Calibration of Beta-Particle-Emitting Ophthalmic

Applicators, NBS SP 250-9 (1987).

188
Division 536, Publications (cont'd.)

Sal Oman, E. G. and Hubbell, J. H., Critical Analysis of Soft X-Ray Cross

Section Data, Nucl . Instr. Meth. A255 , 38-42 (1987).

Schima, F. J., Fu, C., Yang, M. H., and Thonnard, N., Silicon as an Implantation Host for Radioactivity Studies, Bull. Am. Phys. Soc . jU, 798

(1986).

Schrack, Roald A., Measurement System for the 235 U(n,f) Reaction from

Thermal to 1 keV, Bull. Amer. Phys. Soc. 32_ 1046 (1987).

Schroder, Ivan, Gilliam, David M., Carlson, Allan D. , Bright, Sandra W.,

and Hutchinson, J. M. Robin, International 235 U Fission Foil Mass

Intercompari son , Trans. Am. Nucl. Soc. _53_, 473-474 (1986).

Schwartz, R. B., NBS Measurement Services: Neutron Personnel Dosimetry,

NBS Special Publication 250-12 (July 1987).

Seltzer, S. M., Conversion of Depth-Dose Distributions from Slab to Spherical Geometries for Space-Shielding Applications, IEEE Trans, on Nucl.

Sci. NS-33, 1292 (1986).

Seltzer, S. M. , Calculated Response of a 5.5 x 5.5 cm High-Purity Ge

Detector to Gamma Rays with Energies up to 20 MeV, NBS I R -97 - 3 548 (1987).

Seltzer, S. M., and Berger, M. J., Energy Deposition by Electron,

Bremsstrahl ung and 60 CO Gamma-Ray Beams in Multi-Layer Media, Int. J.

Appl . Radiat. Isot. 38, 349-364 (1987).

Simic, M. G., and Hunter, E., Reaction Mechanisms of Peroxyl and CCentered Radicals with Sulfhydryls, J. Free Radical in Biol. & Med. 2, 227

(1986).

Simic, M. G. and Taylor, K. A., Free Radical Mechanisms of Meat Oxidation,

in Flavor Quality of Fresh Meat: Warmed-Over Flavor , eds. A. J. St-Angel o and M. E. Bailey, Academic Press (1987).

Simic, M. G., Mechanisms of Chemical Repair, in Oxygen and Sulfur Radicals

in Chemistry and Medicine, eds. A. Breccia, M. A. J. Rodgers and G.

Semerano, Lo Scarabeo, Bologna 1986, 227-242 (1987).

Soares, C. G., Bright, E. L., and Ehrlich, M., Irradiation of FerrousFerric Dosimeters (Fricke Dosimetry) , NBS SP 250-4 (1987).

Wang, R., Berger, M. J., and Seltzer, S. M., Calculation of Electron

Multiple Scattering, Bull. Am. Phys. Soc. 32 , 765 (1987).

189
Division 536, Publications (cont'cL)

Wasson, 0. A., Progress in the Detection of Low-Energy Neutrons, Neutron

Induced Reactions , pp. 399-411 , Proceedings of the 4th International

Symposium on Neutron-Induced Reactions, Smolenice, Czechoslovakia, June

17-21, 1985, edited by J. Kristiak and E. 8etak (1986).

Wasson, Oren A., Recent Fission Cross Section Standards Measurements,

Proceedings of the XVth International Symposium on Nuclear Physics-Nuclear

Fission , Gaussig, G.D.R., Nov. 11-15, 1985, edited by D. Seeliger, K.

Seidel, and H. Martin, pp. 1301 -139 (April 1986).

190
PUBLICATIONS IN PREPARATION

Division 536, Ionizing Radiation

Abdel -Rahim, F., Zahran, A. H. Ezzedin, F. M., and McLaughlin, W. L.,

Manganese-Activated "Cabal" and "Libal" Glasses for High-Dose Dosimetry SP

(to be submitted to Radiation Physics and Chemistry).

AlSheikhly, M., and Simic, M. G., Inhibition of Autoxidation by Vitamin E and Bilirubin. "Anticarcinogenesis and Radiation Protection" eds. P. Ceruitti, 0. F. Nygaard, M. G. Simic, Plenum (in press).

AlSheikhly, M., and McLaughlin, W. L., A Pulse-Radiolysis Study of the

Mechanism of Radiolytic Dye Formation in Liquid Solutions of Hexa (hydroexyethyly) Pararosanil i ne Cyanide (to be submitted to the Journal of the

American Chemical Society).

Barrett, J. H. , Glover, K. M., McLaughlin, W. L. , Sharpe, P. H. G. , Watts,

M. J., and Whittaker, B., Intercompari son Studies of Gamma-Ray Absorbed

Dose Measured by Radiochromic Dye Films and Red 4034 Perspex (planned for

Applied Radiation & Isotopes).

Behrens, J. W. , On the Systematics of Neutron-Induced Fission Cross

Sections for Nuclear Excitation Energies Above the Fission Barrier, Part

One: Uranium, Neptunium, and Plutonium Isotopes (in preparation, to be

published in Nuclear Science and Engineering).

Behrens, J. W., Ma, Hongchang, Wasson, 0. A., Westerfeldt, Chris, and

Lewis, Harold, Development of a

3 He Gas Scintillation Counter for Measuring the Intermediate Neutron Energy Range from 1 keV to 3 MeV (in preparation, to be published in Nuclear Instruments and Methods).

Berger, M. J., Mic rodosimetric Event-Size Distributions in Small Sites in

Water Vapor Irradiated by Protons, to be submitted to Phys. Med. Biol.

Berger, M. J., ETRAN-Experimental Benchmarks, Proceedings of the Course on Monte Carlo Transport of Electrons and Photons Below 50 MeV , International

School of Radiation Damage and Protection, Ettore Majorana Centre for

Scientific Culture, Erice, Italy, Sept. 24 - Oct. 3, 1987.

Berger, M. J., and Wang, R., Notes on the Treatment of Multiple-Scattering

Angular Deflections and Energy -loss Straggling in Electron Transport

Calculations, Proceedings of the Course on Monte Carlo Transport of

Electrons and Photons Below 50 MeV , International School of Radiation

Damage and Protection, Ettore Majorana Centre for Scientific Culture,

Erice, Italy, Sept. 24 - Oct. 3, 1987.

191
Division 536, Publications in Preparation (cont'd.)

Berger, M. J., Electron Stopping Powers for Transport Calculations, Electron Impact Ionization, Proceedings of the Course on Monte Carlo Transport

of Electrons and Photons Below 50 MeV , International School of Radiation

Damage and Protection, Ettore Majorana Centre for Scientific Culture,

Erice, Italy, Sept. 24 - Oct. 3, 1987 (in press).

Bergtold, D. S., Keng, P. C., and Lett, J. T., The Loss of Structural

Integrity in Rabbit Sensory Cell DNA During Aging (in preparation).

Brenner, D., Coyne, J. J., and Menzel , H., The Evaluation of Non-Elastic

Neutron Cross Sections on Carbon above 14 MeV, Nucl . Sci. Eng. (in

press)

.

Coursey, B. M., and Grau Malonda, A., Standardization of Isomerictransition Radionuclides by Liquid Scintillation Efficiency Tracing with

Hydrogen-3: Application to Techneti um-99m (submitted to I JR A I Part A).

Coursey, B. M., and Grau Malonda, A., Calculation of Beta-Particle

Counting Efficiency for Liquid Scintillation Systems With Three Phototubes

(submitted to Int. J. Appl . Radiat. Isot.; Part A).

Coursey, B. M., Ballaux, C., and Hoppes, D. D., 109 Pd and 109 Cd Activity

Standardization and Decay Data (submitted to Int. J. Rad. Appl. Instrum.,

Part A)

.

Coyne, J. J., Gerstenberg, H. M., and Hennen, L. A., Secondary Charged

Particle Spectra and Kerma Calculations, Proceedings of IAEA Advisory

Group Meeting on Nuclear and Atomic Data (i n press)

.

Creagh, D. C., and Hubbell, J. H., X-Ray Absorption Coefficients, Section

4.2.4 in International Tables for X-Ray Crystallography, Vol . C. (new

series) (in preparation)

.

Desrosiers, M. F. , and Simic, M. G. , Post-Irradi ati on Dosimetry of Meat by

ESR Spectroscopy of Bones (submitted to J. Agr. Food Chem.).

Dias, M. S., Carlson, A. D., Johnson, R. G., and Wasson, 0. A.,

Application of the Dual Thin Scintillator Neutron Flux Detector in a 235 U(n,f) Cross Section Measurement (in preparation)

.

Domen, S. R., Convective Velocity and Temperature Response of a Thermistor

in Water (to be submitted to Phys. Med. Biol.).

Duvall, K. C., Seltzer, S. M., Soares, C. G., and Rust, B. W., Dosimetry

of Monoenergetic High-Energy Photon Fields by Nal Spectrometry, Nuclear

Instruments and Methods (in prepara ti on)

.

192
Division 536, Publications in Preparation (cont'd.)

Duvall, K. C., Seltzer, S. M., Ehrlich, M., Soares, C. G., Rust, B. W,,

and Wasson, 0. A., Charac teri zati on of High-Energy Photon Fields for

Dosimetric Purposes by Nal Pulse-Height Analysis, Proceedings of the

Course on Monte Carlo Transport of Electrons and Photons Below 50 MeV , International School of Radiation Damage and Protection, Ettore Majorana

Centre for Scientific Culture, Erice, Italy, Sept. 24 - Oct. 3, 1987 (in

press)

.

Eisenhauer, C. M. , Schwartz, R. B., and McCall, R. C., Effect of Air

Scatter on Calibration of Instruments for Detecting Neutrons, Radiation

Protection Dosimetry (in press).

Eisenhauer, C. M. and Hunt, J. B., Anisotropic Neutron Emission from a 252 Cf Source, submitted to Radiation Protection Dosimetry.

Eisenhauer, C. M. and Schwartz, R. B., Review of Scattering Corrections

for Calibration of Neutron Instruments, Nucl . Sci. Eng. (in press).

Eisenhower, E. H., Measurement Quality Assurance for the Testing of

Portable Health Physics Instruments (in preparati on)

.

Eisenhower, E. H., Measurement Quality Assurance, Proceedings of the 25th

Hanford Life Sciences Symposium, to be published as a special issue of

Health Physics.

Farahani , M. , and McLaughlin, W. L. , Radiochromic Dye Dosimeter Solutions

as Standard Reference Measurement Systems, (planned for Applied Radiation

& Isotopes).

Gerstenberg, H. M., and Coyne, J. J., Calculated Mic rodosimetric Energy

Distribution Spectra and Their Use to Indicate Neutron Source Quality, to

be published in Proceedings of the Int. Congress of Radiat. Research , Edinburgh (1987).

Ghose, A. M., Bradley, D. A,, and Hubbell, J. H. , Radiation Field from a Rectangular Plaque Source: Critique of Some Engineering Approximations

(in preparati on)

.

Gilliam, D. M. , Hocken, D. G. , Humphreys, J. C., and Lamaze, G. P.,

Neutron Sensitivity of Li F Chip Gamma Dosimeters at Megagray Doses,

Proceedings of 6th ASTM-EURATQM Symposium on Reactor Dosimetry , Jackson

Hole, WY, May 31-June 5, 1987 (to be published as ASTM-STP, in press).

Goodman, Leon J., Correction to "Calorimetric Measurement of the Carbon

Kerma Factor for 14.6-MeV Neutrons", by J. C. McDonald (submitted to Rad.

Res.)

.

193
Division b36, Publications in Preparation (cont'd.)

Goodman, Leon J., A Soft-Tissue-Substitute Liquid (submitted to Health

Phys. ).

Grundl, J., Derivation of Neutron Exposures Parameters from Threshold

Detector Measurements , Proc. of the ASTM-EURATUM Symposium on Reactor

Dosi metry (in press).

Hirshfeld, A. T., and Hoppes, D. D., Anticoincidence Measurements of the

Contribution of the 17-ms. State in 75 Se Activity Calibrations (in preparati on ) . Humphreys, J. C., Hocken, D. G. , and McLaughlin, W. L., NBS Hi yh-Dose

Radiation Calibration Service, NBS SP-BbU-11 (in press).

Humphreys, J., Farrar, H., and Fairand, B. P., ASTM Dosimetry Activities:

A Progress Report, Journal of Radiation Physics and Chemistry (in press).

Hutchinson, J. M. R., Inn, K. G. W., and Briyht, S. J., Low-level

Standards at the National Bureau of Standards, Proc. of 1st Int. Summer

School on Low-level Radioactivity Measurements , Dept, of Atomic and Nucl.

Phys., University of Seville, Spain, 1 y 87 (in press)

.

Hutchinson, J. M. R., A1 pha-parti c 1 e Calibrations at NBS, NBS SP 3bU-b (in

press )

.

Hutchinson, J. M. R., Inn, K. G. W., Fairoank, W., Huneke, J. C., Parks,

J., Evaluation of Two Mass Spect rometri c Based Techniques for the Direct

Measurement of Environmental Radi oacti vi ty (to be submitted to

Envi ronmental Internati ona I )

.

Hutchinson, J. M. R., and Briyht, S. J., The NBS Larye-Area A1 pha-Parti cle

Counting Systems (in preparati on )

.

Inn, K. G. W., State of the Art Bioassay Procedures to Detect and Quantify

Previous Exposures to Radiation, URAU Subcommittee report to the

National Cancer Institute and the U. S. Conyress.

Inn, K. G. W., The National Bureau of Standards Natura I -Mat ri

x

Envi ronmental - I evel Radi oacti vi ty Standard Reference Materials (submitted

to Int. J. Radioanaly. and Nucl. Chem.).

Inn, K. G. W., Coursey, B. M., Fassett, J. D., Raman, S., and Walker, R.

L., Development of the 10 Be/ 9 Be Isotopic NBS Standard Reference Material

(to be published in Nucl. Inst, and Methods in Phys. Research B).

Inn, K. G. W., The NBS Fresh Water Lake Sediment Envi ronmenta 1 -level

Radioactivity SRM (to be published in Int. J. Radioanaly. and Nucl.

Chem. )

.

194
Division 536, Publications in Preparation (cont'd.)

Inn, K. G. W., Raman, S., Coursey, B. M., Fassett, J. D., and Walker, R.

L. , Development of the 10 Be/ 9 Be Isotopic NBS SRM (to be published in Nucl

Inst, and Methods in Physics Res. B.).

Johnson, Ronald G., Detectors for Neutron Scattering in the eV Region, to

be published in Nuclear Instruments and Methods.

Karam, L. R., and Simic, M. G., Ortho-Tyrosi ne as Marker in Post

Irradiation Dosimetry (PID) of Chicken (to be published in J. Agr. Food

Chem. )

.

Karam, L. R., and Simic, M. G., Generation of ®0H Radicals in Muscle

Tissue by Organic Solvents (to be published in Nature).

Kalla, S. L., Leubner, C., and Hubbell, J. H., Further Results on Generalized Elliptic-Type Integrals, Applicable Analysis (in press).

Lamaze, G., Gilliam, D. M., Williamson, T. G., Calibration of a Neutron

Driven Gamma Ray Source, Proc. of the ASTM-EURATOM Symposium on Reactor

Dosimetry (in press). —— "

Lamaze, G. P. , Gilliam, D. M., and Williams, A. P. , Prompt Gamma as a Fluence Rate Monitor in Neutron Beam Experiments, Journal of Radioanalytical Chemistry (in press).

Lamperti , P. J., Loftus, T. P. , and Loevinger, R., Calibration of X-Ray

and Gamma-Ray Measuring Instruments, NBS SP 250-16 (in preparation).

Lumbrusco, P., and Dick, C, E., X-Ray Attenuation Properties of Radiographic Contrast Media, Medical Physics (in press).

McGarry, E., Ruddy, F., Gold, R., Kellogg, L. S., Preston, C. C., Roberts

J. H., Updated PCA Physics-Dosimetry Results and Analyses, Proc . of the

ASTM-EURATOM Symposium on Reactor Dosimetry (in press).

McLaughlin, W. L., Humphreys, J. C., and Chappas, W. J., Radiochromic

Transfer Dosimetry for Validation and Commissioning of Industrial

Radiation Processes, Rad. Phys. Chem. (in press).

