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Center for Radiation Research

U.S. DEPARTMENT OF COMMERCE

National 8ureau of Standards

National Measurement Laboratory

Center for Radiation Research

Washington, DC 20234

February 1983

DEPARTMENT OF COMMERCE

)NAL BUREAU OF STANDARDS
I

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NBSIR 83-2654

TECHNICAL ACTIVITIES 1982

CENTER FOR RADIATION RESEARCH

NATIONAL BUREAU

OF STANDARDS

LIBri'.P.Y Mar p | u

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Chris E. Kuyatt, Director

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Measurement Laboratory

Center for Radiation Research

Washington, DC 20234

February 1 983

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director
IIIIIII
ABSTRACT

This report summarizes research projects, measurement method development, testing and data evaluation activities, carried out during Fiscal Year

1982 in the NBS Center for Radiation Research. These activities fall in the

areas of radiation measurements, atomic and plasma radiation, nuclear radiation,

radiation physics, radiometric physics, and radiation sources and instrumentation.

Key Words: Atomic radiation; nuclear radiation; plasma radiation; radiation

instrumentation; radiation measurements; radiation physics;

radiation sources; radiometric physics.

i
INTRODUCTION

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

Center for Radiation Research (CRR) for the period October 1, 1981 to

September 30, 1982. The Center is one of five 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, measurements

methodology, and measurement services in the areas of optical radiation,

ultraviolet radiation, and ionizing radiation (x rays, gamma rays, electrons,

neutrons, and radioactivity); provides government, industry, and the private

sector with essential calibrations for field radiation measurements needed

in such applied areas as nuclear power, 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 understanding of atomic,

molecular, and nuclear radiation processes; collects, compiles, critically

evaluates and supplements the existing atomic, molecular, and nuclear data

base in order to meet the major demands of the nation for such data; and

participates in collaborative efforts with other NBS Centers in the interdisciplinary applications of radiation.

The summary of activities is organized in six parts, one for the Office

of Radiation Measurement, and one for each of the five Divisions in the

Center: Atomic and Plasma Radiation, Nuclear Radiation, Radiation Physics,

Radiometric Physics, and Radiation Sources and Instrumentation. Each Division

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, Washington, D.C. 20234.
Table of Contents

ABSTRACT o ,

-j

INTRODUCTION ii

OFFICE OF RADIATION MEASUREMENT - 530 1

Invited Talks 7

Publications 8

Technical & Professional Committee Participation & Leadership ... 9

Major Consulting and Advisory Services 10

ATOMIC AND PLASMA RADIATION - Division 531 ........ 11

Atomic Spectroscopy Group ............. 12

Vacuum UV Spectra of Atomic Ions

Atomic Inner-Shell Photoabsorption

Laser Spectroscopy

Atomic Energy Levels Data Center

Atomic Radiation Data Group 14

Theoretical Studies

Data Center

Plasma Radiation Group 15

Colli si onal Rate Coefficient Studies with the 50 kj

Theta Pinch

Tokamak Spectroscopy

Strongly Coupled Plasma

Stark Effect on Autoionization Resonances

Colli sional Redistribution of Radiation

Stark Broadening, Shifts and Asymmetries of Hydrogenic

Ion Lines

Rayleigh Scattering

Vacuum Ultraviolet Radiometry with Plasmas

Quantitative Spectroscopy of D.C. Arcs

Sponsored Conferences 20

Invited Tal ks 21

Publications 23
Technical & Professional Committee Participation & Leadership . . . 27

Major Consulting and Advisory Services 28

Journal Editorships 29

Trips Sponsored by Others 30

Calibration Services Performed 31

NUCLEAR RADIATION - Division 532 .... 32

Dosimetry Standards for Neutron Radiation Therapy

Nuclear Theory Group 34

Elementary Particle Theory

Nuclear Theory

Photonuclear Theory

Theoretical Neutron Dosimetry

Neutron Personnel Monitoring

Civil Defense

Nuclear Research Group 38

Neutron Measurements and Research Group 39

Neutron Field Standards Group 42

Radioactivity Group 47

Standard Reference Materials and Calibration Services

Basic Activity and Nuclear Data Measurements

Other Agency Programs

International Activities

Sponsored Conferences 51

Invited Talks 52

Publications 54

Technical & Professional Committee Participation & Leadership ... 61

Major Consulting and Advisory Services 67

Journal Editorships 69

Trips Sponsored by Others 70
Standard Reference Materials 72

Calibration Services Performed. .................. 74

RADIATION PHYSICS - Division 533 ... 77

Radiation Theory Group 78

Radiological Physics

Cross Sections

Radiation Protection - Civil Defense

Dosimetry Group 81

Calibration and Measurement Assurance Services

Calorimetry

High-Energy Measurement-Assurance Services

Radiation Protection Dosimetry

X-Ray Physics Group ........ 85

Medical Radiography

Industrial Radiography

Pulse Radiolysis

Far Ultraviolet Physics Group 89

Angle Resolved Photoelectron Molecular Spectroscopy

Photoel ectron- Photo ion Coinci dence

Polarized Fluorescence

Surface Science

New High Energy Capability at SURF

Electric Field Effects

The Angular Asymmetry Parameter of Silver

Dosimetry for Industry and Defense

Solid State Studies

He Microbubbles

Laser Prepared States

Symmetry of n=2 State in Helium

Lithography

Photoabsorption Studies of Laser-Ionized Species

Improved Radiometric Accuracy

Spectrometer Calibrations

Transfer Standard Detectors

Electron Physics Group 97

Surface Magnetism and Electron Diffraction

High Energy Resolution Electron Scattering

v
Theory

Electron Optics

Electron-atom Collisions

Sponsored Conferences 101

Invited Talks 102

Publications 110

Technical & Professional Committee Participation & Leadership ... 119

Major Consulting and Advisory Services 126

Journal Editorships 133

Calibration Services Performed 134

RADIOMETRIC PHYSICS - Division 534 135

Spectroradiometry and Optical Pyrometry 138

Instrumentation and Techniques

Studies of the Basis of Accurate Radiometry

Other Agency Projects

Spectrophotometry 141

Diffuse Reflection

Retroreflection

Transmission

Densitometry

Luminescence

Electro-Optical and Quantum Radiometry 144

Photometric-Radiometric Calibrations and Map 149

Sponsored Conferences 151

Invited Talks 152

Publications 153

Technical & Professional Committee Participation & Leadership ... 155

Major Consulting and Advisory Services 157

Trips Sponsored by Others 159

Standard Reference Materials 160

Calibration Services Performed 161

vi
RADIATION SOURCE AND INSTRUMENTATION - Division 535. ......... 162

CW Microtron Project

Planning for New Facility

Consulting and Advisory Services

Linac Operations . 164

SURF Operations ................... 168

SURF Operations Statistics

SURF Users During FY 82

Instrumentation Services 172

Electronic Instrumentation Maintenance and Construction

Control Instrumentation Design and Construction

Instrumentation Support for Physics and Chemistry Projects

Mechanical Instrumentation Services

Radiation Instrumentation Standards . .... 174

Invited Talks 176

Publications 177

Technical & Professional Committee Participation & Leadership . . . 178

Major Consulting and Advisory Services 180

Standard Reference Materials 181

SPONSORED SEMINARS AND COLLOQUIA 182
II11
TECHNICAL ACTIVITIES

530, Office of Radiation Measurement

Task No. 11201 (new task no. 15201) - Radiation Standards Dissemination

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 that may be hazardous. The Office assists the technical organizational components of CRR 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. The

office maintains liaison with organizations that conduct measurementintensive programs in the areas of radiation safety, energy, health, and

environmental contamination. Examples are the Nuclear Regulatory Commission,

Department of Energy, Bureau of Radiological Health, Environmental Protection

Agency, Occupational Safety and Health Administration, and the Conference of

Radiation Control Program Directors. The Office participates in collaborative programs with most of these organizations to satisfy specific measurement traceability and quality assurance requirements. Another function of

the Office is to provide the secretariat and chairman for American National

Standards Committee N43, concerned with equipment for non-medical applications of ionizing radiation.

Because of a growing desire for quality assurance by those who make

routine radiation measurements, the Office is devoting an increasing

fraction of its resources to the development of methods for achieving

measurement quality assurance. The following examples of activities

conducted during the past year will illustrate the various types of

programs that are under development to provide greater assurance that

field measurements are consistent with the national standards.

Radon

As in the past few years, various radon-related projects continue

to occupy a significant share of the Office's activities. A technical

analysis and study of suitable calibration standards and support services

for radon measurements was performed. This study comprised an evaluation

of user needs and present NBS capabilities, an analysis of technical feasibility, and the development of detailed program plans. The proposed

NBS program consists of a broad-based comprehensive effort to upgrade and

expand NBS measurement and calibration facilities, to develop several

types of transfer standards (a solid-source radon transfer standard, an instrument-based radon transfer standard, and a radon flux density transfer

1
Office of Radiation Measurement* Technical Activities (cont'd.)

standard), as well as to provide direct support services to other

laboratories. The results of this study were used to prepare several

internal and external funding proposals for NBS management for two

offices in the Department of Energy, and for the Nuclear Regulatory

Commission. The pursuit of adequate funding for this proposed program

is continuing.

The Office also performed an analysis of the use and advantages of

ionization chambers as radon transfer standards, and as the primary

calibration instruments in user laboratories. This was done as part of

a study of the feasibility and design of a model intermediate calibration

laboratory (ICL) for radon measurements. The analysis considered three

different types of ionization chambers in terms of their technical

advantages and disadvantages, uses and interactions in an NBS-ICL network,

and design and cost considerations. Additional work requires developing

and testing laboratory prototype instruments.

The Office continued to provide direct laboratory assistance to

staff members of Division 532. This assistance was in the form of

volume calibrations of radon sampling bulbs used in an inter! aboratory

radon measurement comparison; completing the design of the radon chamber's

sampling and recirculation systems; plumbing the systems and performing

leak tests; testing and calibrating the chamber's ambient temperature

and dew point probes; testing the performance characteristics of the mass flow transducers for the chamber; and preparing the radium sources

for a prototype regenerative radon-in-water transfer standard.

The Office also continues to coordinate the interactions between

NBS and other radon measurement laboratories , such as the DOE Environmental

Measurements Laboratory, two EPA laboratories at Montgomery and Las Vegas,

the U.S. Bureau of Mines Denver Research Center, and national laboratories

including Lawrence Berkeley Lab, Argonne National Lab, and Oak Ridge

National Lab.

In cooperation with the Radon Measurement Subcommittee of the

Conference of Radiation Control Program Directors (CRCPD), a survey of

the state radiation control program directors was conducted to determine

the radon measurement needs and present activities in state programs.

The survey focused on a wide variety of methods for measurement of radon

and related quantities. This includes methods for measurement of radon

( z22 Rn) concentration in air, potential alpha energy concentration,

individual radon progeny concentrations, radon exhalation or flux density

from surfaces, radon concentration in water, and thoron ( 220 Rn) or thoron progeny concentrations in air. The survey identified the sources

of radon and thoron which necessitate measurements in the states; the

types of measurements and measurement methods that are performed routinely,

or that the states would like to obtain or improve the capability of

performing; existing calibration capabilities for these measurement

methods; and the perceived needs for improving the quality of the measurements. A report summarizing the findings of the survey was published

(NBS GCR 82-394) and distributed. The survey findings have also been

prepared for publication in the journal Environment International.

2
Office of Radiation Measurement, Technical Activities (cont'd.)

The Radon Measurement Subcommittee is continuing its work on a directory and catalog of cornmercially available radon and radon progeny

measurement instrumentation. This catalog should be completed in the

coming year. The subcommittee has also initiated a project to develop a users' handbook of simple radon and radon progeny measurement procedures

to assist inexperienced state laboratories that are just beginning to

perform radon measurements. The results of both of these ongoing projects

will be very useful to the states.

Detection Limits

Over the years, it has become apparent that many persons peforming

low-level environmental radioacti vity measurements continue to confuse

and misapply a priori detection limits and a posteriori criteria for the

presence of activity. To address this, the Office has completed the

theoretical development and sample calculations for a series of papers

on detection limits and statistical hypothesis testing for the presence

of activity. The series considers the purposes of detection limits, and

discusses and illustrates their misapplications; presents the well-known

approaches to calculating detection limits (assuming particular distributions), and develops a set of distribution-free detection limits based

on Chebyshev-Li ke Inequalities; and presents the classical NeymanPearson hypothesis testing approaches for determining whether activity

above background is present, and extends this with a novel Bayesian

statistical approach.

Regional State Laboratories

The regional calibration laboratories being established in the

states of Illinois, Washington, and South Carolina are in various stages

of development. In Illinois, the primary emphasis has been on making

the x-ray beams operational. The basic measurements necessary to

characterize the x-ray beams have been completed but some ancillary

measurements will have to be made. Analysis of the original data revealed

a problem with either the half-value layers or with the true kilovoltage

of the x-ray machine. This will have to be resolved before the laboratory

can become fully operational. In the meantime, protocols are being

developed for x-ray calibrations, procedures for acquiring and monitoring

calibration data are being developed, and details of the calibration

report are being determined. These procedures are being tested by

calibrating state-owned instruments. Preliminary investigations have

begun on methods to characterize the reference fields at radiation

levels suitable for calibrating radiation survey instruments and the

pressurized ionization chambers used by states to monitor nuclear power

plants. For calibrations at higher photon energies a 3-curie cesium-137

source has been obtained, but its implementation awaits completion of

the procedures for x-ray calibrations.

Substantial progress was made during the past year in development

of the State of Washington laboratory. A 3-curie, cesium-137 irradiator

was installed and all equipment necessary for calibrating instruments at

3
Office of Radiation Measurement, Technical Activities (cont'd.)

this energy was delivered. The University of Washington will be responsible for routine operation of the facility, and the radiation control

office will use it to calibrate its own instruments. An on-site training course in calibration procedures was given at the laboratory in May

1982, and the regional aspect was emphasized when personnel from the

Oregon and Idaho radiation control offices attended. During the training

session, preliminary measurements on how well the reference field was being determined were made using a duplicate set of instrumentation.

Since no major problems were encountered, the final physical arrangement

of apparatus is being decided and measurements necessary to characterize

the laboratory and develop protocols has begun.

In South Carolina, the building renovations necessary to house the

laboratory were completed only recently, almost a year behind schedule.

The x-ray machine was installed recently for testing purposes, but

electrical and water connections must be modified to meet specifications.

Radiation survey measurements are presently being made to determine the

need for additional room shielding.

Discussions with representati ves of the State of California are continuing, and a candidate facility was visited. It is likely that

this facility, which presently has limited capability for calibrating

emergency response instruments, will be expanded to increase its range

of capability. Preliminary interactions with the Federal Emergency

Management Agency have indicated that it will probably provide the

necessary funds.

A preliminary draft of a training and procedures manual has been

developed to assist state personnel in setting up the laboratories , in

developing protocols and calibration reports, and in developing quality

control programs. This draft manual was first used in conjunction with

the training course given in Seattle, Washington. Due to a wide variation

in the backgrounds of personnel to be trained, and the complexity of the

material that should be covered for a proper understanding of the fundamentals, the proper balance between introductory and advanced material

must be determined before the manual is revised.

Personnel Dosimetry

The Nuclear Regulatory Commission has officially requested that the

National Voluntary Laboratory Accreditation Program (NVLAP) procedures

be used by NBS to develop an accreditation program for processors of

personnel dosimeters. It is anticipated that the NRC will issue regulations which require its licensees to use only those processors who have

been accredited under this program. Technical support for the NVLAP

program will be provided by several elements of the Center for Radiation

Research, including the Office of Radiation Measurement. During the past

year, some effort has been devoted to preparation for the upcoming program,

including procurement of the services of a proficiency testing laboratory

(PTL) that will test the performance of dosimetry processors. The Request

4
Office of Radiation Measurement, Technical Activities (cont'd.)

for Proposal (RFP) to be used for procurement of the services of a PTL

is nearing completion. It contains preliminary requirements for quality

control in the PTL, for initial testing of the PTL by NBS , and for

periodic review of PTL performance.

During the past year, the interagency committee formed to provide

guidance and coordination for development of a national program for

personnel dosimetry performance testing continued to function under the

chairmanship of an Office staff member. The group agreed to expand its

scope to include the development of similar national programs for testing

the performance of radiation survey instruments and bioassay laboratories.

To reflect this broadened scope, the name was changed to Interagency

Committee on Occupational Radiation Protection Measurements.

Performance Testing Criteria

Because of the increasing demand for performance testing programs,

such as that for personnel dosimetry, the Office has begun to evaluate

the algorithms and criteria used for evaluating measurement performance.

Existing performance algorithms use a relatively simple approach which

is often encumbered with many unverified statistical assumptions.

Efforts have been made to formulate a more general approach which has a sound axiomatic basis. It is hoped that this approach will lead to the

development of improved performance indices which can be used as performance testing criteria.

Measurement Quality Assurance Services

Under an interagency agreement with the Nuclear Regulatory Commission

the Center for Radiation Research is conducting a 3-year program generally

directed toward quality assurance for radiation measurements made by the

NRC. Major tasks include (1) characterization and evaluation of the

thermoluminescence dosimetry system used to monitor power reactors; (2)

development of radiation fields and evaluation of the performance of

selected radiation survey instruments; and (3) development of a measurement

quality assurance (MQA) service for laboratories that calibrate survey

instruments for NRC inspectors. The Office coordinates this program and

has specific responsibility for conducting some of the activities relating

to task 3, development of an MQA service. In cooperation with the

Dosimetry Group, the basic principles for MQA services have been documented and specific procedures are under development. The initial

service will be limited to photon radiation, and will be made available

to four laboratories that serve NRC inspectors, plus seven additional

laboratories that desire similar MQA services from NBS.

Other Activities

For the 36th year, NBS served during 1982 as the secretariat of

American National Standards Committee N43, Equipment for Non-Medical

5
Office of Radiation Measurement, Technical Activities (cont'd.)

Radiation Applications. With leadership, coordination, and assistance

from the Office, a new standard on panoramic, wet-source-storage irradiators was completed and approved by the Committee. The subcommittee

on electron microscopes made substantial progress on developing a draft

standard. Several existing standards are being reviewed under the ANSI

five-year rule that requires either withdrawal, revision, or confirmation.

The Office provided the NBS delegate to a working group of the

International Bureau of Weights and Measures (BIPM) on reporting measurement uncertainties. This group prepared a set of recommendations for

use by international standardizing laboratories. The recommendations

provide an overall philosopy or general approach for reporting uncertainties, and were ratified by the International Committee on Weights and

Measures (CIPM) in October, 1982. A report by the working group on the

recommendations is being published and distributed by BIPM.

In cooperation with the Center for Applied Mathematics, the Office

is preparing a new chapter on measurement uncertainties for the revised

Condon and Odishaw Handbook of Physics .

The directory of commercial services for calibrating ionizing

radiation survey instruments, which was prepared in cooperation with the

CRCPD, proved to be so popular that a second printing was necessary.

Prior to publication of this directory, there was no single source of

comprehensive information on where calibrations could be obtained, types

of services offered, and radiation sources used.

During the past year, the Office continued its participation in a cooperati ve’ agreement with the National Council on Radiation Protection

and Measurements for development of a handbook on measuring neutrons

generated by medical accelerators.

Under the terms of another cooperative agreement, the CRCPD Committee

on Radiation Measurements made further progress on revision of its 1979

publication entitled "Ionizing Radiation Measurement Criteria for Regulatory

Purposes". The revised draft includes more specific references to

regulations that necessitate measurements, terminology for measurement

of ionizing radiation, principles of measurement quality assurance, and

generic characteristics of various types of instruments.

6
INVITED TALKS

530, Office of Radiation Measurement

Colle, R., Panel Discussion on Instrumentation and Measurement Methods,

International Meeting on Radon and Radon Progeny Measurements, Montgomery,

AL, August 28 , 1 981 .

Colle, R., "Radon Measurements: National Needs and the Role of NBS",

American Nuclear Society Winter Meeting, San Francisco, CA, December 1,

1981.

Eisenhower, E. H., "A Quality Assurance Program for Personnel Dosimetry",

14th Annual National Conference on Radiation Control, Portland, ME, May

26, 1982.

Heaton, H. T. , II, "Traceability to NBS for State Regional Calibration

Laboratories", Department of Nuclear Engineering, University of Washington,

Seattle, WA, May 10, 1982.

7
PUBLICATIONS

530, Office of Radiation Measurement

Colle, R., BOOK REVIEW of Nuclear Chemistry: Theory and Applications

by G. R. Choppin and J. Rydberg, International Journal of Applied

Radiation and Isotopes 32^ 687 - 688 (1981 ).

Colle, R., Radon Measurements: National Needs and the Role of NBS,

Transactions of the American Nuclear Society 39^, 84-86 (1981 ).

8
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

530, Office of Radiation Measurement

Ronald Colie

Delegate, Bureau International des Poids et Mesures (BIPM) Working

Group on the Statement of Uncertainties.

Resource Person, Conference of Radiation Control Program Directors,

Subcommittee on Radon Measurements.

Resource Person, Conference of Radiation Control Program Directors,

Task Force on the Clean Air Act.

Member, Ad Hoc Committee on Interlaboratory Calibration of Radon and

Radon Daughter Instruments.

Elmer H. Eisenhower

Alternate Representative, ANSI N44, Equipment and Materials for

Medical Radiation Applications.

Chairman, ANSI N43 , Equipment for Non-Medical Radiation Applications.

Member, ANSI Nuclear Technical Advisory Group for ISO TC85.

Chairman, Interagency Committee on Occupational Radiation Protection

Measurements

Resource Person, Conference of Radiation Control Program Directors,

Committee on Radiation Measurements.

H. Thompson Heaton, II

Secretary, ANSI N43 , Equipment for Non-Medical Radiation Applications.

Member, ANSI N43-3.4, Subcommittee for Gamma Irradiators.

Member, ANSI N43-8, Subcommittee for Electron Microscopes.

9
MAJOR CONSULTING AND ADVISORY SERVICES

530, Office of Radiation Measurement

1. R. Colle advised Wisconsin Health Department on calibration procedures

for radiochemical yield determinations and reviewed the measurement

protocol, data analysis, and results of a radon monitoring program

associated with uranium exploration in northern Wisconsin.

2. R. Colle assisted a field test engineer (contractor) at the Three

Mile Island nuclear power plant by performing a literature search

and providing advice on possible damage to a Nal (Tl) stack monitor

from accidental releases.

3. R. Colle assisted Pylon Electronic Instruments Co. by performing

extensive calculations of the steady-state and time-dependent activity concentrations from flow-through thoron ( 220 Rn) calibration sources.

4. R. Colle advised the radiation safety office at the University of

Maryland Medical Center (Baltimore) on a continuous radon monitoring

system for a radium needle storage facility, and on a calibration

protocol for the system.

5. R. Colle advised University of California at Davis, Crocker Nuclear

Laboratory, on the calculation and propagation of uncertainties in

proton energies for measurements of nuclear reaction excitation

functions by stacked-foil activation methods.

6. R. Colle advised and assisted staff members in various NBS divisions

on the treatment and reporting of measurement uncertainties, and on the interpretation of measurement performance criteria.

7. H. T. Heaton, II, advised the Nuclear Regulatory Commission on a proposed regulatory guide on calibration procedures for radiation

survey instruments.

8. H. T. Heaton, II, was consulted by the Department of Defense on a calibration manual for ionizing radiation instruments that will be

used at DOD calibration laboratories.

9. H. T. Heaton, II, was consulted by Radcal Corporation on using an ionization chamber in the "rate of charge" method for determining

their x-ray field.

10
TECHNICAL ACTIVITIES

Division 531, Atomic and Plasma Radiation

Task No. 11211 (new task no. 15211) - Atomic Radiation Data and Standards

Task No. 11212 (new task no. 15212) - Atomic Processes in Plasmas

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 di electronic rate co- efficients. 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 for the

development of new measurement techniques. Furthermore, well-defined

atomic radiation sources are developed as radiometric standards or wavelength standards.

These activities support several important areas of science and

technology. A good deal 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- interfering plasma probes. Other areas of direct applications are space

physics and vacuum ultraviolet laser development, where atomic radiation

data are one of the basic inputs. In the former area our vacuum ultraviolet radiometry work is now, for the first time, providing small

calibrated source packages to allow radiometric calibrations on board

spacecraft, which are used, for example, for accurate monitoring of the

solar ultraviolet radiation.

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

division has currently 22 professional physicists, among them 18 Ph.D.s,

plus 3 postdocs. Also, during the last year the division had guest

workers from France, China, Yugoslavia, Poland, and Russia.

The past year was again a very productive one, as will be seen from the following sections, where the principal work of the three

technical groups during the last year is briefly described.

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

I . Atomic Spectroscopy Group

(a) Vacuum UV Spectra of Atomic Ions —Me continued our research on spectra of highly ionized atoms needed for high-temperature plasma

diagnostics by exciting, identifying and accurately measuring the

transitions of the type 2sm2p n -2sm~ 1 2p n+1 in boron-like ions of Cl 12+

through Ti 17+ (Z = 17-22, except Ar). The spectra were excited in

laser-generated plasmas and observed with the NBS 10.7-m grazingincidence spectrograph. Also of importance for predicting magneticdipole forbidden lines in plasmas are our new identifications of 3p 6 3d 9 - 3p 5 3d10 lines in eight ions from Ba 29+ to Yb43+ with spectra we observed

earlier at Los Alamos. Our work on the Mg-like ionic spectra from Si 26+

to Rb 33+

, also with the Los Alamos observations, was completed. The

4d 9 -4d 8 5p resonance transitions have been identified in Xe 9+ and Cs 10+ .

We are using two major facilities outside NBS in our work on highionization spectroscopy. With the Plasma Radiation group, we observed

and identified magnetic-dipole transitions within the 3s 2 3p*< ground

configurations of highly ionized Kr in the TEXT tokamak at the Fusion

Plasma Research Facility in Austin, Texas. Accurate calculations of

the wavelengths and intensities of these lines were essential for this

work, which is being continued with the goal of similar identifications

for ions of iron-group and heavier elements. We also recently observed

spectra of highly ionized Nb and Mo with the powerful Nd/glass GDL

laser at the National Laser Users Facility at Rochester. These

observations yielded i soel ectronic extensions of the resonance lines

of F-like ions to Nb 32+ and Mo 33+

; further research with this laser is

pi anned.

Several of our predictions of magnetic-dipole wavelengths for

highly ionized species have recently been used to identify lines in

tokamaks, notably by the Princeton Plasma Physics group in their work

on the PLT and PDX tokamaks.

(b) Atomic Inner-shell Photoabsorption —We have observed a suprising photoabsorption spectrum of neutral Cs and interpreted it as arising from transitions of the type 5p 6 6s-5p 5 6snd and 5p 6 6s-5p 5 6sns

.

In contrast with expectation and with the known 5p absorption in Xe,

the Cs 5p 5 6snd resonances are narrow, whereas the 5p 5 6sns resonances

are broad (autoionization). Attempts to understand the results as due

to strong 5p 5 6sns x 5p 6 ep interactions are in progress. Our 10.7 m grazing-incidence spectrograph was essential for this experiment, since

previous spectroscopy of Cs in other laboratories failed to yield the

resonances with sufficient resolution for a correct analysis.

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

In collaboration with Division 533 and theorists elsewhere (W.R.

Johnson, K.T. Cheng) we recently completed an interpretation of the

striking changes in the photoabsorption spectra along the isoelectronic

sequence Xe to Ba 2+ in terms of the altering relative magnitudes of the

basic interactions involved. We have begun attempts to apply laserdriven ionization techniques to Cs in a source to be used with our

10.7-m grazing-incidence spectrograph in order to provide the experimental data for Cs+

, the intermediate ion of this sequence.

(c) Laser Spectroscopy—Our main goal in this new program is to

apply state-selective and state-sensitive techniques to extend the

structural data for selected complex spectra—especial ly spectra for

which additional data are needed for applications in plasma physics,

laser physics, astronomy, etc. Pending assembly of a second dye-laser

system and development of scanning techniques to cover a broader range,

we have begun an experiment using Doppler-free intermodulated fluorescence spectroscopy to obtain accurate wavelengths for several 4 He I transitions of interest. The results will complement measurements of

two-photon transitions from ls2s levels made in other laboratories.

(d) Atomic Energy Levels Data Center —During the past 6 years we completed new critical compilations of the energy levels for all 235

spectra of the iron-group elements K through Ni (Z = 19-28). The data

were published separately by element. We are now updating and extending

these compilations for a single-volume collection of the data for the

entire iron group. New results for many of the spectra are being

incorporated and extensive use of isoelectronic and other regularities

are being made to increase the reliability of the data. We hope to

complete the major part of this work during the next year.

We have submitted for publication new energy-level compilations for

all the Si spectra. These include extensive recent experimental and

theoretical results (some unpublished) assembled for the first time. The

Si data are part of a project covering the Na-Ar group (Z = 11-18) and

complete the series for Na-Si (Z = 11-14). We have investigated the

derivation of improved ionization energies by combining theoretical and

experimental results along a number of isoelectronic sequences in

connection with these compilations; the results will probably yield the

best available values for many highly ionized species.

We prepared two reports on recent results in atomic spectroscopy of

astronomical interest for the International Astronomical Union. We

monitor the literature on atomic energy levels, wavelengths, wavefunctions

etc., and the resulting reference files and published bibliographies are

made available to a wide clientele.

13
Division 531, Technical Activities (cont'd.)

II . Atomic Radiation Data Group

(a) Theoretical Studies- -The work of this theoretical group has

concentrated on (1) the production of critically evaluated data on basic

atomic processes and (2) the exploration of the basic atomic physics

needed for developing new theoretical methods for producing data. The

processes studied are electron impact ionization, dielectronic recombination, and radiative transitions. To a large extent these data are important for understanding atomic processes in plasmas, particularly

fusion plasmas.

Our research on electron impact ionization has concentrated on the

systematics of light ion data and a further assessment of the distorted

wave (DW) method for the heavier elements. Distorted wave calculations

of ionization cross sections have been done for the L-shell ions of

iron, Fe XV 1

1 -XXV I , and for the M-shell ions of iron and scandium,

Fe IX-XV and Sc IV-X. Also, ionization rate coefficients were calculated, assuming a Maxwellian electron distribution. Simple analytic

fits were made to these data, giving the rate coefficient as a function

of temperature, and in a form easy to use for plasma modelling purposes.

DW calculations were also carried out for the chlorine and krypton

i soelectronic sequences. Just as with the argon sequence, the kryptonlike ions, in low stages of ionization, show pronounced term-dependent

effects in the 1 P channel which improves the agreement with experimental

data at low energies, although significant discrepancies remain at

higher energies. Exploratory studies have also been started in the

direction of modelling the ionization process by an effective transition

potential

.

The work on dielectronic recombination has developed in two parallel

directions. A general computer program is being written to compute the

total rate of recombination for an arbitrary atom in an arbitrary stage

of ionization. This program is based on the single configuration,

LS-coupling and distorted wave approximation. No further approximations

are involved. All the basic codes have been written and we are now in

the process of assembling them into a single program. We are also in

the process of making detailed calculations of the recombination rate of

Fe+23

, via the doubly excited dielectronic states, in order to assess

the importance of both configuration interaction and intermediate

coupling. So far, we have the perplexing result that configuration

interaction has virtually no effect on the total rate, even though

individual LS-channels are affected by as much as 40%.

We continue our collaboration with members of the far UV group

investigating the interesting intricacies of f-shell collapse in the

region of the periodic table around z = 54-57. A variety of pronounced

term dependent effects has been found in both the single- and multi

configuration Hartree-Fock approximation.

14
Division 531, Technical Activities (cont'd.)

The upgraded atomic structure codes are now working, although much

remains to be done to improve their performance and to broaden their

scope to include a variety of approaches to the correlation problem.

Preliminary results have been obtained on the 4s-4p transition probabilities of neutral argon, in which intershell correlation shifts have

been included in the intermediate coupling calculations.

Our group hosted a second workshop on atomic physics problems

related to magnetic fusion research on November 16-17, 1981. This time

the topic was dielectronic recombination rates. Again, the meeting

turned out to be very stimulating and productive. By concentrating on

an assessment of the current state of dielectronic recombination rate

calculations and by identifying promising future directions, the theoretical work in this area was for the first time brought into focus.

(b) Data Center — In the Data Center on Atomic Transition Probabilities, the revision of atomic-transition-probabil i ty tables for

allowed lines of the elements scandium through nickel, which were

published in past issues of J. Phys. Chem. Ref. Data, is nearing com- pletion as the end of 1982 approaches. Work was started on preparing

tables of forbidden lines of these elements. Based on the exploratory

work done by computer scientists at Vanderbilt University on the possibilities of developing a database of atomic spectroscopic data--with

detailed guidance by the Data Center--di scussions are underway with

Office of Standard Reference Data personnel concerning the design of an actual database and the equipment which should be procured and utilized

for such a project. A critical data compilation of atomic transition

probabilities on high ions of titanium was undertaken in collaboration

with K. Mori of the Institute of Physical and Chemical Research, Tokyo.

Also, a critical review and tabulation of Stark widths and shifts for

non-hydrogenic spectral lines of ionized atoms was undertaken in collaboration with N. Konjevic of the Institute of Physics, Belgrade, and

is nearing completion. An extensive report on recent developments in

atomic transition probabilities with a very detailed bibliography for

the last two years was prepared for the International Astronomical

Union. We have also continued to co-edit, in collaboration with Oak

Ridge National Laboratory, the bimonthly newsletter, "Atomic Data for

Fusion.

III. Plasma Radiation Group

(a) Colli signal Rate Coefficients with the 50 KJ Theta Pinch

The

ionization rates of Ti IX, Ne VI and VIII, and 0 VI ions are determined

using a plasma condition characterized by an electron temperature of

'c 55 eV and 2 x 10 16 /cm 3 density. Comparison with theoretical

predictions based on the commonly used semiempirical formula due to Lotz

showed that the theoretical values are a factor of two to three lower

15
Division 531, Technical Activities (cont'd.)

than the experiment. The higher values in the experiment are attributed

to the possible contribution of the two-step process of excitation

followed by ionization. In order to extend this important comparison

over a wider range of temperatures, upgrading of 0-pinch to run at

40 KV with 50 kJ energy is in preparation. At present, the upgrading

procedure is tested out by building a small prototype unit.

(b) Tokamak Spectroscopy—The first experimental results on magnetic dipole transition of highly ionized Kr have been obtained

utilizing the TEXT tokamak at the Fusion Plasma Research Facility in

Austin, Texas. Our NBS group has been the first users group on this

facility. Wavelengths, predicted by a semiempirical method, have

been observed for Kr XVIII through Kr XXII using instrumentation installed

on TEXT by our NBS group. These new observations will allow Doppler

ion temperature measurements on magnetically confined fusion plasmas in

the range 500 to 1500 eV, and will be immediately applied to the TEXT

tokamak.

(c) Strongly Coupled P1asma --This year we began a program to

generate a novel form of matter known as a "strongly coupled plasma"

(SCP). In normal plasmas the interaction energy between the charged

particles is far out weighed by the random motional energy. Just the

opposite case pertains in a SCP. The particle interaction dominates

the randomizing processes, collective effects are extremely important,

the system behaves more like a charged liquid than a gas, and phase

transitions to even a solid-like phase are predicted. Our technique for

generating a SCP is to photoionize a gas of cryogenic hydrogen atoms

with a laser to create a cold (5 degrees Kelvin) plasma of protons and

electrons. Such a plasma is strongly coupled even at relatively low

densities. The experiments are presently performed at MIT in

collaboration with Professor Kleppner's group there, where the cryogenic

hydrogen atom source was recently developed. Recently we have observed

comparatively large ionization signals, as well as the detailed line

shape for the resonant photoionization process. An unexpected result of

potentially great practical application has been the observation of

efficient harmonic generation of coherent La radiation (vacuum

ultraviolet) in the hydrogen beam.

(d) Stark Effect on Autoionization Resonances --0ne of the few

remaining problems in the atomic physics of electric fields is the

effect of such fields on autoionization (AI) resonances. Such resonance

levels actually comprise a considerable portion of the levels relevant

to plasma and astrophysical problems. Last year we reported the first

measurements of the monotonic broadening of AI resonances in an electric

field. Recently we have been developing a theoretical model to explain

why bound-bound mixing appears to be the dominant broadening mechanism,

and in which cases continuum-continuum mixing may be important. The

16
Division 531 s Technical Activities (cont'cL)

model is near completion, and we hope to have numerical results within

the next year. We have also observed the broadening of a very narrow AI

resonance in Gd at extremely low fields on the order of 1 volt/cm. This

surprising result appears to be related to the dense spectrum of opposite

parity levels characteristic of complex atoms.

(e) Col 1 isional Redistribution of Radiation —Polarized light from

a dye laser, tuned to the first Balmer line of hydrogen (Ha ), was used

to probe the collisional redistribution of radiation in a plasma.

Radiation incident in the wing of the line was redistributed to the core

by radiative broadening of the lower level of Ha and by collisions. The

intensity and polarization of the fluorescence were measured as a function of laser detuning from the line center. The line profile was found

to be symmetric and Lorentzian outside the Doppler core, reflecting the

dominant effects of radiative and resonance collision broadening. The

polarization in the absence of collisions was calculated, and compared

to the measured polarization. This led to the conclusion that, on the

average, elastic upper level collisions were about 65% efficient in

depolarizing the atom.

Collisional redistribution has also been observed in a helium line

(2 1 S-3 l P ; X = 502 nm). Preliminary results are currently being analyzed. These represent the first radiation redistribution measurements

in a plasma, and the first made from an excited state. They should

provide fundamental results required to address the principal unsolved

problems in stellar radiative transfer.

(f ) Stark Broadening, Shifts and Asymmetries of Hydrogenic Ion

Li nes- -We are continuing our work on the widths and shifts of Stark

broadened He II hydrogenic ion lines emitted from a pulsed plasma

source. A new pulsed arc source with reduced boundary effects has been

designed and built. This new source allows for more accurate line

profile measurements and should provide improved electron density measurements which are obtained using a laser interferometer. The source

was mounted on the large 10 meter normal incidence spectrometer for

studies in the visible and VUV spectral regions. We have also assembled

a new multichannel spectral detector replacing our aging OMA (Optical

Multichannel Analyzer) device. The detector was integrated to a minicomputer for on-line data acquisition and analysis. $e are currently

measuring the shift of the He II Ha

VUV line at 1640 A, which can be

compared with widely varying theoretical estimates for the shift of

hydrogenic ion lines. Improvements in the measurements using advanced

wavelength calibration techniques are underway. Our new source provides

a versatile tool for measurements on many other species, and we have

also begun measurements on Ar II.

17
Division 531, Technical Activities (cont'd.)

(g) Rayleigh Scattering --We continue the investigation of the

effect of laser temporal pulse shape on Rayleigh scattering, which is

used as an absolute calibration of Thomson scattering to determine

electron densities in plasma diagnostics. Using pulse shaping techniques, we have demonstrated that the Rayleigh scattering cross section

is independent of pulse rise times as well as pulse durations.

We are applying for the first time the near-resonant-Rayleighscattering technique as an ion density measurement to plasma diagnostics.

A barium vapor heat pipe, driven by a pump dye laser tuned at the Ba I resonance transition, provides a low- temperature and homogeneous plasma.

The resultant Ba II population will be measured through a near-resonantRayleigh-scattering method by a probe dye laser, tuned in the neighborhood of a Ba II resonance transition.

(h) Vacuum Ultraviolet Radiometry with Plasmas- -Qur work on early

models of portable low-powered (15 W) rf-excited dimer lamps has shown

that these lamps make good standards of irradiance but are deficient as standards of radiance. Further work by us has shown that changes in the

lamp design can also produce a satisfactory radiance standard, and we are currently evaluating several newly designed lamps to determine their

suitability for use on the FOS (faint-object spectrograph) space shuttle

experiment.

We have also been investigating two new types of radiometric sources. The first is an irradiance source of highly pure Lyman-a radiation which

does not utilize a monochromator. The second is a radiance source in

which an electrostatic discharge is set up in’ a narrow gap between two

metal plates.

A deuterium lamp selected and calibrated by us was flown on the

SUSIM (solar ultraviolet spectral irradiance monitor) space shuttle

experiment as the first in-flight calibration source. As a part of this

project our calibrations of several similar deuterium lamps were compared with calibrations of the same lamps carried out at NPL (England).

This international comparison was made to ensure highest reliability of

the irradiance scales.

Finally, we performed several calibrations of argon mini -arcs for

agencies active in the field of space research. The projects involved

were the HRST (high resolution space telescope) and the FOS. In con- nection with these calibrations, measurements were made to quantitatively

determine radiation damage to the arc windows from long exposures.

(i) Quantitative Spectroscopy of D.C. Arcs- -The computerization of

the data acquisition and analysis system has been completed and refined

18
Division 531, Technical Activities (cont'cL)

to the point that this laboratory now possesses state-of-the-art efficiency, versatility and precision in the study of visible, near-infrared

and near-ultraviolet radiation. An on-line microcomputer is used to

acquire and analyze high resolution spectral line profiles observed in

the radiation emitted from a variety of study gasses injected into a wall -stabil i zed arc source which operates near local thermodynamic

equilibrium. The analysis includes corrections for dark current,

spectral sensitivity, self-absorption, continuum radiation, blended

spectral lines and spectral line-wing truncations. In the first utilization of this apparatus 13 lines of the Ar I 4s-4p transition array

were studied. These measurements yielded relative lifetimes for five 4p

levels. Stark widths and shifts for all 13 lines, level widths for five

4p levels and four 4s levels, and transition probabilities for all 13

lines. The values obtained in all cases rank among the most precise

measurements presently available. Plans for the immediate future

include a further study of Ar I lines to include the transitions from

the 5p levels and similar systematic studies of carbon, oxygen and

ni trogen.

19
SPONSORED CONFERENCES

Division 531, Atomic and Plasma Radiation

NBS Workshop on Dielectronic Recombination Rates, NBS, Gaithersburg,

Maryland, W. L. Wiese and L. J. Roszman, November 16-17, 1981.

20
INVITED TALKS

Division 531, Atomic and Plasma Radiation

Clark, Charles W.,- "Diamagnetism in Excited States of Hydrogen," Proceedings of Centre National de la Recherche Scientific, Aussois, France,

June 6=12, 1982.

Jones, Douglas W., "Precision Computer Automated Transition Probability

Measurements," Naval Postgraduate School, Physics Department, Monterey,

California, March 26, 1982.

Martin, W. C., "Atomic Spectra - Some Recent Data of Astrophysical

Interest," Joint Meeting of Commissions 14, 29, 36; 18th General Assembly

of the International Astronomical Union, Patras, Greece, August 23,

1982.

Reader, Joseph, "Spectroscopy of Highly Ionized Atoms with Laser-Produced

Plasmas," Chemistry Department Colloquium, Howard University, Washington,

D.C. , October 8, 1982.

Wiese, W. L., "Cascading Problems in Beam Foil Spectroscopy,", Physics

Department, Kyoto University, Kyoto, Japan, October 16, 1981.

Wiese, W. L., "The Transition Probabilities of Argon —A Continuing

Problem," Department of Engineering Science, Kyoto University, Kyoto,

Japan, October 16, 1981.

Wiese, W. L., "Spectroscopy of Highly Ionized Atoms," Fall meeting of

the Japanese Physical Society, Niigata, Japan, October 4, 1981.

Wiese, W. L., "Radiation Data and VUV Radiometric Calibrations for Heavy

Ion Lines," Japanese Atomic Energy Research Institute, Tokai, Japan,

October 6, 1981

.

Wiese, W. L., "The Transition Probabilities of Ar I and II—A Continuing

Puzzle," Atomic Spectroscopy Symposium, Tokyo, Japan, October 13, 1981.

Wiese, W. L., "Experimental and Theoretical Studies of Collision Rates

and Cross Sections at NBS," Physics Colloquium at University of Nagoya,

Japan, October 15, 1981.

Wiese, W. L., "Cascading Problems in Beam Foil Spectroscopy," Nuclear

Physics Colloquium, Institute for Physical and Chemical Research,

Saitama, Japan, October 20, 1981.

21
Division 531, Invited Talks (cont'd.)

Wiese, W. L., "Current Topics in Atomic and Plasma Radiation Research at

NBS," Atomic Physics Seminar, Institute for Physical and Chemical

Research, Saitama, Japan, October 22, 1982.

Wiese, W. L., "Progress on Atomic Oscillator Strengths," 18th General

Assembly of International Union (IAU), Patras, Greece, August 23, 1982.

Wiese, W. L., "Atomic Transition Probabilities and Lifetime Studies for

Argon," Xlth international Symposium on the Physics of Ionized Gases,

Dubrovnik, Yugoslavia, August 25, 1982.

Younger, S. M., "Ionization and Recombination in High Temperature

Plasmas," Physics Department, Howard University, Washington, D.C.,

January 22, 1982.

Younger, S. M., "Ionization and Recombination in High Temperature

Plasmas," Lawrence Livermore Laboratory, Livermore, California, December

8, 1981.

22
PUBLICATIONS

Division 531, Atomic and Plasma Radiation

Clark, C. W. and Taylor, W. T., Diamagnetism in Excited States of Hydrogen,

Journal de Physique (France) (in press, 1982).

Corliss, C. and Sugar, J., Energy Levels of Iron, Fe I through Fe XXVI,

J. Phys. Chem. Ref. Data 11_, 135-241 (1982).

Detrich, J. and Weiss, A. W. , A1 kal i -Metal -Atom Doublet anomalies and

the Relation between Relativistic and Nonrelativistic Theories, Phys.

Rev. A 25, 1203-1205 (1982).

Epstein, G. L. and Reader, Joseph, Spectrum and Energy Levels of Triply

Ionized Yttrium (Y IV), J. Opt. Soc. Am. 72_, 476-492 (1982).

Greene, R. L., Comments on the Requirements for a General Stark Broadening Theory, J. Quant. Spectrosc. Radiat. Transfer 27_, 185-190 (1982).

Greene, R. L., A Relaxation Theory of Stark Broadening by Ions, J.

Quant. Spectrosc. Radiat. Transfer 27, 639-651 (1982).

Jones, Douglas W. , Musiol, K. , Wiese, W. L., Stark Widths and Shifts for

Some Ar I 4s-4p Transitions, Reports of Spectral Line Shapes , Vol . 2,

Proc. of 6th International Conference on Spectral Line Shapes (in press,

1982).

Kaufman, V., Sugar, J., and Cooper, D., F I |nd 0 I Isoelectronic

Sequences: Observations of 2sm

2p

n -2sm"

1 2p

n 1 Intersystem Transitions

and Improved Measurements for Cl, K, Ca, Sc, Ti» and V, Phys. Scr. 25,

623-626 (1982).

Kaufman, V., The Spectrum of Neutral Sulfur (S I) in the Vacuum Ultraviolet, Phys. Scr. (in press, 1982).

Kaufman, V., Sugar, J., and Cooler, D., N I isoelectronic Sequence:-

Observations of 2sm

2p

n -2s

m_1

2p

n 1 Intersystem Transitions and Improved

Measurements for CZ XI, K XIII, Ca XIV, Sc XV, Ti XVI, and V XVII,

Phys. Scr. (in press, 1982).

Kaufman, V. and Sugar, J., Ag I Isoelectronic Sequence: Wavelengths and

Energy Levels for I VII through La XI, Phys. Scr. 24, 738-741 (1981).

Kelleher, D. E. and Lombardi, G. G. , Effect of Electric Fields on Autoionizing Resonances, Journal de Physique (France) (in press, 1982).

23
Division 531, Publications (cont'd.)

Lombardi, G. G. , Feynman's Disk Paradox, Am. J. Phys. (in press, 1982).

Lombardi, G. G. and Kelleher, D. E., Redistribution of Radiation in a Low Density Plasma, Reports of Spectral Line Shapes , Vol . 2, Proc. of

6th International Conference on Spectral Line Shapes (in press, 1982).

Lucatorto, T. B., Mcllrath, T. J., Sugar, J. and Younger, S. M., Radical

Redistribution of the 4d Oscillator Strength Observed in the Photoabsorption of Ba, Ba +

, and Ba++ Sequence, Phys. Rev. Lett. 47, 1124-1128

(1981).

Martin, W. C., Report on Structure of Atomic Spectra (1979-1981) for

Commission 14 of the International Astronomical Union, Trans. IAU XVIII

A, Part 1 (in press, 1982).

Martin, W. C. , Series Formulae for the He I-like Spectra Na X through

Ar XVII (Z = 11-18), Phys. Scr. 24, 725-731 (1981).

Musiol, K. , Jones, Douglas W., and Wiese, W. L., Lifetime Ratios for

Ar I 4p Levels, J. Quant. Spectrosc. Radiat. Transfer (in press, 1982).

Nee, Tsu-Jye A. and Roberts, J. R., Investigation of Laser Temporal

Pulse Duration on Rayleigh Scattering, Phys. Rev. A 25, 1000-1003

(1982).

Nee, Tsu-Jye A. and Roberts, J. R., Comment: Authors' Reply to Comment

of Skowronek, Phys. Rev. A (accepted for publication, 1982).

O'Sullivan, G. , Roberts, J. R., Ott, W. R., Bridges, J. M. and Pittman,

T. L., Spectral -Irradiance Calibration of Continuum Emitted from RareEarth Plasmas, Opt. Lett 7_, 31-33 (1982).

Reader, J. and Luther, G., The Copper Isoelectronic Sequence: Ba 27+- W45+

, Phys. Scr. 24, 732-737 (1981).

Reader, Joseph, 2s 2 2p 5 -2s2p 6 Transitions in the Fluorine-like Ions Sr 29+

and Y 30+

, Phys. Rev. A 26 , 501-503 (1982).

Reader, J., 3p 6 3d 9 -3p 5 3d 1

0

Transitions in Cobalt-like Ions from Ba 29+ to

Yb43+

, J. Opt. Soc. Am. (accepted for publication, 1982).

Roszman, L. J., Dielectronic Recombination in Collision of Electrons

with Multicharged Ions, Proceedings VII ICPEAC, Physics of Electronic

and Atomic Col 1 i sions (1 982)

.

Ryabtsev, A. N. and Reader, J., Spectra of the Cobalt-like Ions Sr XII,

Y XIII, Zr.XIV, Nb XV, and Mo XVI, J. Opt. Soc. Am. 72, 710-716 (1982).

24
Division 531, Publications (cont'd.)

Sugar, J. and Kaufman, V., Ag I Isoelectronic Sequence: Wavelengths and

Energy Levels for Ce XII through Ho XXI and for W XXVIII, Phys. Scr. 24,

742-746 (1981).

Sugar, J., Kaufman, V., and Cooper, D., C I Isoelectronic Sequence:

Observations of 2sm2pn -2sm“1 2p n+1 Intersystem Transitions and Improved

Measurements for Cl XII, K XIV, Ca XV, Sc XVI, Ti XVII, and V XVIII,

Phys. Scr. (in press, 1982).

Sugar, J., Kaufman, V., and Cooper, D. , B I Isoelectronic Sequence:

Observation of 2s2p2 -2p3 Intersystem Lines in Sc XVII and Improved Measurements for Cl XIII, K XV, Ca XVI, Sc XVII and Ti XVIII, Phys. Scr.

(in press, 1982).

Tech, J. L., Lovas, F. J. and Fuhr, J. R., National Bureau of Standards

(Atomic Spectra, Molecular Spectra, and Atomic Transition Probabilities),

Bulletin American Astronomical Society 14, 365-369 (Observatory Reports)

(1982).

Weiss, A. W. , Correlation Corrections to Energy Levels of Fe XXI, J.

Phys. B: At. Mol. Phys. (in press, 1982).

Wiese, W. L., Report of Working Group 2 on Atomic Transition Probabilities, for Commission 14 of the International Astronomical Union

(in press, 1982).

Wiese, W. L. and Martin, G. A., Atomic Spectroscopy, in Physics Vade

Mecum , 96-106 (1981 ).

Wiese, W. L. and Konjevic, N., Regularities and Similarities in Plasma

Broadened Spectral Line Widths (Stark Widths), J. Quant. Spectrosc.

Radiat. Transfer 28, 185-198 (1982).

Wyart, J.-F., Kaufman, V., and Sugar, J., The 4f 13 5f Configuration in

the Isoelectronic Sequence of Yb III, Phys. Scr. 23_, 1069-1078 (1981 ).

Wyart, J.-F. and Kaufman, V., Extended Analysis of Doubly Ionized

Thorium (Th III), Phys. Scr. 24, 941-952 (1931).

Younger, S. M. Electron Impact Ionization Cross Sections and Rates for

Highly Ionized Atoms, J. Quant. Spectrosc. Radiat. Transfer 26, 329-337

(1981).

Younger, S. M. , Current Theoretical Problems in the Electron Impact

Ionization of Positive Ions, Comments At. Mol. Phys. 1J_, 193-209 (1982).

Younger, S. M., Electron Impact Ionization Rate Coefficients and Cross

Sections for Highly Ionized Iron, J. Quant. Spectrosc. Radiat. Transfer

27, 541-544 (1982).

25
Division 531, Publications (cont'd.)

Younger, S. M. , Electron Impact Ionization of Lithium, Journal of

Research 37, 49-51 (1982).

Younger, S. M., Electron-Impact-Ionization Cross Sections for Highly

Ionized Chlorine-like ions, Phys. Rev. 25^ 3396-3398 (1982).

Younger, S. M., Dielectronic Recombination Rate Coefficients for Highly

Ionized Helium-like Ions, J. Quant. Spectrosc. Radiat. Transfer (in

press, 1982).

Younger, S. M. , Electron Ionization Rate Coefficients for Highly Ionized

Iron and Scandium, J. Quant. Spectrosc. Radiat. Transfer (in press,

1982).

Younger, S. M., Distorted-Electron Impact Ionization Cross Sections for

the Argon Isoelectronic Sequence, Phys. Rev. A (in press, 1982).
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 531, Atomic and Plasma Radiation Division

Victor Kaufman

Member, 1982 William F. Meggers Award Committee, Optical Society

of America.

Georgia A. Martin

Member, National Academy of Sciences-National Research Council

Committee on Line Spectra of the Elements—Atomic Spectroscopy

Chairperson (effective June 1983), National Academy of SciencesNational Research Council Committee on Line Spectra of the Elements—

Atomic Spectroscopy

William C. Martin

Chairman, Working Group on Structure of Atomic Spectra, Commission 14 of International Astronomical Union.

Member, National Academy of Sciences-National Research Council

Committee on Line Spectra of the Elements--Atomic Spectroscopy

Member, IAEA Network of Atomic Data Centers for Fusion.

Wolfgang L. Wiese

Member, Program Committee for the series of International

Conferences on Spectral Line Shapes.

Member of Organizing Committee, International Astronomical Union,

Commission 14.

Chairman, International Astronomical Union, Commission 14, Working

Group on Atomic Transition Probabilities.

Member, IAEA Network of Atomic Data Centers for Fusion.

Member, Steering Committee of the TEXT users organization (TEXT = Texas Experimental Tokamak, a national plasma research facility).

Member, Program Committee for the 13 Symposium on Ionized Gases.

27
MAJOR CONSULTING AND ADVISORY SERVICES

Division 531, Atomic and Plasma Radiation

1. Numerous evaluation tests and calibrations of four rf dimer

lamps are being performed this year as part of contract work for Martin

Marietta Aerospace. This work involves close consultation with Martin

Marietta personnel concerning the results of each test and plans for

successive tests and calibrations.

2. The Data Centers on Atomic Energy Levels and Transitions

Probabilities routinely fill requests for atomic data or literature

information submitted by scientists in a wide range of research areas. The requests average about 15 per week. On occasion, 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

astrophysical community for the 1982 IAU Transactions, and have given

review reports at the 1982 General Assembly of the International Astronomical Union.

3. W. L. Wiese serves on the steering committee for the TEXT users

organization (TUO). TEXT stands for Texas Experimental Tokamak and is a national plasma users facility. The TUO steering committee considers

the special needs of off-site user groups and has then provided advice

and perspective on the users program to the TEXT managers and the Office

of Fusion Energy at DOE.

28
JOURNAL EDITORSHIPS

Division 531, Atomic and Plasma Radiation

W. C. Martin, Editorial Board, Journal of Physical and Chemical

Reference Data.

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

and Radiative Transfer.

W. L. Wiese, Co-Editor of newsletter, "Atomic Data for Fusion,"

published by the Oak Ridge National Laboratory.

29
TRIPS SPONSORED BY OTHERS

Division 531, Atomic and Plasma Radiation

J. M. Bridges traveled to Boulder, Colorado for consultation with Ball

Brothers concerning calibration work. Entire trip paid by Ball Brothers.

(August 2-4, 1982)

J. M. Bridges consulted with scientists at the National Physical Laboratory in London, England and participated in calibrations. Trip sponsored

by Naval Research Laboratory. (July 10-17, 1982)

Charles W. Clark presented an invited talk at Centre National de la

Recherche Scientific in Aussois, France, entitled "Atomic and Molecular Physics Near Ionization Thresholds in High Fields." The entire

trip was paid by CNRS. (June 6-12, 1982)

Charles W. Clark presented an invited talk at the University of Chicago,

entitled "Negative Ion Resonances in Electron Scattering by Noble Gases."

(September 27-29, 1982) Trip was paid by University of Chicago.

W. L. Wiese, sponsored by The Institute of Physical and Chemical Research

in Tokyo, visited the Thermonuclear Fusion Laboratory in Tokyo and

attended a Symposium on Atomic Spectroscopy. He also visited Kyoto,

Niigata, Tokai, and Nagoya and gave invited talks. (September 23-

October 23, 1981)

W. L. Wiese, sponsored by Yugoslavian grants, attended XI International

Symposium on the Physics of Ionized Gases in Dubrovnik and gave

invited talks on "Atomic Transition Probabilities and Lifetime Studies

of Argon" and "Stark Broadening Regularities of 4s-4p Ar I Lines".

Also did collaborative work at Institute for Applied Physics in

Beograde. (August 23-September 10, 1982)

S. M. Younger traveled to Livermore, California to present an invited

talk at Lawrence Livermore Laboratory, Livermore, California. Entire

trip was paid for by LLL. (December 8, 1982)

30
CALIBRATION SERVICES PERFORMED

Division 531, Atomic and Plasma Radiation

Type of Service Customer SP 250 No. of Tests Income

Mini Arc Sources

and Calibrations

Ball Aerospace 7.5 S 4 23.00 k$

Mini Arc

Cal ibrations

Ball Aerospace 7.5 X 1 1.43

Mini Arc

Cal ibrations

Midwest Research

(SERI)

7.5 S 1 1 .38

Dimer Lamp Ball Aerospace 7.5 S 1 2.00

Dimer Lamp Ball Aerospace 7.5 S 1 1.10

Dimer Lamp Ball Aerospace 7.5 S 1 1.50

31
TECHNICAL ACTIVITIES

Task No.

Task No.

Task No.

Task No.

Task No.

Task No.

Task No.

Task No.

Task No.

11221

11222

11223

11225

11226

11227

14302

14402

14420

Division

(new task no. (new task no. (new task no. (new task no. (new task no. (new task no. (new task no.

(new task no.

(new task no.

532, Nuclear Radiation

15221) - Neutron Radiation Safety

15222) - Nuclear Structure and Standards

15223) - Nuclear Radiation Research

15225) - Neutron Field Standards

15226) - Radioactivity Standards

15227) - Neutron Measurements and Research

15602) - Physical/Technological Property SRM

Research

15645) - Computerization of Standard Reference

Bases

15650) - Physical Data for Energy Applications

The Nuclear Radiation Division encompasses a broad range of activities

including both fundamental and applied research. It includes five groups

designated as Nuclear Theory, Nuclear Research, Neutron Measurements and

Research, Neutron Field Standards, and Radioactivity. Of these the first

two are mostly basic nuclear research, and the last three are mostly

applied research. In addition, a project on Dosimetry Standards for

Neutron Radiation Therapy is attached to the Division Office. Photonuclear

data collection, as part of the Photon and Charged Particle Data Center,

is located in the Nuclear Research Group.

Activities of the Division support important national areas of concern: medicine (e.g. radioactivity standards for nuclear medicine),

fission and fusion nuclear power (neutron cross sections, fission rate

measurements in power reactors, environmental radioactivity standards,

nuclear materials safeguards), environment (environmental radioactivity

in natural matrices), occupational safety (neutron personnel monitoring),

and science (nuclear structure and dynamics through electromagnetic

interactions, and molecular physics with eV neutrons).

We continue to attract many guest workers. Some of our scientific

colleagues who have come to NBS for extended stays are: Hall Crannell

and William Stapor, Catholic University of America; Elisa Wolynec,

University of Sao Paulo, Brazil; Li Linpei, National Institute of Metrology,

Peking, China; Mauro Dias, Instituto de Pesquises Energdticas e Nucleares,

Sao Paulo, Brazil; Hans-Georg Menzel , University of Saarlandes, Hamburg,

West Germany; Bernd Siebert, Physikal isch-Technische Bundesanstal t

,

Braunschweig, West Germany; Augustin Grau Malonda, Junta de Energia Nuclear,

Madrid, Spain; Johann Rafelski, University of Frankfurt, West Germany;

and Sunaryo Wiryosumarto , National Atomic Energy Agency, Republic of

Indonesia.

32
Division 532, Technical Activities (cont'd)

Members of Nuclear Radiation Division staff on extended stays elsewhere include Leonard Maximon and Michael Danos, Centre d' Etudes Nucleaires

de Sac! ay, France; Michael Danos, University of Frankfurt, West Germany;

J. Joseph Coyne, Physikal isch-Technische Bundesanstal t, Braunschweig,

West Germany; Evans Hayward, University of Sao Paulo, Brazil, and MaxPlanck Institut fur Chemie, Mainz, West Germany; and Sydney Meshkov,

California Institute of Technology, University of California, Irvine,

and University of California, Los Angeles.

Dosimetry Standards for Neutron Radiation Therapy . This program,

supported by the National Institutes of Health, has been continued to

improve the accuracy and consistency of absorbed dose measurements for

neutron therapy through provision of national dosimetry standards and

improved theoretical information on neutron interactions with tissue

and tissue-equivalent materials. A longer term goal is to develop a calibration facility at NBS where neutron dosimeters can be calibrated

and their energy dependence studied.

As an initial step in establishing the neutron dosimetry standards

program, measurements of the neutron and gamma-ray kerma rates of a 252 Cf

source were made using tissue-equivalent ionization chambers, magnesiumargon ionization chambers, Geiger-Mul ler dosimeters and a tissue-equivalent

proportional counter. After resolving a problem due to a radiation field

component with low penetration, the measured neutron tissue kerma rates

agreed within 3% with the value calculated from the accurately measured

neutron emission rate of the source. A report describing this study has

been prepared for publication. The experience gained from these measurements showed that the proportional counter can provide valuable information for mixed-field dosimetry and a graphite-walled proportional counter

and auxiliary electronic instrumentation has been acquired for future

use. To facilitate precise monitoring of neutron beams, a voltage-tofrequency module and a frequency divider module have been constructed.

Construction of a tissue-equivalent radiation calorimeter is being negotiated with Battelle-Pacific Northwest Laboratory and the necessary

auxiliary equipment for the calorimetry system is being acquired.

Work was completed on the construction of a new charged particle beam

line into the shielded room of the CRR's 3 MeV Van de Graaff accelerator

for use in producing moderately intense fields of monoenergetic neutrons.

This work included installation and testing of all beam line components

(magnets, vacuum pump, valves, power supplies) and the design, construction, and installation of a radiation safety system.

Three tritium targets and one deuterium target were obtained from the

Oak Ridge National Laboratory specially fabricated on copper target blanks

for water cooling. A maximum deuteron beam current of 62 yA at 0.5 MeV was

33
Division 532, Technical Activities (cont'd)

accelerated onto one of the tritium targets to produce 15 MeV neutrons.

Simultaneous measurements made in this neutron field with a tissueequivalent ionization chamber and a 235 U fission counter yielded neutron

kerma rates which agreed within a few percent, well within the experimental

uncertainties

.

A report titled "The NBS Program in Dosimetry Standards for Neutron

Radiation Therapy" was given at the Advisory Group Meeting on Advances in

the Dosimetry for Fast Neutrons and Heavy Charged Particles for Therapy

Applications conducted by the International Atomic Energy Agency.

I . Nuclear Theory Group

This group works on high energy theory, nuclear theory, Coulomb

interactions, neutron standards theory, and theoretical neutron dosimetry,

relating particularly to the experimental nuclear research and neutron

standards research programs in the Division.

Elementary Particle Theory . Quantum Chromodynamics (QCD), our

present theory of the strong interactions, describes hadrons as being

composed of colored quarks and anti quarks. The strong force between

quarks and between quarks and antiquarks is mediated by the exchange of

massless colored gluons, just as the electrical force between electrons

and between electrons and positrons is mediated by the exchange of

massless photons. Convincing manifestations of the existence of the

gluon have been displayed in recent e +e“ annihilation experiments at 27

and 31.6 GeV. QCD implies that glueballs (gluonia) should exist. These

are mesons which are composed entirely of gluons; they contain no quarks

and have no color.

A current activity of the NBS Elementary Particle Program is the

study of gluonium, i.e., to set criteria for its existence, and to try

to understand how to distinguish gluonic states from the usual quark

states experimentally. Understanding the formation, structure, and

decay of gluonic systems requires a full knowledge of the spectroscopy

of "quarkful" mesons, i.e., those described in the usual way as quarks

and anti quarks moving with a relative orbital angular momentum L.

Fortunately, the latter is a major component of high energy activity

of NBS as manifested by work on charmonium and other "onium" spectroscopy.

Following studies carried out over the past two years in collaboration

with P. Fishbane of the University of Virginia and C. Carlson and F. Gross

of the College of William and Mary, a critical evaluation of our knowledge

of glueball masses, widths and possible production and decay mechanisms

was carried out. In a comprehensive report presented at an International

34
Division 532, Technical Activities (cont'd)

Conference in Florence, Italy, it was concluded that the i ( 1 440 ) and 0(1640)

states, possible glueball candidates, should not be regarded as glueballs,

but are most likely something else, probably quark-antiquark radial excitations. Recent work demonstrating this in a simple mixing model has

been carried out with P. Fishbane and G. Karl (University of Guelph,

Canada) and is being prepared for rapid publication. In addition, it

appears that the various glueball excitations are more massive than previously believed.

Nuclear Theory . In the past, nuclear forces have been treated in

terms of meson exchanges between point nucleons, 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. 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, but due to the unique confining properties

of the quark-quark forces the correlation problem is not easily solved.

The current hadron bag model treats the confinement problem in a purely ad hoc , unphysical, manner, i.e. , by imposing a scalar boundary

condition on the quark wave function. However, no scalar fields exist

in the QCD Lagrangian, which could serve to take up the momentum transfer

implied by the boundary condition. In order to eliminate this drawback,

and to put the description of the hadrons on a more physical basis a reformulation of the quark bag model for the nucleon in terms of the methods of

NBS Monograph 147 has been initiated. The first steps, in progress at

this time, consist of rewriting the QCD Hamiltonian in the Schrodinger

picture, and of computing the specific QCD matrix elements not contained

in 147.

A vexing problem of nuclear physics is the apparent isospin impurity

of the a-particle, which manifests itself in the ratio a(Y,p)/a(y,n)

which does not equal unity. This experimental fact has lead to speculation that the nuclear force itself may not be isospin invariant. A program

has been started to test whether the Coulomb interaction itself, contrary

to previous calculations, can explain the observed cross section ratio.

Photonuclear Theory . A very important source of the high energy

photons used in photonuclear research is the bremsstrahl ung radiation

produced when accelerated electrons collide with a suitable target.

Recently there has been a strong trend toward the utilization of "monochromatic" photon beams rather than bremsstrahl ung photon beams. The

experimental technique which now promises great success in achieving good

35
Division 532, Technical Activities (cont'd)

comprises between the conflicting requirements of small energy resolution,

high flux, low counting rates associated with unwanted photons and a well

defined, and easily and continuously adjustable photon energy is the

bremsstrahlung monochromator or photon "tagging" technique. The tagged

photon technique detects the electron after bremsstrahlung to determine the

emitted photon energy. This detected electron is put in time coincidence

with a nuclear decay product following the photon induced reaction. The

photon tagging technique has become increasingly popular as electron beams

of duty cycle approaching 100%, such as the racetrack microtron currently

under construction at the National Bureau of Standards, become available.

Following a first report (NBSIR 81-2262), prepared for the explicit use of

the experimenters who are designing and using tagged photon systems as a means of doing experiments with monoenergetic photons, we have prepared a second report on polarized tagged photons (NBSIR 82-2454). This report has

already been used by expermental groups both in the U.S. and abroad, for

the design of bremsstrahlung monochromators.

Theoretical work on the photodisintegration of few body systems con- tinues in collaboration with physicists from George Washington University.

Two reports detailing the mathematics needed to incorporate the Coulomb

interaction in reaction amplitudes have been prepared, GWU/DP/TR-82/1 and

GWU/DP/TR-82/2 . This work has already been used by experimenters at M.I.T.

in their analysis of experiments on the photodisintegration of 3 He.

Theoretical Neutron Dosimetry . A theoretical program on Neutron

Interactions with Biological Tissue is carried out with joint support

from NBS and the Office of Health and Environmental Research, Department

of Energy. The objective of this program is to obtain information about

neutron interactions with tissue through secondary charged particles

using theoretical calculations whose input includes neutron cross section data; range, stopping power, and straggling information; and

geometrical properties. This information is basic to radiological

physics, radiation biology, radiation protection of workers, and standards

for neutron dose measurement.

There is increased interest in studying very small cavity sizes (of

the order of nanometers). For these cavity sizes our analytical calculations will not be valid because of the importance of delta rays and

straggling, or track structure in general. For this reason, and because

it will be needed to improve calculations at high neutron energy, we are developing a Monte Carlo code to calculate energy depositon spectra for

fast neutrons. The first version has been designed so as to duplicate

the results of the analytic code. This code is now operating successfully

and gives identical results to the analytic code within the Monte-Carlo

statistics. Preliminary studies have been completed on how to include

straggling and delta-ray effects. As a first step we will use the "Landau"

straggling, which is valid for small thicknesses of material--certainly

the case for nanometer cavities.

36
Division 532, Technical Activities (cont'd)

The analytic code used for neutron energy deposition studies has been

extended in two ways: (1) use of bin-averaged cross sections so that

arbitrary neutron spectra may be calculated, useful even for "monoenergetic"

neutron sources since they are seldom completely monoenergetic, and also

for distributed-energy neutron sources such as cyclotrons with either

protons or deuterons on beryllium as the neutron-producing reaction; and

(2) calculation of ionization yield spectra for small sites which are more

directly comparable to the experimentally-measured spectra obtained with

walled and wall-less tissue-equivalent proportional counters.

Kerma factors have been calculated for 44 compounds and mixtures

encompassing a large number of materials of interest to radiation biology,

radiation therapy, neutron protection, dosimetry, and radiation chemistry.