McLaughlin, W. L., and Humphreys, J. C., Graphite Calorimetry for Calibra

tion of 10 MeV Electron-Beam Absorbed Doses (to be submitted NBS Journal

of Research).

McLaughlin, W. L., Humphreys, J. C., and Chappas, W. J., Radiochromic

Transfer Dosimetry for Validation and Commissioning of Industrial

Radiation Processes, Proceedings of the 6th International Meeting on Radiation Processing , Ottawa, Canada, May 31-June 5, 1987 (in press).

195
Division b36, Publications in Preparation (cont'd.)

McLauyhiin, W. L., and Chappas, W. J., Cellulose Diacetate Film

Dosimeters, Proceedings of the 6th International Meeting of Radiation

Processing , Ottawa, Canada, May 31-June b, 1987 (in press).

McLaughlin, W. L., Kadak, B. B., Silverman, J., Liu Zhan Jun, Miller, A.,

Patsberg-Pedersen, W., and Charlesby, A., Hign-Density Polyethylene Film

Dosimetry by Infrared Spect rophotomet ry of Transvi ny 1 ene Dnsaturation (to

be submitted to Pad. Phys. Chem.).

McLaughlin, W. L., Khan, H. M., Warasawas, W., AlSheikhly, M. and Padak,

B. 8., Optical Waveguide Dosimetry for Gamma Padiation in the Dose Panye

10“ 1 to 3 x lu 4 Gy, (preprint: Pad. Phys. Chem.).

McLaughlin, W. L., and Chappas, W. J., Cellulose Diacetate Film Dosimeters

(accepted for publication in Pad. Phys. Chem.).

McLaughlin, W. L., Hussmann, M. H., and AlSheikhly, M., enhanced

Di chromate Dosimetry, (to be submitted to Pad. Phys. Chem.).

McLaughlin, W. L., Abdel-Pahim, F. and Preisinyer, f.. Temperature

Dependence of Pesponse of Padi ochroini c Film Dosimeters to Electron Beams

(to be submitted to Pad. Phys. Chem.).

McLauyhiin, W. L., Abdel-Pahim, F. and Preisinyer, T . , , Effect of Vacuum a Various Gases on the Pesponse of Padi ochromi c Film Dosimeters to Electron

Beams (to be submitted to Pad. Phys. Chem.).

McLauyhiin, W. L. and Humphreys, J. C., Graphite Calorimetry for Calibration of 10-MeV E 1 ect ron-Beam Absorbed Doses (to be submitted to NBS

Journal of Pesearch).

McLaughlin, W. L., Dosimetry for Food Irradiators, Invited book chapter in

book entitled, Technology of Low Dose Irradiation of Foods (to be

published by Elsevier, London).

Pruitt, J. S., Soares, C. G., and Ehrlich, M., Calibration of BetaParticle Sources and Instruments for Use in Padiation Protection, MBS SP

ZbO-31 (in preparati on )

.

Padak, B. B., Secerov, B. L j . , McLauyhiin, W. L., and Simic, M. G.,

Liquid-Core Optical Waveyuide Dosimetry in Continuous and Pulsed Padiation

Fields (preprint: Proceedings of Tihany Conference on Padiation

Chemi stry , Kubo, Hunyary).

Padak, B. B., McLauyhiin, W. L., Simic, M. G., and Warasawas, W.,

Dosimetry with Liquid-Core Optical Waveyuides for Steady-State Gamma Pays

or Pulsed X-rays (preprint: Pad. Phys. Chem.).

196
Division b36, Publications in Preparation (cont'd.)

Kadak, B . B., McLauyhlin, W. L., Simic, M. G., and Warasawas, W.,

Dosimetry of Steady-State Gamma Kays or Pulsed X-rays Usiny Liquid Optical

Waveguides (submitted to Kad. Phys. Chem.).

Kadak, B. B., McLauyhlin, w. L., and Simic, M. G., Liquid-Core Optical

Waveyuides Applied to Spect rophotometry (preprint: 0. Serbian Chemical

Soci ety )

.

Saloman, E. B., Hubbell, 0. H., and Scofield, J. H., X-Kay Attenuation

Coefficients (Total Cross Sections) for Lneryies 0.1 - 100 keV, Atomic

Data and Nuclear Data Tables (in press).

Saylor, M. C., Tamaryo, T. T., McLaughlin, W. L., Khan, H. M., A Thin Film

Kecordiny Medium for Use in Food Irradiation, (accepted for publication in

Kad. Phys. Chem.).

Schiina, F. 0., Williamson, T. G., Ayers, T. A., Hammersten, W. L., and

Larnaze, G. P., Measurement of the 93 Nb(n,n‘) Fission Spectrum Cross

Section, Proceedings of the ASTM-EURATOM Symposium on Keactor Dosimetry , Oackson Hole, WY, Oune 1987 (in press).

Schima, F. J., Williams, 0. G., Coyburn, C. 0., Hodgson, L. M., Apple, S.

C., McGarry, E. D., Lamaze, G. P., Rogers, 0. W., Gehrke, K., Baker, 0. D.

and Wheeler, F. 0., Measurements of Fission Spectrum Averaged Cross

Sections for the 93mNb Reaction, Proceedings of the ASTM-EUKATUM Symposium

on Keactor Dosimetry , Jackson Hole, WY, June 1987 (in press).

Scnrack, K. A., NBS Work on Neutron Resonance Radiography, Proceedings of

the Neutron Resonance Radiography Workshop , LANL, Los Alamos, NM,

July 87-29, 1987 (to be published).

Seltzer, S. M., Cross Sections for Bremsst rah 1 uny Production and for

Electron Impact Ionization, Proceedings of the Course on Monte Carlo

Transport of Electrons and Photons Below bU MeV , Internati ona I School of

Radiation Damaye and Protection, Ettore Majorana Centre for Scientific

Culture, Erice, Italy, Sept. 24 - Jet. 3, 1987 (in press).

Seltzer, S. M., An Overview of ETRAN Monte Carlo Methods for Coupled

El ectron/Photon Transport Calculations, Proceedings of the Course on Monte Carlo Transport of Electrons and Photons Below bU MeV , International

School of Radiation Damage and Protection, Ettore Majorana Centre for

Scientific Culture, Erice, Italy, Sept. 24 - Oct. 3, 1987.

Seltzer, S. M., Applications of the ETRAN Code to Some Radiation Transport

Problems, Proceedings of the Course on Monte Carlo Transport of Electrons

and Photons Below bU Mev , International School of Radiation Damage and

Protection, Ettore Majorana Centre for Scientific Culture, Erice, Italy,

Sept. 24 - Oct. 3, 1987.

197
Division 536, Publications in Preparation (cont'd.)

Simic, M. G., Karam, L. R., and Desrosiers, M. F., Peptide Irradiation

Products and Crosslinking Mechanisms, Proceedings of 8-ICRR , Edinburgh,

Scotland, July 19-24, 1987 (in press).

Simic, M. G., Hunter, E. P. L., and Jovanovic, S. V., Electron vs. H-atom

Transfer in Chemical Repair, Anticarcinogenesis and Radiation Protection

eds. P. Cerutti, 0. F. Nygaard, M. G. Simic, Plenum Press (in press).

Soares, C. G., Bright, E. L., and Ehrlich, M., Difficulties Encountered

with Some Hi gh-Atomic -Number Personnel Dosimeters Irradiated On-Phantom

with Low-Energy Photons (submitted to Health Physics).

Warasawas, W., and McLaughlin, W. L., High-Dose Dosimetry by Sublimation

of Crystalline Organic Compounds (to be submitted to Radiation and

Chemi stry)

.

Weaver, J. T. , Loftus, T. P. , and Loevinger, R., Calibration of Gamma-RayEmitting Brachytherapy Sources, NBS SP 250-19 (in preparati on)

.

Williamson, T. G., Lamaze, G. P., Gilliam, D. M., and Eisenhauer, C. E.,

Iron and Cadmium Capture Gamma Ray Photofission Measurements, Proc. of the

American Nuclear Society Topical Conference on Radiation Shielding and

Dosimetry (in press).

Williamson, T. G. , Ayers, T. A., Hammersten, W. L. , Lamaze, G. P. , and

Schima, F. J., Measurement of the 9

3

Nb ( n , n

' ) Fission Spectrum Cross

Section, Proc. of the ASTM-EURATOM Symposium on Reactor Dosimetry (in

press)

.

Williams, J. G. , Cogburn, C. 0., Hodgson, L. M., Apple, S. C. , McGarry, E. D., Lamaze, G. P., Gilliam, D. M., Schima, F. J., Rogers, J. W., Gehrke,

R., Baker, J. D., and Wheeler, F. J., Measurements of Fission Spectrum

Averaged Cross Sections for the 93 Nb( n ,n'

)

93lTI Nb Reaction, Proc. of the

6th ASTM-EURATOM Symposium on Reactor Dosimetry , May 31-June 5, 1987,

Jackson Hole, WY (in press).

198
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 536, Ionizing Radiation

James W. Behrens

Chairman, Nuclear Data Committee, Isotopes and Radiation Division,

American Nuclear Society.

Chairman, Transuranic Task Force, Isotopes and Radiation Division,

American Nuclear Society.

Member, Program Committee for the American Nuclear Society/European

Nuclear Society Meeting to be held in Washington, D.C. (Nov.' 1988).

Chairman, Organizing Committee for conference entitled "Fifty Years

with Nuclear Fission" to be held at the NBS (April 1989).

Member, Cross Section Evaluation Working Group Subcommittee on Nuclear Data Review.

Martin J. Berger

Member International Atomic Energy Agency Advisory Group on Nuclear

and Atomic Data for Radiotherapy and Radiobiology.

Chairman, International Commission on Radiation Units and

Measurements (ICRU), Committee on Stopping Power.

Member, National Council on Radiation Protection and Measurements

(NCRP) Committee #52 on Conceptual Basis on Dosimetry.

Member, NCRP Committee #55 (inactive) on Experimental Verification of

Internal Dosimetry.

Jacquel i ne M. Cal houn

EEO Counselor, NBS, two-year re-appointment, January 7, 1987 through

January 7, 1989.

Member, Advisory Panel on Radiopharmaceuticals, U.S. Pharmacopoeia.

A1 1 an D. Carl son

Chairman, Standards Subcommittee, Cross Section Evaluation Working

Group (CSEWG).

199
Division b36, Technical and Professional Committee Participation and

Leadership (cont'd.)

Allan D. Carlson (cont'd.)

Member, Evaluation Committee of CSEWG.

Member, Data Status and Requests Subcommittee of CSEWG.

Chairman, Proyram Committee for conference entitled "Fifty Years with

Nuclear Fission" to be held at the NBS (April 1939).

Randall S. Caswell

Chairman, Science Panel, Committee on interayency Radiation Research

and Policy Coordination (CIRRPC), Office of Science and Technoloyy

Pol i cy

.

Alternate Member, CIRRPC, Office of Science and Technoloyy Policy.

Member, Consultative Committee for loniziny Radiations (CCEMRI),

Conference Generale des Poids et Mesures, Paris, France.

Chairman, Section on Neutron Measurements (Section III), CCEMRI,

Conference Generale des Poids et Mesures, Paris, France.

Member, National Council on Radiation Protection and Measurements

(NCRP).

Member and Secretary, Internati onal Commission on Radiation Units and

Measurements (ICRU).

Sponsor, ICRU Report Committee on Stoppiny Power.

Sponsor, ICRU Report Committee on Absolute and Relative Dosimetry at

Hi yh Doses.

Sponsor, ICRU Report Committee on Material Equivalent and Tissue

Substitutes

.

Sponsor, ICRU Report Committee on Absorbed Dose Standards for Photon

Irradiation and Their Dissemination.

Sponsor, ICRU Report Committee on Characteri zati on of Irradiation for

Materials Effect Studies.

Sponsor, ICRU Report Committtee on Clinical Dosimetry for Neutrons

(Physics )

.

200
Division 536, Technical and Professional Committee Participation and

Leadership (cont'd.)

Randall S. Caswell (cont'd.)

Member, Organizing Committee, Second International Conference on Anticarcinogenesis and Radiation Protection, March 8-12, 1987.

Member, Program Committee for the Sixth Symposium on Neutron

Dosimetry, Munich (Neuherberg ) , October 12-16, 1987.

Ronald Col 16

Staff Assistant to Chairman, Radon Policy Subpanel, CIRRPC.

Member, Radon Working Group, Interagency Committee on Indoor Air

Qual i ty

.

Chairman, International Standards Organization, Working Group on Measurement Uncertainties.

Bert M. Coursey

Member, International Committee for Radionuclide Metrology (ICRM)

Life Sciences Working Group.

Member, ANSI Committee N42.02 on Nuclear Instruments, Procedural

Standards for Calibration of Detectors for Radioactive Measurements.

J. Joseph Coyne

Member, CIRRPC Subcommittee on High-LET Radiation.

Member, European Community Dosimetry Group (EURADOS) Committee 1:

Tissue-Equivalent Proportional Counters as an Instrument for

Radiation Protection.

Member, EURADOS Committee 4: Computational Methods and Benchmark

Calculations in Radiation Protection.

Member, International Atomic Energy Agency Advisory Group on Nuclear

and Atomic Data for Radiotherapy and Radiobiology.

Charles E. Dick

Member, Technical Organizing Committee, Industrial Applications,

International Conference on the Applications of Accelerators in

Research and Industry, Biennial Conference held in even numbered

years at North Texas State University, Denton, TX.

201
Division 536, Technical and Professional Committee Participation and

Leadership (cont'd.)

Charles M. Ei senhauer

Member, CIRRPC Science Panel.

Member, National Council on Radiation Protection and Measurements

(NCRP) Task Group on Atomic Bomb Survivor Dosimetry: SC-40 Biological

Aspects of Radiation Protection Criteria.

Member, ASTM Subcommittee E10.05 on Nuclear Radiation Metrology.

Member, NAS-NRC Advisory Committee on the Radiation Effects Research

Foundation Subcommittee: Panel on the Reassessment of A-Bomb

Dosimetry.

Member, ANS Standards Committee Working Group on Gamma-Ray

Attenuation Data.

Elmer H. Eisenhower

Alternate Representative, ANSI N44, Equipment and Materials for

Medical Radiation Applications.

Representative, ANSI N43, Equipment for Non-Medical Radiation

Appl icati ons.

Chairman, Interagency Committee on Occupational Radiation Protection

Measurements.

Resource Person, Conference of Radiation Control Program Directors,

Committee on Radiation Measurements.

Department of Commerce Representative, Interagency Working Group on Occupational Exposure Guidance.

Member, ASTM Subcommittee E10.04 on Radiation Protection

Methodol ogy

.

Chairman, ASTM Task Group E10.07.05 on Performance of Calibration

Laboratories for Radiation Dosimetry in Industrial Testing and

Processi ng

.

Member, ASTM Committee E10 on Nuclear Technology and Applications.

Member, CIRRPC Science Subpanel on Scientific Basis for Radiation

Protection Standards.

202
Division 536, Technical and Professional Committee Participation and

Leadership (cont'd.)

Elmer H. Eisenhower (cont'd.)

Member, Operations Group for the Accreditation of Instrument

Calibration Laboratories , Health Physics Society.

Leon J. Goodman

Member, ICRU Report Committee on Clinical Neutron Dosimetry--Part I: Determination of Absorbed Dose in a Patient Treated by External Beams

of Fast Neutrons.

Consultant, ICRU Report Committee on Material Equivalents and Tissue

Substi tutes.

Consultant, AAPM Task Group 18, Fast Neutron Beam Dosimetry.

James A. Grundl

Member, NCRP Task Group SC-63 on Public Knowledge About Radiation

Emergenc i es.

Member, ASTM Subcommittee E10.05 on Nuclear Radiation Metrology.

Secretary, Steering Committee for Lady Godiva Display at the National

Atomic Museum.

H. Thompson Heaton, II

Alternate Representative, ANSI N43, Equipment for Non-Medical

Radiation Applications.

Member, ANSI N43-3, Subcommittee for Gamma Irradiators.

Member, ANSI N43-8, Subcommittee for Electron Microscopes.

Resource Person, Conference of Radiation Control Program Directors,

Committee on Radiation Measurements.

Dale D. Hoppes

Secretary, International Committee for Radionuclide Metrology

( ICRM)

.