This material is in press.

Neutron Personnel Monitoring . Under contracts with the DoE and NRC we

have continued studies of calibration of neutron monitoring instruments

used in neutron fields of interest to these two agencies. For DoE we

published an NBS report on "Procedures for Calibrating Neutron Personnel

Dosimeters." This report gives detailed recipes for correcting calibration

measurements for effects of air scatter, room scatter, and scatter in

source encapsulation. We have made both calculations and measurements of

the photon component from 252Cf spontaneous fission neutron sources for

NRC. Also we are reviewing measurements made in maintenance areas of

nuclear power plants in order to recommend optimum procedures for evaluating the radiation dose received by workers in those plants.

We have devised a synthesis of two simple expressions for (1) reflection

of neutrons from a plane surface and (2) reflection of neutrons from a source at the center of a cubical room. Predictions of the combined ex- pression agree very well with Monte Carlo calculations of neutron reflection

for sources at a general position in rooms of arbitrary shape.

Civil Defense . We have written computer codes to evaluate shielding

afforded by structures against neutrons and gamma rays from nuclear weapons.

The codes are consistent with the input data format used by FEMA to evaluate protection in structures from fallout radiation. The shielding curves

used by the codes are based on data generated by L. V. Spencer and by SAI,

under contract to NBS. The codes calculate the protection against both

neutrons and gamma rays at the center of a building and include effects of

internal reflection of neutrons and the shielding effects of nearby buildings.

37
Division 532, Technical Activities (cont'd)

II. Nuclear Research Group

The study of the interactions of high energy photons and electrons

with nuclei is leading to new understandings of how nucleons behave inside

complex nuclei, i.e. in what form they exist and how they interact with

each other. Activities of the Nuclear Research Group cover experimental

and theoretical investigations of many different electromagnetically induced

nuclear reactions. This includes high energy electron and photon scattering

from nuclei, electrodisintegration experiments in which nuclear reaction

products are studied, and electroactivation studies in which integrated

reaction cross sections are studied via induced radioactivities.

The photon scattering work was terminated in August 1981 to make room

for construction of the NBS microtron. Before this time, however, work was completed on the scattering of high energy photons from 16 0 at several

angles. These data along with similar data on 12 C have been analyzed to

yield the E2 strength in these nuclei. A paper is in preparation on this

work.

The electron scattering program has encompassed several different

activities. A precision measurement of the 4 He radius has been made by

comparing it to that of 12 C. This work will constitute the PhD thesis of

W. Stapor of Catholic University. A similar measurement of the proton

radius is now being planned and will form the basis of the thesis of

M. McCord. Maruyama has continued in his study of stretched configurations

in collaboration with the group at the University of Massachusetts; the

measurements are made at the Bates Laboratory. Lightbody and Maruyama are also engaged in a collaboration at Bates to investigate the convection and

magnetization current contribution to the transverse cross section of the

first excited state of 52 Cr.

O'Connell organized a collaboration with a group of physicists from

Lund, MIT, American Unviersity, and NBS to investigate the apparent failure

of the Coulomb sum rule. At the Bates Laboratory, we measured the spectra

of electrons scattered through 20° by six targets at four electron energies.

During the course of the measurements we found an intrumental background

produced by the electrons striking the interface between the spectrometer

and the scattering chamber and established a procedure for subtracting it

off. Within the uncertainties in the experiment our results are consistent

with the sum rule and it is now believed that the discrepancy found in

previous experiments stemmed partly from the instrumental problem.

The electrodisintegration experiments performed in collaboration with

E. Wolynec of Sao Paulo have continued. The work on the isochromat of the

electric dipole virtual photon spectrum for zirconium has been completed

and a paper sent to the Physical Review. We now plan to study the (e,a)

and (e,p) cross sections for Zr. In addition, we will complete the measurement and interpretation of the 63Cr(e,n) cross section.

38
Division 532, Technical Activities (cont'd)

At the present time the Nuclear Research Group is engaged in writing

a proposal to request funds to support the physics that can be done with

the 200 MeV CW microtron now under construction. This proposal describes

the coincidence experiments that we want to perform and the required

instrumentation. They are of the type (e,e'x) or (y,x) using tagged photons.

The proposal also describes a plan to use the 200 MeV machine as an injector for a much larger 1 GeV microtron. This will involve an enlargement of the laboratory which will become a national user facility. Most

of the physics planned for the 1 GeV facility involves studies of the fewnucleon problem. Huge magnetic spectrometers will be required.

III. Neutron Measurements and Research Group

This group is concerned with measurements of neutron interactions

which depend strongly on the neutron's energy. The interactions include

both nuclear and molecular effects and 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% (1 SD)

range. 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 NBS facilities

used are the 100 MeV linac, 3 MV positive-ion Van de Graaff, and nuclear

reactor.

The standards measurements during the past year concentrated on the

neutron induced fission cross section of 235 U. Progress in fusion research

and concerns about tactical neutron warheads are driving current interest

in this standard. Three of the group's previously reported measurements on this standard using different techniques and neutron energies were published in Nuclear Science and Engineering. The first paper covering the

experiment at 14 MeV using the associated-particle technique reported an accuracy of 1.5% (1 SD). An evaluation of all measurements at 14 MeV shows

that the cross section at 14 MeV, with an accuracy of better than 1%, is as well known as at thermal energy. The second paper covering experiments

in the 0.2-1. 2 MeV region using the black neutron detector reported an accuracy of 2.3% (1 SD). The cross sections were approximately 2% lower

than the ENDF/B-V evaluation. Also published was the measurement of the

235 U mass contained in the large fission chamber which is used in several

of the cross section measurements. The shape measurements in the 6-800

keV region using the hydrogen-gas counter flux monitor which were reported

in 1976 were reevaluated and also published.

39
Division 532, Technical Activities (cont'd)

A significant accomplishment was the development of a new neutron

detector for flux measurements in the 1-15 MeV region. The detector

consists of two thin plates of plastic scintillator optically separated

and independently coupled to phototubes. The response of the detector

approximates the proton recoil spectrum from n-p scattering and can be

calculated from the well known hydrogen cross section. The efficiency

of the detector was measured at 2.5 MeV and 14 MeV using the associated

particle technique and was extended into the intermediate energy regions

by means of Monte-Carlo based calculations.

Our measurement efforts concentrated on the low MeV neutron region

where serious discrepancies still exist. Analysis continues of measurements in the 0.3 to 3 MeV region that were made using the black neutron

detector at the linac facility. A similar measurement is in progress

in the 1-6 MeV region using the thin scintillator flux monitor described

above. An experiment at 2.6 MeV using the associated particle technique

with the D(d,n) 3 He reaction at the Van de Graaff is underway but will

require an improved TiD target for completion. Upon completion of this

work, the NBS will have completed 9 measurement efforts on 235 U in the

5 eV to 20 MeV range. It appears that the long existing objective of 1%

for the cross section may also be within reach throughout much of this

energy region when the NBS data is combined with other data in the final

evaluation.

New studies of the few percent deviations of the 6 Li(n,a) to 10 B(n,a) cross section ratios from the ENDF/B-V evaluation observed previously in

the eV energy region continued. Transmission measurements at the NBS

reactor thermal column were done for 2

6 Li glass scintillators so that

accurate self-shielding corrections could be applied to the ratio measurements. These scintillators were used in a collaborative ratio measurement

at Oak Ridge National Laboratory which confirmed the anomalous behavior

in the eV region which might result from molecular effects.

Theoretical studies of electronic excitation in atoms and molecules

by neutron-nucleus scattering have been completed. The work was carried

out in collaboration with Dr. S. W. Lovesey of the Rutherford Appleton

Laboratory. Two mechanisms were considered for producing electronic

excitations, center-of-mass recoil and the coupling between electrons

and nuclei arising from non-adiabatic terms neglected in the BornOppenheimer approximation. A significant cross section for electronic

excitations is predicted in this study. The effect of this previously

neglected energy-loss mechanism on moderation problems is currently

being addressed. The Monte-Carlo technique is being used to study the

differences in moderated neutron spectra with and without the possibility

of electron excitations. These studies are just beginning.

40
Division 532, Technical Activities (cont'd)

Experimental studies of inelastic neutron scattering in the 1-15 eV

range are continuing. A careful measurement of the inelastic scattering

spectrum from H2 0 at 30° reveals that molecular binding effects persist

in this energy range. These results are confirmed by a recent Los

Alamos National Laboratory measurement using a slightly different technique

where inelastic scattering from the hydrogen in H 2 0 is seen at 90°.

Efforts are now underway to fit the present data using the theoretical

model of Nelkin. Preliminary results indicate that this model which

incorporates rotational and vibration excitations can quantitatively

describe the data. It should be noted that this model has been extensively

used in the reactor physics codes but in a lower energy range.

We considered the effect of the thermal neutron absorption cross

section of sulfur on the value of v for 252 Cf obtained in the Mn bath

measurements. A 10&= increase in this cross section (3 times experimental

error) is required to remove the discrepancy between bath and scintillator

measurements of v. Measurements are in progress at the University of

New Mexico of the effective sulfur absorption cross section in the bath

medium. A different value in the medium would indicate that molecular or moderation effects on the neutron absorption could be important and should

be further studied at NBS.

We have also studied the discrepancy between the 4 He production from

10 B measured with integral measurements and that calculated from ENDF/B-V

cross sections. This :: B problem has received considerable attention in

the international community. New evaluation codes are being used which

can utilize both differential and integral measurements and covariance

information. We are involved in this process and if required will investigate possible moderation effects which could affect the flux in the

integral measurements. The most direct approach to the 10 B measurement

discrepancy with calculations is to perform 4 He production measurements

in existing NBS standard neutron fields. The first of such measurements

in the thick shell ISNF began in FY-82 and will continue in FY-S3.

Studies of neutron -induced fission cross section systematics for a wide range of nuclei are yielding encouraging results in the MeV energy

region. The present work involves the prediction of the fission cross

sections of the short-lived nuclides based on the properties of the nearby

long-lived nuclides. The status of the fast fission cross section ratios

is also being maintained for a subcommittee of the Cross Section Evaluation

Working Group.

We were quite pleased to see the technical accomplishments of our

group acknowledged by a national organization. Dr. Roald Schrack was granted the IR-100 Award by Industrial Research magazine for one of the

hundred most important technological advances of the year. This advance

was the development of the micro-channel plate position sensitive neutron

41
Division 532, Technical Activities (cont'd)

detector. This device has a time resolution of approximately one microsecond and a spatial resolution of about one-half millimeter. Using this

detector and the technique of resonance neutron radiography, images have

been produced of the distribution of an isotope in a complex matrix.

Measurements of the special nuclear material content of waste materials

are in progress at the linac facility using this technique.

We continue to maintain strong international relationships through

the BIPM, the IAEA, and the European Nuclear Energy Agency Nuclear Data

Committee and participate in planning internationally coordinated measurement programs. We have established a 14 MeV standard neutron facility at

the Van de Graaff which was used in an international intercomparison of

neutron source strength. The facility is being extended to 2.6 MeV

neutron energy and a 6-7 MeV standard y-ray field using the 19 F(p,ay)

reaction is being developed.

The transfer of NBS neutron measurement results to the outside com- munity has been a significant part of our program during the past year.

The DoE Cross Section Evaluation Working Group (CSEWG) continues to be an effective means of implementing our data improvements quickly into industrial and government programs. Dr. Allan Carlson continues as chairman

of the standards subcommittee of CSEWG. The NM&R group continues an active

program of communication of new neutron measurement methods and related

technology to the U.S. national laboratories. The new analytical methods

for spent fuel analysis, fuel reprocessing material accounting, and breeding ratio measurement have been discussed closely with staff members at

BNL and Argonne National Laboratories. The group has provided consulting

services to LLNL and LANL on new neutron measurement methods and on the

development of new methods for materials science studies using neutrons.

The continued availability of suitable accelerator sources of neutrons

for NBS is a matter of growing concern. The NBS Center for Radiation

Research has commissioned a further study of possible alternatives for

improved accelerator neutron sources at the NBS. This study, which is

also extending the areas of study to include high-LET radiation in order

to broaden the support base within the NBS for an improved accelerator,

will be presented for consideration by the NBS management.

IV. Neutron Field Standards Group

The objectives of this group are to provide neutron dosimetry standardization and neutron source and detector calibrations for energy generation technology and radiation exposure monitoring. Activities are divided between response to calibration and measurement service requests

and the application of existing standard neutron fields and related capabilities to neutron reaction-rate measurement standardization. Strong

42
Division 532, Technical Activities (cont'd)

interactions with outside organizations, both in the federal and private

sector, continue to be the main programmatic characteristics of this

group's activities.

Concern for neutron field measurements is on the increase as was noted last year. More neutron field calibration and related measurements

were undertaken this year than last in order to improve the level of

standardization for personnel neutron dosimetry, for materials performance

under stress of radiation, and for advanced power reactor development.

Fission chamber experiments in a variety of circumstances continue to

dominate our activities: measurements in neutron flux intensities which

differ by 7 orders of magnitude, for example, or in neutron fields under

10 meters of water vs. open air experiments where inverse-r2 field

gradients are closely approximated.

Neutron personnel dosimetry activities involving hundreds of dosimeter and dosimetry instrumentation calibrations were carried out during

the year at NBS with five different standard neutron fields. Clients

ranged from nuclear utilities and dosimetry vendors to DoE laboratories

participating in dosimetry improvement programs. Dosimetry for materials

performance focused on preparing and evaluating the documentation describing reactor pressure vessel (RPV) mock-up measurements at ORNL. Experimental characterization of the neutron field in the RPV mock-up rests

largely upon neutron reaction rate measurements that were referenced to

fission neutron standard fields at NBS. The industry problem behind this

effort, steel embrittlement under stress of radiation in a reactor vessel,

continues to be an important component of our program. The new impetus,

arising from the recognition of thermal shock potential in certain pressure

vessels as a result of post-TMI changes in emergency reactor-shutdown

procedures continues to exercise the industry, the NRC, and even the

media. A paper presented at the Ninth Water Reactor Safety Information

Meeting examined the effectiveness of making supplementary, on-demand

dosimetry measurements in the so-called RPV cavity of older power reactors

where the thermal shock question is of most consequence.

A triumph of sorts occurred when the Subcommittee on Standards

explicitly recognized the fission-spectrum-averaged cross section of U-235

in the Cf-252 fission spectrum as a basic normalization measurement for

the U-235 fission cross section. Remeasurement of this normalization

quantity is continuing and this year included fissionable deposit mass intercomparisons at the thermal column. In addition, a re-evaluation of

earlier measurements was completed and the results forwarded to CSEWG:

a

f (U-235 , X ) = 1216 + 19 mb

There was little change from the previously published value but the error

in the rms sense was reduced by a factor of two. This improvement came

43
Division 532, Technical Activities (cont'd)

from (1) revision of mass scale for NBS fissionable deposits (error

reduced to +0.75%); (2) new detailed Monte-Carlo scattering calculations

for the fission chamber and the fissionable deposit backings carried out

at Los Alamos; and (3) reduction of the error assigned to the source

strength of NBS-I, the National Standard Neutron Source (error reduced

to + 0.9%).

A new and quite different kind of activity was initiated this year.

A thermal -neutron-autoradiography facility for diagnostic irradiations of

art works was undertaken in cooperation with the Reactor Division and the

Smithsonian Institution. Substantial modifications at the thermal column,

fabricated and installed by our group, were designed to achieve a high

intensity flux of thermal neutrons over a large area. The design also

made possible rapid recovery of irradiated paintings so that short-lived

activities could be included in the post-irradiation diagnostic procedures.

Preliminary and successful irradiations of prototype paintings were completed.

Fission cross-section measurements in the thick-shell ISNF were performed for the following isotopes: U-233, Pu-240, Pu-241 , and Th-232.

Combined with earlier measurements of U-235, U-238, Pu-239, and Np-237,

there now exists for ISNF a consistent set of integral fission cross- section data for essentially all of the fissionable isotopes important

for reactor technology. A representative result,

a

f

( Pu-240 , ISNF) = 824 mb + 2.8%,

agrees well with the value predicted by ENDF/B-V (the U.S. nuclear data

file for reactor technology):

Calculated

Observed 1 .00 + 3.0%.

A characteristic of this result which identifies it as coming from a standard neutron field is the inclusion of a component error in the 3.0% total

uncertainty for the propagated effect of ISNF spectrum uncertainties. Each

physical and nuclear parameter of ISNF has been subject to a spectrum

variational analysis which is subsequently propagated to a set of spectrumassociated errors for each species of reaction rate measurements performed

in ISNF. Thus, calculated to observed ratios like the one above for Pu-240,

is an unambiguous check of the corresponding energy-dependent reaction

rate cross section.

An archive deposit of U-233, a recent addition to the NBS set of

fissionable isotope mass standards, was employed for the ISNF measurements

just described as well as for earlier Of fission spectrum cross section

44
Division 532 9 Technical Activities (cont'd)

measurements. The complex alpha spectrum of U-233 and its daughters, and

the fact that the deposit is a fluoride compound rather than the usual

oxide, creates special problems in the mass assay. In order to carry out

the thermal -fission component of the assay, fission fragment self-absorption

in fluoride vs. oxide deposits was investigated this year in a series of

thermal beam measurements.

The testing of neutron personnel dosimetry instrumentation which

continued at a high level made notable and proper institutional use of

the filtered beams, the thermal column, and the D2 0-moderated fission

spectrum irradiation facility. Systematic performance tests have now

been performed on essentially all types of passive neutron dosimeters

used in the United States. Calibration of active neutron dosimetry

instrumentation (remmeters and BF 3 counters) served the needs of a variety

of agencies, laboratories, and commercial vendors, and most significantly,

to meet the vital calibration requirements of a suddenly increased number

of power reactor operators. The latter service often enough was called

upon to accommodate difficult and costly deadlines imposed upon us by the

reactor operators.

Neutron fluence standards prepared with the cavity fission source

were sent to ORNL for calibration of a new dosimetry counting system.

Activation reactions included were In(n,n'), Al(n,a), Ni-58(n,p), and

Fe-54(n,p). The facility at ORNL will be employed for neutron dosimetry

measurements in existing and planned irradiations there designed to test

embrittlement rates in reactor pressure vessel steels. For this work and

other enhanced activities at the cavity fission source, a specialized

fission chamber of small diameter purchased in France was installed at

the entrance penetration of the reactor thermal column cavity. It is now

possible to perform time-history flux monitoring of 235 U fission spectrum irradiations. Other notable improvements in the Cavity Fission

Source were: (1) experimental examination of flux gradients over the

region of detector placement; and (2) receipt of preliminary results of

source detector scattering calculations. The latter are part of extensive

Monte Carlo calculations being carried out at Los Alamos under joint

cooperation and contract.

The cavity fission source, after its varied applications to neutron

dosimetry calibration, was employed for the first time in a cross-section

measurement. The U-235 fission-spectrum-average cross section for the

activation dosimetry reaction Ni-58(n,p) was determined in a set of cavity

fission source irradiations. The absolute flux for the experiment was established by the method neutron flux transfer from the Cf -252 fission

source using the In (n,n‘) reaction. The preliminary result of this

measurement:

a ( N i ,X25 ) =101+3 mb

45
Division 532, Technical Activities (cont'd)

caused some spirited discussion when reported at the Fourth ASTM-EURATOM

Symposium on Reactor Dosimetry in March of this year. The accepted

experimental value of this important cross section is some 8% higher than

the one above. There is added provocation in the fact that the preliminary

NBS experimental value agrees with the calculated spectrum-averaged cross section whereas the accepted measured value does not and, in fact, has

been used to challenge the shape of the U-235 fission spectrum.

Miscellaneous measurement and related activities make poor material

for accomplishment reporting, but unfortunately they constitute a substantial part of the NSF Group effort. A sampling of these activities in

FY-82 are as follows: (1) performance test irradiation of proton-recoil

emulsion detectors with thermal neutrons; (2) post-irradiation checks of

Co-Al and Co-Zr dosimeter wires for validating cobalt concentrations; (3)

quality control tests of navy shipboard area monitors; (4) refurbishing

and check out of fission chambers for CEN/SCK (Belgium), and the University

of Arkansas; (5) performance investigation of position-sensitive, proportional counter to be used for 1 inac-resonance radiography development;

and (6) initial neutron flux measurement at the new 14 MeV Van de Graaff

source.

Specific reference is made here to last year's narrative of technical

activities (Annual Report 1981; Div. 532). Most of the information provided there is applicable to this year's activities. Fourteen publications

and reports were part of the group's activities this year; the total for

FY-81 and FY-82 is twenty-six--see Publications Section.

Meetings and committee work continue to occupy a prominent place in

our program. We provide a secretary for the ASTM Subcommittee on Radiation

Metrology which presently is heavily engaged in the parallel development

of nineteen standards for reactor pressure vessel irradiation surveillance

and steel embrittlement prediction. Participation at symposia and program

reviews in radiation personnel dosimetry continued and the effort to

draft a new IAEA Manual on Neutron Dosimetry Calibrations moved forward.

The Fourth ASTM/EURATOM Symposium on Reactor Dosimetry was held at NBS

this year. We tried our best, and by individual generosity of effort,

probably did cope with playing host, under legislated limitations, to an international group of government and private sector experts accustomed

to European levels of conference facilities (e.g. simultaneous translation)

and hospitality (e.g. a noteworthy banquet). Attendance was rich and

varied with program managers from government agencies and industry organizations mixing it up with the working troops. Formal program review

meetings (a total of four, one held at NBS) for the NRC-sponsored LWRPressure Vessel Dosimetry Irradiation Surveillance Program and the DoEsponsored Personnel Dosimetry Upgrading Program require active participation spread out among five staff members.

46
Division 532, Technical Activities (cont'd)

V. Radioactivity Group

A. Standard Reference Materials and Calibration Services

Most visible of the group activities are the distribution of selected

radionuclides as Standard Reference Materials (SRM's) and the calibration

of submitted radionuclides for which SRM's are not suitable. Traceability

exercises which can be associated with either program test the abilities

of other laboratories to obtain results in satisfactory agreement with NBS

values. Booklets describing both programs are kept current and distributed

to potential users.

Table 1 summarizes SRM distributions, calibrations and some traceability activities for the year ending August 1, 1982. Included are the

significant Atomic Industrial Forum program, which links a major fraction

of U.S. radiopharmaceutical manufacturers with NBS calibrations, and

traceability exercises with regulatory agency laboratories.

Table 1

Standards and Calibration Services No. of Units K$

Standard Reference Materials 1375 260.3

Atomic Industrial Forum, 85 (27.5)

traceability tests of radiopharmaceutical manufacturers

NRC (11) and EPA (6) 17

Traceability Programs

Reports of Test (NBS 94) 40 30.4

Scheduled Calibrations (QMS) 58 34.9

A few new SRM's should be noted. Three natural matrix radioactivi ty

standards were calibrated and issued as SRM's - Peruvian Soil, Human

Liver, and Human Lung. Many laboratories cooperated in the calibrations,

which utilized a variety of low-level measurement procedures. A new mixed-radionuclide gas standard was developed and distributed for supplying

efficiency calibration points at several energies for germanium gamma-ray

spectrometers used in monitoring reactor off gases.

The tests included direct traceability checks on several batches of

mul ti -gamma-ray standards similar to those developed and formerly supplied

by NBS, but now available from commercial suppliers.

47
Division 532, Technical Activities (cont'd)

The result of a careful measurement of the activity of a 238 Pu

solution for the Idaho National Engineering Laboratory was used by them

in determining the gamma-ray-probabil ity per decay for that radionuclide.

B. Basic Activity and Nuclear Data Measurements

Most of the basic calibrations for gamma-ray-emitting radionuclides

are retained on stable ionization chambers or germanium-spectrometry

systems. This permits routine service calibrations or SRM production

with minimum repetitious use of the more complex direct calibration techniques. These techniques can be used instead to produce calibrations for

new radionuclides of growing significance. Spectrometry systems which

are used to check the purity and accuracy of all x- and gamma-ray-emitting

radionuclides are also used to measure accurately probabilities per decay

for some radiations, in order to relate emission rate and activity measurements. Half lives are measured in order to prolong the accurate

application of SRM's, and new techniques for measurement are pursued in

order to improve or expand our measuring abilities. Recent examples of

these follow.

Half lives measured in the group for 50 radionuclides were published

in 1982, together with gamma-ray probabilities per decay for 7 radionucl ides

.

The half life of 121mSn was found to be about 35 years, in disagreement with tabulated values of 55 years.

The 109-minute half-life radionuclide fluorine-18 was calibrated by

three different techniques: calibrated 4tt y ionization chamber, Ge(Li)

gamma-ray spectrometry, and 4tt g liquid-scintillation counting. Results

by the three techniques agreed to within 1.5 percent.

The long-lived radionuclide technetium-99 was standardized by the

method of J. A. B. Gibson using standard solutions of hydrogen-3, carbon14, and cobalt-60. Results using the three radionuclides agreed to

within 0.32 percent. Combined with accurate mass measurements, this

calibration led to a new half life of (2.109 + 0.036) x 10 s years.

The very long extending dead times possible in an anticoincidence

4it e-y system constructed in the group were applied to a preliminary

direct measurement of the contribution of an 18-ms state in the activity

calibration of selenium-75.

A collaboration with members of the neutron field standards group

led to improved values for spectrum-averaged cross sections for 54 Fe(n,p),

58 Ni(n,p), and 115 In(n,n').

48
Division 532 s Technical Activities (cont'd)

Preparations are being made for cooperative studies with D. E.

Murnick of Bell to check the half life of 2 x 10 5 -y krypton-81m by

combining activity measurements with atom counting.

C. Other Agency Programs

In addition to the traceability programs mentioned above, several

other calibration techniques or special sources have been developed for

other agencies. Examples of these in the past year follow.

Calibrated 3 H, 90 Sr, 137 Cs, 235 U, 238 Pu, 241 Am, and natural uranium

solutions were furnished to Pacific Northwest Laboratories (PNL) and

Humanoid Systems as part of the NBS contribution to a joint NRC/DoEsponsored program aimed at testing the quality of bioassays of occupationally exposed individuals. PNL has a formal program to evaluate

technically a draft ANSI standard N13.30, which describes criteria for

the performance of radiobioassay laboratories.

A radon-in-water standard is under development as a portion of an EPA contract. At present, a source which exhales radon at a constant

rate under water has been shown to be stable for at least 4 months. Work

is progressing toward delivering the radon-containing water to whatever

receptacle i*s desired by prospective users of the standard.

The response of several survey instruments immersed in a 133 Xe

atmosphere of known activity concentration was measured for NRC.

Group members cooperated with the Analytical Chemistry Division in

the design of an instrument to assay radioisotopes of xenon for the Air

Force Technical Applications Center. A device, based on the conclusions

of the study document, is being constructed for test. Low-level hydrogen-3

in water samples were also prepared for the Air Force to use in their

internal quality control program.

D. International Activities

Just as accurate U.S. radioactivity measurements are anchored on NBS

standards, our results must be checked on an international basis.

Techniques and calibrations are exchanged and compared with the corresponding laboratories in other nations, and with international organizations. These sometime involve working visits or formal intercomparisons.

Some of our international activities in the past year are given below.

A compilation of data from recent measurements made in ICRM member

laboratories was published as NBS Special Publication 626 in January

1982. The data are useful for the calibration of germanium-spectrometrysystem efficiencies.

49
Division 532, Technical Activities (cont'd)

Cesium-137 was measured as part of a BIPM-sponsored intercomparison

by the method of 4tt B-y coincidence efficiency tracing using cesium-134

for the tracer radionuclide.

Carbon-14, hydrogen-3, and technetium-99 were sent to Poland (IBJ),

but conditions are not favorable for a continuation of these intercomparisons .

Carbon-14 intercomparisons are underway with the USSR (VNIIFTRI) and

United Kingdom (NPL). The NBS calibration for hydrogen-3 was compared

with that of the CBNM (Central Bureau Nuclear Measurements), Geel , Belgium.

The Low-level and Alpha-spectrometry Groups of the ICRM are jointly

organizing a seminar at Harwell, U.K. to discuss the present state of

metrology and quality control in the respective fields and organize

possible new future work.

Advice was given to new standardizing laboratories being established

in Korea and Taiwan.

Sunaryo, a Guest Worker from the laboratory responsible for radioactivity standardization and monitoring in Indonesia, was supported by

th'e IAEA for a 6-month period at NBS. During this time, he studied our

techniques, assisted in the preparation of Standard Reference Materials,

and made activity measurements on selenium-75.

Dr. Augustin Grau Malonda from the Junta de Energia Nuclear in Madrid,

Spain visited NBS as a Guest Worker and collaborated on measurements of

fluorine-18. Plans were also drawn up for a long-term collaboration in

radioactivity calibration techniques involving liquid-scintillation

counting

.

B. M. Coursey visited the National Office of Measures in Budapest,

Hungary as part of the continuing scientific exchange program with

Hungary.

50
SPONSORED CONFERENCES

Division 532, Nuclear Radiation

International Program Review Meeting on Reactor Pressure Vessel Irradiation

Surveillance, NBS, Gaithersburg, Maryland, E. D. McGarry, October 27-31,

1981.

Ninth Annual Water Reactor Safety Information Meeting, NBS, Gaithersburg,

Maryland, sponsored by Nuclear Regulatory Commission, J. A. Grundl , liaison,

October 1981

.

Fourth ASTM-Euratom Symposium on Reactor Dosimetry, NBS, Gaithersburg

,

Maryland, J. A. Grundl, C. M. Eisenhauer, E. D. McGarry, March 22-26, 1982.

Workshop on Electromagnetic Nuclear Reactions Below 1 GeV, Lewes Center for

Physics, Delaware, J. S. O'Connell, coordinator, June 13-19, 1982.

51
INVITED TALKS

Division 532, Nuclear Radiation

Calhoun, J. M., "Radiopharmacy," College of Pharmacy, Howard University,

April 22, 1982.

Caswell, R. S. , "Neutron Interactions with Biological Tissue," Department

of Energy 15th Annual Radiological Physics Contractors Meeting on The

Biological Effects of Ionizing Radiation: Radiological Physics, Gettysburg,

Pennsylvania, May 4-6, 1982.

Coursey, B. M. , "Liquid Scintillation Counting Techniques in Radioimmunoassay," Department of Radiopharmaceutical Chemistry, George Washington

University, Washington, D.C., October 14, 1981.

Coursey, B. M. , "Radioactivity Calibrations and Standard Reference Materials

at the National Bureau of Standards," Orsz^gos Mdrdsugyi Hivatal, Budapest,

Hungary, April 30, 1982.

Eisenhauer, C. M. , "Gamma-Ray Component of 252 Cf Spontaneous Fission Neutron

Source," Ninth DoE Workshop on Personnel Neutron Dosimetry, June 24-25,

1982.

Grundl , J. A., "NRC-EPRI Studies of Pressure-Vessel -Cavity Neutron Fields,"

Ninth Annual Water Reactor Safety Information Meeting, NBS, October 1981.

Hayward, E. V., "Elastic Photon Scattering by 12 C and 16 0," Lehigh University, Bethlehem, Pennsylvania, December 3, 1981.

Hayward, E. V., "Photon Scattering by 12 C," Department of Physics,

University de Montreal, P. Q., Canada, May 31, 1982.

Lightbody, J. W. , Jr., "Tests of the Coulomb Sum Rule in Electron Scattering," Department of Physics, Triangle Universities, Nuclear Laboratory,

Duke University, Durham, North Carolina, January 21, 1982.

Mann, W. B., "Availability and Use of NBS Radioactivity Standards,"

University of Alaska, Anchorage, Alaska, November 25, 1981.

Mann, W. B. , "An International Reference Material for Radiocarbon Dating,"

Eleventh International Radiocarbon Conference, Seattle, Washington, June

20-26, 1982.

Maruyama, X. K. , "Stretched Configuration States in Medium Weight Nuclei,"

Department of Physics and Chemistry, Naval Postgraduate School, Monterey,

California, January 8, 1982.

52
Division 532 9 Invited Talks (cont'd)

McGarry, E. D. , "NBS ISNF and Cavity Fission U 235 Standard Neutron Fields*"

4th ASTM-EURATOM Symposium on Reactor Dosimetry* March 1982.

Meshkov, S., "Glueballs and Oddballs," Theoretical Physics Seminar, Univ.

of Cal ifornia-Irvine , Irvine, California, December 3, 1981.

Meshkov, S. , "Glueballs and Oddballs," Theoretical Physics Seminar,

California Institute of Technology, Pasadena, California, April 1, 1982.

Meshkov, S., "Glueballs and Oddballs," Theoretical Physics Seminar, UCLA,

Los Angeles, California, April 14, 1982.

Meshkov, S., "Glueballs and Oddballs," Part II, Theoretical Physics Seminar,

California Institute of Technology, Pasadena, California, April 16, 1982.

Meshkov, S., "Glueballs, a New Form of Matter," Colloquium, University of

Cal ifornia-Irvine , Irvine, California, May 7, 1982.

Meshkov, S., "Glueballs and Oddballs," Elementary Particle Seminar, University

of Wisconsin, Madison, Wisconsin, May 10, 1982.

Meshkov, S., "Glueballs and Oddballs," Elementary Particle Seminar, University

of Minnesota, Minneapolis, Minnesota, May 11, 1982.

Meshkov, S., "Glueballs and Oddballs," Elementary Particle Seminar, Fermilab,

Batavia, Illinois, May 14, 1982.

Meshkov, S. , "Glueballs and Oddballs," Sixth Workshop on Current Problems

in High Energy Particle Theory, Florence, Italy, June 3, 1982.

Meshkov, S. , "Glueballs and Oddballs," Colloquium, Johns Hopkins University,

Baltimore, Maryland, September 23, 1982.

O'Connell, J. S., "Unsolved Puzzles in Electronuclear Interactions," Dept,

of Physics, Pennsylvania State University, University Park, Pennsylvania,

October 21 , 1981

.

Schrack, R. A., "Resonance Neutron Radiography," Argonne National Laboratory,

Argonne, Illinois, May 20-21, 1982.

Schroder, I. G. , "Neutron Irradiation Facility for Radiographic Study of

Art Works," Ninth International Congress of the International Institute

for Conservation of Historic Art Works, Washington, DC, September 1982.

Schwartz, R. B., "Procedures for Calibrating Neutron Personnel Dosimeters,"

Twenty-seventh Annual Meeting of the Health Physics Society, Las Vegas,

Nevada, June 1982.

53
PUBLICATIONS

Division 532, Nuclear Radiation

Ayres, Robert L., Radioactivity Standardization of "mTc and "Mo,

Proceedings of the 27th Annual Meeting of the American Nuclear Society,

June 9, 1981, Miami Beach, Florida (in press).

Behrens, J. W. , Browne, J. C., and Walden, J. C., Measurement of the

Neutron-Induced Fission Cross Section of Neptunium-237 Relative to

Uranium-235 from 20 keV to 30 MeV, Nucl . Sci. Eng. 80, 393 (1982).

Behrens, J. W. , Browne, J. C., and Abies, E., Measurement of the NeutronInduced Fission Cross Section of Thorium-232 Relative to Uranium-235 from

0.7 to 30 MeV, Nucl. Sci. Eng. 81_, 512 (1982).

Behrens, J. W. , Fast Fission Cross Sections of Pu-233, U-237, Np-239,

Pu-243 , and Am-242, Bull. Am. Phys. Soc. 27, 459 (1982).

Behrens, J. W. , Inferred Fission Cross Sections for Short-Lived Actinides

in the MeV Range, Conf. The Neutron and Its Applications, September 13-17,

1982, Cambridge, England (to be published in proceedings).

Behrens, J. W. , Inferred 238 Pu(n,f) Cross Section in the MeV Range, ANS

Annual Meeting, November 1982, Washington, DC.

Behrens, J. W., Fast Fission Ratio of Th-232 Relative to U-235, Section B,

Part XIII; Fast Fission Ratio of U-233 Relative to U-235, Section B, Part

XIV; Fast Fission Ratio of U-238 Relative to U-235, Section B, Part XVI;

Fast Fission Ratio of Pu-239 Relative to U-235, Section B, Part XVII, Fast

Fission Ratio of Pu-241 Relative to U-235, Section B, Part XVIII, Brookhaven

National Laboratory Report BNL-NCS-51 123 (1982).

Bowman, C. D. and Johnson, R. G. , Measurements of Inelastic Neutron Scattering in the eV Range, Seminar/Workshop "Thermal Reactor Benchmark Calculations, Techniques, Results, and Applications," May 17-18, 1982, Brookhaven National Laboratory (to be published in proceedings).

Bowman, C. D. , Schrack, R. A., Behrens, J. W., and Johnson, R. G. , Neutron

Resonance Transmission Analysis of Reactor Spent Fuel Assemblies, World

Conference on Neutron Radiography, Dec. 7-10, 1981, San Diego, CA (to be

published in proceedings).

Bowman, C. D. and Johnson, R. G. , Neutron-Induced Atomic Excitation and

Neutron Moderation, Nuclear Data for Science and Technology--Int . Conf.,

September 6-10, 1982, Antwerp, Belgium (to be published in proceedings).

54
Division 532 s Publications (cont'd)

Brandon, W. E., Cogburn, C. 0., Culp, R. R. , Sallee, W. W. , and Williams,

J. G. (University of Arkansas); Eisenhauer, C. M. , Grundl , J. A., McGarry,

E. D., and Schwartz, R. B. (NBS), Intercomparison of the D 2 0-Moderated

252 CF Sources at the NBS and at the SEFOR Calibration Center, Proc. 4th

ASTM-EURATOM Symposium on Reactor Dosimetry, Vol . II, 649 (1982).

Broadhurst, M. G., Bur, A. J., and Schwartz, R. B., The Effect of Neutron

Irradiation on Electric Conductivity in Cellulose Acetate, Rad. Prot. Dos.

3, No. 1 (1982).

Burt, P. E., Fagg, L. W., Crannell , H., Sober, D. I., Stapor, W., O'Brien,

J. T., Maruyama, X. K. , Lightbody, J. W., and Lindgren, R. A., Electron

Scattering Study of the 10.32 MeV Transition in 40 Ca, Phys. Rev. C 25.,

No. 5 (May 1982).

Carlson, A. D. and Behrens, J. W., Absolute Measurement of the 235 U(n,f)

Cross Section from 0.3 to 3 MeV Using the NBS Electron Linac, Proc. Conf.

Nuclear Data for Science and Technology, Sept. 6-10, 1982, Antwerp, Belgium

(to be published in proceedings).

Carlson, A. D. , Standard Cross Section Data, Progress in Nuclear Energy

(in press).

Carlson, A. D., Editor, ENDF/B-V Cross Section Measurement Standards, BNL

Report (in press).

Carlson, C. E. , Coyne, J. J., Fishbane, P. M. , Gross, F., and Meshkov, S.,

Hadronic Decays of Low-Lying Glueballs, Nucl Phys. (in press).

Caswell, R. S., Coyne, J. J., and Goodman, L. J., Comparison of Experimental and Theoretical Ionization Yield Spectra for Neutrons, 4th Symp.

on Neutron Dosimetry, GSF, Munich-Neuherberg , Germany, June 1-5, 1981;

Commission of the European Communities Report EUR 7448 1_, 201-212 (1981 ).

Caswell, R. S., Radiation Protection and the International Commission on Radiation Units and Measurements (ICRU), Rad. Prot. Dos. 1_, No. 4, 241 (1982).

Caswell, R. S., and Coyne, J. J., Kerma Values, Neutron, Encyclopaedia

of Physics and Its Applications, Pergamon Press (in press).

Caswell, R. S. , Coyne, J. J., and Randolph, M. L., Kerma Factors of

Elements and Compounds for Neutron Energies Below 30 MeV, Int. J. Appl

.

Rad. Isotopes (in press).

Colie, R., Rubin, R. J., Knab, L. I., and Hutchinson, J. M. R., Radon

Transport Through and Exhalation from Building Materials: A Review and

Assessment, NBS Technical Note 1139 (September 1981).

55
Division 532, Publications (cont'd)

Coursey, B. M. , Hoppes, D. D., and Schima, F. J., Determination of the

Photon Emission Rates of the NBS Long-Lived Mixed-Radionuclide Standard,

Nuclear Instruments and Methods-Special Issue for the Fifth Symposium on

X- and Gamma-ray Sources and Applications, Ann Arbor, Mich. 193 , 1-8 (1982).

Coursey, B. M. , Calhoun, J. M., Inn, K. G. W. , and Lucas, L. L., LiquidScintillation-Counting Techniques for Inorganic Radiochemicals, Trans. Am.

Nucl . Soc. 39, 25 (1981).

Coyne, J. J., McDonald, J. C., Menzel , H.-G., and Schuhmacher, H., Detailed

Intercomparison of Calculated and Measured Ionization Yield Spectra for

20 MeV Neutrons and the Implication for High Energy Dosimetry, Proceedings

of the 4th Symposium on Neutron Dosimetry, June 1-5, 1981, GSF, MunichNeuherberg, Germany; Commission of the European Communities Report EUR 7448

1, 213-223 (1981).

Danos, M., The Bohm-Aharonov Effect: The Quantum Mechanics of the Electrical

Transformer, Am. J. Phys. 50_, 64-66 (1982).

Dias, M. S. and Renner, C. , Si (Li) Efficience Curve for X-Ray Parallel Beam,

Nucl. Instr. and Meth. 193 , 91 (1982).

Dias, M. S., Johnson, R. G., and Wasson, 0. A., An Absolute Neutron Flux

Detector for the 1-20 MeV Energy Range, Nuclear Data for Science and

Technology Conference, September 6-10, 1982, Antwerp, Belgium (to be published in proceedings).

Dias, M. S., Johnson, R. G., and Wasson, 0. A., Absolute Neutron Flux

Detector of 1-15 MeV Neutrons for a Measurement of 235 U Fission Cross

Section, 1982 Fall Meeting of the APS, October 14-16, 1982, Amherst, MA,

(to be published in Bull. Am. Phys. Soc.).

Dodge, W. R. , Leicht, R. G. , Hayward, E., and Wolynec, E., Electrodisintegration of 56 Fe , 59 Co , and 64 Zn, Phys. Rev. C24, 1952 (1981 ).

Dodge, W. R. , Hayward, E., and Wolynec, E., An Experimental Test of Virtual

Photon Theory, Phys. Rev. C (in press).

Eisenhauer, C. and Schwartz, R. , Difficulties in Calculating SpectrumAveraged Values of Neutron Dose Equivalent, Health Phys. 41_, No. 5,

774-777 (November 1981).

Eisenhauer, C., Schwartz, R., and Johnson, T., Measurement of Neutrons

Reflected from the Surfaces of a Calibration Room, Health Phys. 42_,

489-495 (April 1982).

56
Division 532 9 Publications (cont'd)

Fishbane, P. M. , Horn, D., Karl, G., and Meshkov, S., Flavor Symmetry and

Glueballs, Phys. Rev. (in press).

Fuller, E. G. and Gerstenberg, H. , Photonuclear Data Index, 1973 through

1981 , NBSIR 82-2543 (1982).

Gilliam, D. M. , Fuller, J. L., Grundl , J. A., and Daughtry, J. W., Absolute

Fission Rates in the FFTF, Trans. Am. Nucl . Soc. _39, 901 (November 1981).

Goodman, L. J., Coyne, J. J., and Caswell, R. S., The NBS Program in

Dosimetry Standards for Neutron Radiation Therapy, Proc. IAEA Advisory

Group on Advances in Dosimetry for Fast Neutrons and Heavy Charged Particles for Therapy Applications, June 14-18, 1982, Vienna, Austria (in press).

Grundl, J. A., Eisenhauer, C. M. , and McGarry, E. D., Neutron Flux Measurements in the Pressure. Vessel Cavity of an Operating U.S. Power Reactor,

LWR Pressure Vessel Irradiation Surveillance Dosimetry Progress Report,

HEDL-TME 8218, NUREG/CR-2805 1 (January 1982).

Grundl, J. Eisenhauer, C. , Lamaze, G. , McGarry, E. D. , Cogburn, C.,

Tsoulfanidis, N. , Kellogg, !_., and McElroy, W. , NRC-EPRI Studies of

Pressure-Vessel -Cavity Neutron Fields, NRC Ninth Water Reactor Safety

Information Meeting (Oct. 1981) (to be published in proceedings).

Hoppes, D. D. and Schima, F. J., eds., Nuclear Data for the Efficiency

Calibration of Germanium Spectrometer Systems, NBS Special Publication 626

(1982).

Hoppes, D. D. , Hutchinson, J. M. R. , Schima, F. J., and Unterweger, M. P.,

Nuclear Data for X- or Gamma-Ray Spectrometer Efficiency Calibrations, NBS

Special Publication 626 (1982).

Hutchinson, J. M. R. and Mullen, P. A., Calibration of K-x-Ray Emission

Rates in the Decay of Vanadium-49 (in press).

Hutchinson, J. M. R. and Mullen, P. A., "Pin-Wel 1"-Nal (T1 ) Counting of

59.5-

keV Gamma Rays in the Decay of Americium-241 (in press).

Hutchinson, J. M. R. , Noyce, J. R. , and Kolb, W., Radiochemical Isolation

of Radium-228 and its Calibration by Liquid-Scintillation Counting and

Gamma-Ray Spectrometry, Int. J. Anal. Radiochem. (in press).

Johnson, R. G. and Bowman, C: D., Inelastic-Scattering Measurements of

1.5-

15 ev Neutrons, Phys . Rev. Lett. 49_, No. 11 , 797-800 (September 13,

1982).

57
Division 532, Publications (cont'd)

Johnson, R. G., Behrens, J. W., and Bowman, C. D. , Source Imaging Using

Neutron Pinhole Cameras Based on Position-Sensitive Proportional Counters,

Nucl . Technol . 55_, 724 (December 1981).

Lamaze, G. P., McGarry, E. D., and Schima, F. J., Integral Reaction Rate

Measurements in 252 Cf and 235 U Fission Spectra, International Conference

on Nuclear Data for Science and Technology, September 6-10, 1982, Antwerp,

Belgium (to be published in proceedings).

Lightbody, J. W. , Jr., Spectrometer Requirements for (e,e'2N) Studies,

Proceedings of the Workshop on High-Resolution, Large-Acceptance Spectrometers, Sept. 8-11, 1981, Argonne, IL; ANL/PHY-81 -2 , Section IV, J-l-10

(1982).

Lightbody, J. W., Jr., Stapor, W. J., Crannell, H., Maruyama, X. K., and

O'Brien, J. T. , A Flowing Gas Target System for Precision Electron Scattering Measurements, Nucl. Instr. Meth. (in press).

Lightbody, J. W., Jr., Bellicard, J. B., Cavdeon, J. M., Frois, B., Huet, M.

Leconte, Ph., Nakada, A., Xuan Ho, Phan, Platchkow, S. K., Turck, S.,

de Jager, C. W. , Lapikcis, J. J., and de Witt Hubert, P. K. A., Elastic and

Inelastic Electron Scattering from 50,52,54Q rj Phys. Rev. C. (in press).

Lindgren, R. A., Plum, M. A., Gerace, W. J., Hicks, R. S., Parker, B.,

Peterson, G. A., Singhal, R. , Williamson, C. F., Maruyama, X. K. , and

Petrovich, F. , Isospin Splitting of Isovector High Spin "Stretched" Particle

Hole Excitations in Non-Selfconjugate Nuclei, Phys. Rev. Lett. 47, No. 18

(November 2 , 1981).

Lippincott, E. P., Schmittroth, F. A., Oberg, D. L., McElroy, W. N.,

Gold, R. , Fabry, A., Minsart, G., McGarry, E. D., Kam, F., Stallman, F.,

Analysis of Experimental Data and Calculations in an LWR Pressure Vessel

Mockup, Trans. Am. Nucl. Soc. 39_ (Dec. 1981).

Lovesey, S. W. , Bowman, C. D., and Johnson, R. G., Electron Excitation in

Atoms and Molecules by Neutron-Nucleus Scattering, Z. Phys. B-Condensed

Matter 47, 1 37 (1982)

.

Lovesey, S. W. , Bowman, C. D., and Johnson, R. G., Non-Adiabatic Transitions in Molecules by Neutron Scattering, EPS Conf. on Condensed Matter,

March 22-25, 1982, Manchester, U.K. (to be published in proceedings).

Lucas, L. L. and Noyce, J. R. , The Half-Life of Plutonium-240, Int. J.

Appl . Radiat. Isotopes (in press).

Mann, W. B., Unterweger, M. P., and Coursey, B. M., Comments on the NBS

Triated-Water Standards and Their Use, Int. J. Appl. Radiat. Isot. 33_,

383-386 (1982).

58
Division 532 s Publications (cont'd)

Mann, W. B., An International Reference Material for Radiocarbon Dating,

Radiocarbon (June 1982) (abstract only).

Maximon, L. C., Ganz, E., de Miniac, A., and Aniel, T., Polarized Tagged

Photons, An Analysis of the Differential Cross Section for Polarized

Bremsstrahlung in the Range of Interest for a Tagged Photon System,

NBSIR 82-2454 (January 1982).

Maximon, L. C., Eskandarian, A., Lehman, D. R., and Gibson, B. F.,

Momentum-Space Solution of the Bound Three-Body Problem with Two Charged

Particles, Bull. Am. Phys. Soc. II 26, 566 (1981).

Maximon, L. C., Integral Representations for the Regular and Irregular

S-wave Coulomb Wave Functions, W . 1 (-2iqr), M . 1 (-2iqr), W 1 (2$r),

“1 h ,--2 ~ • P k s'l M^ ^(2 Br). George Washington University, Department of Physics, Technical

Report GWU/DP/TR-82/1 (1982).

Maximon, L. C., A Method for Making Coulomb Effect Corrections to Reaction

Amplitudes, George Washington University, Department of Physics, Technical

Report GWU/DP/TR-82-2 (1982).

McDonald, J. C. and Goodman, L. J., Measurements of the Thermal Defect for

A- 1 50 Plastic, Phys. Med. Biol. 27, No. 2, 229-233 (1982).

McGarry, E. D. , Requirements for Reference Reactor Pressure Vessel Dosimetry to Benchmark Neutron Fields, Proc. IAEA Advisory Group Meeting on Nuclear Data for Radiation Damage Assessment and Reactor Safety Aspects

(October 1981 )

.

McGarry, E. D. , Lamaze, G. P., Eisenhauer, C. M., Gilliam, D. M., and

Schima, F. J., NBS ISNF and Cavity Fission U-235 Standard Neutron Fields,

Proc. Fourth ASTM-EURATOM Symposium on Reactor Dosimetry, Washington, DC

(March 1982).

Meshkov, S., Glueballs and Oddballs, The 6th Johns Hopkins Workshop on Current Problems in High Energy Particle Theory, June 2-4, 1982, Firenze,

Italy, 185-209 (1982).

O'Connell, J. S., Electromagnetic Nuclear Reactions: I. Introduction,

Operators, and Sum Rules, NBSIR 82-2547 (September 1982).

O'Connell, J. S. , Measuring Nucleon Charge and Magnetization Inside the

Nucleus, Comments on Nuclear and Particle Physics XI_, No. 1 , 1-7 (1982).

59
Division 532, Publications (cont'd)

O'Connell, J. S., Photonuclear Reactions Above the Pion Threshold, Proceedings of International School of Intermediate Energy Nuclear Physics,

July 16-26, 1982, Verona, Italy, 189-215 (1982).

Schrack, R. A., Behrens, J. W., Carlson, A. D., Bowman, C. D., and Johnson,

R. G., Quantitative NDE in the Nuclear Industry, Recent Developments in

Resonance Neutron Radiography Fifth Int. Conf . , May 10-13, 1982, San Diego,

CA (to be published in proceedings).

Schrack, R. A., Behrens, J. W., Johnson, R. G., and Bowman, C. D., Resonance

Neutron Radiography, World Conf. on Neutron Radiography, Dec. 7-10, 1981,

San Diego, CA (to be published in proceedings).

Schwartz, R. B., Endres, G. W. R., and Cummings, F. W., Neutron Dosimeter

Performance and Associated Calibrations at Nuclear Power Plants, NUREG/CR2233 (July 1982).

Schwartz, R. B. and Eisenhauer, C. M. , Procedures for Calibrating Neutron

Personnel Dosimeters, NBS Special Pub. 633 (May 1982).

Siebert, B. R. L. , Coyne, J. J., and Caswell, R. S., Calculation of Quality

Factors for Fast Neutrons in Materials Composed of H, C, N and 0, Eighth

Symposium on Microdosimetry , September 27-0ctober 1 , 1982, JCilich, Federal

Republic of Germany (to be published in proceedings).

Wasson, 0. A. and Meier, M. M., Measurement of the 235 U Mass in a Large Volume Multiplated Fission Ionization Chamber, Nucl . Instr. Methods

190 , 571 (1981).

Wasson, 0. A., Carlson, A. D. , and Duvall, K. C., Measurement of the 235 U Neutron Induced Fission Cross Section at 14.1 MeV, Nucl. Sci. Eng. 80, 282,

(1982).

Wasson, 0. A., Meier, M. M. , and Duvall, K. C., Absolute Measurement of the

235 U Fission Cross Section from 0.2 to 1.2 MeV, Nucl. Sci. Eng. 81, 196

(1982).

60
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 532, Nuclear Radiation

Robert L. Ayres

Member, International Committee for Radionuclide Metrology (ICRM)

Life Sciences Working Group.

Member, Board of Directors, Technical Group for Biology and Medicine,

American Nuclear Society.

Consultant, U.S. Pharmacopeia, Advisory Panel on Radiopharmaceuticals.

James W. Behrens

Member, DoE Cross Section Evaluation Working Group (CSEWG), Data

Status and Requests Committee.

Member, Isotopes and Radiation Division, American Nuclear Society,

Transuranium Task Force.

Charles D. Bowman (resigned May 1982)

Member, DoE Nuclear Data Committee.

Technical Advisor, DoE Cross Section Evaluation Working Group (CSEWG)

Standards Committee.

Allan D. Carlson

Chairman, DoE Cross Section Evaluation Working Group (CSEWG),

Standards Committee.

Member, DoE CSEWG, Data Status and Requests Subcommittee.

Member, DoE CSEWG, Evaluations Committee.

Randall S. Caswell

Delegate, Comite Consultatif pour les Etalons de Mesure des

Rayonnements Ionisants (CCEMRI), Conference Gdndrale des Poids et

Mesures, Paris, France.

Chairman, Section on Neutron Measurements (Section III), CCEMRI,

Conference Generale des Poids et Mesures, Paris, France.

61
Division 532, Technical and Professional Committee Participation and

Leadership (cont'd)

Randall S. Caswell (cont'd)

Member, National Council on Radiation Protection and Measurements

(NCRP)

.

Member, NCRP Board of Directors (until April 1982).

Chairman, NCRP Ad Hoc Committee on SI Units.

Chairman, NCRP Ad Hoc Committee on Publications.

Member and Secretary, International Commission on Radiation Units

and Measurements (ICRU).

Sponsor, ICRU Report Committee on Stopping Power.

Sponsor, ICRU Report Committee on Dosimetry at High Doses.

Member, Radiation Research Accelerator Facility (RARAF) Scientific

Advisory Committee, Columbia University.

Bert M. Coursey

Member, International Committee for Radionuclide Metrology (ICRM)

Life Sciences Working Group.

Member, ANSI Subcommittee N42.2 on Procedural Standards for Calibration of Detectors for Radioactive Materials.

Delegate, Bureau International des Poids et Mesures (BIPM), Consultative Committee for Standards of Ionizing Radiations Task Group on the

Feasibility of Liquid Scintillation Counting for the Standardization

of Radionuclides which Decay by Emitting Low-Energy Radiations.

Member, Executive Committee, Biology and Medicine Technical Group,

American Nuclear Society.

J. Joseph Coyne

Chairman, National Nuclear Data Center (NNDC), Panel on Reference

Nuclear Data.

Member, International Commission on Radiation Units and Measurements

(ICRU) Committee on Microdosimetry.

62
Division 532, Technical and Professional Committee Participation and

Leadership (cont'd)

Michael Danes

Member, Program Review Committee for the Sad ay Electron Linac,

Saclay, France.

Charles M. Eisenhauer

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, Subcommittee on Radiation Research Strategy Implementation,

Interagency Radiation Research Committee.

Member, ASTM Subcommittee El 0.05 on Nuclear Radiation Metrology.

Member, NAS-NRC Advisory Committee on the Radiation Effects Research

Foundation; also subcommittee: Panel on the Reassessment of A-Bomb

Dosimetry.

Everett G. Fuller

Member, National Council on Radiation Protection and Measurements

(NCRP), Scientific Committee 60, Neutrons from Medical Accelerators.

Leon J. Goodman

Consultant, American Association of Physicists in Medicine, Task

Group 18: Fast Neutron Beam Dosimetry Physics.

Member, International Commission on Radiation Units and Measurements, Committee on Clinical Dosimetry for Neutrons.

James A. Grundl

Member, Organizing Committee for Fifth ASTM-EURATOM Symposium on Reactor Dosimetry, NBS, March 1985.

Co-chairman, Steering Committee for Developing ASTM Standards for

Reactor Pressure Vessel Irradiation Surveillance.

Member, ASTM Subcommittee El 0.05 on Nuclear Radiation Metrology.

Evans V. Hayward

Member, Maryland Governor's Science Advisory Council.

63
Division 532, Technical and Professional Committee Participation and

Leadership (cont'd)

Evans V. Hayward (cont'd)

Member, Argonne Universities Association Special Committee for the

Medium Energy Electron Accelerator Facility.

Member, Board of Directors of the Southeastern Universities Research

Association.

Member, The Nominating Committee of The American Physical Society.

Dale D. Hoppes

Member, International Committee for Radionuclide Metrology (ICRM)

Work Group on Alpha-, Beta-, and Gamma-Ray Spectrometry Group.

Member, Atomic Industrial Forum (AIF)-NBS Standards Program Committee,

Standards Steering Committee.

Member, International Committee of Weights and Measures (BIPM),

Consultative Committee on Standards for Measuring Ionizing Radiations,

Subcommittee Section II: Radionuclide Measurements.

Member, Calibration Advisory Group, NBS.

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, American Society for Testing and Materials (ASTM) Committee

C26.05 Environmental Methods Task Group on Nuclear Fuel Cycle.

Member, Methods of Radiochemical Analysis in Water and Water Deposits,

Committee D19.04.

George Lamaze

Secretary, American Society for Testing and Materials (ASTM),

Subcommittee El 0.05, Nuclear Radiation Metrology.

64
Division 532, Technical and Professional Committee Participation and

Leadership (cont'd)

J. W. Lightbody, Jr.

Chairman, 1982 Gordon Research Conference on Photonuclear Reactions.

Member, Scientific Advisory Committee to Southeastern Universities

Research Association, Program Advisory Committee for the MIT Bates

accelerator.

Wilfrid B. Mann

Member, Executive Board, International Committee for Radionuclide

Metrology.

Consultant, International Commission on Radiation Units and

Measurements (ICRU).

Member, DoE Half-Life Evaluation Committee for Pu Isotopes Physical

Constants

.

Member, American National Standards Institute (ANSI) Institute of

Nuclear Materials Management (INMM) Committee on Methods of Nuclear

Material Control.

Member, ANSI-INMM Subcommittee N15.8 on Calibration Techniques for

Nuclear Material Control.

Member, ANSI-INMM Work Group INMM 8.04 on Calibration Techniques for

Calorimetric Assay of Plutonium-Bearing Solids.

Chairman, National Council on Radiation Protection and Measurements

(NCRP) Committee 18A on Standards and Measurement of Radioactivity

for Radiological Use.

Emmert D. McGarry

Member, Organizing Committee for the Fifth ASTM-EURATOM Symposium

on Reactor Dosimetry, NBS, March 1985.

Member, Steering Committee for Developing ASTM Standards for Reactor

Pressure Vessel Irradiation Surveillance.

Member, American Society for Testing and Materials (ASTM) Committee

on Nuclear Applications and Measurement of Radiation Effects.

Member, Review Committee on Energy Deposition in Fuel Rods During

Power Facility RIA Testing.

Member, ASTM Subcommittee El 0.05 on Nuclear Radiation Metrology.

65
Division 532, Technical and Professional Committee Participation and

Leadership (cont'd)

Sydney Meshkov

Member, Advisory Board, Aspen Center for Physics. Actively

participated in running the center during the summer months.

Organized the Program for the Orbis Scientiae (High Energy Conference)

at the Center for Theoretical Studies at the University of Miami.

Session Chairman, Orbis Scientiae (High Energy Conference) at the

Center for Theoretical Studies at the University of Miami, January

1982.

Member, Advisory Board for the Lewes Center for Physics at the Univ.

of Delaware at Lewes, Delaware.

J. S. O'Connell

Member, Nuclear Science Advisory Committee to NSF and DoE.

Member, Program Advisory Committee for the MIT Bates accelerator.

Francis J. Schima

Vice-Chairman, Washington Area Data General Computer Users Group.

Roald A. Schrack

Member, Organizing Committee of Fifth International Conference on Quantitative Non-destructive Essaying in the Nuclear Industry,

May 10-13, 1982, San Diego, CA.

Robert B. Schwartz

Member, International Standards Organization (ISO) Technical

Committee on Nuclear Energy (ISO/TC 85).

Member, ISO Subcommittee 2 on Radiation Protection.

Member, ISO Work Group 3 on Neutron Reference Radiations.

Michael P. Unterweger

Member, American Society for Testing and Materials (ASTM) Committee

D-22 on Methods for Sampling and Analysis of Atmospheres.

66
MAJOR CONSULTING AND ADVISORY SERVICES

Division 532, Nuclear Radiation

1. J. W. Behrens consulted with Industrial Quality, Inc. on nuclear

detection systems for neutron radiography and gauging.

2. A. D. Carlson organized the national effort for the Department of

Energy to prepare the neutron cross section standards for the ENDF/B-VI

evaluation.

3. B. M. Coursey and A. T. Hirshfeld provided assistance to the Nuclear

Medicine Division at NIH in the calibration of several detectors used

for fluorine-18 measurements.

4. B. M. Coursey and J. M. Calhoun provided calibration services and

reviewed methodology for iodine-123 measurements at George Washington

University.

5. M. Danos served as advisor and scientific consultant to the Chief

of Nuclear Physics, Saclay, France.

6. Charles M. Eisenhauer and L. V. Spencer prepared a report for the

Federal Emergency Management Agency (FEMA) which provides guidelines

for research on the protection provided by various types of structures

against initial radiations from nuclear weapons.

7. D. M. Gilliam advised Hanford Engineering Development Laboratory on fission chamber performance in high energy neutron fields.

8. J. Grundl consulted with Electric Power Research Institute (EPRI) on program directions in support of reactor pressure vessel dosimetry.

9. R. J. Johnson consulted with the Lawrence Livermore National Laboratory on neutron capture cross section measurements.

10. G. Lamaze led effort to revise ASTM Standard on definition for neutron

dosimetry.

11. L. Maximon is consultant to two groups in the Department of Nuclear

Physics at CEN, Saclay: The High Energy Nuclear Physics Group which

does electron nuclear scattering and the Metrology and Fundamental

Neutron Physics Group which does photo-nuclear physics.

12. E. D. McGarry provided planning and calibrations for in-situ neutron

source strength measurement at SEFOR facility in Arkansas.

67
Division 532, Major Consulting and Advisory Services (cont'd)

13. E. D. McGarry served on management group for dosimetry characterization program at NRC/ORNL pressure-vessel mock-up facility.

14. E. D. McGarry and J. A. Grundl consulted with and acted as referee

for EPRI on achieving optimal dosimetry results for pressure vessel

cavity measurements.

15. S. Meshkov served as visiting professor at the California Institute

of Technology, Pasadena, California and at the University of California,

Irvine, California.

16. I. G. Schroder provided basic design study for Neutron Radiography

Facility sponsored by the National Gallery of Art.

68
JOURNAL EDITORSHIPS

Division 532, Nuclear Radiation

R. S. Caswell, Member of Editorial Board, Journal of Physical and Chemical

Reference Data.

B. M. Coursey, Editor, International Journal of Applied Radiation and

Isotopes.

W. B. Mann, Editor, Environment International.

W. B. Mann, Editor, International Journal of Nuclear Medicine and Biology.

W. B. Mann, Editor-in-Chief for North America, International Journal of

Applied Radiation and Isotopes.

69
TRIPS SPONSORED BY OTHERS

Division 532, Nuclear Radiation

R. S. Caswell, National Council on Radiation Protection and Measurements,

Ad Hoc Committee on Potential New NCRP Publications, Chicago, Illinois,

March 24, 1982.

R. S. Caswell, Annual Meeting of the International Commission on Radiation

Units and Measurements, Reisensburg, Germany, September 16-25, 1982.

B. M. Coursey, College of American Pathologists, Nuclear Medicine Resources

Committee Meeting, West Palm Beach, Florida, March 24, 1982.

B. M. Coursey, scientific exchange program with Orsz^gos Mdrdsiigyi Hivatal,

Budapest, Hungary, April 24-May 2, 1982.

B. M. Coursey, Editorial Board Meeting, International Journal of Applied

Radiation and Isotopes, Oxford, United Kingdom, May 7, 1982.

M. Danos, Center for Nuclear Studies (CEN), Paris (Saclay) France to

continue collaboration with Dr. V. Gill et and staff on relativistic nuclear

physics, many-body correlations in nuclei, and heavy ion collisions, October

1-31, 1981; January 12-March 19 and May 1-June 12, 1982.

M. Danos, Duke University, collaboration with Prof. Biedenharn on nuclear

physics, March 31 -April 2 and September 15-20, 1982.

L. J. Goodman, International Commission on Radiation Units and Measurements

Clinical Neutron Dosimetry Committee meeting, Houston, Texas, February 8-9,

1982.

E. V. Hayward, Argonne Universities Association Special Committee for the

Medium Energy Electron Accelerator, Argonne, Illinois, November 9-10, 1981.

E. V. Hayward, American Physical Society Nomination Committee Meeting,

Dallas, Texas, March 7-8, 1982.

E. V. Hayward, Argonne Universities Association Special Committee for the

Medium Energy Electron Accelerator, Argonne, Illinois, May 19-20, 1982.

E. V. Hayward, Meeting to discuss photonuclear reactions, University de

Montreal , P. Q., Canada, May 31 -June 2, 1982.

E. V. Hayward, Max-Planck Institut fur Chemie, Mainz, Germany, collaborations with Prof. B. Ziegler on photon scattering experiments, September

1982.

70
Division 532, Trips Sponsored by Others (cont'd)

j. W. Lightbody, Jr., Duke University, to give talk, "Tests of the Coulomb

Sum Rule in Electron Scattering," January 21, 1982.

J. W. Lightbody, Jr. Gordon Research Conference on Photonuclear Reactions,

Col by-Sawyer College, New London, N.H., August 9-13, 1982.

W. B. Mann, Editorial Board Meeting, International Journal of Applied

Radiation and Isotopes, Oxford, United Kingdom, May 7, 1982.

W. B. Mann, Executive Board Meeting, International Committee on Radionuclide Metrology, Physikalisch-Technische Bundesanstal t, Braunschweig,

West Germany, May 18-19, 1982.

X. K. Maruyama, University of Massachusetts, Amherst, Massachusetts, for

a collaborative experiment, February 24-March 4, 1982.

X. K. Maruyama, Naval Postgraduate School, Dept, of Physics and Chemistry,

Monterey, California to give talk, "Stretched Configuration States in

Medium Weight Nuclei," January 8, 1982.

S. Meshkov, Elementary Particle Seminar, University of Wisconsin, Madison,

Wisconsin, to give lecture, "Glueballs and Oddballs," May 10, 1982.

S. Meshkov, Elementary Particle Seminar, University of Minnesota, Minneapolis,

Minnesota, to give lecture, "Glueballs and Oddballs," May 11, 1982.

S. Meshkov, Elementary Particle Seminar, Fermilab, Batavia, Illinois, to

give lecture, "Glueballs and Oddballs," May 14, 1982.

S. Meshkov, California Institute of Technology, Pasadena, California and

University of California, Irving, California, as visiting professor,

September 1981 -June 1982.

J. S. O'Connell, Physics Colloquium, Pennsylvania State University,

University Park, Pennsylvania, to give lecture, "Unsolved Puzzles in

Electronuclear Interactions," October 22, 1981.

R. A. Schrack, Argonne National Laboratory, Argonne, Illinois, to lecture

on resonance neutron radiography, May 20-21, 1982.
STANDARD REFERENCE MATERIALS

Division 532, Nuclear Radiation

Standards Issued - 1 September 1981 through 31 August 1982

SRM Radionucl ide Principal Use

4410H-G Technetium-99m Calibration of instruments for

activity measurements of radiopharmaceutical s

4406L-E Phosphorus-32 II

4407L-G Iodine-125 II

4401 L-H Iodine-131 II

4412L-G Molybdenum-99 II

4415L-F Xenon-133 II

4416L-C Gal 1 ium-67 II

4404L-E Thallium-201 ll

4400L-E Chromium-51 il

4307-G Xenon-1 33 Calibration of instruments for moni

toring reactor off-gases

4310 Mixed-radionuclide gas

II

4275 Mixed radionuclide Calibration of the efficiency of

germanium gamma-ray or x-ray spectrometry systems as a function of

energy

4276 Mixed radionuclide ll

4265-B Iodine-125 II

4250-B Cesium-134 ll

4904-F Americium-241 Calibration of alpha spectrometers

72
Division 532, Standard Reference Materials (cont'd)

SRM

4949-B

4350-B

4352

4355

Radionucl ide Principal Use

Iodine- 129 For use in monitoring long-lived

radioactive waste

Columbia River Sediment Natural matrix materials for monitoring radioactivity in the environment

Human Liver

Peruvian Soil

73
CALIBRATION SERVICES PERFORMED

Division 532, Nuclear Radiation

Type of Service Customer SP ;250

No. of

Calib. Incoi or Tests k$

Neutron Source Calib. R. Schwartz, NBS 8.1 A 3* NC**

Neutron Source Calib. R. Schwartz, NBS 8.1 B NC

Neutron Source Calib. NBS Health Physics 8.1 B 1 NC

Neutron Source Calib. Lawrence Livermore

Lab. , Dr. C . Grahm

8.1 B 1 1 .2

Neutron Source Calib. Univ. of Arkansas

SEFOR Fac. Special 

2 --

Neutron Source Calib. Los Alamos Lab.

Dr. G. Eccelston

8.1 B 1 1.1

Neutron Source Calib. Los Alamos Lab.

R. W. Davis

8.1 A 1 0.7

Irradiation of dosimeters in thermal neu- tron density standard

Dept, of Army

Lexington Cal. Lab.