Member, ICRM Beta- and Gamma-Ray Spectrometry Working Group.

Member, Atomic Industrial Forum (AIF)-NBS Standards Program

Commi ttee

.

203
Division 536, Technical and Professional Committee Participation and

Leadership (cont'd.)

Dale D. Hoppes (cont'd.)

Member, International Committee of Weights and Measures (BIPM),

Consultative Committee on Standards for Measuring Ionizing

Radiations, Subcommittee Section II: Radionuclide Measurements.

Member, ANSI Subcommittee N42.2 on Procedural Standards for

Calibration of Detectors for Radioactive Materials.

John H. Hubbell

Chairman, General Radiation Protection Section, Health Physics

Society Standards Committee.

Organizer and Overseer, Task Groups: ANSI Standard N- 319 on Personnel

Neutron Dosimeters; and ASTM-E-10.04 PI anCo 56 on Radiation

Protection Survey Documentation, PI anCo 57 on Airborne Radioactive

Particulates, and PI anCo 58 on Low-level Radwaste.

Chairman, American Nuclear Society (ANS) Radiation Protection and

Shielding Division, ANS-6 Ad Hoc Committee on SI Units.

Member, ANS Isotopes and Radiation Division Nuclear, Atomic, and

Radiation Data Committee; Organizer and Chairman of sponsored

session: "Atomic and Radiation Data and Applications", for November

1987 ANS Meeting.

Member, ANS Isotopes and Radiation Division Industrial Radiation

Measurement Applications Committee.

Member, ANS Technical Program Committee for Sponsored Topical

Meeting, "Industrial Radiation and Radioisotope Measurement

Applications", September 1988.

Executive Councilor, International Radiation Physics Society; Member

Nominating Committee for 1988 elections.

Secretary, X-Ray Absorption Task Group, International Union of

Crystal 1 ography Commission on Crystal 1 ographic Apparatus.

Member, Cross Section Evaluation Working Group (CSEWG) Subcommittee

on Shielding.

204
Division 536, Technical and Professional Committee Participation and

Leadership (cont'd.)

Jimmy C. Humphreys

Secretary, ASTM E10.07 Subcommittee, Ionizing Radiation Dosimetry

and Radiation Effects on Materials and Devices.

Member, ASTM Subcommittee FI. 11, Hardness Assurance of Electronics.

Member, AAMI (Association for the Advancement of Medical

Instrumentation) subcommittee task groups on dosimetry of gamma and

electron beam sterilization of medical products and devices.

J. M. Robin Hutchinson

Chairman, International Committee for Radionuclide Metrology (ICRM)

Subcommittee on Low-level Techniques.

Member, American National Standards Institute (ANSI) Committee on Nuclear Instruments and Detectors.

Secretary, ANSI Subcommittee N42.2 on Procedural Standards for

Calibration of Detectors for Radioactivity Measurements.

Kenneth G. W. Inn

Member, ASTM Committee C26. 05.01 , Methods of Test, Test Methods,

Environmental Methods.

Member, ASTM Committee D19, Water, Radioactivity Test Methods.

George P. Lamaze

Vice-Chai rman, ASTM Subcommittee E10.05, Nuclear Radiation

Metrol ogy

.

Chairman, Membership Subcommittee, ASTM Committee E10, Nuclear

Technology and Applications.

Secretary, Planning Committees for the 6th and 7th ASTM-EURATOM

Symposia on Reactor Dosimetry.

Robert Loevinger

Member, BIPM Consultative Committee for Standards for Measurement of

Ionizing Radiation, Section I, X- and Gamma-Rays and Electrons.

Member, Medical Internal Radiation Dose Committee, Society of Nuclear

Medicine.

205
Division 536, Technical and Professional Committee Participation and

Leadership (cont'd.)

Robert Loevinger (cont'd.)

Consultant, American Association of Physicists in Medicine (AAPM)

Radiation Therapy Committee.

Member, AAPM Radiation Therapy Committee Task Group 3, Accredited

Dosimetry Calibration Laboratories.

Consultant, ICRU Report Group on Determi nation of Dose Rate at a Point in the Vicinity of a Brachytherapy Source.

Wil frid B. Mann

Consul tant, ICRU.

Member, ANSI-INMM Working Group INNM 8.04 Calibration Technique for

the Calorimetric Assaying of Plutonium-Bearing Solids applied to

Nuclear Materials Control.

Honorary Council Member, NCRP.

Chairman, NCRP Committee 18A, Standards and Measurement of

Radioactivity for Radiological Use.

Life Member, ICRM.

Emmert D. Me Garry

Member, ASTM Committee E10; Subcommittee E10.05, Nuclear Radiation

Metrol ogy

.

Chairman, Awards Committee of ASTM Subcommittee E10.05.

Member, Planning Committee for the 7th ASTM-EURATOM Symposum on Reactor Dosimetry.

Wil 1 i am L. Me Laughl i

n

Chairman, ICRU Report Committee on Absolute and Relative Measurements

of High Doses.

Technical Advisor, ICRU Report Committee on Chemical Dosimetry.

Technical Advisor, ISO WG-1, Nuclear Energy Terminology, Task on the

ISO TC/85, Committee on Nuclear Energy.

206
Division 536, Technical and Professional Committee Participation and

Leadership (cont'd.)

William L. McLaughlin (cont'd.)

Technical Advisor Council of Europe Parliamentary Assembly, Work

Group on Aerospace Physiology, Medicine, and Radiation Measurement.

Technical Advisor, Council of Europe Pari i amentary Assembly, Work

Group on Space Biophysics.

Member, R & D Associates Committee on Irradiated Food Products.

Member, International Atomic Energy Agency (IAEA), Advisory Group on High Dose Measurement and Standardization for Radiation Processing.

Member, Association for Advancement of Medical Instrumentation,

Subcommittee on Radiation Sterilization Dosimetry (Working Groups on Gamma Ray Sterilization and Electron Beam Sterilization).

Technical Advisor, National Council on Radiation Protection and

Measurement, Scientific Committee 63, Radiation Exposure Control in a Nuclear Emergency.

Science and Technology Consultant, CIRRPC.

Chairman, Advisory Panel on Electron Beam Dosimetry for Industrial

Radiation Processing, International Atomic Energy Agency.

Member, Organizing and Program Committees, 7th International

Conference on Radiation Processing, Amsterdam 1989.

Member ASTM Subcommittee E10.07 on Ionizing Radiation Dosimetry and

Radiation Effects on Materials and Devices.

Member, Interdepartmental Committee on Food Irradiation (Secretariat,

Department of Commerce).

Robert C. Placious

NBS Representative, Advisory Board, Center for NDE, Iowa State

Universi ty

.

Session Chairperson: ASNT Topical Conference Automating and

Advancing Radiographic NDT.

207
Division 536, Technical and Professional Committee Participation and

Leadership (cont'd.)

Francis J. Schima

Research Associate Member, IAEA, Coordinated Research Program on Gamma-ray Standards for Detector Efficiency Calibration.

Member, ICRM Working Group on Gamma- and Beta-ray Spectrometry.

Scientific and Technical Consultant, CIRRPC.

Robert B. Schwartz

Member, International Standards Organization (ISO) Technical

Committee 85 (Nuclear Energy), Subcommittee 2 (Radiation Protection),

Working Group 2 (Reference Radiations). Chairman, Neutron

Sub-Group.

Member, ICRU Report Committee on Measurements of Dose Equivalent.

Member, Health Physics Society Standards Committee, Working Group on Neutron Radiation Instrumentation.

Member, European Radiation Dosimetry Group, (EURADOS), Working

Committee 4 (Numerical Dosimetry).

Stephen M. Sel tzer

Member, Program Advisory Board, Conference on High Energy Radiation

Background in Space, November 3-5, 1987.

Member, ICRU Committee on Stopping Power.

Member, ANS Nuclear Data Committee.

Member, ANS Radiation Effects Committee.

Chri stopher G. Soares

Member, Health Physics Society Scientific Subcommittee Work Group for

the Revision of ANSI N13.ll, Personnel Dosimetry Performance -- Criteria for Testing.

Michael P. Unterwerger

Member, ASTM Committee D22 on Sampling and Analysis of Atmospheres.

208
Division 536, Technical and Professional Committee Participation and

Leadership (cont'd.)

Oren A. Wasson

Member, Department of Energy Nuclear Data Committee.

General Chairman, for conference entitled "Fifty Years with Nuclear

Fission" to be held at the NBS (April 1989).

209
MAJOR CONSULTING AND ADVISORY SERVICES

Division 536, Ionizing Radiation

1. J. W. Behrens consulted with Lawrence Livermore National Laboratory

on neutron measurements.

2. R. Col 1 ^ assisted and advised the Radon Policy Subpanel of the

Committee on Interagency Radiation Research and Policy Coordination

in developing a report on the extent and adequacy of federal radon

programs

.

3. C. E. Dick consulted with Mr. Richard V on Metter of Eastman Kodak

Corp. on the applications of single photon counting for measuring the

Swank noise of medical x-ray intensifying screens.

4. C. E. Dick consulted with Mr. Peter Soltani of Quantex Corp. on the

electron irradiation of photostimul abl e phosphors.

5. C. E. Dick consulted with Mr. Peter Soltani of Quantex Corp. on the

method of single photon counting for the evaluation of x-ray sensitive phosphors.

6. C. E. Dick consulted with Mr. Robert Kissel of the U.S. Navy EOD Tech

Center, NAVEODTECHCEN, on the use of PIN x-ray imaging detectors for

ordnance inspection.

7. C. E. Dick consulted with Mr. Donald Snyder, Eglin Air Force Base, on the use of real time high resolution x-ray imaging in the development

of aircraft ordnance.

8. S. R. Domen consulted with members of the Radiological Sciences

Department at the University of Lowell, to help them establish a research program in absorbed-dose calorimetry.

9. S. R. Domen visited the Radiology Department of the Yale Medical

School to provide consultation on theoretical problems in measurement

of radiation absorbed dose using a water calorimeter, and the consultation has been continued by correspondence.

10. S. R. Domen provided extensive consultation on the absorbed-dose

water calorimeter during a two-day visit to NBS by the head of the

Dosimetry Laboratory of Ghent University (Belgium), and the consultation has continued by correspondence.

11. E. H. Eisenhower advised the International Committee for Radionuclide

Metrology regarding the distinction between traceability and measurement quality assurance.

210
Division 536, Major Consulting and Advisory Services (cont'd.)

12. E. H. Eisenhower advised the Federal Emergency Management Agency

regarding negotiations with the manufacturer of leaking sealed

sources procured by FEMA.

13. David M. Gilliam advised and assisted Babcock and Wilcox (B&W) in

preparation of high-level dosimeters for measurements in mixed gamma

and neutron radiation fields at commercial nuclear reactors. These

measurements are being made for assessing the integrity of reactor

pressure vessels and understanding radiation shielding for reducing

personnel exposures.

14. David M. Gilliam developed an automatic data acquisition and processing system for new exposure room neutron monitors at the Armed Forces

Radiobiological Research Institute reactor.

15. H. T. Heaton, II consulted with the U.S. Air Force calibration lab at

Newark Air Force Station on models of exposure rate from gamma

sources and methods for comparing model parameters to observed ion

chamber measurements.

16. H. T. Heaton, II consulted with Radcal Corporation on ion chamber

correction factors.

17. H. T. Heaton, II consulted with Battelle Northwest Laboratories on making HVL measurements with energy-dependent ion chambers.

18. J. H. Hubbell responded to 310 inquiries (technical advice, data,

bibliographic search, publication requests, referencing of journal

manuscripts, etc.) to the Photon and Charged Particle Data Center

during the reporting period, 7/1/86 to 6/30/87.

19. J. C. Humphreys, along with W. L. McLaughlin and D. Hocken, provided

an in-depth on-site review (lasting approximately 3 or 4 days) of

dosimetry measurement procedures for Geraldine Barrett at Neutron

Products Inc., Dickerson, MD.

20. J. C. Humphreys provided advice about six times over a period of

several months to Arnold Fero of Westinghouse Electric Corp.,

Pittsburgh, PA, on the Li F chips as dosimeters for “in-situ" measurements in a power reactor core. Advice was needed on how to determine

the gamma/neutron sensitivity of these dosimeters in the mixed radiation field and the appropriate analysis methods.

21. J. C. Humphreys provided advice to David Bigbee of the FBI on appropriate methods for the use of the FBI Laboratory 320 kV x-ray machine

to sterilize blood specimens containing the AIDS virus to make these

specimens safe to handle.

211
Division 536, Major Consulting and Advisory Services (cont'd.)

22. R. G. Johnson and R. A. Schrack consulted with Princeton Plasma

Fusion Laboratory on 14 MeV neutron measurements.

23. R. G. Johnson and K. C. Duvall consulted with MESA Services

Internati onal on neutron detectors.

24. R. Loevinger served as consultant to the Dosimetry Section of the

Internati onal Atomic Energy Agency at a meeting of the Scientific

Committee of the Secondary Standard Dosimetry Laboratory Network, in

Vienna, Austria, June 1-5, 1987.

25. E. D. McGarry provided consultation, and 235 U Standard Neutron

Irradiations on a (successful) try-and-see basis, to Westinghouse

Electric Corporati on ' s Research Division (Monroeville, PA), to establish mass scales for ultralight fissionable deposits whose masses are

in the fractional nanogram/cmr range.

26. E. D. McGarry provided consultation to Materials Engineering Branch

of the Nuclear Regulatory Commission regarding benchmarking of pressure vessel surveillance dosimetry.

27. W. L. McLaughlin, Northern California Transplant Bank, Ban Francisco,

CA (Dr. James Forsell). Consultation on dosimetry for JA in the

steri 1 i zati on of prosthetic tissues (for biocompatible transpl ants )

.

28. W. L. McLaughlin, Children's Hospital, National Medical Center, ENT

Department (Dr. Colin Barber). Assisted in irradiation of transplant

tissue (trachea) as a means of sterilization biocompatibility prior

to surgery.

29. W. L. McLaughlin, Rensallear Po lytechni cal Institute, Physics

Department (Dr. Brian Methe). High-dose measurement and irradiation

of thermoluminescent powders in order to extend useful range of

conventional TLD materials to higher doses than usual.

3D. W. L. McLaughlin, PPG Industries, Dak Creek, WI (Dr. Roy Modjewski).

Provide means for calibrating response of thin radiochromic films

irradiated to very low energy electron beams (1UU kev).

31. W. L. McLaughlin and J. C. Humphreys, Becton-Di cki nsen Research

Laboratory, Research Triangle Park, NC (Dr. Lois Jones). Assisted in

the design of BD dosimeter calibration laboratory and calorimetry

systems for high-dose measurements.

32. W. L. McLaughlin, Acme United Corporat i on . , Fairfield CN (Dr. Louise

Wheeler). Provided consultation on ferrous-cupri c chemical dosimetry

as a means of calibrating red Perspex dosimeters for sterilization of

gauze dressings.

212
Division b36, Major Consulting and Advisory Services (cont'd.)

33. W. L. McLaughlin, Kendal 1 -McCaw, Irvine, CA (Dr's Steven Smith and

Royer Morrison). Devised a novel experimental means of mapping dose

distribution in polypropylene tubes and sleeves irradiated with

12-MeV electrons.

34. W. L. McLaughlin, Merck, Sharpe and Dome (Dr. Brenda Staehlee).

Provided means for calibrating medical supplies using radiochromic

thi n-fi lm dosimeters.

3b. W. L. McLaughlin, IRT Corporation, San Diego, CA (Dr. Elaine Condos).

Supplied a new type of radiochromic film prototype for large-scale

mapping in semi-conductors being processed by electron beams at very

high beam powers (3UUkW).

36. W. L. McLaughlin, Radiation Sterilizers, Inc., Atlanta CA (Dr. Thomas

Fisher). Consultation on standardizing spect rophotometers in their

applications with chemical dosimeters use for DA in radiation sterilization of disposable medical devices.

37. W. L. McLaughlin, Suryikos (Johnson & Johnson), Arlington, TX (Dr.

Kathy Harris). Supplied temperature and rate dependence data for the

response of thin-film radiochromic films to electron beams (4-MeV).

38. W. L. McLaughlin, McDonnell Douylas, Vitak Systems, Hazleton, MI (Dr.

William J. Bakich). Consultation on the use of radiochromic dosimeters as a mean of QA in the radiation sterilization of bone grafts.

39. W. L. McLaughlin, US Department of Eneryy, Environmental Branch (Dr.

David Balletine). Consultation on radi oacti vi ty induced in the irradiation of foods by b-lU MeV x-rays and 1U-12 MeV electron beams.

4D. W. L. McLaughlin, IBM, San Jose, CA (Dr. Hans Coufal). Consultation

on the radiation effects on plastics (e.g. po ly vi ny I i dene fluoride)

used for piezoelectric devices and new possibilities for hiyh-dose

dosiinet ry

.

41. W. L. McLaughlin, State of California Department of Food and

Agriculture Sacramento, CA (Joseph Rothleder). Devised a detailed

testiny procedure and evaluation protocol for optical waveyuide

dosimeters to be used for standardizing the irradiation of foods.

42. W. L. McLauyhlin, Abbott Labs, Austin, TX (Carlos Parra). Design of

validation dosimetry procedures for setting sterilization dose

levels, using radiochromic dosimetry.

213
Division S36, Major Consulting and Advisory Services (cont'd.)

43. W. L. McLauyhlin, North American Science Associates, Northwood, OH

(Jacqueline Breno). Designed a radiation experiment for testiny and

validating the appropriate sterilization doses for standardized

microbiological spore strips.

44. W. L. McLauyhlin, Westi nyhouse, Nuclear Technology Systems Division,

Pittsburgh, PA (Dr. Arnold Fero). Designed high-dose calibration

methods using opti ca I -qual i ty lithium fluoride crystals and

color-center formation.

4b. W. L. McLauyhlin, Monsanto, U'Fallen, IL (Dr. Donald Hines).

Consultation on nigh-dose dosimetry methods in the radiation

synthesis of macromo lecul ar specialty chemicals.

46. W. L. McLauyhlin, Monsanto, St. Louis, MU (Dr. Daniel Steinmeyer).

Supplied details of tne radiation chemistry in the radiolysis of

nitrous oxide (products, yields, etc.).

47. W. L. McLauyhlin, K. S. Landauer, Inc., Chicayo, IL (Steven Scharf)

Supplied details of food irradiation dosimetry requirements, as well

as samples of typical dosimetry systems for quality assurance.

48. W. L. McLaughlin and J. C. Humphreys, Convertors-Travenol , LI Paso,

IX (Dr. Harry Shaffer). Consultation on energy dependence and

temperature dependence of radiochromic response to ionizing photons

(x-and gamma rays).

49. W. L. McLauyhlin, Franrica Company, Stockton, CA (Dr. Steven

Kechtstei ner ) . Provided details of differences in response of

anaerobic and aerobic bacteriological spores to electrons and

photons, as well as radi ati on-resi stant microbes (e.g. Clostridium

botulinum type E and viruses).

bU. W. L. McLauyhlin, Tnermon Manufacturing Co., San Marcos, TX (Dr. Fred

Weber). Devised a method for dosimetry at very hiyh doses (2UU-bUU

k Gy) for polymers irradiated with 3-MeV electron beams.

bl. W. L. McLauyhlin, USDA, Entomology Department, Yakima, WA (Dr. Arthur

Burditt). Supplied dosimetry for low-dose irradiation as a means of

quarantine control of fruits and vegetables.

b2. W. L. McLauyhlin, Drug and Device Associate, Inc. (Dr. Donald J.

Cattaneo). Provided validation and steri I i ty-cont ro I data and procedures in the sterilization of pharmaceuti cal and medical devices.

214
Division 536, Major Consulting and Advisory Services (cont'd.)

53. W. L. McLaughlin, Kimberl y-Cl ark , Roswell, GA (Dr. Elizabeth

Jackson). Consultation on the use of radiochromic film dosimetry as

a means of evaluating the safety of sterilization of medical devices

by ionizing radiation.

54. W. L. McLaughlin, Boeing Aerospace, Seattle, WA (Dr. William

Vartholep). Supplied means and procedures for dosimetry of 20-ns

pulsed beams at 10 13 Gy s _1

, 2kHz, at very high electron beam powers

(elevated temperatures).

55. W. L. Me Laughl i n, Insul tab Corp., Woburn, MA (Dr. Clement Bourgaul t)

Assisted in the dosimetry as a means of QA in the curing of wires,

cables, tubing and laminated plastic films.

56. W. L. McLaughlin, Michigan Tissue Bank, Lansing, MI (Dr. Nancy Webb).

Supplied special radiochromic dosimeters and procedures for

monitoring radiation sterilization of prosthetic devices.

57. W. L. McLaughlin, Food and Drug Administration (Dr. H. Herman).

Consultation on monitory of radioisotope labeled proteins in the

testing of latex barriers to AIDS virus; testing of mechanical

properties following sterilization.

58. W. L. McLaughlin, Abbott Laboratories, Abbott Park, IL (Dr. Richard

A. Domanik). Consultation on in-vivo dosimeters for diagnostic and

clinical radiology, utilizing optical waveguide sensors.

59. W. L. Me Laughl i n, IBM Corp., Yorktown Heights, NY (Dr. Ronald

Del 1 aguardi a) . Provided means of standardizing low-energy x-ray

exposures at high doses, in the fabrication of lithographic masks for

sub-micron semi-conductor architectures.

60. W. L. McLaughlin, SAIC Corp., San Diego, CA (Dr. Michael Hyman; Dr.

David Del esderni er) . Supplied technology in the fabrication of

optical waveguide systems under contract with DOD for use as radiation dosimeters for military personnel.

61. W. L. McLaughlin, Physics Department, University of California,

Berkeley, CA (Dr. Buford Price). Consultation on sensitive glasses

for use in the dosimetry of heavy charged particles and the regi stration of nuclear tracks.

62. W. L. McLaughlin and J. C. Humphreys, 3M Company, St. Paul, MN (Dr.

Nate Postma). Consultation on the production of magnetic tapes,

discs etc. for use of electron beams scanned over wide-webbi ngs and

supplying dosimetry for quality control.

215
Division b3b, Major Consulting and Advisory Services (cont'd.)

63. W. L. McLaughlin, Allied Corporation, Morristown, NJ (Dr. Theodore

Prusik). Consultation on the development of new dosimeters for food

irradiation. NBS supplied tests and standards for assisting Allied

in meeting regulatory requirements and product specifications.

64. W. L. McLaughlin, Atomic Energy of Canada Ltd., Ottawa, Canada (Dr.

Joseph McKoewn). Provided measurement systems and expertise as means

of JA for industry producing large radionuclide sources and accelerator technology.

6b. W. L. McLaughlin, Bichron Corporation, Newbury, OH (Dr. Joseph

Bellian, President). Consultation on development for DOE and indus-*

try of new dosimeters for environment radiation and for radiation

protection measurements.

66. W. L. McLaughlin, DOD, EKADCOM Ft. Monmouth, NJ (Dr. Stanley

Kronenbery). Designed and tested practical field radiation dosimeters for military personnel.

67. W. L. McLauyhlin and J. C. Humphreys, Energy Sciences Inc., Woburn,

MS (Dr. Samuel V. Nablo). Supplied quality control assistance for

low-energy (O.l-O.b MeV) electron accelerators being used for curing

coatinys and laminates at high assembly- 1 i ne speeds.

68. W. L. McLauyhlin, European Organization for Nuclear Research, Geneva,

Switzerland (Dr. H. Schonbacher ) . Designed dosimetry as a convenient

and inexpensive means of monitoriny larye doses of high -energy

charged particles and chronic radi ati on-i nduced damaye in steering

magnets

.

by. W. L. McLauyhlin and J. C. Humphreys, Far West Technology, Inc.

(K. C. Humphreys). Supplied innovations and new chemical dosimetry

formulations and film fabrication methods, as well as optical

waveguide materials and designs for new dosimetry applications in

radiation processing, radioloyy, and protection.

7U. W. L. McLauyhlin and J. C. Humphreys, FMC Corporation, Central

Engineering Laboratori es , Santa Clara, CA (Dr. George Hsieh).

Supplied measurement systems and means for measurement quality assurance (including traininy course to FMC personnel) for applications in

radiation processing food preservati on

.

71. W. L. McLauyhlin, GAF Corporation, Wayne, NJ (Dr. David Lewis).

Provided testing and applications in the development of a new family

of dosimeter materials which are expected to have an impact on radiation measurement technology.

216
Division 536, Major Consulting and Advisory Services (cont'd.)

72. W. L. McLaughlin, Gesellschaft fur Strahl en-und Umwel tforschung

,

Neuherberg/Munich , Federal Republic of Germany, (Dr. Dieter Regull a).

Supplied primary standards and dosimetry i ntercompari sons for the

development of reference standard dosimeters (alanine) used in the

IAEA International Dose Assurance Service.

73. W. L. McLaughlin, W. R. Grace & Company, Duncan, SC (Dr. James Pike)

Collaboration on the development of polyolefin films and dyed cellulose films for the measurement of very large doses delivered by

industrial electron accel erators at relatively high temperatures.

74. W. L. McLaughl i n, Harwell Laboratory, Oxfordshire, UK (Dr. Brian

Whittaker). Supplied dosimetry i ntercompari sons and standards for

industrial radiation processing applications and international dose

assurance services.

75. W. L. McLaughlin, IOTECH, Inc., Northglenn, CO (Dr. Gary Pageau and

Dr. Steven Kruger) . Established quality control procedures and

measurement methods for industrial sterilization of medical devices.

76. W. L. McLaughlin and J. C. Humphreys, ISOMEDIX, Inc., Whippany, NJ

(Michael Sayl or) . Provided calibrations and consultation on the use

of optichromic dosimeters for quality assurance in the radiation

processing of tropical fruits for quarantine control.

77. W. L. McLaughlin and J. C. Humphreys, Radiation Dynamics, Inc.,

Melville, NY (Laura Tampanick and Marion Stelchnk). Assisted with

beam diagnostics and characterization of processing efficiencies of

high-power industrial electron accel erators.

78. W. L. McLaughlin and J. C. Humphreys, Radiation Sterilizers, Inc.

Westerville, OH (Dr. Barry Fairand). Designed MQA procedures and

training courses for industrial plant personnel performing sterilization of medical devices.

79. W. L. McLaughlin and J. C. Humphreys, Johnson & Johnson, Somerville,

NJ (Dr. Jeffrey Beck). Assisted with radiation dosimetry used as MQA

for safe release of radiation sterilized sutures for surgical use.

80. W. L. McLaughlin, Medical Sterilization, Inc., Syosset, NY (Dr.

Kennard H. Morgenstern and Dr. Michael Fogerty). Supplied

specialized dosimetry for measuring accurately radiation doses in

highly heterogeneous materials used in recyclable medical supplies.

81. W. L. McLaughlin, National Cancer Institute (NIH), Bethesda, MD (Dr.

Gordon Cragg). Consultant on QA and dosimetry for sterilization of

natural products as chemotherapy agents.

217
Division 536, Major Consulting and Advisory Services (cont'd.)

82. W. L. McLaughlin, Naval Surface Weapons Center (DOD), White Oak, MD

(Dr. Stanley H. Stern). Provided dosimetry and calibrations for

detailed emergency dose mapping in the vicinity of strategic weapons

and simulators.

83. W. L. McLaughlin, RPC Industries, Hayward, CA (Dr. Anthony Rodriguez

(VP) and Dr. Sherman Farrell). Assisted with beam diagnostics and QA

dosimetry control for processing with large accelerators and ultraviolet sources used for radiation curing and processing.

84. W. L. McLaughlin, Travenol Laboratories Inc., Round Lake, IL (Dr.

William Fitzgerald). Supplied contracted QA expertise and radiation

processing training courses for radiation sterilization of hospital

and medical disposable materials.

85. Robert B. Schwartz participated in the following intercomparisons:

a) neutron dosimeters with Battel le Pacific Northwest Laboratory; b)

neutron remmeters with University of Arkansas; and c) neutron rem- meters with National Physical Laboratory (U.K.); Commissariat a L'Energie Atomique (France); and Physikalisch - Technische

Budesanstal t ( FRG)

.

86. Robert B. Schwartz assisted the U. S. Navy in evaluating a new type

of neutron personnel dosimetry.

87. Robert B. Schwartz worked with a representa ti ve of the French Atomic

Energy Commission to evaluate a new type of neutron remmeter.

88. Julian Sparrow has performed major advisory services on radiographic

inspection of rocket motors for the following groups: Jerry Lyman and

Richard O'Brien at the Strategic Weapons Facility Pacific, Bremerton,

WA; Martin Johnson, Polaris Missile Facility Atlantic, Charleston,

SC; Dick Shafer and Gary Barrett, Hercules Bacchus Division, Magna,

UT ; and Kent Robertson, Morton-Thi okol Inc., Brigham City, UT.

89. Julian Sparrow has consulted with Lockheed and Atlantic Research

Corporation personnel on radiographic procedures to be used to

inspect missile motor components.

90. Jul i an Sparrow has consulted with personnel from the University of

West Virginia, Morgantown, on the construction of an x-ray phantom to

standardize the x-ray geometry in medical radiography.

91. Julian Sparrow demonstrated the Hand-Held, Dental X-Ray Unit in film

mode and real-time mode for General Chandler of the U.S. Army Medical

Research and Development Center, at Ft. Detrick, MD.

218
Division 536, Major Consulting and Advisory Services (cont'd.)

92. Julian Sparrow has hosted an NBS and NDT meeting for the Navy Special

Programs Office and served as the recording secretary. The meeting

was attended by Navy field representati ves , consultants and the program officer of the prime contractor to discuss the status of nondestructive testing techniques being used in the D-5 missile program.

93. Julian Sparrow consulted with Frank Ameduri, Los Alamos National

Laboratory on the use of compact paral 1 el -pi ate ionization chambers

with Ross filter-pairs for absolute fluence measurements of high

intensity pulsed 1 to 10 KeV x-rays.

94. Julian Sparrow consulted with Lynn Spence, Lockheed Missile and Space

Corp., and Maynard Grove, Atlantic Research Corp., on the thickness

of polystyrene equilibrium build-up cap required for small volume

ionization chamber used to measure x-ray fluence from an 8 MeV linear

accel era tor.

219
JOURNAL EDITORSHIPS

Division 536, Ionizing Radiation

B. M. Coursey, Editor, International Journal of Radiation

Applications and Instrumentation, Part A. Applied Radiation and

Isotopes.

B. M. Coursey, Editor, International Journal of Radiation

Applications and Instrumentation, Part B. Nuclear Medicine and

Biol ogy

.

J. H. Hubbel 1 , Editorial Board, Journal of the Nigerian Association of

Medical Physicists.

W. B. Mann, Editor-in-Chief for North America, International Journal

of Radiation Applications and Instrumentation, Part A. Applied

Radiation and Isotopes.

W. B. Mann, Editor-in-Chief for North America, International Journal of

Radiation Applications and Instrumentation, Part B. Nuclear Medicine and

Bi ol ogy

.

W. L. McLaughlin, Editor, International Journal of Radiation Applications

and Instrumentation, Part. A. Applied Radiation and Isotopes.

W. L. McLaughlin, Editor, International Journal of Radiation Applications

and Instrumentation, Part C. Radiation Physics and Chemistry.

W. L. McLaughlin, Editorial Board, Radiation Physics and Chemistry.

J. W. Motz, Editor, Computerized Radiology.

M. G. Simic, International Editorial Board, Free Radical Biology and

Medici ne.

220
TRIPS SPONSORED BY OTHERS

Division 536, Ionizing Radiation

M. J. Berger and S. M. Seltzer attended meeting of the ICRU Committee on Stopping Powers, Argonne, IL. All expenses paid by the ICRU (October

22-24, 1986).

M. J. Berger and S. M. Seltzer lectured at the Ettore Majorana Center for

Scientific Culture, International School of Radiation Damage and

Protection, Erice, Sicily. Expenses were paid by the Ettore Majorana

Center for Scientific Culture (September 24 - October 3, 1987).

Randall S. Caswell traveled to Beijing, Xian, Shanghai, and Hangzhou,

China to give a series of lectures on ionizing radiation measurement and

neutron interactions with biological tissue. All expenses while in China

were paid for by the Institute of Atomic Energy, Beijing, China (June

1986).