8.1 H 3 0.3

Irradiation of gold

foils in thermal neutron density standard

Cornell University

Mr. Alder

8.1 P 4 0.3

Reactor pressure vessel

irradiation surveillance dosimetry program

special irradiations

Nuclear Regulatory

Commission

N/A 2Q** -*-** 4.0

252 Cf irradiation of

titanium foils for

measurements

CEN/SCK

Mol , Belgium

N/A 2 NC

*NBS Sources SR-Cf-132, SR-Cf-136, NS-39

**NC=No Charge for Division Personnel

***NBS Sources NS-54, NS-79, NS-86

 NBS personnel (2) travel to Arkansas to on-site calibrate a source

too large (>10 10 n/s) to calibrate at NBS; this work led to FY-83

contract.

** ***T n excess of 300 hours of irradiations in neutron benchmark fields.

74
Division 532, Calibration Services Performed (cont'd)

Type of Service Customer SP ;250

No. of

Cal ib. or Tests

Dosimeter Calibration Dosimeter Corp. 8.1 H 32

Dosimeter Calibration DoE NA 469

BF 3 Tube Calibration US Army 8.1 H 4

Remmeter Calibrations Balto. Gas & Elec. 8.1 L 15

Remmeter Calibrations Wash. Public

Power Supply

8.1 L 6

Remmeter Calibrations Phil adel phi a Electric

8.1 L 2

Remmeter Calibrations Rochester Gas &

Electric

8.1 L 2

Remmeter Calibrations Mississippi Power

& Light

8.1 L 9

Remmeter Calibrations Carolina Power

& Light

8.1 L 4

Remmeter Calibrations Duke Power 8.1 L 1

Remmeter Calibrations Omaha Public Power 8.1 L 1

Remmeter Calibrations US Army 8.1 L 14

Remmeter Calibrations Duquesne Light 8 L 1

Remmeter Calibrations Knolls Atomic

Power Lab.

8.1 L 1

Dosimeter Calibrations GPU Nuclear 8.1 L 28

Dosimeter Calibrations Siemens Gommasonics 8.1 H 42

Dosimeter Calibrations Siemens Gommasonics 8.1 L 20

Total 722

This summary is for the time period August 1 , 1981 - August 1 , 1 982

Income

k$

o25

30

.2

2.5

1.0

.4

.4

1.3

.75

.25

.25

1 .8

.25

.25

1 .0

1.0

.9

50.1

75
Division 532, Calibration Services Performed (cont'd)

Radioactivity Calibrations for time period August 1

,

1981 to August 1 , 1982

Scheduled Tests ^ ^ Non-scheduled Tests

Number

of

Sources

Total

Fee

$k

Number

of

Sources

Total

Fee

$k

Category

Alpha-Particle Sources

8.2 H, I, J 42 23.2 1 1 .5

Beta-Particle Point Sources

and Gases ( 85 Kr)

8.2 P, Q, R

3 4.3 4 5.5

Gamma-ray Solutions, Point

Sources, and Gases ( 133 Xe)

8.2 B, C, D

13 7.4 13 10.2

Mixed Radionuclide Sources,

Solutions. Point Sources,

and Gases^)

— — 22 8.6

Other Services

58 34.9^ 3) 40

4.6

30.4^

Footnotes

^

Four sources under one Test Folder are counted as 4 calibrations.

(?) v ' Replicate samples are not considered as separate sources. For example,

Amersham submits 2 each of 3 different source forms. This is counted

as 3 samples.

(3) v ' The average fee for a schedules test was $602 compared to $372 one year

ago.

(4) v ' The average fee for a non-scheduled test calibration was $644.

Summary

Aug. 1 - Aug. 1 Total Calibrations Total $

1 80-'81 79 40.5 k$

' 81 -

1 82 98 65.3 k$

76
TECHNICAL ACTIVITIES

Division 533, Radiation Physics

Introduction

The Radiation Physics Division consists of five groups,

• Radiation Theory (Non-Nuclear; M. J. Berger)

• Dosimetry (Photons, Electrons; R. loevinger)

• X-Ray Physics (J. Motz)

• Vacuum Ultra-Violet Physics (includes the SURF II program;

R. Madden)

• Electron Physics (R. Celotta)

The first three groups are largely concerned with radiation energies

above about 10 keV, while the last two groups focus on lower, usually

much lower energies.

The functional statement for the Division identifies the following

types of activity:

• Provides the central national basis for the system of measurements of electron and photon radiation;

• develops advanced electron- and photon-based measurement

standards and techniques;

• studies and measures the fundamental mechanisms by which

electrons, photons, and other radiations transfer energy to

gaseous and solid materials, and are transported in them;

• develops, operates, and maintains well-characterized sources

of electrons and photons;

• establishes, verifies, and disseminates ultraviolet, x-ray and

electron standards, calibrations and services for medical,

industrial, and government users for applications in fields

such as radiography, radiation protection and therapy, and

fusion plasma diagnostics;

t maintains and acquires new competence, such as the development

of new sources of positrons and polarized electrons for the

investigation and measurement of the electronic structure of

atoms, molecules, and solids.

As can be seen from the reports below, all of the groups in the

Division have been active and productive.

77
Division 533, Technical Activities (cont'd)

RADIATION THEORY GROUP

Radiological Physics

Spectral Characterization of NBS X-ray Beams . In a collaborative

effort involving S. M. Seltzer of the Theory Group, and M. Ehrlich and

C. Soares of the Dosimetry Group, accurate determinations were made of

the energy spectra from all the x-ray beams used at NBS for calibration

purposes. 'This has involved the measurement of pulse-height distributions

with intrinsic germanium detectors, the calculation of the detector

response function (relation between pulse-height distribution and true

energy spectrum), and the conversion (using a stripping procedure) of

the measured pulse-height distributions into x-ray spectra. The output

spectra include both the continuous bremsstrahl ung spectrum, and characteristic

x-ray lines, for various voltages and many conditions of beam filtration.

Ionization and Excitation Yields . L. V. Spencer has developed an approximate analytical solution of the Fowler equation in order to

calculate the yield of excitations and ionizations in a medium irradiated

with fast electrons. The first application has been made to electrons

in a molecular-hydrogen medium, and results have been obtained that

agree within 2 percent with the results of direct numerical calculations,

for electron sources energies down to 300 eV. The extension of the

method to other molecules, and to other charged particles, is discussed

but has not yet been carried out.

Stopping Power Theory . The methods for computing the collision

stopping power for charged particles have been reviewed and updated by

M. J. Berger and S. M. Seltzer with emphasis on the region in which the

Bethe stopping-power theory is applicable (above ^ 10 keV for electrons,

above ^ 1 MeV/amu for heavy charged particles). Particular attention

has been paid to the various quantities that enter into the Bethe formulas

and must be evaluated with the use of empirical data. These include

the mean excitation energy, the shell correction, the density-effect

correction, and the z

3 and z

4 corrections (departures from first

Born approximation). In regard to mean excitation energies, modified

Bragg additivity rules have been derived from experimental data, with

which the mean excitation energies for compounds can be estimated from

the mean excitation energies of the atomic constituents, taking into

account the effects of chemical binding and physical aggregation.

Extensive stopping-power and range tables for electrons have been prepared

for elemental substances as well as many compounds of dosimetric interest.

Similar work for protons is now in progress. The electron stoppingpower tables also include results for the radiative stopping power due

to the emission of bremsstrahl ung photons. These have been computed

taking into account the new bremsstrahl ung cross sections of Pratt and

col 1 aborators , and interpolated cross sections in the 2- to 50-MeV

region, as described below.

78
Division 533, Technical Activities (cont'd)

Modeling of the Radioactive Decay of Iodine-125 . The decay of this

nuclide results in electron capture from the K, L, M, or N shell, the

emission of internal conversion electrons from the K, L, M, and N shells,

and the subsequent emission of a complex cascade of x-rays and Auger

electrons. In order to characterize iodine-125 as a source of electrons

for radiation transport calculations, the decay process has been modeled

by M. J. Berger using the Monte Carlo method, taking into account the

possibilities for the emission of a variable number of electrons per

decay, with 11 possible electron energies between 0.3 and 35.3 keV. Due

to the various branching ratios, the stochastic model allows for 700

possible outcomes whose relative probabilities have been computed. The

electron source characteristics thus obtained will be used later to

compute the stochastics of energy deposition in tissue-equivalent material

as a function of distance from a point-isotropic Iodine-125 source. The

product nucleus (Tellurium-125) is left highly charged due to the loss

of electrons. The relative probabilities for charge states 1 to 17 have

been calculated, and the mean number for electrons lost has been found

to be 8.8.

Cross Sections

Form Factors . Tabulations have been prepared of new relativistic

Hartree-Fock-Slater modified atomic form factors from x = 0 to 28 A” 1 for all elements from z = 1 to 100. This work was done by M. Schumacher

and colleagues of the University of Goettingen (West Germany) in collaboration with John Hubbell of CRR, NBS . The modification consists of the

insertion of a factor mc 2 /(E - V( r ) ) into the defining integral for

the form factor, where E is the relativistic total energy of the bound

electron V(r) is the central potential, and me 2 is the electron rest

energy. The modified form factors are designed to represent the atomic

Rayleigh scattering amplitudes with good accuracy at energies well above

the K-shell binding energies and for small momentum transfers, and

should be used in place of previously tabulated relativistic form factors.

Photon Attenuation and Energy Absorption Coefficients . Taking

advantage of recent improvements in the knowledge pf photon cross sections,

John Hubbell has prepared improved tables of photon attenuation and

energy absorption coefficients in the energy region from 1 keV to 20 MeV,

for 40 elements and for 45 compounds and mixtures of interest in radiation

dosimetry. The atomic photoeffect cross sections are taken from the

1973 computations of Scofield combined with more recent empirical modifications.

The incoherent (bound-electron Compton) and coherent (Rayleigh) scattering

cross sections, and the pair and triplet production cross sections are taken from recent results obtained at CRR in collaboration with scientists

at Los Alamos, Livermore, Max Planck Institute (Mainz), and the University

of Trondheim (Norway). The differences between the new attenuation and

energy absorption coefficients and those in earlier tables are of the

order of 1 percent or less over most of the element-energy range, but in

some cases are as much as 5 percent.

79
Division 533, Technical Activities (cont'd)

Bremsstrahlung Cross Sections . As part of the updating of the

widely used electron-photon transport computer program ETRAN, S. M. Seltzer

and M. J. Berger have reviewed and improved the information on electron

bremsstrahlung. Experimental data are scarce and reliance must be

placed mainly on theoretical results. Reliable theoretical cross sections

are available at electron energies below 2 MeV from recent numerical

calculations of Pratt and collaborators, and above 50 MeV from the

analytical high-energy approximation of Davies, Bethe, and Maximon. The

systematic upward extension of the numerical calculations would be

prohi bitively expensive in computer time, and the downward extension of

the analytical theory is not feasible. Up to now, it was necessary to use Bethe-Heitler Born-approximation theory, together with rough empirical

correction factors, in the energy region from 2 to 50 MeV. It has now

been found possible to obtain reliable cross sections (differential in

the energy of the emitted photon) through an appropriate interpolation

procedure which uses the low- and high-energy results below 2 and above

50 MeV as anchor points. The accuracy of these interpolations has been

confirmed through comparison with the few cases (aluminum and uranium

targets, 5 and 10 MeV electrons) for which accurate numerical calculations

have been done. The groundwork has thus been laid for a planned systematic

tabulation of the bremsstrahlung cross section for all elements, covering

energies from 1 keV to 1 GeV.

Radiation Protection - Civil Defense

A paper by L. V. Spencer, delivered at a symposium held under the

auspices of the NCRP, outlined the types of nuclear disasters and the

radiation environment associated with them. The situations discussed

include multi-weapon attacks on the U.S., single-weapon attacks, power

reactor accidents (with or without core melt), accidents during the

transport of weapons, or during the transport of spent fuel elements,

and transoceanic fallout. In relation to these situations, summary

information is provided regarding radioisotope hazards, radiation spectra

and decays, counter measures, and dosimetry requirements.

A report by C. M. Eisenhauer and L. V. Spencer, prepared for FEMA,

contains the first stage in the development of procedures for the routine

evaluation of the protection provided by complex structures against

initial radiations from nuclear explosions. The following radiation

components were considered: early fission-product gamma rays, airsecondary gamma rays generated by neutron interactions in air, neutrons,

and wall-capture gamma rays generated by neutrons through interactions

with structural materials. The computer codes developed so far pertain

mainly to the protection provided by elementary enclosures. However,

the description of the programs also contains references to planned

modifications, now in progress, to extend the applications to more

complex shielding configurations.

80
Division 533 9 Technical Activities (cont'd)

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 in order 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 and more precise measurements 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 responsibility for providing an up-to-date

basis for reliable measurement of ionizing radiation, principally in

medicine and radiation protection. This program involves establishment

and maintenance of the national primary dosimetry standards, dissemination

of the units established by those standards by means of calibration

services and measurement quality assurance programs, other measurement

assurance activities to test whether measurements by radiation users are

in adequate agreement with NBS standards, research and development of

measurement technology as necessary for any part of the program, and

participation in the relevant national and international activities of

the community of radiation users.

Calibration and Measurement Assurance Services

Calibration of x-ray and y-ray measuring instruments has increased

by about 40% compared to the previous fiscal year. Since other calibrations

have remained at about the same level, the overall calibration activity

of the Dosimetry Group -- counting only items listed in NBS Special

Publication 250 -- has increased by only about 20%. The increase in

calibration activity for photon-measuring instruments is the response to

a need for increased calibration facilities expressed to the NBS Director

by officials of the American Association of Physicists in Medicine. The

increase was made possible by improved efficiency due to reassignment of

responsibilities within the calibration project following loss of one person in the recent staff reductions, along with improved data acquisition

and processing facilities. Additional memory has been added to the

previously used dedicated minicomputer, and an additional data acquisition

and processing system has removed the bottleneck caused by servicing

five calibration ranges with a single data acquisition system.

The long-awaited 300-kV x-ray generator arrived (about 15 months

behind schedule) and at the time of writing awaited installation. It

will replace an obsolete 250- kV x-ray generator that has provided NBS

standard x-ray beams for more than 30 years. The new generator includes

circuits that allow computer control. The properties of the new standard

x-ray beams must be determined accurately, so the changeover is expected

to require a downtime of about two months in FY83.

Measurement quality assurance services were provided for the three

Accredited Dosimetry Calibration Laboratories (ADCL's) --formerly known

as Regional Calibration Laboratories (RCL's) -- of the American Association

81
Division 533, Technical Activities (cont'd)

of Physicists in Medicine. The Victoreen ADCL stopped calibration in

June 1982, and its place was taken several months later by K & S Associates,

of Nashville, Because of the need for additional calibration facilities,

technical help was provided by NBS to K & S Associates to prepare for

AAPM accreditation. A representative of K & S Associates spent a day at

NBS and was given an in-depth explanation of relevant NBS measurement

and calibration techniques. Following a site visit to K & S Associates,

a calibrated instrument was shipped by NBS to provide a measurement

quality assurance test as the last step in qualifying K & S Associates

for AAPM accreditation as an ADCL.

A measurement quality assurance program for a CaF(Mn) thermoluminescence

(TL) dosimetry system has been operated for the Naval Electronic Systems

Command. The program involves preparation by NBS of sealed boxes of 15

TL dosimeters, 12 of which have been given known exposures to 137 Cs

Y rays . The boxes are dispatched to designated naval units for readout,

the results of which are returned to NBS for comparison with the NBS

exposures. TL readers that indicate exposures that differ from the NBS

exposure by more than ±10% are repaired and recalibrated. About 200

such boxes, containing 2400 exposed dosimeters, were dispatched during

FY82.

Collaboration with the 3M Company has continued in development of

an exposure calibration service for the radionuclide iodine-125. The

sources are in the form of titanium-clad seeds that have been measured

using an NBS free-air ionization chamber, the calibration data then

having been transferred to a re-entrant ionization chamber for routine

calibration. The desired routine calibration serv-ice has been made

available for the original type of seed (containing iodine-impregnated

resin microspheres and a gold x-ray marker), which were somewhat geotropic,

and for a second type of seed (containing an iodine-impregnated silver

rod), which was less geotropic but the spectrum of which contained some silver lines. The 3M Company has developed a third type of seed, containing

only iodine-impregnated resin microspheres in the titanium cladding.

This last type has been measured with the free-air chamber and an independent calibration factor has been established. Improved measurement techniques allowed exposure calibration of the latest seed type to

be performed more rapidly and accurately than for the two earlier types.

The spectrometry of all current bremsstrahl ung sources used for instrument calibration was completed, including the unfolding of all

pulse-height distributions. Before the final tabulations can be prepared

for publication, it will be necessary (a) to average the spectra from

repeated runs; (b) to interpolate spectral values for photon energies of

multiples of, say, 5 keV; and (c) to verify that the spectra from the new 300-kV x-ray generator are comparable to the spectra from the 250-kV

generator that is being retired from service.

82
Division 533, Technical Activities (cont'd)

Calorimetry

Early in FY82, S. R. Domen visited the Hungarian standards laboratory in Budapest and the Austrian standards laboratory at Seibersdorf

to assist in proper operation of a copy of the NBS graphite absorbeddose calorimeter that was built cooperatively by those laboratories and

by the International Atomic Energy Agency (IAEA). Participants at these

laboratories expressed their satisfaction at the speed and ease with

which the calorimeter could be brought into accurate operation. Starting

at room temperature, with the calorimeter at atmospheric pressure, it was possible to make 40 runs at a dose rate of 1.6 mGy/s (about 10

rad/mi n) with a standard deviation of about 1% for a single run, in 6

hours. As a result of this successful performance, it was decided to

construct several more graphite calorimeters, so that each of these

laboratoreis would have one, and possibly also supply calorimeters for

the Italian and the G.D.R. standards laboratories. The increasing

interest in graphite absorbed-dose calorimeters seems to be due to

techniques developed at NBS for rapid control of the troublesome temperature drifts, which otherwise prevent these instruments from being

adopted as convenient laboratory instruments.

During FY82 the focus of NBS calorimetry activity was on completion

of a detailed description of the absorbed dose water calorimeter, now published in the NBS Journal of Research. This work has had considerable

influence on other institutions: water calorimeters are being used for

absorbed-dose measurements on electron and photon beams at the M. D. Anderson Hospital, the Massachusetts General Hospital, the Yale University

Medical School, the Groote Schuur Hospital in South Africa, the Calgary

Cancer Center in Canada, and the Sahlgrenska Hospital in Sweden.

Interest has also been expressed at other institutions.

The main new activity in calorimetry at NBS has been, and will

continue to be in the near future, investigating the 3.5% difference

between the absorbed dose rate to water in a cobalt-60 gamma-ray beam,

as determined by a graphite calorimeter and as determined by the water

calorimeter. There appears to be a negative heat defect in water, i.e.,

the measured dose rate is higher in water than would be calculated from

the graphite calorimeter. This result, first found at NBS, has been

confirmed at other institutions. To investigate this matter, apparatus

has been constructed for studying the heat defect in water. Absorbed

dose rate will be measured in carefully isolated distilled water saturated

with ultra-pure hydrogen, under which conditions there should in theory

be no heat defect. By comparing the dose rates measured with the calorimeter

using hydrogen and other gases, it is hoped to elucidate the source of

the 3 to 4% discrepancy between water and graphite. Tests of the apparatus

with available gases indicate that it will work satisfactorily

.

J. W. Fletcher of Chalk River, Canada, has reported the results of

extensive theoretical investigations of the heat defect in water, an investigation that was made in response to the NBS results with the two

83
Division 533, Technical Activities (cont'd)

calorimeters. His results indicate that the heat defect can vary

depending on the conditions of irradiation and the radiation history of

the water, but it is of interest that he finds a 2.6% exothermic effect

in water with small initial concentrations of hydrogen and oxygen.

High-Energy Measurement-Assurance Services

The chemical (Fricke) dosimetry service for testing the uniformity

of high-energy electron therapy dosimetry was carried out twice during

FY82, the second time in two sections because the number of dosimeters

requested exceeded the number available. A total of about 30 hospitals

participated in each of the two tests. Holders were designed and built

for use in a high-energy electron and photon measurement-assurance ser- vice using TLD that eventually is to replace (or supplement) the present

Fricke-dosimetry service. A pilot test is planned for early in FY83.

Radiation Protection Dosimetry

Most of the extensive testing program carried out for the past two

years on the Panasonic TLD system has been completed. The system is now

being used by the NRC for environmental dosimetry. The tests were in

accord with (and went beyond) the specifications of ANSI Standard N545

(1975).

Preparations have been made for a facility for the calibration of

beta-particle instrumentation and sources used in radiation-protection

dosimetry. An irradiation range has been designed and built for the

beta-particle sources and the extrapolation chamber that have been

ordered. Once this equipment arrives (early in FY83), it is planned to

compare the PTB calibration of the sources with an independent NBS calibration in terms of absorbed dose to water. Preparations have also been

made to supplement the envisaged beta-particle instrument-calibration

service by response functions obtained on selected beta-particle instruments

with monoenergeti c electrons, over the range of electron energies of

interest. For this purpose, equipmnt for scanning the monoenergeti

c

electron beams from the 500-keV linear electron accelerator and the 4-

MeV electron Van de Graaff has been assembled. A surface Si detector

for use in the beam characterization has been ordered.

Work has proceeded on the development of high-energy photon-instrument calibration facilities. A photon beam of approximately 7 MeV was produced in the positive ion Van de Graaff using the 19 F(p,ay)0 16 re- action. (This work is a joint venture of the Radiation Physics and the

Neutron Physics Divisions.) The angular distribution of the photon beam

has been measured. Preliminary measurements and computations have shown

that beam intensities sufficient for instrument calibration will be

achievable. A large high-resolution Ge-Lt detector was rented (with

rights for later purchase of an intrinsic Ge detector) and is being used

for spectral characterizations.

84
Division 533, Technical Activities (cont'd)

Extensive work was done first in answer to the objections, and then

in answer to the appeal, by the DOE against the ANSI Standard NJ3.11

(Criteria for Testing Personnel Dosimetry Performance), developed by a HPSSC working group under M. Ehrlich's chairmanship.

Work proceeded on a cooperative effort between the CRR and NVLAP,

on preparations for the selection of a testing laboratory that is to

administer the mandatory tests to the organizations offering personnel - dosimetry services. (This testing program is to be in accord with the

disputed ANSI Standard.) Progress also was made on the formulation of

criteria for the selection of a peer group that is to carry out on-site

inspections of the work of these organizations -- another step that

would lead to their accreditation by NVLAP.

X-RAY PHYSICS GROUP

The X-Ray Physics program has been involved with problems arising

out of the utilization of x rays in technological applications including

medical and industrial radiology, radiation processing of materials and

food, hot plasma nuclear energy sources, and applications which are con- cerned with radiation protection.

Medical Radiography

In medical radiology, the X-Ray Physics Group program has been con- cerned with a systematic examination of the transfer of image information

through the individual components of an imaging system. This program

has provided an assessment of the image information transfer efficiency

for each component of a medical imaging system, and present efforts are now being focused on the image recording media. Of particular interest

is the transfer of information from the intensifying screen to the

recording device. Since photographic film is at present the most widely

used image receptor, initial efforts are aimed at examining the response

and noise properties of a variety of film types to determine whether

significant improvements in image information transfer can be achieved.

In cooperation with the National Institute of Dental Research and

with the U.S. Army Institute of Dental Research, the X-Ray Physics Group

has initiated a program to develop non-film photoel ectronic imaging

systems for dental applications. These systems will be able to utilize

digital image processing techniques and can be expected to provide new diagnostic information for the dentist. In the development of these

systems, the X-Ray Physics Group will focus on any specific standards or calibration services that may be required by the user community and that

can be provided by the NBS program.

The program to develop a new dental radiographic system to provide

multiple projection angle geometries and possible tomographical reconstructions

is continuing. Detailed measurements indicate that of the possible

85
Division 533, Technical Activities (cont'd)

combinations of x-ray source and detector geometries, the most viable

option is provided by a miniature extraoral x-ray source and an active

extraoral detector. Preliminary designs have been completed on several

possible detector configurations which utilize fibre optic bundles and

either multichannel plates (MCP) or charge coupled devices (CCD) as the

imaging element. In addition, several miniature x-ray fluence and

projection geometries are being investigated. A new image processing

system is in the final stages of testing. This system will provide the

capability of digital image manipulation to enhance the dental pathologies

of interest. Measurements on dental phantoms with simulated artifacts

indicate that digital subtraction techniques can provide dramatic improvements in the diagnosis of dental disorders.

Industrial Radiography

The X-Ray Physics program in industrial radiography seeks to provide

those standards and devices which will permit better nondestructive

inspections of industrial output. The program is geared to providing in

a more quantitative way the characterization of an image, or of the

total x-ray system or any component. As mentioned in the last report, a standard for measuring equivalent image quality sensitivity at low

energies has been published and the test device described in the publication

is available through NBS as an SRM. Present effort is focused on producing

an equivalent standard for high energy inspections. In a related activity,

effort is being directed toward producing master patterns for a visual

acuity standard according to the prescription given in an NBS publication.

When completed, this is expected to fulfill an important need--the

qualifications of the radiographic inspection.

In another project, an attempt was made to quantify radiographic

definition (unsharpness) using standards published by others. The

results revealed inadequacies in these methods and the continuing need

for better measurement procedures for this quantity. Our efforts to

provide a better way, or induce others to consider the problem, continues.

Digital techniques in radiographic inspection promises to provide

improved methods for the detection and diagnosis of hidden flaws in

industrial components. The past year has seen the installation of and

initial applications to this work of a sophisticated digital image

processing system having the ability to process an image in real time.

In connection with this, we have engaged in a cooperative effort with

other laboratories having similar equipment to ascertain their ability

to process an image furnished by NBS.

The program to develop quasi -monoenergetic photon beams in the

100-300 keV range for the evaluation of radiographic systems is continuing.

Measurements to date indicate that by an appropriate choice of incident

electron energy, x-ray target materials, and beam filters, beams with

sufficient intensity for the evaluation of the image information transfer

properties of typical industrial radiography systems can be generated

86
Division 533, Technical Activities (cont'd)

utilizing the NBS 1.5 MeV electron accelerator. Efforts are at present

underway to determine the spectral characteristics of these beams.

Dosimetry for Industry and Defense

The high-dose calibration services have broadened considerably to

include the radiation hardness testing industry and national laboratories.

These services have provided calibration of 60 Co irradiators and electron

beam accelerators used in the testing of electron devices and systems

employed in the missile systems of both DoD and NASA as well as other

systems used by national laboratories such as Sandia. Efforts continue

on the determination of complex photon spectra in various multilayer

materials irradiated by S0 Co and flash x-ray machines, and the effects

of these spectra on dose interpretations in multilayer semiconductor

devices. New dosimetry standards have been adopted within the American

Society for Testing and Materials (ASTM) that should help the industrial

electronics facilities to maintain and improve their proficiency in

dosimetry measurements. These ASTM standards recently approved include

a method for calculation of absorbed dose in materials due to neutron

irradiation, measurement of electron beam fluence with a Faraday cup,

and a calorimeter standard for use in flash x-ray fields.

The standard service to radiation processing users has grown considerably especially in the area of radiation sterilization of medical suppliers

Some companies have reached 20 or 25 calibrations during the five-year

listing of this service and require regular calibration of dosimeters as

a means of quality control of the process and safe release of medical

products to the customer. There is also the likelihood of an additional

dimension to this service, with the recent disclosure by the FDA that

there will be a relaxing of regulation in the use of ionizing radiation

in the processing of foodstuffs. Dosimetry and traceability of measurement

to NBS standards will undoubtedly be the means of quality assurance in

food irradiation as discussed by W.L. McLaughlin at several Workshops on Food Irradiation Processing a D0AD0E meeting, University of Maryland,

and the 1982 Annual Meeting of the American Nuclear Society. Some of

the most active participants in the present high-dose calibration service

are Ethicon, Inc., Neutron Products, Inc., Brookhaven National Labs.,

Radiation Dynamics, Inc., IMED Corp., Radiation Technology, Inc., Howmedica

Inc., General Electric Co., Alza Corp., Tremco, Inc., Monoject Division

of Sherwood Medical, National Semiconductor, Raychem Corp., Suragikos

Division of Johnson and Johnson, IBM Research Lab., Becton Dickinson

Co., Energy Sciences, Inc., Lederle Laboratories , Baxter Travenol , Inc.

Lawrence Livermore Labs., Sandia Corp., Radiation Sterilizers, Inc.,

International Nutronics, Inc., and Texas Instruments. The most recent

(Dec 1981) National Seminar of the Pharmaceutical Manufacturers Association made several strong recommendations to utilize the NBS Laboratories

service to maintain quality control and safety of medical products.

87
Division 533, Technical Activities (cont'd)

Two new projects are being initiated relative to the high-dose

dosimetry research effort. One project supported by the Federal Emergency Management Agency began in FY81 , to investigate in detail the

response characteristics, kinetics, and mechanisms of some radiochromic

dyes in order to select a most stable, sensitive, and reproductible

chemical system which can be developed into a suitable inexpensive fiber

optics dosimeter for use in civil defense and military operations. The

other project will begin in FY82 sponsored by Sandia Labs (DOE) to make

an experimental study of the response characteristics of several key

radiochromic film types, for electron and photon radiations. These

films will be calibrated against a new thin-film calorimeter presently

under development.

Several areas of international cooperation have helped fertilize

development of the radaition measurement technology. McLaughlin initiated

a new Research Agreement with the IAEA on dosimetry for food processing,

with results to be published as a part of Proceedings of a 1983 IAEA

Seminar on Radiation Processing Dosimetry. NBS-CRR continues to participate

in an International Atomic Energy Agency Advisory Group on High Dose

Standardization. This involves dose intercomparison studies and roundrobin

intercomparisons with 14 other national laboratories and industrial

radiation processing labs around the world (UK, Netherlands, Denmark,

Austria, India, France, Yugoslavia, Hungary, Austria, Canada, Mexico,

Egypt, Argentina, West Germany). The result of the second phase of

these intercomparisons was published in 1982 by IAEA in the Proceedings

of the IAEA Symposium on Biomedical Dosimetry held in Paris in Oct 1981.

This international standardization program with NBS will continue until

at least 1984, helping bring important measurement assurance on an international scale. Part of the efforts of NBS-CRR to this end is the

design and implementation of a high-dose graphite calorimeter by J.C.

Humphreys, W.L. McLaughlin, and S.R. Domen, This instrument proved its

worth in a 4-nation intercomparison study (U.S., U.K., West Germany, and

Denmark), when Humphreys and McLaughlin took the calorimeter as a primary

standard to make absorbed dose intercomparisons in 10-MeV electron beams

at PTB, NPL, and Risd National Laboratory. This work will be published

in an IAEA document in 1983. Another international collaboration of

note was with the Institute of Physics and the Institute of Nuclear

Energy of the University of Mexico. McLaughlin was invited to the

Physics Institute of the University of Mexico in Dec 1981 to give two

weeks of lectures on dosimetry. Dosimetry developments between NBS and

Mexico include ESR techniques for analyzing irradiated polymers and dye

systems. Dr. Roberto M. Uribe of NCRRT is visiting NBS as a guest worker

during 1982 to further develop this method as a promising technique in

practical radiation processing applications. Some of the results of

dosimetry collaboration will be published in the Transactions of the 4th

International Meeting on Radiation Processing to be held in Dubrovnik,

Yugoslavia in Oct 1982. In another international activity, McLaughlin

is invited to give several academic courses on dosimetry at an IAEA

Seminar on Radiation Processing held in Denmark in September 1982. He

also served on the organizing and program committees for the 4th International Meeting on Radiation Processing mentioned above.

88
Division 533, Technical Activities (con'td)

An interesting new type of dosimeter is being studied in collaboration

with the U.S. Army Electronics R&D Command, for use as an emergency

dosimeter. The new system was developed in this collaboration in 1981

and is based on fibre optics and offers biologically-relevant dose

interpretations at dose levels encountered in radiation accidents. A

U.S. patent has been filed by McLaughlin with an associated publication

in Nuclear Instruments and Methods in Dec 1981. This work is generating

much interest also in the areas of environmental dosimetry, medical

applications (diagnosis and therapy), and personnel monitoring, and a new commercial product called "Opti-chromi c" dosimeter will soon be

marketed by Far West Technology, Inc. of Goleta, California.

Pulse Radiolysis

Instrumentation

The build-up of radiation facilities for use in radiation-chemical

studies of the effects of ionizing radiations relevant to biological

systems as part of the Ionizing Radiation Competence Program has continued.

1. The Febetron 705 pulse radiolysis system has been fully computerized using a Tektronix 761 2 D programmable digitizer which was interfaced

to a Tektronix CP1164X minicomputer for processing, storing, and displaying

of signal waveforms. Appropriate software was developed in order to

measure absorption spectra of short-lived intermediates (0.1 ys and up)

and the kinetics of their formation and subsequent reactions.

2. Capability to measure absorption spectra of transients in one pulse has been developed using a Jarrell-Ask Mark X spectrograph (No.

82-484) coupled to EG&G Princeton Applied Research Optical Multichannel

Analyzer, OMA, system consisting of a Model 1420 silicon photodiode

array and Models 1218 and 1215 controller and processor units. This

enabled whole transient spectra to be recorded anytime greater than 1 ys

after a single electron pulse.

3. The conversion of the 4 MeV Van de Graaff accelerator to a pulsed mode as well as a dc mode is 95% completed. This accelerator is now capable of producing electron beam pulses with pulsed currents in excess of 1 Ampere with pulse widths from 5 ns to 15 ys. The installation

of a new accelerating tube, charging belt, and column resistors have

increased the voltage stability of the accelerator. At the present time,

efforts are underway to install a pulsed radiolysis experimental system

on one output port of the accelerator.

Chemical Studies

1. GC and HPLC methods have been successfully developed for the

study of free radical processes in amino acids, peptides and proteins,

through the measurement of final radiolytic products. Coupling of pulse

89
Division 533, Technical Activities (cont'd)

radiolytic studies of the intermediates and the measurements of the

resulting products provides pertinent information for complete kinetic

and mechanistic understanding of radiation effects in proteins, nucleoproteins and symposes. Nature of crosslinks has been defined between

Ala-Ala, Met-Met and Phe-Phe.

2. Pulse radiolytic studies of oxidizing radicals such as R*,R00«,

- CC1 3 > 00 CC13 , * Co 3 ” etc. have been conducted in order to understand

the rules governing their interaction with antioxidants. Intermediates

of various antioxidants including Vitamin E were examined in collaboration

with Dr. Ingold from NRC, Canada. Understanding of these reactions is

crucial in comprehensive mechanistic studies of radiation induced and

chemical carcinogenesis as well as of protection from carcinogenesis

(anticarcinogens). These studies should be also useful in the unraveling

of the synergism between radiation and chemical agents.

3. A new theory of chemical carcinogenesis has been developed

based on the reactivities, i.e. selectivities , of free radicals in

question. For example, OH radicals are highly reactive but totally

unselective and are poor carcinogens. On the other hand, some radicals,

e.g. R00* are much less reactive and considerably more selective and

could be much more damaging respective to the "target" molecule. Further

experimental work is in progress to provide comprehensive experimental

support.

4. Investigation of radioprotectors has been conducted by pulse

radiolysis and the measurement of intermediates. Since most radioprotectors have sulfur as a reactive component (RSH, RSSSR etc.) and the

information regarding reactivities of S radicals is rather poor, the

emphasis of this project has been shifted to general studies of sulfur

radi cal s

.

FAR ULTRAVIOLET PHYSICS GROUP

Angle Resolved Photoel ectron Molecular Spectroscopy

In the area of gas-phase photoionization, we have carried out

angle-resolved, vibrationally-resolved, variable-wavelength photoelectron

spectroscopy on six molecular systems this year using our two-inch mean

radius hemisherical analyzer and our high-flux normal-incidence monochromator at SURF- II. (This instrument delivers up to 2 x 10 11 photons/s-A

of monochromatic flux to an experimental sample—higher than that

reported by any other synchrotron radiation laboratory . ). These studies

investigate the effects of resonance phenomena on the angular distribution

parameters and on the branching ratios in molecular photoionization. We

have found large departures from Franck-Condon predictions of relative

vibrational intensity over an energy range of many electron volts in the case of shape resonances. Autoionization can also lead to transitions

90
Division 533, Technical Activities (cont'd)

within a vibrational progression which violate Franck-Condon predictions.

Studies of such phenomena have been carried out for HCN, C 2 H 2 , BF3 , C0 2 , CH 3 CN, SFs, and a number of diatomic molecules. For example in the case of acetylene, Franck-Condon considerations would predict that only

a few vibrational modes would be expected to be excited. It was found

that in the ground state of the ion, many vibrational modes were being

excited. Furthermore, in the region of strong autoionization, bending

modes of the ion were excited. Such modes are not usually excited in a linear molecule due to symmetry constraints.

An entirely new apparatus for SURF II has been constructed and is

in the preliminary stages of testing. The instrument features two 4-

inch mean radius hemispherical electron energy analyzers, one of which

is rotatable. The sample inlet system has both effusive jets and a supersonic nozzle system. The chamber is triply magnetically shielded

so that a residual field of less than 500 microgauss can be maintained.

The chamber can be rapidly converted to accept a threshold photoelectron

photoion coincidence spectrometer which is now being developed.

During FY 83, a new grazing-incidence monochromator will provide

high flux dispersed radiation down to about 10 nm. This will permit the

study of inner valence shell and core level excitations using both

triply differential photoelectron and threshold photoelectron photoion

techniques. Little is known about fragmentation kinetics, total and

partial ionization cross sections, and angular distributions in this

high energy region. Initial studies will be concerned with moTecular

systems such as C0 2 , C 2 H 2 and the C 3 H 4 isomers. This work is a collaboration between CCP, SURF staff, SURF* fellows, Argonne National Laboratory

and SURF guest workers. 8 papers, 13 invited talks.

Photoel ectron-Photoion Coincidence

The unimolecular fragmentation of the iodobenzene cation was studied by two distinct photoelectron-photoion coincidence techniques.

One technique employed variable wavelength activation with threshold

electron detection. The other approach involved constant wavelength

activation coupled with variable electron energy detection. The former

technique included both direct and autoionization processes and the

latter included only direct ionization processes. A new, more detailed

method of data analysis was developed. The experiments covered a much

larger range of residence times than previous experiments, from 1 to 57

microseconds. The fragmentation rate-energy dependences deduced in the

two experiments were in excellent agreement with one another and the

resulting heat of formation determined for the phenyl cation was in

agreement with results of earlier studies from this laboratory on the

fragmentation of chlorobenzene and bromobenzene cations. The iodobenzene

rate-energy dependence is proposed as an absolute benchmark for ion

fragmentation rate measurements.

91
Division 533, Technical Activities (cont'd)

Experimental work on the coincidence apparatus was completed on ionic fragmentation in azobenzene compounds and in acetone, acetic acid,

and methyl acetate. The azobenzene results will give information on isomerization barriers in these ions. The other three compounds fragment

to give the acetyl ion, which corresponds to protonated ketene. A

determination of the heat of formation of the acetyl ion at 300K will

lead to an absolute proton affinity of ketene for calibration of the gas

phase proton affinity scale. The scale of relative proton affinities

has been generated by measurements of equilibrium constants for proton

transfer equilibria in the ion cyclotron resonance spectrometer and high

pressure pulsed electron mass spectrometer.

Plans for photoelectron-photoion coinicidence studies during FY 83

include work on the fragmentation of the parent ions of dimethyl ether,

phenol and anisole, to look for state-specific fragmentation processes.

Studies of selected organic cations will be carried out to examine the

competition between emission and fragmentation. This is a collaboration

between SURF staff, CCP and the University of Basel in Switzerland. 7

papers

.

Polarized Fluorescence

A series of studies has been carried out of polarized fluorescence

from molecules excited by photons from SURF ' s high-throughput normalincidence monochromator. The studies involved gases such as CO 2 , COS

and CS 2 . Results demonstrate a wide range of polarization of the

fluorescence over the wavelength range around autoionizing resonances.

Information was obtained about the symmetry signatures and dynamical

properties of the autoionizing resonances. Studies of the fluorescence

excitation spectra of N 2 in the region of the N 2 B

2 Z threshold in an electric field of up to 6 KV/cm demonstrated the ability to use this

technique to study shifts of threshold which lie above the first ionization

potential. Such shift are difficult to measure by other techniques.

This work is a collaboration between SURF staff, SURF guest workers, and

Argonne National Laboratory.

Surface Science

We have also supported at SURF, the establishment by the Surface

Science Division of CCP of an experimental capability to study adsorbed

molecules on surfaces. These studies use several SURF monochromators

and an ultrahigh vacuum system. Photon stimulated desorption of ions is

being studied to understand the desorption mechanism and energetics.

Variable wavelength ultraviolet photoemission spectroscopy is also

utilized to characterize the surface species formed upon adsorption of

the molecules on a clean metal substrate. Ion desorption mechanisms

for ionically and covalently bonded adsorbates have been investigated.

Results have been obtained for 0, CO, H 2 0 and CH 3 0H on Ti(001) and

92
Division 533, Technical Activities (cont'd)

Nb(001). In addition, H 2 0, CH 3 0H and C 6 Hi 2 have been studied as thick

multilayers in an effort to understand the effects of layer thickness,

hydrogen bonding and charge exchange reactions on ion desorption from

condensed layers. 10 papers, 4 invited talks.

New High Energy Capability at SURF

The success of our programs utilizing the high-flux normal -incidence

monochromator has led us to proceed with the extension of our capabilities

to shorter wavelengths. We have designed and procured most of the

components of a new high-throughput grazing-incidence monochromator for

SURF II. Only the delay in delivery of the gratings has delayed completion

of the monochromator. This instrument will use SURF's orbiting electron

beam as its entrance slit--thus taking advantage of SURF's small vertical

beam size and high brightness. The grating will be placed as close as possible to the orbit and will intercept 51 mrad of horizontal orbit and

(for wavelengths below 500A) the full vertical radiation output. Using

three independently optimized gratings, the monochromator will cover the

30-600A spectral range. Its resolution is expected to be about 0.6 eV

at full intensity. This may be improved to, perhaps, 0.1 eV by stopping

down the grating in experiments where the full intensity is not required.

The new monochromator will allow us to extend our programs in surface

science, ultraviolet photoemission spectroscopy, and gas-phase angleresolved photoelectron spectroscopy to higher photon energies. 2 papers.

Electric Field Effects

The high-resolution 3-m grazing-incidence monochromator was used to

study the effect of electric fields of strengths up to 30KV/cm on the

absorption spectra of helium near the ionization limit. The results

demonstrated a strong dependence on the polarization of the incident

radiation, in contrast to previous work on the heavier noble gases. A

simple model was used to explain the observations and the results have

been published. Work is continuing to prepare for publication previously

obtained results for the H 2 and N 2 molecules as well as the heavier

noble gases. Additional experimental studies await the proposed installation of a 6.65m high-resolution spectrometer at SURF In the meantime,

a series of measurements will be made to determine the absolute absorption

cross section of atomic barium from threshold (2378A) to about 400A.

This work is a collaboration between CAPQ , SURF staff, and a SURF guest

worker. 3 papers, 1 invited talk.

The Angular Asymmetry Parameter of Silver

The angular asymmetry parameter, 6, has been measured at SURF. The

high-throughput normal -incidence monochromator was utilized over the

energy range 14-20eV, to obtain the 3 parameter for the four J=1 levels

associated with the ionization of the 4d core electron of silver vapor.

93
Division 533, Technical Activities (cont'd)

Solid State Studies

Our guest users from NRL have studied, at SURF, the vacuum ultraviolet

reflectance, absorptance and photoelectron spectra of vitreous and

crystalline Be£^, allowing the first determination of its optical band

gap and the Be Is core exciton binding energy. The first allowed

exciton reflectance peak in crystalline BeF 2 is at 12.9 eV, similar to

the 12.8 eV peak found in the glass. Optical transmission extends at

least to 9.5 eV, and can be assumed to be impurity-1 imited in available

material. Since theory indicates that BeF2 should have an optically

forbidden band edge similar to that in S i

0

2 , the ultimate transparency

range of purified BeF2 will depend on the strength of the forbidden

exciton absorption, not yet observable above the jippurity background.

Grazing-incidence reflectance spectra near the Be

++

K edge are interpreted

in terms of a core exciton state lying at or slightly below the conduction

band minimum as determined from x-ray photoelectron data and the optical

band gap. 1 paper.

He Microbubbles

Absorption measurements of high density helium in microbubbles in

thin films of aluminum and tin continued. Recent low temperature

absorption measurements suggest the solidification of helium in the

microbubbles near 90°K. Measurements of the efficiency of electron beam

excited fluorescence from helium microbubbles in metals by comparison to

SURF through the 2.2 m grazing-incidence monochromator are encouraging

for the development of a new ultra-high vacuum, molecular helium continuum

source. This work is a collaboration between two guest workers (1 from

the NRL group)

.

Laser Prepared States

While limited resources have delayed the implementation of a new

class of experiments at SURF which utilize both lasers and synchrotron

radiation, it was possible to continue a collaborative research program

at LURE in Orsay, France. In one class of experiments, it was possible

to produce even parity autoionizing resonances by step-wise excitation

(laser plus VUV). These are detected by electron spectroscopy . It is

also possible to determine the effective oscillator strength of these

autoionizing states. Similar results have been obtained for barium. In

sodium and barium, it was possible to obtain a population of 30% in the

3p state of sodium and of 50% in the 5d state of barium. Furthermore, it was possible to study collisional ionization in these vapors for a variety of pressures and a wide range of laser powers. We are continuing

to search for funds outside of NBS and seeking collaborators within NBS

in order to implement a similar program here. 3 papers, 5 invited

tal ks

.

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Division 533, Technical Activities (cont'd)

The asymmetry parameter showed a large variation near autoiom'zing

resonances, but off resonance, the value of B averaged over all four

levels was in close agreement to a scaled relativistic random phase

approximation calculation of the 3 parameter. The experiment was carried out by a collaboration of SURF staff and SURF fellows with Oak

Ridge National Laboratory. One paper is being prepared.

Symmetry of n=2 State in Helium

The Coulomb field provides a unique opportunity to study different

theoretical many-body formalisms because the Coulomb force governing the

correlated motion of the atomic electron cloud is precisely known.

Helium is the simplest system that exhibits correlation effects in the

photoionization processes. Because of its general importance as a test

case, the photoionization cross section has been studied in great

detail over a broad energy range. As part of a continuing collaboration

with LURE in Orsay, France, one of the SURF staff members participated

in an experiment to use angle resolved photoelectron spectroscopy with

synchrotron radiation to determine the ratio, R, of the 2p to 2s partial

photoionization cross sections and the weighted angular asymmetry

parameter, 3, for these two states. The experimental values of R suggest that final-state correlation has a dominating influence on R as

is shown by calculations that include final-state and ground-state

correlation. These measurements of R are in close accord with the manybody calculation of T.N. Chung which suggests that the cross section is

dominated by the photoionization process that leaves the ion in the 2s

state at threshold. At high photon energies, the sudden approximation

becomes more appropriate and R approaches zero as it becomes a measure

of overlap between the hydrogenic 2s final state and the correlated,

initial state. The experiment is in agreement with both calculations

at high energies. 1 paper.

Lithography

In collaboration with researchers from the Naval Research. Laboratory

(NRL) , we have set up an experimental exposure system for studies of

high resolution photoresists for lithography. This is part of NRL K s comparative study of various UV, XUV and x-ray sources for lithography,

particularly with regard to radiation damage. Preliminary exposures

have been made with PBS and COP resists. Test masks supported on thin

polyimide films have been replicated. The results extrapolate to quite

reasonable exposure times. A new exposure chamber has been assembled

and is slated for trials at SURF II in September 1982. This chamber

accommodates a magnetic mask alignment clamp and will be used to fabricate

test circuits in conjunction with the NRL microelectronics facility,

1 paper.

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Division 533, Technical Activities (cont'd)

Photoabsorption Studies of Laser-Ionized Species

Off SURF, the technique of Resonant Laser-Driven Ionization (RLDI)

discovered here, has been used to refine our understanding of 4f-shell

collapse and the connection between electron-electron correlation and

au^ionization. Studies of the 4d-photoabsorption of the Ba, Ba

+ and

Ba isonuclear sequence has led to the discovery of shell "contraction".

Un 1 i ke

N fi 1 1 ed d-shell ground state atoms with configurations

4d 10 4f 5s

2 5p

6 5d

x 6s

2 which undergo a sudden 4f shell collapse at La(Z=57),

the optically allowed photoexcited 4d 9 4f l P terms in the Ba isonuclear

sequence and in the Xe isoelectronic sequence undergo a more gradual

"contraction". This work is expected to have important implications in

molecular and solid state physics and has already been used as a model

to explain valence fluctuations in solids. With the help of W. Johnson

at Notre Dame and K.T. Cheng at Argonne, we ijave perj(j>rmed a thorough

analysis of the 5p-photoabsorption of Xe, Cs and Ba . This analysis

has demonstrated a very clear connection between a decrease in autoionizing rates in the 5p

5 nd ' Rydberg series and the decrease in electronelectron correlation associated with the increasing charge state of the

nuclear core. Plans for the near term future include the conversion

from the photographic recording of VUV spectra to the photoelectric

recording with a specially designed, state-of-the-art, VUV optical

multichannel analyzer. This new instrument will be used to enlarge our studies into the effects of "tuning" the strength of the nuclear attraction

in atoms b^ selectee ionization. New candidates for investigation are

the Ca, Ca arjid Ca ++ isonuclear sequence (Ca is on the edge of 3d collapse)

and the Ar, K , Ca isonuclear sequence. 3 papers, 10 invited talks.

Improved Radiometric Accuracy

The principle uncertainty in specifying the irradiance from SURF at

all but the shortest wavelengths comes from the determination of the

orbital electron current (previously known to about 2% by means of

visible radiometry). A new technique has been developed which reduces

this uncertainty to less than 0.5%. It combines single electron counting

which exactly counts the number of electrons orbiting at very low currents

with a silicon photodiode which is known to be linear to within 0.2%

over nine decades. Thus, the absolute uncertainty in the photon flux

from SURF should be reducible to a value of 1.0% or less over the wavelength

range 10-200 nm. In collaboration with the Radiometric Physics Division,

an intercomparison is being made between SURF, the self-calibrated

silicon photodiode, and other standards in the Radiometric Physics

Division. It has been demonstrated that the SURF/silicon intercomparison

can be made to a stability of better than one percent. Using the silicon

radiometers as a transfer, SURF was compared with the tungsten-halogen

lamps constituting the NBS spectral irradiance scale in the visible.

Agreement was found to about 1%. Work is continuing on a direct comparison

between SURF and the silicon photodiode. 2 papers, 1 invited talk.

96
Division 533 s Technical Activities (cont'd)

Spectrometer Calibrations

The cal culabil ity of the irradiance from SURF II has been applied

by means of the SURF spectrometer irradiance calibration beam line and

its associated spectrometer calibration chamber to the calibration of

spectrometer and photometer systems in the spectral region 4-400 nm. These calibrations are primariliy in support of the programs of NASA and

the Department of Energy. For example, the NRL Solar Ultraviolet

Spectral Irradiance Monitor (SUSIM) was calibrated at SURF both before

and after its flight on Space Shuttle earlier this year. Recalibration

of SUSIM both before and after flight are expected to occur many times

in the next decade. Other calibrations this year have been made for

NASA/Goddard, NRL, Princeton Plasma Physics Lab, U. Colorado-LASP, and

for three groups from Johns Hopkins University. 2 papers, 3 talks.

Transfer Standard Detectors

The far UV radiometry effort at NBS includes the calibration and

supply of transfer standard photodiode detectors, some of which are fabricated in-house. Facilities both at SURF and in the laboratory are utilized. During FY 82, 29 outgoing calibrations were performed,

serving such disciplines as aeronomy, astronomy, ICF, MFE, plasma solar

and solid state physics, and furnishing the radiometric basis in the far

UV for other standards laboratories. We also collaborated with Los

Alamos National Laboratory in the characterization of photocathode

materials used for laser fusion diagnostics. The design and construction

of a new and improved detector calibration facility at SURF was initiated.

3 papers, 1 talk.

ELECTRON PHYSICS GROUP

The Electron Physics Group has ongoing research efforts in electron

collision physics including electron-surface interactions, surface magnetism, electron interaction theory, electron polarization phenomena,

electron-atom and electron-molecule 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 problems.

Surface Magnetism and Electron Diffraction

Our work on the scattering of spin polarized electrons from surfaces

continues with a high level of activitiy. As a consequence of our advancement of polarized electron source and detector technology, almost

every experiment we do is breaking new ground and being done for the

first time. This is particularly true of our most recent work on surface

magnetism. By using our polarized electron gun to observe the effects

97
Division 533, Technical Activites (cont'd)

of the exchange interaction, we are able to sense 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 surfacesensitive unlike neutron scattering.

During the past year we have extended our study of surface magnetism

in a number of ways. We have used ferromagnetic glasses as targets in

these investigations, so that our work no longer depends upon the effects

of crystal diffraction. In one experiment we measured the temperature

dependence of the surface magnetization hear liquid nitrogen temperature.

We found that the surface magnetization varied as (1-BT 3 ' 3 ), the same

power dependence as in the bulk magnetization except that the coefficient

B is about three times the size as the corresponding bulk coefficient.

It was predicted, about 15 years ago, that surface magnons would cause

the temperature power law to be the same with a coefficient twice as large as that of. the bulk. Our measurement substantially confirmed this

theory but raised some questions of detail that must now be addressed.

In a second experiment we studied the polarization of secondary

electrons emitted when a 500 eV unpolarized incident electron is scattered from a magnetic material. We made use of a new type of polarization detector developed at NBS last year and performed both energy and

polarization analysis on the low energy (1-20 eV) secondary electrons.

We found low energy secondary polarizations in rough agreement with the

bulk valence band electron polarization. At higher secondary energies

the polarizations decrease to about half the low energy values. For an iron based glass, polarizations of approximately 25% were obtained.

These data have stimulated efforts among theorists interested in modeling

the spin dependence of secondary electron production and have suggested

to us a major, new avenue of experimental work. Up until now, our surface magnetism measurements have been made by observing the intensity

variation in the scattered electrons when the polarization of the incident

electrons is modulated. Now, as a result of these experiments, we could

alternatively use an unpolarized incident electron beam and measure the

magnetization by monitoring the polarization of the secondary electrons

produced. Normally this would be a more difficult procedure but in one particular case it offers a substantial advantage. This situation

occurs in scanning electron microscopy. It is very difficult to determine

the size and direction of magnetization in microscopic magnetic samples.

We envision a modification of a conventional scanning electron microscope

to accomplish this task. In such a microscope the spatial resolution

comes from the use of a highly focused, unpolarized incident electron

beam. The beam is scanned in X and Y and the number of secondaries produced at any location is used to modulate the brightness of the picture

element at that location in the final photograph. We would add polarization analysis to a conventional scanning electron microscope so that

at each X,Y location in the final picture we will be able to measure the

strength and direction of the magnetization. We hope to be able to

98
Division 533, Technical Activites (cont'd)

study very small magnetic structures and to probe the transition of spin

directions as a domain wall is crossed. We are currently attempting to

arrange for a one-year feasibility study of this promising new experimental

method.

In our most recent experiment, we (in collaboration with Neville

Smith and Peter Johnson of Bell Laboratories) performed the first spin

polarized, inverse photoemission experiment. With the coming of high

intensity UV storage rings, groups worldwide are beginning to tool up to

measure spin polarized, angle-resolved, energy-resol ved photoemission.

Such measurements allow one to map out the spin dependent band structure.

We have performed an inverse photoemission experiment prior to the

measurement of the comparable direct process. In this experiment spin

polarized electrons at a specific energy and angle to the crystal were

scattered from a target and UV photons at a particular wavelength were

collected. We successfully demonstrated that in nickel only minority

spin electrons would give rise to absorption in the unfilled d-bands.

This method allows measurement of the spin polarized density of unfilled

states near the Fermi level. We will be using this technique during the

next year to study the effect of adsorption on the unfilled d-band in

nickel and the possible polarization of the unfilled states in the

adsorbates

.

High Energy Resolution Electron Scattering

During the past year we have used our high energy resolution electron

spectrometer to resolve a dilemma which has occurred in the study of the

diamond (111) surface. The difficulty was that LEED and photoemission

studies showed that this surface had no atomic rearrangement while

theory and our knowledge of other semiconductors predicted that a rearrangement should be expected. Our electron energy loss spectrometer (EELS)

was used to observe the surface composition of a diamond (111) crystal

used in other studies. We found that as prepared this diamond surface

was terminated by hydrogen atoms. We could remove or replace these

atoms with hydrogen or deuterium in a reproducible manner. Our discovery

that hydrogen is hindering the reconstruction of the diamond surface

explains all the conflicting experimental results to date. We have

begun to revitalize our electron spectrometer system through various

mechanical and electrical changes which should greatly enhance its

performance in the future.

Theory

We have recently been studying theoretical ly the polarization of

secondary electrons produced in ferromagnetic metals. A number of new experiments, e.g., photoemission and electron excitation on Co, Fe, and

Ni in which the spin polarization of the low energy electrons is measured

have exhibited very dramatic results. The electron spin polarization is

found to increase rapidly with decreasing energy rising to several times

99
Division 533, Technical Activites (cont'd)

the bulk value at the lowest measurable energies. We have modeled these

experiments by solving a Boltzmann-type transport equation that includes

electron spin. We obtain results consistent with the experimental ones

due to a physical mechanism that amounts to a spin flip. A minority

spin electron has a higher probability of being scattered to an empty d

state in a Coulomb collision than a majority spin electron due to the

larger number of unfilled minority spin d states. The resulting minority

to majority spin flips produce a large polarization at low energies

where scattering is most probable. This mechanism also produces a spin

dependent electron mean free path.

Electron Optics

Our electron optical design program has supported many of the new experimental efforts described above. Modification of our electron

optics was made for the inverse photoemission experiment and for the

secondary electron polarization experiment. In addition a complicated

modeling of the trajectories of the secondary electrons in crossed

magnetic and electric fields was used to interpret data on our secondary

electron polarization measurements. The overall computer program used

for electron optics calculations has been modified to allow greater

flexibility and graphical output of the results of the calculation.

Electron-atom Collisions

Data accumulation on polarized electron-polarized atom scattering

began in earnest this past year. We are investigating the electron-atom

scattering problem in an experiment where all the parameters are determined

so that we can make the step from measuring cross sections to the determination of quantum phases and amplitudes. For this purpose we have con- structed a crossed beam, polarized atom, polarized electron scattering

apparatus. Sodium atoms are polarized by optical pumping with a tunable

CW-dye laser; even the nuclear spin will be aligned. The electron beam comes from our second GaAs polarized electron source, and will have an energy resolution less than 0.15 eV. The use of the laser to optically

orient the sodium beam will also facilitate reading out the polarization

of the beam through laser fluorescence or Faraday rotation measurements.

We could also use the laser to study scattering from excited, oriented

atomic states. During this past year we have been able to measure the

asymmetry for ionization for the electron atom system in the singlet or triplet state. Our first results will soon be submitted for publication.

We will then quickly move on to ionization from the first excited state

of sodium and to ground state polarized electron-polarized atom elastic

scattering.

100
SPONSORED CONFERENCES

Division 533, Radiation Physics

M. J. Berger organized and chaired a session on "Radiation Physics and

Modeling" of a Workshop on the Interface Between Radiation Chemistry and

Radiation Physics," held at the Argonne National Laboratory on September

9 and 10 under the sponsorship of the Department of Energy.

First Conference on Radioprotectors and Anti carci nogens , June 21-24,

1982, National Bureau of Standards, Gaithersburg, MD, Conf. Chairman,

M. G. Simic.

Biological Effects of Radiation, American Nuclear Society Annual Meeting,

Los Angeles, CA, June 7-11, Symposium Chairman, M. G. Simic.

Symposium on the "Control of Exposure of the Public to Ionizing Radiation

in the Event of Accident or Attack," April 27-29, 1982, Res ton, VA,

L. V. Spencer, Chairman, NCRP Committee 63 sponsor.

101
INVITED TALKS

Division 533, Radiation Physics

Berger, M. J. and Seltzer, S. M. , "Tables of Energy- Deposition Distributions in Water Phantoms Irradiated by Point-Monodirectional Electron

Beams with Energies from 1 to 60 MeV, and Applications to Broad Beams,"

Presented at the Electron Dosimetry and Arc Therapy Symposium, Wisconsin

Clinical Cancer Center, University of Wisconsin, Madison, Wisconsin,

September 10-11, 1981. NBSIR 82-2451, January 1982.

Berger, M. J. and Seltzer, S. M. "Mean Excitation Energies for Use in

Bethe's Stopping Power Formula," Proceedings of Seminar on Charge States

and Dynamic Screening of Swift Ions in Solids; Honolulu, Hawaii, January

24-29, 1982.

Celotta, R. J., "Recent Applications of Electron Spin Polarization

Measurements," Exxon Research and Development Laboratory, Linden, NJ,

November 12 , 1 981

.

Celotta, R. J., "The Use of Electron Polarization Measurements in Surface

Physics," Materials Science Colloquium, Massachusetts Institute of

Technology, Cambridge, MA, November 13, 1981.

Celotta, R. J., "Recent Advances in the Use of Electron Spin Polarization

Measurements," Joint JILA-Physics Department Colloquium, University of

Colorado, Boulder, CO, April 13, 1982.

Celotta, R. J., "Electron Spin Polarization Measurements: Applications

in Surface and Atomic Physics," University of Oregon, Eugene, OR, April

15, 1982.

Celotta, R. J., "The Application of Electron Spin Polarization Measurements in Surface and Atomic Physics," Interdepartmental Physics Colloquium, Westinghouse Electric Corporation, Pittsburgh, PA, April 29,

1 982.

Celotta, R. J., "Possibilities for the Use of Electron Spin Polarization

in Scanning Electron Microscopy," Microbeam Analysis Society Conference,

Washington, DC, August 11, 1982.

Celotta, R. J., "Application of Electron Polarization Technique to Surface Physics," XI Yugoslav Summer School and International Symposium on the Physics of Ionized Gases, Dubrovnik, Yugoslavia, August 25, 1982.

Celotta, R. J., "Use of Polarized Electrons in Atomic Physics," XI Yugoslav Summer School and International Symposium on the Physics of Ionized

Gases, Dubrovnik, Yugoslavia, August 25, 1982.

102
Division 533, Invited Talks (cont'd)

Celotta, R. J., "Electron Polarization Phenomena at Surfaces," Physics

Seminar City College of New York, New York, NY, September 22, 1982.

Domen, S. R., "Absorbed Dose Water Calorimeter," Hungarian and British

National Standards Laboratories, and Ghent Univerity, Belgium, December

1981

.

Ederer, D. L., "Observation of Ionization in Laser Excited Sodium Atoms

by Synchrotron Radiation," Conference for Laser Techniques for Extreme

Ultraviolet Spectroscopy , Boulder, CO, March 1982.

Ederer, D. L., "Photoelectron Spectroscopy in Atoms and Molecules," Yale

University, New Haven, CT, May 1982.

Ederer, D. L., "Use of Synchrotron and Laser Radiation to Study Col 1 isional

and Photoionization Processes in Metal ic Vapors," Eidgenossiche Technische

Hochschule, Zurich, Switzerland, July 1982.

Ederer, D. L, "Studies on Photoionization Processes from Ground State

and Excited State Atoms and Molecules," Workshop on Techniques for

Production and Utilization of Polarized Radiation in the VUV, London,

England, August 1982.

Hill, W. T., "Absorption Spectroscopy of Ions," Corning Glass Works,

Corning, NY, November 1981.

Hill, W. T., "Quantum Defect Studies of the Rydberg Levels in Xe-like

Ba ++ ," University of Maryland, College Park, MD, November 30, 1981.

Hill, W. T. , "Quantum Defect Studies of the Rydberg Levels in Xe-like

Ba ++ ," Division of Electronic and Atomic Physics Meeting, New York, NY,

December 1981.

Hill, W. T., "Laser-Assisted MQDT Studies in Xe-like Systems," Notre

Dame University, Notre Dame, IN, March 1982.

Hill, W. T., "Laser-Assisted MQDT Studies in Xe-like Systems," Argonne

National Laboratory, Argonne, IL, March 1982.

Hill, W. T., "Laser Generated Plasma Studies and VUV Photoabsorption,"

Stanford University, Stanford, CA, March 1982.

Hill, W. T., "Laser Generated Plasma Studies and VUV Photoabsorption,"

University of Southern California, Los Angeles, CA, March 1982.

Hill, W. T., "Absorption Spectroscopy of Ionized Vapors," Bell Laboratories,

Murray Hill, NJ, April 1982.

103
Division 533, Invited Talks (cont'd)

Hill, W. T., "VUV Spectroscop^

+of the 5p

5 2 P 3/2 ns, nd Discrete and

Autoionizing Resonances in Ba ," Workshop on'Techniques for Production

and Utilization of Polarized Radiation in the VUV, London, England,

August 1982.

Hill, W. T., "VUV Spectroscop^

+of the 5p

5 2 P 3 , 2 ns, nd Discrete and

Autoionizing Resonances in Ba ," VII International Colloquium on Ultraviolet and X-Ray Spectroscopy of Astrophysical and Laboratory

Plasmas, University College, Dublin, Ireland, August 1982.

Hubbell, J. H., "Photon Attenuation Coefficients and Cross Section Data

100 eV to 100 GeV: Current Status and Prospects." Proc. 2nd International

Symposium on Radiation Physics, Universiti Science, Penang, Malaysia,

May 25-29, 1982.

Kelley, M. H., "Polarized Electron-Polarized Atom Scattering," University

of Texas, Austin, TX, November 24, 1981.

Kelley, M. H., "Spin Dependence in Electron Atom Scattering," Rice University, Houston, TX, June 8, 1982.

Kelley, M. H., "Spin Dependence in Electron Atom Scattering," University

of Texas, Austin, TX, June 9, 1982.

Loevinger, R., "Radiation Quantities and Units," preparation course for

the American Board of Health Physics Certification Examination, Gaithersburg, MD, January 1982.

Loevinger, R., "Radiologic Physics Activities and Need at NBS," at a Workshop on Radiologic Physics Research and Support, National Cancer

Institute, Bethesda, MD, May 1982.

Loevinger, R. , "The NBS Program in Electron-beam Dosimetery," Symposium

on Electron Beam Dosimetry at Memorial Hospital, New York, NY, June

1982.

Loevinger, R. , "Audience Participation Presentation: Discussion and

Vote on Exposure vs_ Air Kerma vs_ Water Kerma," a Continuing Education

Lecture at the 24th Annual Meeting of the American Association of Physicists in Medicine, New Orleans, LA, August 1982.

Lucato^Jo, T. B. and Hill, W. T., "A Laser-Assisted Voyage Through Ba, Ba

+

, and Ba : Shell Collapse, Term Dependence and Photoionization," Center

for Absolute Physical Quantities Seminar, NBS, November 1981.

Lu^atorto, T. B., "Effect of Valence Electrons on Core Absorption in Ba,

Ba and Ba ++ ," University of Maryland, College Park, MD, November 1981.

104
Division 533, Invited Talks (cont'd)

"4° “j30}

0 Lucatorto, T. B., "A Laser-Assisted Journey Through Ba, Ba and Ba : Shell Collapse Term- Dependence and Autoionization," University of North

Carolina, Raleigh, NC, March 1982.

Lucatorto, T. B. and Mcllrath, T. J., "Optical Studies of Atomic Systems:

Do You Need Coherent Light to do Coherent Physics?," Bell Laboratories,

Holmdel , NJ, April 1982.

Lucatorto, T. B. and Mcllrath, T. J., "Resonant Laser-Excitation and

Ionization of Dense Vapors: A Object of Study and as a New Tool in

Atomic Physics," Princeton University, Princeton, NJ , April 1982.

+ ++ Lucatorto, T. B., "The 4d Photoabsorption of Ba, Ba and Ba : A View of

Shell Collapse vs. Contraction," X-82 Conference, Eugene, OR, August

1982.

Madden, R. P. Traveling Lecturer for Optical Society of America, Orlando,

FL, October 1981; Norwalk, CT, December 1981; Rochester, NY, February

1982; and Phoenix, AR, April 1982.

Madden, R. P., "SURF-II Calibration Facility Users and Capabilities,"

NASA, Washington, DC, May 1982.

Madden, R. P., "Status Report: NBS Far Ultraviolet Transfer Standard

Detector Program," Middle Atmospheric Program, Washington, DC, May 1982.

Madden, R. P., "Status Report: NBS/SURF Far UV Spectrometer Radiometric

Calibration Facility," Middle Atmospheric Program, Washington, DC, May

1982.

Madden, R. P., "SR Radiometry at the National Bureau of Standards SURF

Storage Ring", PTB, Berlin, W. Germany, August 1982.

Mcllrath, T. J. and Lucatorto, T. B., "Observations of the Effect of

Valence Electrons on Core Absorption Spectra in Alkaline Earths,"

Atomic and Molecular Physics Close to Ionization Thresholds in High

Fields, CNRS International Colloquium, Savoie, France, June 1982.

Mcllrath, T. J., "Pulsed Plasma Light Sources," Workshop on Techniques

for Production and Utilization of Polarized Radiation in the VUV,

London, England, August 1982.

McLaughlin, W. L. , "Pulse Radiolysis of Triphenylmethane Dyes," Accelerator Department and Chemistry Department, Risd National Laboratory,

Denmark, November 2, 1981.

McLaughlin, W. L. , "Dosimetry for Quality Control of Radiation Preservation of Foods," Advisory Group on High-Dose Radiation Measurement, IAEA,

Vienna, Austria, November 10, 1981.

105
Division 533, Invited Talks (cont'd)

McLaughlin, W. L. , "Dosimetry for Quality Control of Radaition Sterilization of Medical Supplies," Advisory Group on High- Dose Radiation Measurement, IAEA, Vienna, Austria, November 13, 1981.

McLaughlin, W. L., "Fibre Optics for Ionizing Radiation Measurement,"

Institute of Physics, University of Mexico, Mexico., December 2, 1981.

McLaughlin, W. L., "Neutron Dosimetry With Radiochromic Dyes," National

Institute of Nuclear Studies, University of Mexico, Mexico, December 7, 1981.

McLaughlin, W. L., "Ultra High-Dose Measurements in Charged-Particle

Beams," Accelerator Group, Nuclear Center of Mexico, Salazar, Mexico,

December 9, 1 981

.

McLaughlin, W. L. , "Low-Energy Electron Beam Diagnostics and Industrial

Quality Control , "Tel eCom Product Division, 3M Company, St. Paul, MN,

January 22, 1982.

McLaughlin, W. L., "Fibre Optics Dosimetry," Defense Nuclear Agency

Planning Committee, March 30, 1982.

McLaughlin, W. L., "Dosimetry," D0A-D0E Workshop on Low Dose Irradiation

of Agricultural Products, April 1 9-23, 1 982.

McLaughlin, W. L., "Radiation Dosimetry in Food Irradiation Technology,"

American Nuclear Society Annual Meeting, The Western Bonaventure, Los

Angeles, CA, June 8, 1982.