Randall S. Caswell traveled to New York City, NY to participate in the

National Cancer Institute review of the Radiological Research Program at

Columbia University. All expenses were paid for by the National Cancer

Institute (August 1986).

Randall S. Caswell traveled to Brussels, Belgium to attend the Annual

Meeting of the International Commission on Radiation Units and

Measurements (ICRU). All expenses were paid for by the ICRU (September

1986).

B. M. Coursey attended the Rome, Italy meeting of the ICRM for the purpose

of editing the proceedings of a Seminar for the International Journal of

Radiation Applications and Instrumentation. Pergamon Press paid for air

transportation and partial per diem (June 15-24, 1987).

B. M. Coursey provided consulting services, audit source certification,

and QA procedures under the framework of the AIF/NBS MAP for the Nuclear

Power Industry, Analytics, Inc., Atlanta, GA. Travel expenses paid by

Analytics, Inc. (April 20, 1987).

E. H. Eisenhower lectured at the Health Physics Society Summer School on Practical Statistics for Operational Health Physics, in Pocatello, ID.

All expenses were paid by Idaho State University (July 1987).

H. T. Heaton, II traveled to Pocatello, ID to present a talk at the Health

Physics Society Summer School. All expenses were paid by Idaho State

University (July 1987).

221
Division 536, Trips Sponsored by Others (cont'd.)

J. H. Hubbell lectured and held laboratory discussions in the People's

Republic of China at the Institute of Applied Physics, and Computational

Mathematics and at the Institute of Atomic Energy, In Beijing. The host

organi zati ons covered all living expenses (September 10-12, 1987).

J. H. Hubbell, under the terms of the Protocol and Cooperation between the

U.S. Department of Commerce and the PRC State Bureau of Metrology (SBM)

,

lectured and held laboratory discussions at the SBM in Beijing and in

other SBM-affil iated institutions in the People's Republic of China. The

SBM covered all living expenses (September 13-30, 1987).

J. M. R. Hutchinson attended the "First International Summer School on Low-Level Measurements and Their Applications to Environmental

Radioactivity," and presented three lectures at the Department of Atomic

and Nuclear Physics of the University of Seville, Spain. The University

of Seville provided all expenses (September 27 - October 10, 1987).

R. Loevinger traveled to the People's Republic of China and gave lectures

at institutions in Beijing, Taiyuan, Xian, and Shanghai. His expenses

within the PRC were paid by the Chinese government (October 15 - November 5, 1986).

R. Loevinger traveled to San Francisco, CA to take part in a meeting of

the MIRD Committee of the Society of Nuclear Medicine. The trip was paid

for by the Society of Nuclear Medicine (March 12 & 13, 1987).

R. Loevinger traveled to Vienna, Austria as a member of an Advisory Group

on Procedures and Data for the Calibration of Radiation Protection

Monitoring Instruments at the International Atomic Energy Agency. The

trip was paid for by the IAEA (May 18 - 22, 1987).

R. Loevinger traveled to Vienna, Austria to serve as consultant to the

Dosimetry Group of the International Atomic Energy Agency at a meeting of

the Scientific Committee of the Secondary Standard Dosimetry Laboratory

Network. The trip was paid for by the IAEA (June 1-5, 1987).

William L. McLaughlin taught a training course at Travenol Labora tories

,

Round Lake, IL. All expenses paid by Travenol Laboratories (October

1986).

F. J. Schima attended the International Atomic Energy Agency research

associate's meeting, Rome, Italy. As part of the Research Agreement with

the IAEA, per diem and airfare were provided by IAEA (June 11-13, 1987).

222
Division 536, Trips Sponsored by Others (cont'd.)

R. A. Schrack attended the Workshop on Neutron Resonance Radiography held

at Los Alamos National Laboratory, NM. They paid travel expenses (July

1987).

Michael G. Simic gave a talk and discussed research of mutual interest at

the University of California, Berkeley, CA. The University of California

paid all expenses (November 1986).

Michael G. Simic was invited to give a talk and discuss research of mutual

interest at Stanford University, Stanford, CA. Stanford University paid

subsistence (November 1986).

Michael G. Simic gave an invited talk and discussed research of mutual

interest at the University of California, San Francisco, CA. The

University of California paid subsistence (November 1986).

Michael G. Simic was invited to give a talk and discuss collaborative

research at the University of Southern California, Los Angeles, CA. The

University of California paid subsistence (February 1987).

Michael G. Simic was invited to give a Symposium talk at the annual meeting of the American Institute of Physics at Crystal City, VA. The

American Institute of Physics paid subsistence (April 1986).

Michael G. Simic traveled to LaJolla, CA to serve as chairman of 4th

International Congress on Oxygen Radicals. Conference paid for all expenses (June-July 1987).
STANDARD REFERENCE MATERIALS

Division 536, Ionizing Radiation

Radioactivity Group Standards Issued - 1 August 1986 through 31 July 1987

SRM

4417L-F

4410H-K

4419C

4407L

4401L-M

4412L-L

4415L-K

4416-H

4404L-J

4400L-I

4321

4322

4323

4354

4361B

490 6C

4945F

42078

Radi onucl ide

Indi um-111

Tec hneti um-99m

Ytterbi um-169

Iodi ne-25

Iodi ne-131

Mol ybdenum-99

Xenon-133

Gal 1 i um-67

Thai 1 i um-201

Chromi um-51

Natural Uranium Solution)

Americum-241 Solution ) Plutonium-234 solution ) Cobalt-60, Strontium-90,

Cesium-137, Thorium-228, 232

Uranium-235, 238

Plutonium-238, 239+240

Americum-241

Low-level Tritium in water

Plutonium-238 point source

Strontium-89 solution

Cesium-137 point source

Principal Use

Calibration of instruments

for activity measurements

of radiopharmaceuticals

Environmental monitoring

i n the nucl ear fuel

cycl e Fresh water lake sediment

Natural Matrix

International Standard

for ground-water dating

Cal ibration of al pha

counting equipment in

environmental monitoring

Cal i brati on of betacounting equipment in the

Nuclear Power Industry

Calibrating Ge(Li) semiconductors used for

monitoring radionuclide

levels under operation and

accident conditions in

nuclear power facilities

224
CALIBRATION SERVICES PERFORMED

Division 536, Ionizing Radiation

I. Neutron Dosimetry Group

No. of

Type of Service Customer Sp 250 Tests

Certi fi ed Univ. of Arizona 8.1R 1 FI uence AFRRI 8.1R 6

Standards AFRRI 8. IQ 1

Total 8

Neutron Personnel AFRRI 44060C 2

Protection Georgia Power 44060C 4

Instrumentation Rochester Gas & Electric 44060C 3

Virginia Power 44060C 5 Calvert Cliffs 44060C 12

Caroline P&L 8. 1

J

7 Omaha Public Power 8.1J 3

U. S. Army 8. 1

J

10

Illinois Power 8.1J 2

WPPSS 8.1J 2

Barlett Nuclear Corp. 8.1J 2

Eberline Inste. Corp. 8.1J 2

Penn. Power & Light 8.1J 1

Total 55

Neutron Source Oak Ridge National Lab 44010C 2

Cal ibration Sandia National Lab 44010C 4

Naval Research Lab 44010C 2

West inghouse/ Betti

s

Lawrence Livermore

44010C 1

National Lab 44010C 1 U. S« Air Force, Newark 44010C 1

Sub Total 11

In-house (NBS) Sources N/A 4

Total 15

225
Division 536, Calibration Services Performed (cont'd)

II. Radioactivity Group

August 1, 1986 to August 1, 1987

Schedul ed

Calibrations Non-scheduled

Number Total

of Fee

Sources $k

Number

of

Sources

Category

Alpha-particle Sources 21 17.1 4

8.2 H, I, J

Beta-Particle Solutions -- — 5

and Gases ( 85 Kr)

8.2 P, Q, R

Gamma-ray Solutions, Point 3 2.9 19

Sources, and Xe Isotopes

Mixed Radionuclide Sources, -- -- 8

Solutions and Gases

Other Services

24 20.0 36

Tests

Total

Fee

$k

4.6

6.8

9.2

4.1

2.8

27.5

226
Division 536, Calibration Services Performed (cont'd.)

III. X-Ray Physics Group

Customer

Cl assi ficati on Type of

Service

No. of

Customers

No. of Tests

Performed

Service

Fee

Income

Industrial : A 26 148 $34,508

medical product B 4 11 5,237

steril i zation C 7 40 2,742

Industrial : A 11 27 6,618

electronic hardness B 3 43 11,221

testi ng C 0 0 0

Industrial : A 0 0 0

pol ymer B 0 0 0

modi ficati on C 0 0 0

National Laboratory: A 0 0 0

electronic hardness B 1 34 8,807

testi ng C 0 0 0

Dept, of Defense: A 0 0 0

electronic hardness B 0 0 0

testi ng C 0 0 0

Second ary A 0 0 0

Cal i brati on B 1 2 1,222

Laboratory C 0 0 0

Universi ty

:

A 1 1 200

Research B 0 0 0

C 0 0 0

Subtotal s

:

A 38 176 $41,326

B 9 91 26,487

C 7 40 2,742

Grand Total s: XXX 54 307 $70,555

Service Code Type of Service SP250 Number

A Irradiate Dosimeters 49010S

B Supply Transfer Dosimeters 49020S & 49030S

C Special Measurements 49040S & 49050S

227
Division 536, Calibration Services Performed (cont'd.)

IV. Dosimetry Group and X-Ray Physics Group

Type of Service

Customer

Type*

SP 250 Number of

Item No. Tests Income

Calibration of x-ray 1-7 46010-50 316 $141 k

and y-ray measuring

instruments, and

irradiation of TL

dosimeters

Calibration of y-ray 2-6 47010-40 17 $ 11 k and 3-particle sources

Chemical dosimetry 2 48010-20 146 $ 29 k measurement assurance

service for electron

beam

High-dose irradiation 3-7 49010-50 383 $ 74 k and interpretation

Irradiat. of TLDs and Navy N.A. 285 $100 k prep, of units for

shipboard measurement

Instrument calibration 5 N.A. 10 $ 10 k and evaluation

Total

s

1160 $330 k

^Column 2: 1, calibration labs; 2, hospitals; 3, nuclear energy establishments; 4, industry; 5, US government labs; 6, DoD labs;

7, universities.

228
SPONSORED SEMINARS AND COLLOQUIA

Division 536, Ionizing Radiation

Elfinn Larsen, Ri s0 National Laboratory, Denmark, "Mass Spectrometry at

Ris0," January 20, 1987.

Thomas Werge, Institute of Mic robi ol ogy , University of Copenhagen, "InVitro Regulation of Cellular and Viral Oncogenes by Antisense RNA,"

February 17, 1987.

Sigmund Guldbakke, Physi kal i sch-Techni sche Bundesand tal t, Braunschweig,

West Germany, "High Energy Photon Fields: Production, Dose Calibration,

and Contamination," April 9, 1987.

Gunther Dietze, Physi kal i sch-Techni sche Bundesanstal t, Braunschweig, West

Germany, "Determination of Neutron Cross Sections and Kerma Factors on Carbon," April 14, 1987.

Marc F. Desrosiers, Argonne National Laboratory, Agronne, IL, "Detection

of Transient Organic Radical Cations Produced in Pulse Radiolysis. TimeResolved Fluorescence Detected Magnetic Resonance," April 28, 1987.

Krzysztof Morstin, Brookhaven National Laboratory, Upton, NY, "Nuclear

Model Calculations for High-Energy Neutron Dosimetry," May 26, 1987.

John T. Lett, Colorado State University, "Towards a General Theory of

Cellular Radiosensitivity: Recent Experimental Results," May 27, 1987.

Wolf Mannhart, Physi kal i sch-Techni sche Bundesanstal t, Braunschweig, West

Germany, "Introduction to Generating Covariances of Experimental Data,"

July 14, 1987.

Wolf Mannhart, Physi kal i sch-Techni sche Bundesanstal t, Braunschweig, West

Germany, "Evaluation of the Californium Neutron Spectrum," July 16, 1987.

Gideon Barnea, Raphael Laboratory, Haifa, Israel, "Electron/Photon Transport Calculations with Application to Radiography, Dosimetry and Radiation

Shielding," August 21, 1987.

Elizabeth K. Bal cer-Kubiczek , University of Maryl and School of Medicine,

"Effects of Neutron Dose Rate on Carcinogenesis in Vitro," August 27,

1987.

Melvin Siedband, Department of Radiology, "Digital Radiography,"

University of Wisconsin, September 10, 1987.

Tony Berejka, Radtech International, Huntington, NY, "International

Industrial Markets for Electron Beam Accel erators ," September 16, 1987.

229

TECHNICAL ACTIVITIES

Division 530.1 - Nuclear Physics Group

The Center for Radiation Research conducts a fundamental research

program in nuclear and high energy physics. This program includes both

theoretical and experimental projects that address priority questions in

these areas. The personnel in this group are strongly coupled to related

research efforts around the world through active collaborations with

leading scientist at several major facilities or institutions. This

program maintains a window for the Bureau into forefront research on the

fundamental structure of matter and provides a source of expert advice and

skills to other NBS scientists engaged in nuclear radiation measurements

or studies of radiation interactions at the nuclear level.

The CRR experimental program in this area is now being carried out at

world-class facilities operating or being constructed in the US and Canada

for fundamental nuclear and particle physics. This user mode of operation

has become necessary with the curtailment of operation of the NBS Linac

and the shift in commitment of the RTM to that of injector for the free

electron laser being constructed at NBS.

Theory activities are carried out by M. Danos, L.C. Maximon, S.

Meshkov, and J.S. O'Connell, while experimental work is carried out by

W. R. Dodge, E. Hayward, J.W. Lightbody Jr., and until recently,

X. K. Maruyama. Dr. Maruyama resigned in July and accepted a faculty

position at the Naval Postgraduate School in Monterey, California. The

experimental effort currently involves measurements at several major

nuclear facilities, including: the MIT/Bates laboratory, the SLAC/NPAS

facility, the Berkeley 88" Cyclotron, the Triangle Universities Nuclear

Laboratory (TUNL), the Saskatchewan linac/pulse stretcher CW electron

facility, the Indiana University Cyclotron Facility (IUCF), and other

1 aboratori es . The NBS Nuclear Group is also heavily involved in user

activities and planning for CEBAF, the DoE funded flagship facility

dedicated to nuclear research. This facility will be the center of

nuclear research in the US for the rest of this century. Theoretical

efforts include studies of coincidence electron scattering processes,

few-nucleon physics, CoulomD distortion and dispersive effects in electron

scattering, neutrino reaction rates, muon catalyzed fusion, quark gluon

plasmas and related phenomena, and the spectroscopy of elementary

particles using QCD. Approximately two-thirds of our theory effort is

related to intermediate energy nuclear physics, the balance in high energy

physics. Both the theoretical and experimental members of the group

continue to work at the forefront of particle and nuclear physics.

The NBS research program profits greatly from the participation of

guest scientists and col 1 aborators (university faculty and graduate

students), who extend our resources and bring in new ideas. This year

many visitors and guest scientists contributed to our basic and applied

231
research programs. The list of scientific colleagues who have

participated in collaborative research with the Nuclear Physics Group

includes: Everett Fuller, retired NBS Nuclear Physics Group employee;

Miles McCord, Hall Crannell, Dan Sober, and Larry Fagg from the Catholic

University of America; Dennis Skopik from the University of Saskatchewan,

Canada; Bent Schroder and co-workers from the University of Lund, Sweden;

Haaken Olsen from the University of Trondheim, Norway; Uohann Rafelski,

University of Arizona; George Chang and Chul Park, University of Maryland;

Ralph Fiorito and Don Rule from the Naval Surface Weapons Center. We

encourage these involvements and, additionally, have a seminar program

which brings outside speakers to NBS.

In addition to guest scientists visiting NBS, a few members of the

Nuclear Physics Group have had extensive stays at other nuclear

laboratories: M, Danos , Centre d'Etudes NuclSaires de Saclay, France;

Institute for Theoretical Physics, University of Frankfurt, West Germany;

Institute of Theoretical Physics and Astrophysi cs , University of Cape

Town, South Africa; L. Maximon , Centre d'Etudes Nucleaires de Saclay,

France; S . Meshkov , Aspen Center for Physics (Aspen, CO); Institute for

Theoretical Physics of the University of California at Santa Barbara; and

E. Hayward, Duke University. During this year, E. Hayward began a three

month leave to teach a graduate physics course at Duke University, and

U. Lightbody began a one year leave to become Program Director for

Intermediate Energy Nuclear Physics at the National Science Foundation.

These visits provide valuable new insights to our current research and

often provide the perspective to plan and direct our future research

activities.

This year the experimental part of the Nuclear Physics Group

underwent several changes. The most important of these is the

concentration on outside user activities. In support of our research, we have been highly successful in competing for beam time at various major

facilities, including MIT/Bates linac, Saskatchewan linac/pulse stretcher

ring, SLAC/NPAS, Berkeley 88" cyclotron, IUCF (detector tests), and the

Groningen (Holland) cyclotron. Although Xavier Maruyama, of our staff,

has left NBS to take a position as Professor of Physics at the Naval

Postgraduate School, we expect to have a continued involvement with him in

both our nuclear experiments and in our applied studies of transition

radiation and other sources of coherent radiation.

In the following sections we outline the groups primary research

activities during FY87. This list includes experimental activities at

other 1 aboratori es , electromagnetic nuclear physics theory, nuclear

theory, elementary particle physics, and miscellaneous activities.

External Activities . Last year we presented a proposal to study the

3 He(y,2p) reaction using a CW bremsstrahl ung beam at the Saskatchewan

linac/pulse stretcher ring facility in Saskatoon. This work will be

carried out using the 10 ua beam expected late calendar year 1987. The

goal of the experiment is to look for evidence of three-body effects in

232
nuclear photodisintegration. Laget has estimated the cross section

including three-body effects. The (y,2p) process should be down by two

orders of magnitude from the (y,pn) process. By selecting kinematics that

suppress the dominant one- and two-body dipole and quadrupole breakup

amplitudes, we hope to get an estimate of the magnitude of three-body

effects. By choosing photon energies below pion threshold we have a kinematically complete experiment when the proton energies and angles are measured, even when a bremsstrahl ung beam is used. Our plan is to use two

plastic scintillator DE-E telescopes for this measurement, which should

provide sufficient particle identification to separate 2-body and 3-body

breakup processes. We feel that the additional use of polarized gammas

from off-axis bremsstrahl ung may provide an extra handle on the nature of

any background processes related to the dominant quasi deuteron absorption

process. Collaborating in this experiment with the NBS group are researchers from the University of Saskatchewan, the University of Regina,

and the University of Maryland. Detectors and target cells have been

constructed. Detector tests have been performed at the parasite proton

beam facility at IUCF. This experiment will be the PhD thesis of C. Park

of the University of Maryland. (W.R. Dodge, J.W. Lightbody, and

J.S. O'Connell)

In a continuing effort, members of our group are collaborating with

H. Weller and M. Whitton of Duke University in an experiment to study the

D-state in 4 He. This experiment uses beams of vector and tensor polarized

deuterons provided by the 88" Berkeley cyclotron and by the University of

Groningen (Holland) cyclotron. Polarized deuterons are captured by the

deuterons in a CD 2 target and the ground-state capture gamma rays are detected over an angular range extending from 45 to 135 degrees. Tensor

and vector analyzing powers have been measured. New data have been taken

in which alpha/gamma coincidence techniques were employed to reduce backgrounds. Further measurements are planned using a spin precession

solenoid, in order to access other components of the analyzing power. A

number of interesting questions have arisen as a result of these data.

Our group provided one of the two detector systems used in this experiment. (W.R. Dodge and E. Hayward)

This year our group, in collaboration with groups from CEBAF,

University of Virginia, William and Mary College, and Stanford, has made a proposal to make an (e,e'p) measurement on 4 He at the SLAC/NPAS facility.

This is a forefront experiment to search for medium modifications to

nucleon electromagnetic structure functions when nucleons are bound in

nuclei. The experiment (NE16) was approved by the SLAC Program Advisory

Committee in a very strong competition for beam time. We have been given

the go-ahead for a month long run next year. The existing detection

systems for the SLAC 1.6 and 8 GeV spectrometers will have to be modified

to enhance the fast rejection of events not originating in the target.

This is a problem arising from the low duty factor of the SLAC

accelerator. Our group has assumed the responsibility for upgrading the

8 GeV detector package. This involves constructing two large plastic

233
scintillator hodoscopes with x-y position sensitivity. This experiment is

a predecessor for experiments to come when CEBAF comes on-line. It addresses questions about the quark substructure of nucleons and their

possible deconfinement in nuclei. (W.R. Dodge, J . W . Lightbody, and

J.S. O'Connell)

Our work at the MIT/Bates laboratory this year includes the following

list of currently active experiments in which we are involved, or those in

final stages of analysis:

(1) 238 U(e,e'f) in the delta resonance region,

(2) 52 Cr(e,e‘) 180 degree scattering,

(3) 3 H, 3 He( e ,e

1 )

,

(4) (e,e'p) quasielastic studies using polarized electrons,

(5) (e,e'p) ,(e,e'alpha) giant resonance decay,

(6) (e,e'p) quasielastic studies of attenuation lengths,

(7) (e,e'p) quasielastic studies of current operators,

(8) transition radiation studies.

The 238 U(e,e'f) work is in collaboration with the University of Lund

and University of New Hampshire nuclear physics groups. Preliminary data

were taken two years ago. When the fission data are integrated to give

the partial contribution to the inclusive results we obtain a rather flat

spectrum in energy loss. This is in contrast to the result expected on the basis of arguments that all knockout and delta processes at this

energy loss should lead to fission. Apparently in the quasielastic

scattering process at this momentum transfer there is insufficient

residual interaction to induce fission. However, in the delta region we

appear to arrive at the full inclusive cross section, consistent with the

delta damping strongly into many-body channels, and thus providing the

residual energy required to induce fission. During June 1987 new data for

238 U and 233 U were taken with the Bates 800 MeV electron beam, using

improved parallel plate avalanche detectors for the fission fragments.

These data are currently undergoing analysis. (W.R. Dodge,

J.W. Lightbody, J.S. O'Connell, and X.K. Maruyama)

The 52 Cr(e,e') 180 degree scattering experiment to study properties

of the first 2+ state transverse form factor is in final stages of

analysis. These data have been taken in collaboration with J. Flanz of

MIT and R. Lindyren of the University of Virginia. Data have been taken

at momentum transfers between 0.5 and 1.2 fur 1

. The preliminary results

have been compared with shell model calculations by R. Mooy of Drexel

University, and also with a result obtained from the measured longitudinal

form factor using the continuity equation to relate the transverse and

longitudinal form factors. The shell model results use effective charges

of 2.16e for protons and 1.16e for neutrons. Both the shell model and

phenomenological model fail to predict sufficient transverse strength.

DWBA calculations are planned during the coming year. (J.W. Lightbody and

X.K. Maruyama)

234
The 3 H, 3 He(e,e') experiment is a collaboration involving many of the

Bates users, too numerous to mention here. The target was a cooled gas

system developed at Bates, and was operated near 45 K. at a pressure of

approximately 220 psia. Data were taken at electron beam energies between

100 and 815 MeV, and for scattering angles between 54 and 134 degrees.

The data are being analyzed at Bates and at UVA. The primary results will

be improved radii determinations, threshold measurements to compare with

breakup calculations, quasielastic measurements, and measurement of the

delta production cross section. Together with earlier measurements on the

deuteron and recent Saclay data on 3 H, these data should provide a data

base with which stringent tests of few-body calculations can be made. The

elastic scattering results will be published in Physical Review Letters

shortly. All inelastic data are in the final stages of analysis, and will

be the basis for further publications. (W.R. Dodge, J.W. Lightbody, and

X.K. Maruyama)

A proposed (e,e'p) experiment to measure the polarization- related,

fifth structure function in the quasielastic region was deferred until

detector development could be made and a reliable polarized electron beam

was available. Work is continuing to develop large area, high-purity Ge

detectors, and to see if such detectors can be made to operate in the

Bates beam environment. Directors reserve beam time at Bates will be used

in the fall for this effort. Protons of 135 MeV kinetic energy will be

detected t backwards angles in the Ge detectors, and electron coincidences

will be sought in the ELSSY spect rometer. Recirculator energies will be

required. Calculations in support of this experiment have been performed

by VanOrden of the University of Maryland using a relativistic potential

model. We are currently examining several options for measuring the beam

polarization including (1) polarization of synchrotron radiation, (2)

Miller scattering from a magnetized iron foil, and (3) Compton

scattering of laser light by the electron beam. In addition to this work

we are conducting background tests this fall to determine operating

characteri sties of our out-of-plane spectrometer required in this

measurement. (W.R. Dodge, J.W. Lightbody, and J.S. O'Connell)

In collaboration with the University of Maryland, the University of

New Hampshire, Stanford, and MIT we are determining the feasibility of

measuring the (e,e'p) and (e,e'a) cross sections for 12 C and 16 0 in the

GDR excitation region. Initial studies made two years ago seemed

encouraging, but runs made in May 1985 indicated severe beam halo

problems. Progress in reducing the beam halo has been made recently by

observing the beam on a series of ZnS screens with holes in the center

through which the most intense part of the beam could pass. The most

recent tests indicate that the proposed experiments may indeed be possible

at Bates. (W.R. Dodge)

The A-dependence of the ratio of (e,e'p) coincidence to (e,e‘) events

was measured during this past year to determine the macroscopic

attenuation of 140 MeV nucleons. This was a collaborative study involving

Argonne National Laboratory, Northwestern University, MIT, the University

235
of Maryland, Mount Holyoke College, and NBS. The OHIPS spectrometer was used to detect 600 MeV/c electrons in coincidence with 400 to 600 MeV/c

protons detected in the BIGBITE spectrometer . The data from this experiment is presently under analysis and should provide information on proton

propagation in nuclei which is essential for the analysis of many

processes, including pion absorption and inclusive proton induced

reactions. (X.K. Maruyama)

The use of transition radiation as a source of hard x-rays for applications is being investigated in collaboration with M.A. Piestrup of

Adel phi Technology, M.J. Moran of LLNL, and B.L. Berman of George

Washington University. A Bates experiment was run during this past year

to demonstrate that high fluxes of x-rays can be obtained from high,

average current electron beams at moderate energies. The goal of the

preliminary experiment was to (1) to measure the absolute flux of x-rays

from foil stacks of transition radiators, and (2) to destructively test

these stacks over long periods of time. Potential applications for

transition radiation include uses for angiography, x-ray lithography, beam

diagnostics, and particle detection. This work is continuing.

(X.K. Maruyama)

In addition to the above active areas of investigation, we published

an expanded paper describing our earlier work (in collaboration with the

University of Lund, MIT, and UNH) on the excitation of the delta resonance

by forward angle electron scattering (J.S. O'Connell et al . , Phys. Rev.

Lett. 5_3, 1984.) The expanded work contains the complete data set

including data taken at 537 MeV as well as the 730 MeV data. Details of

the data analysis and comparison to 6-hole model calculations by Koch and

Ohtsuka were presented. The 6-hole calculations were found to underestimate the measured cross sections in the resonance region by about

20 percent, but describe the shape rather well. (W.R. Dodge,

J.W. Lightbody, X.K. Maruyama, and J.S. O'Connell)

In order to analyze data tapes generated by off-site collaborations,

a Digital MicroVAX II computer was acquired this year. A MicroVAX II is

directly compatible with the computers used in all of the laboratories

with which we now have collaborations. Installation of hardware and

software has begun. We will be installing the Los Alamos MP Group's Q

system in order to replay data taken at the MIT/Bates and Saskatchewan

labs. A link to the NBS CYBER computer will be established so that

network facilities of the NBS CYBER can be employed. This addition is a very important resource for our group's user activities. (W.R. Dodge,

J.W. Lightbody, and J.S. O'Connell)

Finally, this year we participated in an evaluation of synthetic

diamonds as radiation damage insensitive, radiation detectors. These

detectors have very poor resolution but are indeed very radiation

resistant. This study was undertaken at the request of the U.S. Army

standardization group stationed in London. The small size of these

detectors suggests their possible use as beam halo monitors in electron

scattering experiments. (W.R. Dodge)

236
Electromagnetic Nuclear Theory Activities . In connection with the

design of tagged photon systems, a detailed analysis of the fully

differential cross section and polarization for bremsstrahl ung is being

carried out for small angles and high energies of the final electron and

photon. In addition, simple, analytic closed form expressions have been

developed for the angular distribution of the scattered electron

(integrated over photon angles) including the effects of atomic screening.

A study of wide angle bremsstrahl ung has been initiated in order to

estimate the cross section for low energy photon production, extending

down to 10 1 s of keV. This fundamental work is being undertaken because of

the importance of this process to the successful operation of the 10-20 M$

large acceptance detector being built at CEBAF for an extensive program of

coincidence measurements. In addition to studies of bremsstrahl ung

,

analysis of electron and positron scattering from nuclei is continuing in

collaboration with experimentalists at the University of Illinois and at

the Division of High Energy Nuclear Physics, Saclay, France.

Investigation has continued into the photo and pionic disintegration of

few body systems ( 2 H, 3 H, 3 He), particularly in the region dominated by the

isobar (200-400 MeV). The aim is the formulation of a relatively simple

model for these reactions, for comparison with currently existing data, in

particular, the recent experimental data on the radiative capture of

polarized protons by deuterons. Finally, work is beginning on a calculation of continuum 3-body final states, including rescattering to

all orders. This work is a collaboration between NBS, George Washington

University, and several universities in Europe and Japan, and will be very

important in the analysis of data for a

3 He(y,2p) measurement which the

NBS experimental group has undertaken. (L.C. Maximon)

In addition to the above investigations, work is continuing in

connection with the momentum transfer dependence of the quasi -el asti c peak

position observed in electron scattering. This effect, observed for 4 He

and 1

2

C , can be related to the concept of effective mass and in turn to

momentum dependence in the mean field experienced by the knock-out

nucleon. This work is being carried out in collaboration with the

University of Lund photo-nuclear group. In a collaboration with E.

Dressier of Penn State, a calculation of the (e ,e

1 Nir ) cross section is

being carried out within the context of the Fermi gas model. This type of

calculation will be useful for estimating counting rates for experiments

planned for CEBAF and other CW electron beam facilities. The delta

resonance is a composite ttN system and dominates pion and photon reactions

at intermediate energies. Its production, propagation, and subsequent

decay into the pion-nucleon channel is therefore of great importance. In collaboration with T. Gaiser of the Bartol Research Foundation, work has

continued on calculating the spectra of leptons generated by cosmic ray

neutrinos. (J.S. O'Connell)

Finally, in connection with CEBAF planning, we are continuing to

examine the prospects for studying the two-nucleon knockout reaction with

the high energy beams planned for CEBAF. We are looking at the various

known processes that contribute to this reaction, including final state

237
effects, meson exchange currents, as well as initial state two-body

correl ati ons. We are also examining the processes that will form the

experimental backgrounds to the two-nucleon knockout reaction. We have

modeled the proton el ectro-producti on process including quasi-free knockout, delta production and decay, and quasi -deuteron breakup. We have also

modeled the single arm electron scattering process in the quasi-free,

delta production, higher resonance, and x-scaling regions. Through these

efforts we hope to find the sensitivity of the various measurable

structure functions to the processes of interest, using this as a guide to

plan measurements at CEBAF. We have produced a FORTRAN program for these

purposes. Many university nuclear groups around the country have utilized

this program for planning their experiments at the future CEBAF

laboratory. A published version of this effort will soon be available.