McLaughlin, W. L. , "Electron Beam Dosimetry and Standardization,"

Becton-Dickinson Company Headquarters Staff and Quality Assurance Personnel,

June 22, 1982.

McLaughlin, W. L., "Lyoluminescence and Free Radical Analysis in Radioprotectors," Radiation and Anti carcinogens Conference, NBS, June 23,

1982.

Parr, A. C. , "Resonance Phenomena in Molecular Photoionization," Georgetown

University, Washington, DC, November 1982.

Parr, A. C. , "Triply-Differential Photoelectron Studies of Autoionization

and Shape Resonance Effects in Molecular Photoionization," Division of

Electronic and Atomic Physics Meeting, New York, NY, December 1981.

Parr, A. C. , "Triply-Differential Photoelectron Spectroscopy of Atoms

and Simple Molecule," Center for Absolute Physical Quantities Seminar,

NBS, January 1982.

Parr, A. C. , "Resonance Phenomena in Molecular Photoionization," University

of Alabama, University, AL, March 1982.

106
Division 533, Invited Talks (cont'd)

Parr, A. C., "Resonance, Autoionization and Kinetic Effects in Photoionization," American Society for Mass Spectrometry Conference, Honolulu, HI , June 1 982.

Parr, A. C., "Resonance Phenomena in Molecular Photoionization," California

Institute of Technology, Pasadena, CA, June 1982.

Parr, A. C., "Resonance Phenomena in Molecular Photoionization," University

of California, Santa Barbara, CA, June 1982.

Parr, A. C, "Photoelectron Spectrometer for High Resolution Angular

Resolved Studies," International Conference on X-Ray and VUV Synchrotron

Radiation Instrumentation, Deutsches Elektronen-Synchrotron , Hamburg,

West Germany, August 1982.

Parr, A. C., "Resonance Phenomena in Molecular Photoionization," University

of Uppsala, Uppsala, Sweden, August 1982.

Parr, A. C., "Effects of Resonance in Molecular Photoionization Measured

with Triply Differential Photoelectron Spectroscopy," 9th International

Mass Spectrometry Conference, Vienna, Austria, August 1982.

Parr, A. C. , "Resonance Phenomena in Molecular Photoionization," Centre

National Researche Scientifique, SACLAY, France, September 1982.

Penn, D. R. , "Surface Photoeffect in Small Spheres," American Physical

Society, Dallas, TX, March 11, 1982.

Penn, D. R., "Surface Enhanced Photoabsorption in Small Spheres," Drexel

University, Philadelphia, PA, April 15, 1982.

Penn, D. R. , "Surface Photoeffect in Small Spheres," Xerox Corporation,

Palo Alto, CA, August 13, 1982.

Pierce, D. T. , "Spin Polarized Electron Studies of Surface Magnetism,"

Centro de Investigacion y de Estudios, Avanzados del Instituto Pol i

technico Natcional, Organization of American States, Mexico City,

Mexico, December 7, 1981.

Pierce, D. T., "Spin Polarized Electron Scattering - A New Probe of

Surface Magnetism," Physics Department Colloquium, University of Chicago,

Chicago, IL, January 21, 1982.

Pierce, D. T., "Spin and Energy Analyzed Secondary Electron Emission

from a Ferromagnet ," Gordon Research Conference on Electron Spectroscopy

,

Wolfeboro, NH, July 19, 1982.

Pierce, D. T., "New Information from Electron Spin Polarization in

Surface Studies," Korean Standards Research Institute, Seoul, Korea,

August 31 , 1 982

.

107
Division 533, Invited Talks (cont'd)

Pierce, D. T., "Spin Polarized Electron Scattering from Surfaces,"

Korean Advanced Study Institute, Seoul, Korea, September 1, 1982.

Pierce, D. T., "Spin Polarized Electron Scattering Studies of Surface

Magnetism," International Conference on Magnetism, Kyoto, Japan, September 10, 1982.

Pierce, D. T., "Surface Magnetic Properties of Amorphous Ferromagnets

Studied Using Electron Spin Polarization," 10th International Colloquium

on Magnetic Films and Surfaces, Yokahama, Japan, September 14, 1982.

Pierce, D. T., "Spin Polarized Electrons in Condensed Matter Physics,"

Tribuvan University, Kathmandu, Nepal, September 23, 1982.

Pierce, D. T., "Electron Spin Polarization Probes of Surface Magnetism:

Recent NBS Results," Swiss Federal Institute of Technology, Zurich,

Switzerland, October 4, 1982.

Pierce, D. T., "Electron Spin Polarization Studies of Surface Magnetism,"

Solid State Physics Seminar, Cambridge University, Cambridge, England,

October 7, 1982.

Rogers, W. T., "Polarized Electron-Polarized Atom Scattering," General

Atomic Corporation, San Diego, CA, November 10, 1981.

Rogers, W. T. , "Polarized Electron-Polarized Atom Scattering," Lawrence

Livermore National Laboratories, Livermore, CA, November 12, 1981.

Rogers, W. T., "Polarized Electron-Polarized Atom Scattering," E. I. duPont de Nemours & Co., Inc., Wilmington, DE , November 19, 1981.

Simic, M. G. , "Kinetics and Mechanisms of Auto-Oxidation Reaction," The

University of Maryland Baltimore County, Catonsville, MD, November 9, 1981.

Simic, M. G. , "Chemistry, Biological Effects and Dosimetry of Ionizing

Radiation," University of Florida, Agricultural Research and Education

Center, Lake Alfred, FL, November 24, 1981.

Simic, M. G., "Pulse Radiolysis and its Limitations in Autoxidation and

Antioxidants," National Research Council, Ottawa, Canada, February 26,

1 982.

Simic, M. G. , "Radiation-Induced Racemization of Amino Acids," U.S.

Department of Agriculture, Eastern Regional Center, Philadelphia, PA,

March 31 , 1 982

.

Simic, M. G. , "Radiation-Induced Racemization of Amino Acids," Massachusetts Institute of Technology, Dept, of Nutrition and Food Science,

Cambridge, MA, April 5, 1982.

108
Division 533, Invited Talks (cont'd)

Simic, M„ G. s "Mechanisms of Radiation-Induced Racemization and Dimerization of Aliphatic Peptides," Annual Radiation Research Society Meeting,

Hotel Utah, Salt Lake City, UT, April 19, 1982.

Simic, M. G., "Radiation-Induced Autoxidation Processes", Lawrence

Livermore Laboratory, Livermore, CA, April 22, 1982.

Simic, M. G., "Oxygen a Problem or a Detriment in Food Irradiation."

Radiation in Food Processing Symposium, American Nuclear Society Annual

Meeting, Los Angeles, CA, June 6-11, 1982.

Spencer, L. V., "Types of Nuclear Disaster and their Radiation Environment," Proc. NBRP Symp. The Control of Exposure to the Public to Ionizing

Radiation in the Event of Accident or Attack, Reston, VA, April 27-

29, 1982.

Waclawski, B. J., "Direct Verification of Hydrogen Termination of the

Semiconducting Diamond (111) Surface," Ninth Annual Conference on Physics and Chemistry of Semiconductor Interfaces, Pacific Grove, CA,

January 27, 1982.

109
PUBLICATIONS

Division 533, Radiation Physics

Berger, M. J. and Seltzer, S. M. , Tables of Energy-Deposition Distributions in Water Phantoms Irradiated by Point-Monodi recti onal Electron

Beams with Energies from 1 to 60 MeV, and Applications to Broad Beams,

NBSIR 82-2451 (January 1982).

Berger, M. J. and Seltzer, S. M. , Mean Excitation Energies for Use in

Bethe's Stopping Power Formula, Proc. of Seminar on Charge States and

Dynamic Screening of Swift Ions in Solids; Honolulu, Hawaii (January

24-29, 1982).

Berger, M. J. and Seltzer, S. M. , Stopping Powers and Ranges of Electrons

and Positrons, NBSIR 82-2550 (August 1982).

Berger, M. J. and Seltzer, S. M., Tables of Energy Deposition Distributions in Aluminum and Copper Irradiated by Point-Monodirection Electron

Beams with Energies from 1 to 60 MeV. NBSIR (in press).

Celotta, R. J. , Pierce, D. T. , Kelley, M. H., and Rogers, W. T. , Polarized Electrons, in Physics of Electronic and Atomic Collisions , S. Datz,

ed., North Holland Publishing Co. (1982).

Celotta, R. J. and Pierce, D. T. , Possibilities for the Use of Electron

Spin Polarization in Scanning Electron Microscopy, Proc. of Microbeam

Analysis Society (in press).

Cole, B. , Saloman, E. B. , and Ederer, Q. L., Ba II Fluorescence from Ba

Atoms Resonantly Photoionized with 584A Radiation, J. Opt. Soc. Am. 7J_,

1458 (1981 ).

Day, R. H. , Lee, P. , Saloman, E. B., and Nagel, D. J., Photoelectric

Quantum Efficiency and Filter Window Absorption Coefficients from 20 eV

to 10 KeV, J. Appl . Phys. 52_, 6965 (1981 ).

Degraff, E. , and McLaughlin, W. L. , Quality Control for Electron Beam

Processing of Polymeric Materials by End-Point Analysis, 3rd International Meeting on Radiation Processing, Tokyo, Radi at. Phys. Chem. J_8

,

975-985 (1981).

Dizdaroglu, M. , and Simic, M. G. , Hydroxycyclophexadienyl Peroxy Radicals,

in Oxygen Radicals, Eds. M. A. J. Rodgers, E. L. Powers, Academic Press,

p. 619 (1981).

Dizdaroglu, M. , Krutzsch, H. C. , Simic, M. G. , Separation of Angiotensins

by High-Performance Liquid Chromatography on a Weak Anion-Exchange

Bonded Phase, Anal. Biochem. 123 , 190-193 (1982).

110
Division 533, Publications (cont'd.)

Dizdaroglu , M. , Krutzsch, H. C. , Simic, M. G. , Separation of Peptides by

High-Performance Liquid Chromatography on a Weak Anion-Exchange Bonded

Phase, J. Chromatogr. , 237 417-428 (1982).

Dizdaroglu, M. , Simic, M. G. , Separation of Dipeptide Diastereomers by

High-Resolution Gas Chromatography, J. Chromatogr. (in press).

Dizdaroglu, M. , Simic, M. G. , Isolation and Characterization of Radiation

Induced Aliphatic Peptide Dimers, Biophys. Biochem. Acta, (in press).

Dizdaroglu, M. , Simic, M. G. , Rioux, F. , and St-Pierre, S., Separation

of Diastereomers and Analogues of Neurotensins by Anion-Exchange HighPerformance Liquid Chromatography , J. Chromatogr. (in press).

Dizdaroglu, M. , Gajewski, E. , Simic, M. G., and Krutzsch, H. C., Radiolytic

Products as Indicators of OH Radical Site of Attack on Lysozyme, Int. J.

Radiat. Biol, (in press).

Domen, S. R. , An Absorbed Dose Water Calorimeter: Theory, Design, and

Performance, JRNBS (U.S.) 87_, 211 (1982).

Ederer, D. L. , Parr, A. C. , Cole, B. E. , Stockbauer, R., Dehmer, J. L.,

West, J. B. and Codling, K. , Vibrational State Dependence of Partial

Cross Sections and Photoelectron Angular Distributions Through Autoionizing Resonances: The n=3 Rydberg State Converging to the B

2 Z+

State of C0+, Proc. R. Soc. Lond. A 378, 423 (1981).

Ederer, D. L. , Parr, A. C. , West, J. B., Holland, D. M. P. , and Dehmer,

J. L. , Measurement of Spin-Orbit Branching Ratios and the Angular Asymmetry

Parameter in the Region of the 4s4p 6 5p Resonances in Krypton and the

5s5p 6 6p Resonances in Xenon, Phys. Rev. A 25_, 2006 (1982).

Ederer, D. L. , LeGouet, J. L. , Picque, J. L. , Wuilleumier, F., Bizau, J.

M. , and Koch, P. , Direct Observation of Hot Electron Spectra from Laser

Illuminated Sodium Vapor, Phys. Rev. Lett. 48, 600 (1982).

Ederer, D. L, Krummacher, S. , Schmidt, V., Bizau, J. M. , Dhez, P., and

Wuilleumier, F. , Inner Shell Photoemission Studies of Alkali Metals in

the 40 to 80 eV Photon Energy Range, Inner Shell and X-Ray Physics of

Atoms and Solids, Plenum Publ. Corp. , (1981).

Ederer, D. L. , Bizau, J. M. , Wuilleumier, F. , Dhez, P., Picque, J. L. , LeGouet, J. L. and Koch, P. , Observation of Ionization in Laser Excited

Sodium Atoms by Synchrotron Radiation, Proc. of Conf. on Laser Techniques

for Extreme Ultraviolet Spectroscopy, Boulder, CO (1982).

Ederer, D. L. , Bizau, J. M. , Wuilleumier, F. , Dhez, P., Chang, T. N.

,

Krummacher, S. and Schmidt, V. , Final State Symmetry for the n=2 States

in Photoionized Helium by Theory and Experiment, Phys. Rev. Lett. 48,

588 (1982). ~

111
Division 533, Publications (cont'd.)

Ederer, D. L. , The Development of Far UV Spectrometers for Synchrotron

Radiation Facilities, Nucl. Inst. Meth. 195 , 191 (1982).

Ederer, D. L. , Larsen, P. K. , van Bers, W. A. M. , Bizau, J. M. , Wuilleumier, F. , Krummacher, S. and Schmidt, V., Design and Performance of a Toroidal Grazing Incidence Monochromator for the 20-200 eV Photon Energy

Range, Nucl. Inst. Meth. 195 , 245 (1982).

Ehrlich, M. , Choice of Conversion Factors to Shallow and Deep Dose

Equivalents for Use in a U.S. Personnel Dosimetry Performance Testing

Programme, Radiat. Protect. Dosim. , 1_, 271 (1982).

El-Assy, N. B. , Roushdy, H. M. , Rageh, M., McLaughlin, W. L. , and Levine,

H. , y-Ray Dosimetry Using Pararosani line Cyanide in Dimethyl Sulfoxide

Solutions, Int. J. Appl. Radiat. Isot. 33_, 641-645 (1982).

El-Behay, A. Z. and McLaughlin, W. L. , Dose Distribution Mapping in

Intense y-Ray Fields Using Dye Film Dosimetry, Technical Note, Int. J.

Appl. Radiat. Isot. 33_, 384-387 (1982).

Gajewski, E. , Dizdaroglu, M. , and Simic, M. G. , Kovats Indices of Trimethylsilylated Amino Acids on Fused Silica Capillary Columns, J. Chromatogr.

(in press).

Holland, D. M. P. , Parr, A. C. , Ederer, D. L. , Dehmer, J. L. and West,

J. B. , The Angular Distribution Parameters of Argon, Krypton and Xenon

for use in Calibration of Electron Spectrometers, Nucl. Inst. Meth. 195,

331 (1982).

Holland, D. M. P. , West, J. B. , Parr, A. C. , Ederer, D. L. , Stockbauer,

R. , Buff, R. D. and Dehmer, J. L. , Constant Photoelectron Energy Spectroscopy of Acetylene, J. Chem. Phys. (in press).

Hubbell, J. H. , Radiation Gauging, in the Encyclopedia of Materials

Science and Engineering , M. B. Bever, ed., Pergamon Press, Oxford/New

York, Toronto (in press).

Hubbell, J. H. , Photon Mass Attenuation and Energy-Absorption Coefficients from 1 keV to 20 MeV. Int. J. Appl. Radiation and Isotopes (in

press)

.

Schaupp, D. , Schumacher, M. , Smend, F. , Rullhusen, P., and Hubbell,

J. H. , Small-Angle Rayleigh Scattering of Photons at High Energies. J. Phys. Chem. Ref. Data (in press).

Hubbell, J. H. , Photon Attenuation Coefficients and Cross Section Data

100 eV to 100 GeV. Current status and prospects. Proc. 2nd International

Symposium on Radiation Physics (May 25-29, 1982).

Hughey, L. R. , Williams, R. T. , Rife, J. C. , Nagel, D. J. and Peckerar,

M. C. , Instrumentation for XUV Lithography at SURF II, Nucl. Inst. Meth.

195 , 267 (1982).

112
Division 533, Publications (cont'cL)

Hughey, L. R. , and Schaefer, A. R. , Reduced Absolute Uncertainty in the

Irradiance of SURF-II and Instrumentation for Measuring Linearity of

X-Ray, XUV and UV Detectors, Nucl . Inst. Meth. 195 , 367 (1982).

Humphreys, J. C. , and McLaughlin, W. L. , Dye Film Dosimetry for Radiation

Processing, Proc. 6th Int. Conf. on Use of Small Accelerators in Business

and Industry, N. Texas State University, IEEE Trans. Nucl. Sci. NS-28,

1797-1801 (1981).

Kronenberg, S. , McLaughlin, W. L. , and Siebentritt, C. R., Broad-Range

Dosimetry with Leuko Dye Optical Waveguides, Nuclear Instruments and

Methods 190, 365-368 (1981).

Loevinger, R. , Calculation of Absorbed Dose in High Energy Photon and

Electron Beams Using a Calibrated Ionization Chamber, Proc. of a Symposium in Paris, France, by the International Atomic Energy Agency, Vienna

(1981).

Loevinger, R. , The Role of the Standards Laboratory in Brachytherapy , in

Medical Physics Monograph No. 7, American Institute of Physics (1981).

Loevinger, R. , National Standards for Radiation Dosimetry, in NBS Spec.

Publ . 609, U.S. GPO (1982).

Lucatorto, T. B. , Mcllrath, T. J. , Sugar, J. and Younger, S. M., Radical

Redistribution of the 4d Oscillator Strength Observed in the Photoabsorption of the Ba, Ba + and Ba ++ Sequence, Phys. Rev. Lett. £7, 1124

(1981).

Lucatorto, T. B. , Mayo, S. and Luther, G. G. , Laser Ablation and Resonance

Ionization Spectrometry for Trace Analysis of Solids, Anal. Chem. 54,

553 (1982).

Lucatorto, T. B. , Mcllrath, T. J., Hill, W. T. , and Clark, C., The AdPhotoabsorption of Ba, Ba + and Ba ++

: A View of Shell Collapse vs. Contraction, Proc. of X-82 Conference, Eugene, OR (1982).

Madden, R. P. and Parr, A. C. , Resonance Phenomena in Molecular Photoionization: Impact of Synchrotron Radiation, Appl. Opt. 21_, 179 (1982).

Madden, R. P. and Canfield, L. R. , Status Report: NBS Far Ultraviolet

Transfer Standard Detector Program, Middle Atmospheric Program Handbook,

Paul Simon, ed. (in press).

Madden, R. P. , Ebner, S. C. , and Hughey, L. R. , Status Report: SURF Far

Ultraviolet Spectrometer Radiometric Calibration Facility, Middle Atmospheric Program Handbook, Paul Simon, ed. (in press).

113
Division 533, Publications (cont'd.)

Mcllrath, T. J. , and Lucatorto, T. B. , Quantitative VUV Absorption

Spectroscopy of Free Ions, Laser Spectroscopy V, Proc. of the 5th

International Conference (1981).

Mcllrath, T. J. , and Lucatorto, T. B. , Observations of the Effect of

Increasing Core Charge on Rydberg Spectra in the Xe-Isoelectronic

Sequence, Journal de Physique (in press).

Mcllrath, T. J. , and Lucatorto, T. B. , High Resolution Spectroscopy,

Proc. Conference on Laser Techniques for Extreme Ultraviolet Spectroscopy,

Boulder, CO (1982).

McLaughlin, W. L. , Simic, M. G. , and Miller, A., Dosimetry by Means of

the Radiation Reduction of Hemin in Aprotic Solvents, Proceedings of 3rd

Symposium on Nuclear Chemistry, and Radiation Chemistry, Mexico, D.F.,

December 1980 (in press).

McLaughlin, W. L. , Humphreys, J. C. , Levine, H., Miller, A., Radak, B.

B. , and Rativanich, N. , The Gamma-Ray Response of Radiochromic Dye Films

at Different Absorbed Dose Rates, 3rd Int. Meeting on Radiation Processing, Tokyo, Radiat. Phys. , Chem. 1_8, 987-999 (1981 ).

McLaughlin, W. L. , Humphreys, J. C. , and Miller, A., Dosimetry for

Industrial Radiation Processing, Proc. of Seminar on Traceability of

Ionizing Radiation Measurement, NBS, Washington, DC, NBS Special Publication 609, 171-178 (1982).

McLaughlin, W. L. , Jarrett, R. D. , and Olejnik, T. A., Chapter 8 Dosimetry,

Volume 1, Preservation of Food by Ionizing Radiation , Editors: Dr. E.S.

Josephson and Dr. Martin S. Peterson., CRC Press, Inc. (in press).

Mehlman, G. , Cooper, J. W. , and Saloman, E. B. , The Absolute Photoabsorption Cross Section of the K Shell of Atomic Lithium, Phys. Rev. A

25, 2113 (1982).

Miller, A. and McLaughlin, W. L. , Evaluation of Radiochromic Dye Films

and Other Plastic Dose Meters Under Radiation Processing Conditions,

High-Dose Measurements in Industrial Radiation Processing , Technical

Reports Series 205, International Atomic Energy Agency, Vienna, pp. 119-

138 (1981).

Miller, A. and McLaughlin, W. L. , Calculation of the Energy Dependence

of Dosimeter Response to Ionizing Photons, Int. J. Appl. Isotopes,

Trends in Radiation Dosimetry (Ed. W.L. McLaughlin) Pergamon Press,

Oxford (in press).

Motz, J. W. and Danos, M. , Quantum Noise-Limited Images in Screen-Film

Systems, SPIE/SPSE Proceedings of Applications of Optical Instrumentation in Medicine (in press).

114
Division 533 , Publications (cont'd.)

Parr, A. C. , Ederer, D. L. , West, J. B. , Holland, D. M. P. , and Dehmer,

J. L. , Tri ply-Differential Photoelectron Studies of Non-Franck-Condon

Behavior in the Photoionization of Acetylene, J. Chem. Phys. 76_, 4349

(1982).

Parr, A. C. , Status Report on the SURF-II Facility at NBS , Nucl . Inst,

and Meth. 195, 7 (1982).

Parr, A. C. , Ederer, D. L. , Dehmer, J. L. and Holland, D. M. P., Characterization of Some Autoionizing Resonances in C0 2 Using Triply Differential Photoelectron Spectroscopy, J. Chem. Phys. 77., 111 (1982).

Parr, A. C. , Buff, R. and Jason, A., The Photoionization of Ally! Chloride

from Onset to 20 eV, Int. J. of Mass Spectrom. Ion Phys. 40, 31

(1981).

Parr, A. C. , Holland, D. M. P. , Ederer, D. L. and Dehmer, J. L., Effects

of Resonances in Molecular Photoionization Measured with Triply Differential Photoelectron Spectroscopy, Nucl. Instrum. Methods (in press).

Parr, A. C. , Southworth, S. H. , Dehmer, J. L. , and Holland, D. M. P.,

Photoelectron Spectrometer for High Resolution Angular Resolved Studies,

Int. J. Mass Spectrom. Ion Phys. (in press).

Parr, A. C. and Rosenstock, H. M. , Resonance, Autoionization and Kinetic

Effects in Photoionization, Proc. of American Society for Mass Spectrometry Conference, Honolulu, HI, (1982).

Penn, D. R. , and Rendell , R. W. , Surface Enhanced Photoadsorption and

Photoyield in Small Spheres, Phys. Rev. Lett. 47, 1067 (1981).

Penn, D. R. , Girvin, S. M. , and Mahan, G. D. , Dispersion Relation Approach to the X-Ray Edge Problem, Phys. Rev. B 24, 6971 (1981).

Penn, D. R. , and Rendell, R. W. , Surface Photoeffect in Small Spheres,

Phys. Rev. (in press).

Pierce, D. T. , Celotta, R. J. , Unguris, J., Siegmann, H. C., SpinDependent Elastic Scattering of Electrons from a Ferromagnetic Glass,

Ni 40 Fe 4 0 B 2 o> Phys. Rev. (in press).

Pruitt, J. S. , and Loevinger, R. , The Photon-Fl uence Scaling Theorem for

Compton-Scattered Radiation, Med. Phys. 9., 176 (1982).

Rativanich, N. , Radak, B. B. , Miller, A., Uribe, R. M. , and McLaughlin,

W. L. , Liquid Radiochromic Dosimetry, 3rd Int. Meeting on Radiation

Processing, Tokyo, October 1980, Radiat. Phys. Chem. 1_8, 1001-1010 (1981 ).

115
Division 533, Publications (cont'd.)

Rendell , R. W. , and Girvin, S. M. , Abstract: Quantum Hall Effect: Role

of Inversion Layer Geometry and Random Impurity Potential, Surf. Sci.

113, 39 (1982).

Rendell, R. W. , and Bryant, G. W. , New Field Theory Formulation of

Localized States in Disordered Systems, J. Phys. C: Solid State Phys.

14, L881 (1981).

Rendell, R. W. , Aravind, P. K. , and Metiu, H., A New Geometry for Field

Enhancement in Surface-Enhanced Spectroscopy, Chem. Phys. Lett. 85, 396

(1982).

Rosenstock, H. M. , Stockbauer, R. and Parr, A. C. , Unimolecular Kinetics

of Pyridine Ion Fragmentation, Int. J. Mass Spectrom. Ion Phys. 38,

323 (1981).

Rosenstock, H. M. , Chickos, J. S. , Greenberg, A., Ladon, L. H., Lee, C.

M. , Rybczynski, P. J., Van Vechten, C. C. and Liebman, J. F. , Macroincrementation: Simple Methods for Estimating Molecular Properties,

Proc. High-Energy Hydrocarbon Fuels Workshop , November 1981, Naval Air

Systems Command Research and Technology Group, pp. 162-191 (1981).

Rosenstock, H. M. , Buff, R. , Ferreira, M. , Lias, S., Parr, A. C.

,

Stockbauer, R. and Holmes, J. , Fragmentation Mechanism and Energetics

of Some Alkyl Halide Ions, J. Am. Phys. Soc. 104, 2337 (1982).

Rosenstock, H. M. , Dannacher, J. , and Liebman, J. F. , The Role of Excited Electronic States in Ion Fragmentation: C 6 H 6 +

, Radiat. Phys. Chem.

(in press).

Rosenstock, H. M. , Dannacher, J., Buff, R. , Parr, A. C., Stockbauer, R.

,

Bombach, R. and Stadelmann, J.-P., Benchmark Measurement of Iodobenzene

Ion Fragmentation Rates, Chem. Phys. (in press).

Saloman, E. B. and Cooper, J. W. , The Stark Effect on the Oscillator

Strength Distribution of Helium Near the Ionization Limit, Phys. Rev.

(in press).

Saloman, E. B. , Ebner, S. C. and Hughey, L. R. , VUV and XUV Radiometry

Using Synchrotron Radiation at the National Bureau of Standards, Optical

Engineering (in press).

Seltzer, S. M. and Berger, M. J. , Status of Electron Transport Cross

Sections, Trans. Amer. Nucl . Soc. 41_, 477 (1982).

Seltzer, S. M. and Berger, M. J., Status of Electron Transport Cross

Sections, NBSIR 82-2572 (1982).

116
Division 533, Publications (cont'd.)

Seltzer, S. Mo and Berger, M. J. , Evaluation of the Collision Stopping

Power of Elements and Compounds for Electrons and Positrons, Int. J.

Appl . Radiat. & Isotopes (in press).

Seltzer, S. M. and Berger, M. J. , Procedure for Calculating the Radiation Stopping Power for Electrons, Int. J. Appl. Radiat. & Isotopes (in

press)

.

Simic, M. G. , Vitamin-E Radicals, In Oxygen Radicals, Eds. M. A. J.

Rodgers, E. L. Powers, Academic Press, p. 109 (1981).

Simic, M. G. , Free Radical Mechanisms in Autoxidation Processes, J.

Chem. Ed. 58, 125 (1981).

Simic, M. G. , Chapter 9. Radiation Chemistry of Water-Soluble Food Components, in Preservation of Food by Ionizing Radiations , Eds. E. S.

Josephson and M. S. Peterson, CRC Press (in' press).

Simic, M. G. and DeGraff, E. , Radiation Chemistry Principles for Commercial

Food Applications, Food Development 1_5, 54 (1981 ).

Simic, M. G. and DeGraff, E. , Oxygen - A Problem or a Detriment in Food

Irradiation, Proc. of 4th Int. Mtg. on Rad. Processing, Dubrovnik,

Yugoslavia (October 1982).

Simic, M. G. and Hunter, E. P. L. , Interaction of Free Radicals and Antioxidants, Proc. of 1st Conf. on Radioprotectors & Anticarcinogens, June

1982 (in press).

Soares, C. G. and Ehrlich, M. , NBS Traceability Programs for Radiation

Therapy, in NBS Spec. Publ. 609, U.S. GPO (1982).

Spencer, L. V., Types of Nuclear Disaster and their Radiation Environment, Proc. NBRP Symp. The Control of Exposure to the Public to Ionizing

Radiation in the Event of Accident or Attack, Reston, VA (April 1982).

Sternheimer, R. , Seltzer, S. M. and Berger, M. J. , Density Effect for

the Ionization Loss of Charged Particles, Phys. Rev. (in press).

Stockbauer, R. and Madden, R. P., Design of a High Throughput Grazing

Incidence Monochromator for SURF- 1 1 , Nucl. Inst. Meth. 195 , 207 (1982).

Stockbauer, R. , Hanson, D. M. and Madey, T. E., Photon Stimulated

Desorption and Other Spectroscopic Studies of the Interaction of Oxygen

with a Titanium (001) Surface, Phys. Rev. B 24, 5513 (1982).

Uribe, R. M. , Pina, M. C. and McLaughlin, W. L. , ESR Studies of Polymer

Films Containing Leucodyes Irradiated with 60 Co Gamma Rays, Proceedings

of 3rd Symposium on Nuclear Chemistry Radiochemistry, and Radiation

Chemistry, Mexico, D.F. , December 1980 (in press).

117
Division 533, Publications (cont'd.)

Uribe, R. M. , McLaughlin, W. L. , Miller, A., Dunn, T. S. and Williams,

E. E. , Possible Use of Electron Spin Resonance of Polymer Films Containing

Leucodyes for Dosimetry, 3rd Int. Meeting on Radiation Processing,

Tokyo, Radiat. Phys. Chem. ]_8, 1011-1016 (1981).

Waclawski, B. J. , Pierce, D. T. , Swanson, N. and Celotta, R. J., Direct

Verification of Hydrogen Termination of the Semiconducting Diamond (111)

Surface, J. Vac. Sci. Technol. 21_ (2), 368 (1982).

Waclawski, B. J. , Pate, B. B. , Stefan, P. M. , Bins, C. , Ohta, T. , Hecht,

M. H. , Jupiter, P. J. , Shek, M. L. , Pierce, D. T. , Swanson, N. , Celotta,

R. J. , Lindau, I. and Spicer, W. E. , The Diamond (111) Surface: A

Dilemma Resolved, Proc. of 16th Inti. Conf. on the Physics of Semiconductors (in press).

Wang, G.-C., Unguris, J. , Pierce, D. T. and Celotta, R. J., PLEED Study

of Temperature and Hydrogen Induced Reconstruction and Reordering of

W(100), Surf. Sci. Lett., L35 (1982).

Wang, G.-C., Celotta, R. J. and Pierce, D. T. , A Constant Momentum

Transfer Average Study of PLEED Data from W(100), Surf. Sci. 119 (1982).

Werner, B. L., Kahn, F. M., Deibel, F. C. and Seltzer, S. M. , Model for

Predicting Depth Dose Distributions for Broad Electron Beams, Med. Phys.

(in press).

Yin, Lo I, Trombka, J. I., Ruitberg, A. P. and Seltzer, S. M. , A Small

Battery-Operated Fluoroscopic System: LIXISCOPE with X-Ray Generator,

Nucl. Instr. Meth. (in press).

118
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 533, Radiation Physics

Martin J. Berger

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 of Dosimetry.

Member, National Council on Radiation Protection and Measurements

(NCRP), Committee #55 on Experimental Verification of Internal

Dosimetry.

Robert J. Celotta

Chairman, NBS Research Advisory Committee

Editorial Board, Review of Scientific Instruments

Member, American Physical Society, Division of Electron and Atomic

Physics Program Committee, 1982-1983.

Charles E. Dick

Member of the Technical Program Committee, Seventh Conference on the Application of Accelerators in Research and Industry.

David L. Ederer

Member, NSLS User Committee.

Member, Optics News Editorial Committee.

Margarete Ehrlich

Chairman, Health Physics Society Standards Committee, Work Group on Criteria for Testing Personnel Dosimetry Performance.

Member, ISO/TC 85/SC2, WG2 , Photographic Dosimeters and Reference

Radiation.

Member, Health Physics Society Standards Committee, Work Group on Criteria for Testing Environmental Dosimetry Performance.

Member, American Nuclear Society Work Group on revision of ANSI/ANS

6.1.1, Neutron and Gamma-Ray Flux-to-Dose Rate Factors.

119
Division 533* Technical and Professional Committee Participation and

Leadership (cont'd.)

John H. Hubbell

Secretary, Commission on Crystallographic Apparatus, International

Union of Crystal lography , Task Group on X-ray Absorption Coefficients.

Chairman, Health Physics Society, Intersociety Liaison Committee

(Assigned to Society of Nuclear Medicine).

Chairman, American Nuclear Society (ANS) Radiation Protection and

Shielding Division ANS-6 Ad Hoc Committee on SI Units.

Member, Cross Section Evaluation Working Group (CSEWG) Subcommittee

on Shielding.

Member, American Nuclear Society (ANS) Isotopes and Radiation Division

Committee on Radiography and Gauging.

Jimmy C. Humphreys

Member, ASTM F-l.ll Subcommittee on Quality and Harness Assurance

of the F-l Electronics Committee.

Vice Chairman, ASTM Committee E.10 Nuclear Technology and Application

E10.07 Subcommittee on Radiation Effects on Electronic Materials

and Devices.

Robert Loevinger

Member, BIPM Consultative Committee for Standards for Measurement

of Ionizing Radiation, Section I, X and Gamma Rays and Electrons.

Member, OIML, SP.16-SR.1, Performance of Dosimeters.

Member, OIML, SP.16-SR.2, Secondary Standard Dosimetry Laboratories.

Member, IAEA-WHO Network of Secondary Standard Dosimetry Laboratories, Advisory Council.

Member, IEC/TC 62/SC C/WG 3, Performance of Dosimeters.

Member, ANSI/N44 Equipment and Materials for Medical Radiation

Appl i cations.

Member, ANSI/N44/SC2 Therapeutic Radiology.

Member, Society of Nuclear Medicine, Medical Internal Radiation

Dose Committee.

120
Division 533, Technical and Professional Committee Participation and

Leadership (cont'd.)

Robert Loevinger (cont'd.)

Consultant, AAPM Radiation Therapy Committee.

Member, AAPM Radiation Therapy Committee Task Group 3, Regional

Calibration Laboratories.

Member, AAPM Radiation Therapy Committee Task Group 21, High-Energy

Photon and Electron Dosimetry.

Member, AAPM Radiation Therapy Committee Task Group 22, Brachy therapy

.

Consultant, AAPM Radiation Therapy Committee Task Group 24, Physical

Aspects of Quality Assurance in Radiation Therapy.

Chairman, AAPM Science Council Committee on the Effect of Si Units.

Thomas P. Loftus

Member, ANSI/N13, Radiation Protection.