(J.W. Lightbody and J.S. O'Connell)

During this year we have continued to address the problem of the

polarizability of the nucleon. This quantity is of fundamental importance

relating to basic predictions of QCD, and plans are being drawn for the

experiinental study of both the electric and magnetic polarizability using

the new generation CW electron machines. The photonuclear absorption

cross section of the proton is dominated by the delta-resonance, a magnetic dipole state. This resonance overlaps an electric dipole

continuum and is followed at higher energies by other pion-nucleon

resonances of electric dipole and quadrupole character. It is difficult

to reconcile what we know about the total photo-absorption cross section

with the results of earlier and somewhat imprecise photon scattering

experiments, which conclude that the electric polarizability is ten times

the magnetic polarizability. The theoretical answer to this problem might

lay in a proper treatment of retardation effects. Experimentally, the

magnetic pol ari zabi 1 i ty should be better determined. One possibility is

to use a linearly polarized photon beam and measure the scattering

intensity along the polarization direction. (E. Hayward)

Nuclear Theory . The activities described in this section were carried

out by M. Danos and co-workers. In the past, nuclear forces have been

treated by computing a nucleon-nucleon 2-body force in terms of meson

exchanges between point nucleons treated n second order perturbati on

,

although it was realized that these nucleons were not point particles but

in fact occupied a large part of the volume of nuclei. Now the origin of

nuclear forces must be rethought in terms of the underlying quark

structure. There are two aspects to this problem. First, the short range

part of the interaction must be re-done in terms of explicit quark degrees

of freedom. The model available for this treatment is the bag model.

However, two-nucleon interactions in this model have six quarks in the

bag, and if an exchanged meson is included then there are seven quarks and

an anti -quark. There are many-body correlations among the quarks. A

program to investigate these forces has been started.

238
To replace the ad hoc boundary conditions of the bag model by a correct description of the hadron vacuum interface in fact requires a solution, or at least a semi -quanti tati ve understanding, of the confinement problem. In fact, it is nuclear physics which will have to yield

information on the confinement effect. As a first step one must achieve

an understanding, i.e., a description, of the vacuum itself before

considering the interface. It is widely believed that the confinement in

QCD, in analogy with superconductivity, results from the existence of a physical vacuum which is removed from the remainder of the spectrum by an energy gap, which exhibits a Mei ssner-Ochsenfel d effect, and which can not

be described by perturbative quantum field theory. More parti cul arly , it

is believed that these characteri sti cs of the physical vacuum result from

the infrared properties of QCD. Utilizing these considerations, an attempt is underway to construct a model of the QCD vacuum with the

techniques developed in the context of superconductivity theory.

The other aspect concerns the long-range part of the interaction,

i.e., that part where the microscopic structure of the vertex is

unimportant. There the many-body aspects of the system nucleon-plusmesons have to be accounted for, which are neglected in the presently

employed perturbation treatment of the nuclear force. This proper

description requires that the nucleus be treated as a relativistic manybody system. A program of such a treatment is underway.

A new emerging field of nuclear physics concerns the question of

explicit manifestations of QCD effects in nuclear reactions. A promising

approach is the observation of a quark-gluon plasma in the high energy

collision of two heavy nuclei. Diverse aspects of this subject are being

expl ored.

An example of the importance of quarks in the nucleus is a recent

study in which experiments at SLAC and CERN have been used to show that

between 2 and 10 percent of the quark wave function occupies the nucleus

as a whole rather than being correlated into individual nucleons.

In a more applied direction, work is continuing on the study of muon

catalyzed fusion. New experimental developments on the effectiveness of muons to catalyze d-t fusion have been impressive, with as many as 150

fusions per rnuon being produced. If this rate can be increased 2- or 3-fold, we will be on the verge of breakeven in raw energy production.

Atomic, molecular, and nuclear theorists are actively examining the theory

of this process to see where theoretical limits set in. This is a large

cross disciplinary effort. Our work was cited in a recent Scientific

American article examining this important and exciting field. (M. Danos.)

Elementary Particle Theory . The elementary particle theory program

under S. Meshkov is varied, with activity on several fronts. QCD : Two

comprehensive reviews of Glueballs and Meson Spectroscopy were presented

at the Division of Particles and Fields meeting of the American Physical

Society, Salt Lake City, January 1987, and at the Recontre de Moriond, Les

239
Arcs, France, March 1987. These reviews presented by S. Meshkov and done

in collaboration with W. Palmer and S. Pinsky of Ohio State University,

examined the most recent data on the i/E systems to elucidate the

quark/glue nature of these particles. Recent data implies that the

system is comprised of two or more states: a high mass state, the

i ( 1 460-1500 MeV), has JPC=0"+ and has a considerable amount of glue in its

wave function. The low mass state (or states) around 1420 MeV, has

JPC=0"+ and /or 1 ++

. The latter states are of interest in understanding

hadron spectroscopy, t-quark mass : Recent experiments on B°-B° mixing

imply a mass for the t (top) quark of greater than 100 GeV. This is far

higher than previously anticipated. A new area of research by S. Meshkov,

in collaboration with P. Kaus (U.C.- Riverside), has been to find mass

matrices that explain the quark spectroscopy for the u(up), d(down),

s(strange), c(charm), b(bottom), and t(top) quark masses. Carrying out

thi s_ program involves research on CP violation as manifested by K0-K0 and

B^-B 0 mixing. This study also involves predicting the spectrum of heavy

tt states, meson states, which provides the first spectroscopic test of

the running of the strong coupling constant as predicted by asymptotic

freedom.

Miscellaneous Activities . During the past year members of our staff

have participated extensively in outside activities. S. Meshkov has been

heavily involved in the administration of the Aspen Center for Physics as head of the Summer Program Committee and as Chairman of the 1988 Aspen

Elementary Particle Physics Winter Conference. J.S. O'Connell continues

his activities on the Physical Review C Editorial Board. He delivered

lectures at the NSF sponsored National Summer School on Intermediate

Energy Nuclear Physics, held at Georgetown University. E. Hayward

continues as a member of the American Physical Society's DNP Executive

Board, and the Southeastern Universities Research Association (SURA) Board

of Directors. She is Chairperson of the 1988 Spring Meeting of the

American Physical Society to be held in Baltimore. X.K. Maruyama was responsible for the successful FEL proposal and 5 M$ construction award

made to NBS early in 1987. This facility will be one of the major new NBS

research facilities during the coming decade. M. Danos was responsible

for running a DoE sponsored workshop on muon catalyzed fusion, which is

becoming an important and promising new direction for long range planning

of energy production in the U.S. J.W. Lightbody chaired the multi-hadron

working group at CEBAF, is Chairman of the CEBAF Users Group, and served

on the CEBAF National Advisory Board (NAB) and Program Advisory Committee

(PAC). He serves on the Saskatchewan Accelerator Laboratory PAC, lectured

at the Summer School for Intermediate Energy Nuclear Physics held at the

International Center for Theoretical Physics in Trieste (Italy), and is now on temporary assignment to the NSF as Program Director for

Intermediate Energy Nuclear Physics. Every member of the group has given

lectures at other institutions and participated heavily in user

240
activities. The theorists of the group have, in addition to carrying out

their own research, provided guidance and advice to the experimental

members of the group whenever needed.

We feel that the Nuclear Physics program represents the long range

NBS goals in nuclear research, and there is a growing vitality and

enthusiasm from strong involvement with the larger nuclear research

community. The theoretical efforts cover the full spectrum of current

interest in nuclear research. The experimental effort represents a strong

fundamental research program which makes full use of world class

faci 1 i ti es.

241
SPONSORED WORKSHOPS, CONFERENCES AND SYMPOSIA

Division 530.01, Nuclear Physics Group

Danos, Michael, Workshop On Muon Catalyzed Fusion, Department of Energy,

April 29-30, 1987.

242
INVITED TALKS

Division 530.01, Nuclear Physics Group

Danos, Michael, "Anomalies In Quantum Field Theories", Physics Seminar,

University of Bonn, Germany, February 26, 1987.

Danos, Michael, "Recent Developments In D-T Muon Catalyzed Fusion; Outlook

For The Future", Physics Seminar, University Of Maryland, Baltimore,

Maryland, April 6, 1987.

Danos, Michael, "Sticking In Muon Catalyzed Fusion", International

Symposium Muon Catalyzed Fusion - 87, Gatchina, Leningrad, May 26-29,

1987.

Danos, Michael, "Interplay Of Molecular And Nuclear Degrees Of Freedom In

Muon Catalyzed D-T Fusion", Physics Seminar, Rutgers University, New

Brunswick, New Jersey, September 14-15, 1987.

Dodge, William R., "Differential Virtual Photon Spectra For All Electric

Multi poles In The Long Wavelength Approximation", APS Meeting, Denton,

Texas, November 10-12, 1986.

Hayward, Evans V., "The Polarizability Of The Nucleon", Physics Seminar,

Duke University, Durham, North Carolina, October 2, 1986.

Hayward, Evans V., "The Pol ari zabil i ty Of The Nucleon", Physics Seminar,

Center For Radiation Research, National Bureau Of Standards, Gaithersburg,

Maryland, December 4, 1987.

Hayward, Evans V., "The Polarizability Of The Nucleon", Physics Seminar,

University Of Maryland, College Park, Maryland, April 6, 1987.

Hayward, Evans V., "The Polarizability Of The Nucleon", Kernfysisch

Versneller Instituutder Ri jksuni versi tei t, Gronigon, The Netherlands,

September 8, 1987.

Lightbody, John W., "A Program Of (e,e'2N) Reaction Studies At CEBAF",

CEBAF, Newport News Virginia, February 13, 1987.

Lightbody, John W., "(e,e'2N) Reactions AT CEBAF", International Summer

School On Intermediate Energy Nuclear Physics, Trieste, Italy, May 21,

1987.

Lightbody, John W., "(e,e'2N) Knockout Reactions", CEBAF Summer Workshop,

Christopher Newport College, Newport News, Virginia, June 24, 1987.

243
Division 530.01 , Invited Talks (cont'd)

Lightbody, John W., Summary: "Working Group On Multihadron Knockout

Reactions", CEBAF Summer Workshop, Christopher College Newport College,

Newport News, Virginia, June 26, 1987.

Lightbody, John W., "The 3 He(y,2p) Reaction And The Three-Body Force",

Saskatchewan Accelerator Laboratory, University Of Saskatchewan,

Saskatchewan, Canada, August 11, 1987.

Lightbody, John W., "A Study Of Three-Body Forces Using The 3 He(y,2p)

Reaction", University Of Maryland, September 28, 1987.

Maruyama, Xavier K., "Microwave Cerenkov Radiation As A Diffraction

Phenomenon", 9th Conference On The Application Of Accelerators In Research

And Industry, North Texas State University, Denton, Texas, November 12,

1986.

Maruyama, Xavier K., "Cerenkov Radiation As a Diffraction Phenomenon",

Plasma Fusion Center Seminar, Massachusetts Institute Of Technology,

Cambridge, Massachusetts, March 13, 1987.

Maruyama, Xavier K., "Threshold Cerenkov Radiation And Beam Diagnostics",

1987 Particle Accelerator Conference, Omni -Shoreham Hotel, Washington,

D.C., March 16-19, 1987.

Maximon, Leonard C., "Tagged Photons", Saskatchewan Accelerator

Laboratory, University of Saskatchewan, Saskatchewan, Canada, October 16,

1986.

Meshkov, Sydney, "Glueballs And Meson Spectroscopy", Physics Department,

University of Washington, Seattle, Washington, October 12, 1986.

Meshkov, Sydney, "Glueballs And Meson Spectroscopy", Nuclear, Radiological

And Accel erator Physics Seminar, Center For Radiation Research, National

Bureau Of Standards, Gaithersburg, Maryland, November 7, 1986.

Meshkov, Sydney, "i/E System", DPF Meeting of American Physical Society,

Salt Lake City, Utah, January 11-17, 1987.

Meshkov, Sydney, "Glueballs and the i/E System", Theoretical Seminar,

University of Florida, Gainesville, Florida, February 3, 1987.

Meshkov, Sydney, "Glueballs and Meson Spectroscopy", Colloquim, University

of Miami, Coral Gables, Florida, February 10, 1987.

O'Connell, James S., "Electromagnetic Excitation Of The Delta Resonance In Nuclei", Brookhaven National Laboratory, Upton, New York, November 18,

1986.

244
PUBLICATIONS

Division 530.01, Nuclear Physics Group

Beck, D., J. W. Lightbody, Jr., et al , Elastic Electron Scattering from 3 H

3 He at Low Q, Proceedings, PANIC Conference, Sendai, Japan, (1987).

Danos, M., B. Muller, and J. Rafel ski , Detuning Reduction of Muon Sticking

in Resonant Muon-Catalyzed d-t Fusion, Phys. Rev. A34 , 3642 (1986).

Danos, M., B. Muller, and J. Rafel ski , Comment on Muon-Alpha-Particle

Sticking Probability in Muon Catalyzed Fusion, PHys. Rev. A35, 2741

(1987).

Danos, M., The QCD Vacuum, Maratea Summer School, W. Greiner, ed., Plenum

Pres (1987).

Lightbody, J. W., Jr., Possible (e,e'2N) Experiments at CEBAF,

Proceedings, International Summer School on Intermediate Energy Nuclear

Physics, Trieste, Italy, (1987).

Maximon, L.C., A. de Miniac, T. Aniel, and E. Ganz, Tagged Photons, An

Analysis of The Bremsstrahl ung Cross Section, Physics Reports, 147, No. 4

(1987).

Maximon, L.C. and S. E. Williamson, Piece-Wise Analytic Evaluation of

the Radiative Tail from Elastic and Inelastic Electron Scattering, Nucl . Instr. Methods in Physics Research A258, 95 (1987).

Meshkov, S., Glueballs and Meson Spectroscopy, Proceedings of Aspen Winter

Conference 1986 (1987).

O'Connell, J. S., et al , Electromagnetic Excitation of the Delta Resonance

in Nuclei Conference on Pion Nucleus Physics, Los Alamos, New Mexico,

(1987).

Rafel ski , J., B. Muller, and M. Danos, Muon Sticking in Catalyzed d-t

Fusion: Nuclear Resonance Effects, Proceedings, 4th International

Conference on Emerging Nuclear Energy Systems, 1986, Madrid, G. Velarde

and E. Minguez eds., World Scientific Publishing Co., Singapore (1987).

Rafel ski , H., B. Muller, J. Rafel ski , D. Trautman, R. D. Viollier and M.

Danos, Muon Sticking in Muon-Catalyzed d-t, Fusion, Mu. Cat. Fus. 1, 315

(1987).

245
Division 530.01, Publications (cont'd)

Rafel ski , J., and M. Danos, Possible Signature for and Early Hadroni zation

Mechanisms of Quark-Gluon Plasma, Phys. Lett. B192 , 432 (1987).

Tupper, G., M. Danos, B. Muller, and J. Rafel ski , On the Detection of

Cosmic-Background Neutrinos by Acoustic Phonon Scattering, Phys. Rev. D35,

394 (1987).

Whitney, R., J. W. Lightbody, Jr., et al , Inelastic Electron Scattering

from 3 H and 3 He, Proceedings, Particle and Nuclear Physics Interface

Conference (PANIC), Sendai, Japan, (1987).

246
PUBLICATIONS IN PREPARATION

Division 530.01, Nuclear Physics Group

Cardman, L. (Univ. Illinois), W. P. Trower (VPISU), Lightbody, J. W., Jr

Elastic Electron Scattering from 12 C.

Danos, M., L. C. Biedenharn, A. Stahl hofen, J. Rafel ski , and B. Muller,

Theory of the Muon-Catalyzed d-t Fusion.

Danos, M. and L. C. Biedenharn, Anomalies in Lagrangian Field Theory,

Phys. Rev. D (in press).

Flanz, J. and J. W. Lightbody, Jr., 180° Electron Scattering from the

Low-lying States in 52 Cr (MIT).

Maximon, L. C., D. R. Lehman, and J. L. Friar, Coni omb Effects in

Asymptotic Normalization Constants: A Soluble Model, (submitted to Phys

Rev. C).

Meshkov, S., i/E System, Proceedings of DPF Meeting of American Physical

Society, Salt Lake City, Utah.

Meshkov, S., Current View of i/E System, Proceedings of XXII Rencontre d

Moriond, Les Arcs, Savoie, France.

O'Connell, J. S., and J. W. Lightbody, Jr., Modeling Single Arm Electron

Scattering and Nucleon Production from Nuclei by GeV Electrons.

247
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 530.01, Nuclear Physics

Hayward, E. V.

Member, Program Committee for the Conference on Fifty

Years of Fi ssi on.

Member, SURA Board of Trustees.

Member, Subcommittee on Science and Technology of SURA.

Chairman, Program Committee for the Spring meeting of the APS.

Member, Real Photon Collaboration (Mainz).

Lightbody, J. W., Jr.

Chairman, CEBAF User Group.

Member, CEBAF National Advisory Board.

Member, CEBAF Program Advisory Committee.

Member, University of Saskatchwan Accelerator Laboratory Program

Advisory Committee.

Director, NSF Intermediate Energy Nucl ear Physics Program (as of

September 14, 1987).

Chairman, CEBAF (e,e'2N) Working Group.

Co-Chairman, CEBAF Multihadron Knockout Working Group, CEBAF 1987

Summer Workshop.

Meshkov, S.

Member, Organizing Committee 1987 Aspen Winter Elementary Particle

Physics Conference.

Chairman, Organizing Committee 1988 Aspen Winter El erne nt ry

Particle Physics Conference.

Member, Advisory Board, Aspen Center for Physics.

248
Division 530.01 , Technical and Professional Committee Participation and

Leadership (cont'd)

Meshkov, S.

Member, Interagency Seminar Series (Wash).

Member, Keystone Committee on Future Funding of American Science.

Chairman, Program Committee for Summer 1988 Aspen Center for

Physic s.

0 ' Connel 1 , J. S.

Member, Editorial Advisory Board for Physical Review C.

President, Users Group, Bates Linear Accel ereator Center.

249
MAJOR CONSULTING AND ADVISORY SERVICES

Division 530.01, Nuclear Physics

J. W. Lightbody, Jr. consulted with The Physical Review C_.

J. W. Lightbody, Jr. consulted with DoE Intermediate Energy Nuclear Pysics

Grants Program.

J. W. Lightbody Jr., consulted with Program Advisory Boards of CEBAF and

the University of Saskatchewan Accelerator Laboratory.

J. W. Lightbody, Jr., participated on National Advisory Board, CEBAF,

Newport News, Virginia.

L. C. Maximon consulted by invitation, with experimentalists at Brookhaven

National Laboratory and planned experiments on photon scattering.

L. C. Maximon consulted by invitation, with experimentalists at the

Saskatchewan Accelerator Laboratory, University of Saskatchewan,

Saskatoon, Saskatchewan, Canada, on the design of a tagged photon system

for the accelerator laboratory.

L. C. Maximon consulted by invitation, with experimentalists at the Linear

Accelerator of the Center for Nuclear Studies, Saclay, France, on the

design of photon tagging systems.

L. C. Maximon consulted by invitation, with experimentalists at the

Nuclear Physics Laboratory of the University of Illinois at Urbana,

Champaign, on the analysis of position scattering experiments.

L. C. Maximon consulted by invitation, with experimentalists at CEBAF,

Newport News, Virginia, on the analysis of background radiation in

conjunction with large angle spectrometers.

S. Meshkov helped organize QCD - Glueball session for Moriond; also

advised Moriond organizers on future relationship between Aspen and

Mori ond

.

S. Meshkov participated in SSC meeting of states.

250
TRIPS SPONSORED BY OTHERS

Division 530.01, Nuclear Physics Group

Danos, M., Centre d'Etudes Nucleaire de Saclay, France, January 15-30,

1987; CERN, Switzerland, February 1-14, 1987; University of Bonn, West

Germany, February 15-March 4, 1987.

Dodge, W. R., Consultation with members of the Nuclear Physics Laboratory

of the City University of Sao Paulo, Brasil, February 1-18, 1987.

Hayward, E. V., Participation in an experiment, and seminar at Duke

University, Durham, North Carolina, September 27-0cotber 3, 1986.

Hayward, E.V., Participated in an experiment at TUNL, North Carolina,

March 26-April 3, 1987.

Hayward, E.V., Worked on experiment in Berkeley, CA May 28-June 13. This

trip was also jointly sponsored by TUNL, The Lawrence Berkeley Lab, and

The Hayward Foundation.

Hayward, E.V., Traveled to Europe, August 24-September 15 and attended a workshop and a conference on capture gamma-rays. Also participated in an experiment on D-D Capture in Gronigen. This trip was jointly supported by

NBS, Kernfysisch Versneller Institut, and The Hayward Foundation.

Lightbody, J. W., Jr., University of Virginia, Consultation, December,

1986.

Lightbody, J. W., Jr., CEBAF Program Advisory Committee Meeting, February

19-21, 1987, sponsored by CEBAF.

Lightbody, J. W., Jr., Trieste International Summer School on Intermediate

Energy Nuclear Physics; Trieste, Italy, May 18-22, 1987 sponsored by the

International Center for Theoretical Physics.

Lightbody, J. W., Jr., CEBAF Summer Workshop, Chri stopher Newport College,

Newport News, Virginia, June 22-26, 1987 sponsored by CEBAF.

Lightbody, J. W., Jr., University of Saskatchewan Accelerator Laboratory

Mi ni workshop , August 10-13, 1987, sponsored by University of

Saskatchewan.

Maximon, L. C., Saskatchewan Accelerator Laboratory, University of

Saskatchewan, Saskatoon, Saskatchewan, Canada, October 15-19, 1986.

251
Division 530.01, Trips Sponsored by Others (cont'd)

Maximon, L. C., Center for Nuclear Studies, Saclay, France, December

20-January 12, 1987.

Maximon, L. C., Beijing, PRC International Symposium on Medium Energy

Physics, June 23-27, 1987.

O'Connell, J. S., Brookhaven National Laboratory November, 1986.

O'Connell, J. S., University of Virginia, January 1987.

O'Connell, J.S., Los Alamos National Laboratory, Los Alamos New Mexico,

August 1987.

252
CALIBRATION SERVICES PERFORMED

Division 530.01, Nuclear Physics

Pennsylvania State University, high energy physics detector calibration

using the NBS Li nac . University of Indiana, calibration using a hadron detector system.

253
SPONSORED SEMINARS

Division 530.01, Nuclear Physics

J. M. Laget, Center for Nuclear Studies, Saclay, France, Studies of

Correlations Using Electron Scattering, July 9, 1987.

254
LIST OF ACRONYMS

AAMI

AAPM

AEC

AERE

AFRRI

AIF

ANL

ANS

ANSI

APRES

APS

ASNT

ASTM

Association for the Advancement fo Medical Instrumentation

American Association of Physicists in Medicine

Atomic Energy Commission

Atomic Energy Research Establishment (U.K.)

Armed Forces Radiobiology Research Institute

Atomic Industrial Forum

Argonne National Laboratory

American Nuclear Society

American National Standards Institute

Angle Resolved Photoelectron Spectroscopy

American Physical Society

American Society for Nondestructive Testing

American Society for Testing and Materials

Beval ac BGO

BIPM

Name of a heavy ion accelerator at Berkeley

Bismuth germanate

Bureau International des Poids et Mesures

BPNL

BSDF

(International Bureau of Weights and Measures)

Battel 1 e-Pacific Northwest Laboratory

Bidi recti onal Scattering Distribution Function

CAC

CAD

CAE

CEA

CEA

CAMAC

CCEMRI

CCPR

CEBAF

CERN

CIE

CIPM

CIRRPC

Center for Analytical Chemistry

Computer-aided Design

Computer-aided Engineering

(French) Atomic Energy

(U.S.) Council for Energy Awareness

Computer Automated Measurement and Control

Consultative Committee for Ionizing Radiations (to CIPM)

Consultative Committee on Photometry and Radi oinet ry

Continuous Electron Beam Accelerator Facility

European Center for Nuclear Research (Switzerland)

International Commission on Illumination (French)

Comite International des Poids et Mesures

Committee on Interagency Radiation Research and Policy

Coordination, OSTP

CRCPD

CRDS

CRR

CSEWG

CW

Conference of Radiation Control Program Di rectors

Charles River Data System

Center for Radiation Research

Cross Section Evaluation Working Group

Continuous Wave

DNA

DoC

DOD

DOE

DOELAP

DRIP

DSA

DTS

DWBA

Deoxyribose nucleic acid

Department of Commerce

Department of Defense

Department of Energy

Department of Energy Laboratory Accreditation Program

Detector Response Intercomparison Package

Digital Subtraction Angiography

Dual thin scintillator

Distorted Wave Born Approximation

255
ACRONYMS (Continued)

EC

EEO

ELSSY

EMA

ENDF

EPA

ESONE

ESR

ETL

EURADOS

Electron Capture

Equal Employment Opportunity

Energy Loss Spectrometer System

Ellipsoidal Mirror Analyzer

Evaluated Nuclear Data File

Environmental Protection Agency

European Standards on Nuclear Electronics

Electron spin resonance

Electro-Technical Laboratory (Japan)

European Community Dosimetry Committee

FASCAL

FDA

FEMA

FEL

FERDoR

FGR

FIMS

FOS

FT

FTIR

FWHM

FY

Facility for Automatic Spectroradiometric Calibrations

Food and Drug Administration

Federal Emergency Management Agency

Free Electron Laser

(computer code)

Federal Republic of Germany

Fissionable Isotope Mass Standards

Faint Object Spectrograph

Fourier Transform

Fourier Transfor Infrared

Full Width at Half Maximum

Fiscal Year

GC/MS

GDR

GPIB

Gas chromatography/mass spectrometry

Giant Dipole Resonance

General Purpose Instrumentation Bus

HAFM

HPGe

HPLC

HP

HPS

HPS

HVL

Helium Accumulation Fluence Monitor

High-purity germanium detector

High performance liquid chromatography

Hewlett Packard

High Pressure Sodium

Health Physics Society

Half-value layer

IAEA

IAU

IBM

ICIAQ

ICRM

ICRU

IEC

IEEE

IMFP

INEL

INMM

International Atomic Energy Agency (Vienna)

International Union

International Business Machine Corporation

Interagency Committee on Indoor Air Quality

International Committee for Radionuclide Metrology

International Commission on Radiation Units and Measurements

International Electrotechnical Commission

Institute of Electrical and Electronics Engineers

Inelastic Mean Free Path

Idaho National Engineering Laboratory

Institute for Nuclear Materials Management

256
ACRONYMS (Continued)

IPNS

IR

ISCC

ISNF

ISO

ITP-UCSB

IUCF

JAERI

JEN

JET

KEK

KENS

KRI

LANL

LBIR

LEED

LET

LINAC

LLNL

LTEC

MCNP

MEA

MIRD

MIT

MQA

MRG

NAB

NAM

NASA

NAS-NRC

NBS

NCAR

NCRP

NCSL

NDE

NUT

NESSUS

NIM

NIR

nmNPL

\

Intense Pulsed Neutron Source

Infrared

Inter-Society Color Council

Intermediate Energy Standard Neutron Field

International Organization for Standards

Institute for Theoretical Physics - University of

California, Santa Barbara

Indiana University Cyclotron Facility

Japan Atomic Energy Research Institute

Junta de Energia Nuclear (Spain)

Joint European Torus

National Laboratory for High Energy Physics (Japan)

High Energy Neutron Source (Japan)

Khlopin Radium Institute (USSR)

Los Alamos National Laboratory

Low Background Infrared

Low Energy Electron Diffraction

Linear Energy Transfer

Linear Accelerator

Lawrence Livermore National Laboratory

Lamp Testing Engineer's Conference

(computer code)

Materials Engineering Associates

Medical Internal Radiation Dose (committee)

Massachusetts Institute of Technology

Measurement quality assurance

Materials Research Group

National Advisory Board

National Atomic Museum

National Aeronautical and Space Administration

National Academy of Sciences-National Research Council

National Bureau of Standards

National Center for Atmospheric Research

National Council on Radiation Protection and Measurements

National Conference of Standards Laboratories

Nondestructive evaluation

Nondestructive testing

Reactor pressure vessel irradiation mockup facility

Nuclear Instrumentation Module

Near Infrared

Nanometer

National Physical Laboratory (U.K.)

257
ACRONYMS (Continued)

NRL Naval Research Laboratory

NRRS Near resonance Rayleigh scattering

NSF National Science Foundation

NSLS National Synchrotron Light Source

NTOFF Neutron Time-of-Fl i ght Facility

NVLAP National Voluntary Laboratory Accreditation Program

ONR Office of Naval Research

ORNL Oak Ridge National Laboratory

OSA Optical Society of America

OMEGA 24 Beam Laser Facility at Rochester

P Polarization parallel to plane of incidence

PAC Program Advisory Committee

PAC Particle Accelerator Conference

PC Personal Computer

PID Post irradiation dosimetry

PNL Battel le Pacific Northwest Laboratories

PRC People's Republic of China

PRT Proton recoil telescope

PSD Photon Stimulated Desorption

PTB Pnysi kal i sch-Techni sche Bundesanstal t (West Germany)

PTFE Polytetraf 1 uoroethylene

PTW Physi kal i sch-Techni sche Werkstatten

QA Quality assurance

QCD Quantum Chromodyanimcs

QED Quantum electrodynamics

RARAF Radiological Research Accelerator Facility (Columbia

Uni versity)

RF Radio Frequency

RFP Request for Proposals

RIMS Resonance Ionization Mass Spectrometry

RIS Resonance Ionization Spectroscopy

RTM Racetrack Microton

S Polarization perpendi cul ar to plane of incidence

SCK-CEN Studiecentrum voor Kernenergi e-Centre d'Etude de l'Energie

Nucleaire (Belgium)

SDIO Strategic Defense Initiative Office

SEM Scanning Electron Microscope

SEMPA Scanning Electron Microscopy with Polarization Analysis

SIRIS Sputter Initiated Resonance Ionization Mass Spectrometry

SLAC Stanford Linear Accelerator Center

SLAC/NPAS Stanford Linear Accelerator Center/Nucl ear Physics At Stanford

Linear Accelerator Center

258
ACRONYMS (Continued)

SNS

SPAO

SPIPES

SRM

SSTR

STM

STOS

SURA

SURF

Spallation Neutron Source

Neutron exposure estimating code

Spin Polarized Inverse Photoemission

Standard Reference Material

Solid State Track Recorder

Scanning Tunneling Microscope

Space Telescope Optical Simulator

Southeastern Universities Research Association

Synchrotron Ultraviolet Radiation Facility

TAMS

TC

TEPC

TEXT

TLD

TRIGA

TUD

TUNL

TUO

Tandum Accelerator Mass Spectrometry

Technical Committee

Tissue Equivalent Proportional Counter

Texas Experimental Tokamak

Thermoluminescent Detector

(research reactor design made by General Atomic)

Technical University of Dresden (East Germany)

Triangle Universities Nuclear Laboratory

TEXT Users Organization

UK

UNH

UPS

URPs

USSR

USUHS

UV

UVA

United Kingdom

University of New Hampshire

Ultraviolet Photoemission Spectroscopy

Unique radiolytic products

Union of Socialist Soviet Republic

Uniformed Services University of Health Sciences

U1 traviol et

University of Virginia

VI AS

VIS

VME

VUV

(computer code)

Vi si bl

e

(computer bus system)

Vacuum Ultraviolet

WNR-PSR Weapons Neutron Source-Proton Storage Ring (Los Alamos)

XUV Soft X-Ray and Ultraviolet Wavelength Range, 4-50 nm

259

NBS-114A (rev. 2 -ec) U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET (See instructions)

4. TITLE AND SUBTITLE

1. PUBLICATION OR

REPORT NO. NBSIR-87-3571

2. Performing Organ. Report No. 3. Publication Date OCTOBER 1987

Technical Activities 1S87

Center for Radiation Research

5. AUTHOR(S)

C. E. Kuyatt

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions) 7. Contract/Grant No. NATIONAL BUREAU OF STANDARDS

U.S. DEPARTMENT OF COMMERCE

GAITHERSBURG, MD 20899

8. Type of Report & Period Covered

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. Stote, ZIP)

10.

SUPPLEMENTARY NOTES

J Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bi bliography or literature survey, mention it here)

This report summarizes research projects, measurement method development,

calibration and testing, and data evaluation activities that were carried

out during Fiscal Year 1987 in the NBS Center for Radiation Research.

These activities fall in the areas of atomic and plasma radiation,

radiation physics, radiometric physics, radiation sources and instrumentation,

ionizing radiation, and nuclear physics.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) Atomic radiation, ionizing radiation; measurement support; nuclear radiation;

plasma radiation; radiation instrumentation, radiation measurements; radiation

physics, radiation sources; radiometric physics.

13. AVAILABILITY

| X| Unlimited

| | For Official Distribution. Do Not Release to NTIS

~~\ Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

QX] Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

265

15. Price

$24.95

U ScOMM-DC 6043-P80

*U. S. GOVERNMENT PRINTING OFF ICE : 1 987 -1 9 5-904 : 70432