Member, ANSI/N42, Working Group on Inspection and Test Specifications for Direct and Indirect Reading Quartz Fiber Pocket Dosimeters.

Robert P. Madden

Member, Advisory Committee for the Stoughton Storage Ring (Tantalus)

of the University of Wisconsin.

Member, Advisory Editorial Board of Optics Communication .

Member, International Committee for the International Conference on VUV Radiation Physics.

President, Optical Society of America.

Member, American Institute of Physics (AIP) Board of Directors.

Member, Optical Society of America Committee on Finance and

Investment.

Member, Council of Scientific Society Presidents, (CSSP).

Member, Middle Atmospheric Program (MAP) International Working

Group on Solar Spectral Irradiance Measurements.

Member, Council of U.S. Synchrotron Radiation Laboratory Directors.

121
Division 533, Technical and Professional Committee Participation and

Leadership (cont'd.)

Robert P. Madden (cont'd.)

Visiting Lecturer, Local Sections of the Optical Society of

America.

Member, Program-Advisory Committee of the International Conference

on X-Ray and VtlV Synchrotron Radiation Instrumentation, Hamburg,

West Germany, August 1982.

Member, American Institute of Physics (AIP) Nominating Committee, 1982.

Thomas J. Mcllrath

Member, Technical Council, Chairman Atomic Spectroscopy Technical

Group, Optical Society of America.

Co-Chairman, OSA Conference on Spectroscopy in Support of Atmospheric Measurements.

Member, Program Committee, Optical Society of America, Annual

Meeting.

Member, Program Committee, Division of Electron and Atomic Physics,

American Physical Society.

Chairman, Conference on Use of Lasers for High Resolution Spectroscopy

inthe Vacuum Ultraviolet.

Co-chairman, Workshop on Techniques for Production and Utilization

of Polarized Radiation in the Vacuum Ultraviolet, London, England,

August 1982.

Participant and Panel Chairman, Workshop on Current Trends in

Atomic Spectroscopy, Tucson, AR, October 1982.

General Chairman, Optical Society of America, 1983 Annual Meeting.

Wi 1 1 i am L. McLaughl in

Chairman, American Nuclear Society (ANS) 9, Nuclear Terminology and

Units, Subcommittee 9.1, Health Physics and Dosimetry.

Member, ANS 6, Radiation Protection and Shielding Subcommittee 6.5,

Units and Terminology.

122
Division 533, Technical and Professional Committee Participation and

Leadership (cont'd.)

William L. McLaughlin (cont'd.)

Member, ASTM El 0.07, Radiation Effects on Electronic Materials and

Devices.

Member, Association for the Advancement of Medical Instrumentation

Subcommittee on Radiation Sterilization of Medical Devices, Task on Radiation Dosimetry.

Member, ANS 9.2 Subcommittee on Shielding of the Nuclear Terminology

and Units Committee.

Technical Advisor, ISO WG-1 , Nuclear Energy Terminology Task on the

ISO TC/85 Committee on Nuclear Energy.

Technical Advisor, Council of Europe Pari iamentary Assembly Work Group

on Aerospace Physiology and Medicine.

Technical Advisor, Council of Europe Pari iamentary Assembly Work

Group on Space Biophysics.

Member, ANSI N12, General Administration and Standards for Nuclear

Energy.

Daniel T. Pierce

Local Committee for 1982 National Meeting of the American Vacuum Society.

Robert C. Placious

Chairman, ASTM E7.01.08, Subcommittee on Industrial Radiographic Film

Cl assi fi cation.

Member, ASTM E10.07, Nuclear Technology and Application Subcommittee

on Radiation Effects on Electronic Materials and Devices and Pulsed

Radiation Effects.

Member, ANSI PH 2.31, Committee on Photographic Sensitometry Subcommittee on X-Ray Film Standards.

Member, ASTM F12.60, Controlled Access Security Search and Screening

Systems.

Member, ASTM E7.01, Nondestructive Testing Committee on Radiographic

Practice and Penetrameters.

123
Division 533 s Technical and Professional Committee Participation and

Leadership (cont'd.)

Daniel Polansky

Member, ASTM E07.01, Nondestructive Testing Committee on Radiographic

Practice and Penetrameters.

Member, ASTM E07.02, NDT Committee on Radiographic Standards.

Member, ASTM E07.05, NDT Committee on Neutron Radiography.

Member, ASTM E07.91, ISO/TCI 35.

Member, ANSI PH2 : 31 , Medical X-Ray Film Sensitometry.

Henry M. Rosenstock

Member, ASTM Committee E-14 on Mass Spectrometry.

Member, American Society for Mass Spectrometry (ASMS).

Member, Editorial Review Board of the International Journal of

Mass Spectrometry and Ion Physics.

Member, American Association for the Advancement of Science.

Edward B. Sal Oman

Chairman, 5th Workshop on the Use of XUV and X-Ray Radiometry for

Plasma Diagnostics 5 eV to 10 KeV.

Michael G. Simic

Member of the Military R&D Associates.

Member of the CAST (Council on Agricultural Science and

Technology) Task Force.

Lewis V. Spencer

Consociate Member, National Council on Radiation Protection and

Measurements (NCRP).

Chairman, National Council on Radiation Protection and Measurements

(NCRP) Committee #63 on Emergency Radiation Exposure Control.

Member, National Council on Radiation Protection and Measurements

(NCRP) Committee #52 on Conceptual Basis of Dosimetry.

124
Division 533, Technical and Professional Committee Participation and

Leadership (cont 1 d.

)

Lewis V. Spencer (cont'd.)

Member, National Council on Radiation Protection and Measurements

(NCRP) Committee #40, Task Group on A-Bomb Survivor Dosimetry

Biological Aspects of Radiation Protection Criteria.

Member, Panel on the Re-assessment of A-Bomb Dosimetry, Advisory

Committee on the Radiation Effects Research Foundation, National

Academy of Science-National Research Council (NAS-NRC).

Member, American Nuclear Society (ANS) Shielding Glossary Committee.

Member, Interagency Committee on Federal Guidance for Occupational

Exposure to Ionizing Radiation.

125
MAJOR CONSULTING AND ADVISORY SERVICES

Division 533, Radiation Physics

1. M. J. Berger is a consultant to the ICRU committee on High Energy

Electron Dosimetry.

2. M. J. Berger is a consultant to the AAPM Task Group on Photon and

Electron Dosimetry.

3. R. 0. Celotta and D. T. Pierce advised on construction and provided

drawings of an electron polarization source which ANAC, Inc. will

market as a commercial product.

4. S. R. Domen consulted on construction and operation of absorbed

dose graphite calorimeters and water calorimeters, at the Hungarian

standards laboratory in Budapest, the Austrian standards laboratory

near Vienna, the British standards laboratory in Teddington, and

the University of Ghent, Belgium.

5. S. R. Domen consulted at NBS on construction and operation of

absorbed dose water calorimeters with representatives of the

Massachusetts General Hospital; the Groote Schuur Hospital,

Capetown, South Africa; the Tom Baker Cancer Center, Calgary,

Canada; the Sahlgrenska Hospital, Gothenburg, Sweden; and the

National Institute of Radiation Protection, Stockholm, Sweden.

6. S. R. Domen advised J. A. Mason from the University of London

Reactor Centre on needed improvements on a calorimeter for absorbed

dose measurement on neutrons in a reactor.

7. S. R. Domen advised J. C. McDonald and I-chang Ma on layout and

construction of a spiral heater for a calorimeter for measurement

of absorbed dose from hi gh- LET radiations at Memorial Hospital in

New York City.

8. J. H. Hubbell responded to inquiries to the X-Ray and Ionizing Data

Center on matters pertaining to photon cross sections from over 300

scientists in the U.S. and abroad.

9. J. H. Hubbell is a consultant to the ICRU Task Group II-B-1 Radiation

Dosimetry; X-rays from 5-150 keV. (Task Group Chairman: Dr. John

Greening, Department of Medical Physics, University of Edinburgh,

Edinburgh EH3 9YW, Scotland).

10.

R. Loevinger and E. H. Eisenhower consulted with officials of the

Nuclear Regulatory Commission concerning calibration aspects of

proposed revisions of medical licensing regulations.

126
Division 533 5 Major Consulting and Advisory Services (cont'd.)

11. T. P. Loftus and R. loevinger consulted with representatives of the

3M Company, and with medical physicists from George Washington

Medical School and the Memorial Hospital, New York City, concerning

development and calibration of iodine- 125 brachytherapy sources for

cancer therapy.

12. T. P. Loftus advised members of the Naval Electronics Command on establishment of a protection-level thermoluminescence dosimetry system for

use on ships.

13. T. P. Loftus consulted on the final evaluation of a series of dosimetry

measurement quality assurance tests, with representatives of the Lexington and Sacramento Signal Depots (Army), Charleston Naval Shipyard,

Aberdeen Environmental Health Facility (Army), and the Armed Forces

Missile Command.

14. W. L. McLaughlin gave advice to James Myron of Applied Radiation Energy

Corp. on the effects of radiation on acrylic plastics and their

prospects for dosimetry, as well as radiation damage.

15. W. L. McLaughlin gave advice to William Slauson of Texas Instruments

on high-dose radiation dosimetry for quality control in treating

electronic devices (also damage effects in solar cells, mosfits,

diodes, etc.).

16. W. L. McLaughlin consulted with William Fitzgerald of Baxter Travenol

,

Chicago, IL on quality control and medical product release based on traceable dosimetry.

17. W. L. McLaughlin had extended discussions with Doug Weiss and group

from 3M Co. on their plans to use electron beams to process thin

laminated films for a number of products. They require high-resolution

dose mapping for quality control of the new radiation-cured products.

18. W. L. McLaughlin discussed dosimetry with A. Scheve of Hercules Plastics,

who plan use of gamma radiation and/or electron beams to cross-linking

polymers, e.g. polyethylene, polyethylene-vinyl acetate, to improve

their molding properties.

19. W. L. McLaughlin received a visit from Dr. Randy Culp and Dr. Ival

Toepke of Bicron Corp. , Cleveland, OH, who need assistance in

radiation dosimeter design based on radiochromic dyes in liquid and

solid phase (neutron dosimetry).

20. W. L. McLaughlin served as Chairman of IAEA Advisory Group Meeting

on Dosimetry for Radiation Processing (IAEA, Vienna).

127
Division 533, Major Consulting and Advisory Services (cont'd.)

21. W. L. McLaughlin provided detailed advice to Bob Becker of Radiation

Dynamics, Inc., Melville, NY, on electron beam mapping and highresolution dosimetry as a means of quality control - depth data at

1 .5 and 2 MeV.

22. W. L. McLaughlin assisted Dr. D. Ross and Vicki Spots of Research

Reactor, Univ. of Missouri, with standardization of their high-dose

dosimeters.

23. W. L. McLaughlin collaborated with Dr. S. Kronenberg of ERADCOM

(Electronics Command), Ft. Monmouth, NJ, in development of tissueequivalent fibre optics dosimeters for neutron measurements at

low-dose equivalents.

24. W. L. McLaughlin provided lectures and assistance in setting up dye

dosimetry project at Institute of Physics, University of Mexico.

25. W. L. McLaughlin consulted with Prof. A. Charlesby of UK Royal

Military College of Science on radiation effects in polyethylene

and means of analysis (ESR, NMR, infrared).

26. W. L. McLaughlin had discussions with Jim McKenzie of Sandia Labs on the possibility of designing thermochromic dye systems similar to

radiochromic systems.

27. W. L. McLaughlin advised Joseph Rothleder, State Metrologist of

Department of Food and Agriculture, California, on possibilities of

use of dosimetry as a safe and effective means of quality control

in food preservation by ionizing radiation (especially citrus fruits).

28. W. L. McLaughlin received visitors from Kal-Kan pet and stock food

industrial, to discuss prospects for disinfecting and extending

shelf life of animal foods.

29. W. L. McLaughlin provided advice and consulting to Donald Spaulding

of USDA- Florida (tropical fruits) on radiation dosimetry as a means

of quality control and release of wholesome and disinfested fruits

to the market.

30. W. L. McLaughlin had an extended discussion with Dr. S. V. Nablo, VP

of Energy Sciences, Inc., Woburn, MA, on ways to improve low-energy

electron beam dosimetry for radiation curing industries (paints, inks,

coil coatings, battery separators, thermal shields, building and

insulating materials, etc.).

31. W. L. McLaughlin provided assistance to Jack O'Leary of IBM, San

Jose, CA, on ways to thin films for standardizing radiation dose

delivery to a variety of heterogeneous materials.

128
Division 533, Major Consulting and Advisory Services (cont'd.)

32. W. L. McLaughlin assisted Paula Wells (coop student in NBS Building

Research) on ways to determine high resolution dose deposition profiles in honeycomb building materials.

33. W. L. McLaughlin received a one-week visit from Dr. K. Glover of

AERE/Harwell , UK, to help them standardize their high-dose dosimetry

system using 60 Co gamma radiation pool source at NBS.

34. W. L. McLaughlin assisted David Sieverdiz of Valleylab, Boulder, CO,

with determinant of electron beam dose rates. He also provided

electron collision stopping power data for various compounds.

35. W. L. McLaughlin consulted with William Owens of Isomedix, Inc., NJ, on NBS standard dose traceability for medical device sterilization by

ionizing radiation, according to Assoc, for Advancement of Medical

Instrumentation (AAMI) protocols.

36. W. L. McLaughlin assisted C. Pollock of NBS, Boulder, with standardization of irradiation of pure and doped alkali halide single crystals,

and with analysis of color centers formed at very high doses.

37. W. L. McLaughlin assisted H. Turk of Tremco, Pittsburg, PA, with doselevel and dose-rate affects on irradiated duct-sealing materials used

in reactor environments.

38. W. L. McLaughlin provided consultation with R. Novak and R. Morrisy

of Johnson and Johnson on the role of standards in maintaining

required radiation sterilization levels.

39. W. L. McLaughlin gave advice to Tom Simpson of 3M Company on photochromic systems for ultraviolet actinormity in UV curing of thin

layers

.

40. W. L. McLaughlin advised Dr. S. Tveekran, Firestone Tire and Rubber

Company, on electron beam curing of elastomers and radiation dose

distribution measurements in laminated multilayers.

41. W. L. McLaughlin provided consultation with Diane Lopez of Stanford

Research Inst. International, to describe dosimetry protocols and

regulations for food irradiation, especially at doses less than

100 krad (10 3 Gy).

42. W. L. McLaughlin provided assistance to Atomic Energy of Canada, Ltd.,

in intercomparison and standardization of their chemical dosimetry

systems, so that they can take over regional calibration of high dose

dosimeters and relieve overloaded NBS calibration services to U.S. and

Canadian industries.

129
Division 533, Major Consulting and Advisory Services (cont'd.)

43. W. L. McLaughlin assisted Drs. Backenstow and Steven Resan of

Carlisle Tire and Rubber Co., Carlisle, PA, with setting up traceable dosimetry for quality control of radiation processing of

elastomers

.

44. W. L. McLaughlin provided consultation with Dr. Donald Boure of Army

Chemical Corp. (Aberdeen) on development of high-dose neutron dosimeters and standard fission spectrum radiation fields at high-dose

rates

.

45. W. L. McLaughlin consulted with Dr. Santanu Basu of RayChem Corp.,

giving him information on high-resolution imaging in dyed thin

plastic films - a commercial development they would use in radiation

treatment of plastic and electronic components.

46. W. L. McLaughlin consulted with Lt. Paul Blake of Armed Forces Radiological Research Institute on methods of electron beam calibration in

Uni vac radiation fields.

47. W. L. McLaughlin assisted Steven Thomas of Radiation Technology, Inc.,

in design of special dosimeters for food irradiation quality control.

48. W. L. McLaughlin assisted Dr. M. Nakata of Energy System Group,

Rockwell International, in setting up radiochromic dosimetry system

for a more accurate radiation measurement capability in photon and

electron beams.

49. W. L. McLaughlin provided assistance to Becton Dickinson Company in

setting up standardized dosimetry for their new electron accelerator

facility at Canaan, CT.

50. W. L. McLaughlin gave a talk and tour, with demonstrations of

industrial radiation dosimetry for quality control, to NBS visitors

from Plastic Products Manufacturing Association, Research Triangle

Park, NC.

51. W. L. McLaughlin assisted Dr. J. Kennerly of Brookhaven National

Laboratory's High-Intensity Research Laboratory in setting up a traceable dosimetry program based on NBS calibration and radiochromic

systems

.

52. W. L. McLaughlin provided Tom Ohlhaber of Bureau of Radiological

Health with dosimetry for an Indiana radiation accident involving

an x-ray crystallographic facility.

53. W. L. McLaughlin provided consultation with F. Deacon-Smith of Plessy

Company (UK) on emerging dosimetry instrumentation and design of

albedo dosimeters.

130
Division 533, Major Consulting and Advisory Services (cont'd.)

54. W. L. McLaughlin provided consultation for NCRP Committee in writing

of proposed new handbook for Federal Emergency Management Agency:

"Radiation Safety in Shelters".

55. W. L. McLaughlin provided a design for Laboratory for Radiation and

Polymer Science University of Maryland quartz "suprasil" vacuum

cells for real-time spectrophotometric and electron spin resonance

analysis of thin films during irradiation.

56. W. L. McLaughlin consulted with Martin Bressler of IRT Corp. , San

Diego, CA, on radiochromic dosimetry and high-dose dosimetry standard

zation of 10-12 MeV electron beams for various industrial purposes.

57. W. L. McLaughlin provided consultation with Dr. J. McHenry of Houston

University of Petroleum and Materials on use of radiation to treat

petroleum and minerals as a means of radiation processing.

58. W. L. McLaughlin assisted Tom Fisher of Becton Dickinson Company,

Sumpter, SC, Laboratory, in setting up a technician's course in

radiation dosimetry for sterility control.

59. W. L. McLaughlin provided assistance to Charles Lawyer of Howmedica,

Inc., Rutherford, NJ, in setting up traceable dosimetry and standardi

zation for sterilization of prosthetic devices.

60. W. L. McLaughlin sponsored a high school student (Tom Preisinger)

project involving high-dose dosimeter development.

61. W. L. McLaughlin was a host to Dr. J. G. Haides of the International

Atomic Energy Agency, Vienna.

62. W. L. McLaughlin assisted J. A. Poublon of Poublon Associates, Inc.,

Yorba Linda, CA, in designing an indicator dye "go-no go" radiation

monitoring system for radiation sterilization applications.

63. W. L. McLaughlin provided consultation to Dr. J. Blank of Radiation

Technology, Inc., Rockaway, NJ, in selection of special dosimetry

systems for proprietary new radiation industrial applications.

64. W. L. McLaughlin provided trouble-shooting for Dr. John Chasman of

3M Co., for the response in nitrogen of standard radiochromic film

dosimeters to low-energy electron beams used for curing thin-film

products.

131
Division 533, Major Consulting and Advisory Services (cont'd.)

65. J. W. Motz is collaborating with the research staff at Eastman Kodak

Company on the development of medical x-ray film which will have the

capability of storing more image information content than that con- tained in the present day medical x-ray films.

66. J. W. Motz consulted with University of Arizona Medical Center on comparisons of analog and digital image processing systems, and

comparisons of digital and screen-film imaging systems.

67. R. C. Placious and D. Polansky, in support of other NBS programs,

provided radiographic service and consultation to the NBS investigation

of the Kansas City Hotel and the East Chicago Bridge disasters. There

also exists a continuing service to the Department of Defense in maintaining and improving the radiological programs for the inspection of

large diameter rocket motors by defense contractors.

68. S. M. Seltzer is a consultant to the ICRU Committee on Stopping Power.

69. S. M. Seltzer consulted and advised on radiation transport and spaceshielding problems with members of the Radiation Effects Branch, Naval

Research Laboratory; and with members of Goddard Space Flight Center,

NASA.

70. S. M. Seltzer consulted with staff members of the Department of

Therapeutic Radiology of the University of Minnesota Hospitals regarding the spatial patterns of energy deposited by electron beams.

71. M. G. Simic is a consultant of the Norris Cotton Cancer Center,

Dartmouth Medical School, Hanover, NH.

72. L. V. Spencer and C. M. Eisenhauer prepared a report for the Federal

Emergency Management Agency (FEMA) which provides guidelines for

research on the protection provided by various types of structures

against initial radiations from nuclear weapons.

132
JOURNAL EDITORSHIPS

Division 533, Radiation Physics

M. J. Berger, Editorial Board, Journal of Radiation Research, Japan

Radiation Research Society.

R. J. Celotta, Co-editor, Methods of Experimental Physics, Academic

Press

.

R. J. Celotta, Member-Editorial Board, Review of Scientific Instruments,

American Physical Society, 1982-1984.

W. L. McLaughlin, Editor, International Journal of Applied Radiation and

Isotopes

.

W. L. McLaughlin, Editor, Radiation Physics and Chemistry.

J. W. Motz, Editor, Computerized Radiology.

H. M. Rosenstock, Member-Editorial Board, International Journal of Mass

Spectroscopy and Ion Physics.

133
CALIBRATION SERVICES PERFORMED

Division 533 s Radiation Physics Division

Number of

Type of Service Customer SP 250 Cal ib'ns Income

Item No. or Tests

Calibration of x-ray 1-7 8. 3B,C, 417 ) and y-ray measuring D,H,I ) instruments )

) $1 18K

Irradiation of TL

dosimeters

2-6 8. 3M,N 32 )

)

) Calibration of ) penetrameters

1 8. 3K 1

Calibration of y-ray 2-4 8. 4E,F 8 ) sources )

) $ 5K

Calibration of

8-particle sources

2,4-6 8. 4K 7 )

Chemical dosimetry measurement assurance ser- vice for electron beams

2 8. 5B ,C 55 $ 16K

High-dose irradiation 3-7 8.6B 314 )

)

)

)

)

Dose interpretation 4-7 8.6C 26 $ 26K

Spectrophot. reading of

dosimeters

4-6 8.6D 492

Irradiat. of TLD dosims, Navy N.A. 180 $ 60K

& prep, of units for s hi

board measurement

PInstrument calibration Nucl . Reg. N.A. 30 $ 25K

& evaluation Commi ssion

Far UV radiometric 1 ,3-8 N.A. 29 $ 34K

transfer standard detectors

(photodiode calibrations)

Totals 1590 $280K

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.

Column 4: 8.3, 8.4, 8.6, number of calibrations or tests; 8.5, individual

hospitals; N.A., estimates comparable to 8.3, 8.4, 8.6.

Columns 4&5: 8. 3-8. 6, from Sept. 1 computer print-out, extrapolated to end

of FY 82; N.A., comparable estimates.

134
TECHNICAL ACTIVITIES

Division 534, Radiometric Physics

Task No. 11241 (new task no. 15241) - Advanced Optical Radiation Measurements

Task No. 11242 (new task no. 15242) - Maintenance and Dissemination of

Optical Radiation Measurements

INTRODUCTION

The Radiometric Physics Division is the primary focal point within

NBS for carrying out the traditional Bureau mission of promoting accurate,

meaningful, and compatible optical radiation measurements in the wave_

length region between 200 nm and 14 pm. The Division fulfills this

mission by

o conducting fundamental research aimed at new approaches

' to optical radiometry,

o conducting applied research to extend existing radiometric

standards and calibration procedures,

o maintaining and disseminating the U.S. radiometric scales,

o developing resources of expertise for the solution of

radiometric problems within NBS, government, industry, and the

publ ic sector.

The Division's efforts are closely coupled to the radiometric programs

of other CRR Divisions in the vacuum ultraviolet below 200 nm. The

Division also interacts strongly with other programs at NBS, such as the

Offices of Measurement Services and Standard Reference Materials, areas

of CAC pursuing standards activities in analytical absorption spectrometry

and spectrofl uorimetry , areas of CBT pursuing vision research and

illuminating engineering, and areas of CMS pursuing materials property

research. Our staff is engaged in numerous interactions with professional

societies and standards committees at the national and international

level. These interactions, as well as the feedback received from

calibration customers, are essential in ensuring the relevance of our

programs.

Since radiometry involves the characterization of electromagnetic

radiation generated by sources, propaged by optical systems components,

and received by detectors, the research activities of the Division are organizational ly subdivided in terms of these three categories of

radiometric measurements:

Spectroradiometry and Optical Pyrometry (J. Shumaker, Group Leader) -- Responsible for the development of source standards and improving

the accuracy of state-of-the-art radiometric and pyrometric

measurements

.

135
Division 534, Technical Activities (cont'd)

Spectrophotometry (J. J. Hsia, Group Leader) -- Provides highaccuracy spectrophotometric measurements and standards, and

develops new methods for the radiometric characterization of

optical media and components.

Electro-Optics and Quantum Radiometry (J. Geist, Group Leader) —

Develops new, detector-based radiometric standards and methods to

complement and extend our traditional source-based capabilities.

The fourth Group serves the vital function of providing measurement

services to the Radiometric community at large:

Photometric Radiometric Calibrations (D. A. McSparron, Group

Leader) -- Provides, improves, and extends radiometric and

photometric calibrations, implements measurement assurance

programs, and participates in radiometric intercomparisons.

The following reports of the four Group Leaders show that important

progress was made Division-wide during FY 1982. The Spectroradiometry

and Optical Pyrometry Group completed applied research that will allow

a more efficient realization of our spectral irradiance scale, and

also finished a comprehensive study of the effects of coherence in

high-accuracy radiometry. The Electro-Optics and Quantum-Radiometry

Group gained further insight into semiconductor physics as an independent

basis for absolute radiometry, and devised simplified detector configurations and calibration procedures that will facilitate the transfer of

photodiode technology to radiometrists in general. Both Groups

collaborated with the Far-UV Physics Group of the Radiation Physics

Division in the radiometric intercomparison between the NBS synchrotron

storage ring (SURF), self-calibrated silicon photodiodes, and blackbody

radiation standards. A further effort to implement detector-based

radiometry, aimed at allowing developing countries to realize their

own photometric base units in terms of the recent redefinition of the

candela, was initiated by the Calibrations Group in collaboration with

the Egyptian National Standards Institute. The Spectrophotometry

Group moved close to completing the development of measurement assurance

packages for retroreflection and diffuse reflection, and has already

started new programs in photoluminescence spectrometry and high transmission

density measurements for non-destructive evaluation. The volume of

Standard Reference Materials and special spectrophotometric calibrations

provided by this Group increased again during FY 1982. Likewise, the

Calibrations Group performed a large volume of pyrometric, photometric

and spectroradiometric routine calibrations and, in addition, started

a new calibration service in the long-wave infrared (LWIR) spectral

region from 2 pm to 25 pm. This new service was developed in close

collaboration with the Spectroradiometry and Optical Pyrometry Group,

and aims at the accurate characterization of cryogenic blackbodies in

a space-like environment.

136
Division 534 , Technical Activities (cont'd)

The continuing evolution of the Division's programs received the

full attention of upper NBS management during the fiscal year. Our

calibrations and related R&D efforts were reviewed by the Director and

won his approval. The Division submitted a major radiometric component

to an FY'84 Budget Initiative for increased congressional funding of

NBS base activities in measurement science. We also collaborated with

the Council on Optical Radiation Measurements (CORM) in formulating

the 1982 CORM Report on "Pressing Problems and Projected National

Needs in Optical Radiation Measurements." In this report CORM presented,

for the first time, a prioritization of needed efforts and urged

industry and NBS to work together in solving the problems identified,

thus establishing a cooperative "National Measurement System in Radiometry

and Spectrophotometry."

137
Division 534, Technical Activities (cont'd)

SPECTRORADIOMETRY AND OPTICAL PYROMETRY

The program of this group in the Division focuses on providing

the standards and techniques required for improving the accuracy of

routine as well as state-of-the-art measurements in spectroradiometry

and optical pyrometry. Our current efforts in this direction are of

two kinds: advances in instrumentation and techniques, and an indepth study of the theoretical and practical basis of optical radiometry. In the first area we are developing a new NBS pyrometer and

improved transfer standards with which we hope to reduce by a factor

of three the uncertainties of our temperature scales above 2000 K

and of our spectroradiometric scales between 250 nm and 1600 nm. These developments are now possible because of improved facilities

reported in previous years for spectral and flux responsivity measurements, advances in automation, and the experience of the Division

with stable silicon photodiodes. In the second area we are thoroughly

reviewing and systematizing the entire field of radiometry in a series of publications appearing under the general title of SelfStudy Manual on Optical Radiation Measurements. In addition to

these efforts a significant portion of our resources is devoted to

providing measurement services, special calibrations, and consultation for a number of other government agencies and their contractors.

Instrumentation and Techniques

One of the major accomplishments this year was the completion

of the basic research paving the way to a more efficient spectral

irradiance scale realization process. The technique relies upon our

ability to perform rapid, accurate determinations of radiometer

linearity with an automated beam conjoiner. With this capability it

is no longer necessary to perform the tedious flux matching which

has been a characteristic of this scale realization process in the

past. A forthcoming scale realization this fall will partially

incorporate the new approach to verify its validity.

Current techniques for realizing the International Practical

Temperature Scale (IPTS) at 2500 K are accompanied by uncertainties

of about 1 kelvin. We expect to improve this by a factor of three

(resulting in a 0.1 percent inaccuracy in terms of spectral radiance) by using a new NBS pyrometer now being developed. This

instrument uses automation and computer techniques to permit

frequent, rapid scale realizations for optimum accuracy. Between

scale realizations the scale will be carried on detectors instead of

on lamps as at present. Progress on the assembling of the system

has been slowed somewhat due to staff shortages and the press of

other tasks: continuing maintenance of gold-point blackbodies and

the existing pyrometry temperature scale, expansion of the long-wave

infrared program, and the continuing administrative overburden.

138
Division 534 9 Technical Activities (cont'd)

Nevertheless this instrument system should be undergoing preliminary

testing and evaluation within the next month or two.

Studies of the Basis of Accurate Radiometry

Complementing our experimental program to achieve improved

accuracies in radiometric measurements is our preparation of a SelfStudy Manual on Optical Radiation Measurements (SSM) in which we are

attempting to write a thorough treatise on the science of accurate

optical radiometry. Although intended primarily to be a means of

improving the competence and techniques of the radiometry community

within the national measurement system, a vital benefit to NBS of

such a complete study is the quantitative delineation of the physical,

mathematical, and instrumental approximations and compromises which

are inevitable in these measurements, and the resulting refined

estimates of accuracy and increased measurement confidence. This

project has been under way for half a dozen years now and many

fundamental subjects have been treated and published: the distribution of radiation with position, direction, wavelength, and polarization; beam-defining apertures; the slit-scattering function and

deconvolution; and the over-all measurement equation.

Chapters on coherence in radiometry and the measurement of

solar terrestrial spectral irradiance in the ozone cut-off region

have been completed this year. Chapters on blackbody radiation and

temperature scales, thermal radiation properties of materials,

spectrophotometry, linearity, and the time variable in radiometry

have been started this year. These latter two subjects are particularly appropriate now because of the importance of the measurement

of detector linearity in our efforts to improve the accuracy of our

temperature and spectroradiometric scales and because of the Division's

growing interest in pulse radiometry.

Other Agency Projects

Other government agencies continue to provide valuable support

in the form of specific tasks which, from our point of view, enable

us to acquire equipment or experience which is important to our

program.

In previous years the EPA has generously funded research

directed toward accurate ground level solar irradiance measurements

in the 285-340 nm spectral region. A draft of a description of this

work has been prepared for journal publication.

We are continuing to provide BRH with radiometric consultation

and instrument evaluation in order to insure a sound spectroradiometric measurement base for their regulatory responsibilities. One

139
Division 534, Technical Activities (cont'd)

such activity was the calibration of an infrared thermovision camera

as a quantitative thermometer.

Our facility for calibrating 200 K-400 K blackbodies in a space-like environment (20 K and high vacuum) was used early this

year for performing a special calibration for a DoD contractor.

This facility uses an electrically calibrated black detector operating below the lambda point of helium with germanium resistance

thermometers for temperature sensing. We have also undertaken two

calibrations of 200 K-400 K blackbody sources in a dry nitrogen

purged chamber for a DoD contractor. In this chamber a narrow pass

band infrared radiometer directly compares the test source with a high-quality variable temperature blackbody whose temperature is

measured by platinum resistance thermometry. A feature of this

facility added this year is a vacuum chamber to permit operating

test sources in a vacuum with a 77 K background.

140
Division 534, Technical Activities (cont'd)

SPECTROPHOTOMETRY

This group:

(1) establishes and improves high-accuracy spectrophotometric and densitometric scales in the National

Measurement System by developing new instrumentation,

establishing new measurement capabilities, and improving

basic standards;

(2) disseminates these scales by developing measurement

assurance programs (MAP), developing transfer standards

and standard materials, performing calibration services,

and providing consultation to the measurement community;

and

(3) studies and develops new methods for radiometric

characterization of optical media and components for

scientific research and for emerging technologies.

Major achievements were made during FY 82 in the areas of

diffuse reflection, retroreflection, transmission, densitometry, and

1 umi nescence.

Diffuse Reflection

The diffuse-reflectance standards for the Measurement Assurance

Program (MAP) have been recalibrated. The diffuse-reflectance MAP

transport package consists of one set of neutral -density filters, one

set of 45°/0° and one set of 6°/hemi spherical diffuse reflectors.

Two completed diffuse-reflectance transport packages were sent to two

instrument manufacturers to serve as a pilot MAP.

The Group Leader has been appointed International Chairman of

the CIE Subcommittee on Standards and Technique in the Committee on Characterization of Materials. He has served as discussion leader of

Session 5 on wavelength selection during the 1982 USDA Conference on Diffuse Reflectance Spectroscopy.

Retrorefl ection

Studies on the MAP transport package reached the final stage. A

fractional factorial design experiment requiring 486 measurements was performed on the two-orientation hexagon cube corner reflector. This

study permits estimation of errors due to geometrical setting errors.

Measurements were performed on the complete package periodically to

establish an internal NBS MAP by means of control charts. One MAP

transport package was sent to an instrument manufacturer, and one

141
Division 534, Technical Activities (cont'd)

package was sent to a manufacturer of retroreflectors to serve as a pilot MAP. The package was received favorably by the two laboratories.

The instrument has been put under control of a dedicated microcomputer with increased measurement efficiency.

A light source and a detection system have been prepared for

the purpose of making spectral measurements of chromaticity of

retroreflectors under night-time geometry. However, due to other

projects with higher priority this project is to be postponed.

Group personnel consulted with ASTM Committee E-12 on the

statistical data analysis of an intercomparison, and on the preparation

of a precision statement for an ASTM test method for measuring

retroref! ectors.

Transmission

Several sets of neutral density filters have been re-calibrated.

These filters are for linearity checking in the diffuse reflectance

MAP package.

The CCG Project 81-153, with the assistance of a guest worker,

is near completion. The purpose of this project was to extend the

range of our high-accuracy reference spectrophotometer from 800 to

2500 nm. This required changing the source, grating, and detector.

Construction of an averaging sphere with a bell assembly to contain

a new thermoelectrical ly cooled PbS cell was completed. Also, we required a chopped system utilizing a lock-in amplifier. A microcomputer

system with an NBS developed interfaced system was connected to the

spectrophotometer for data acquisition and data analysis. Software

was developed to acquire data for different characterization needs,

and data were analyzed. Characterizations included instrument

sensitivity functions, uniformity of the receiver system, beam

stability of the system, wavelength calibration, stray light, and

linearity (using the double aperture system). The latter was accomplished

by using two lenses of equal focal length to image the tungsten

source on the chopper blade and then re-col limate the beam.

Staff members consulted with Rensselaer Polytechnical Institute

on spectral transmittance of liquid filters for realizing one of the

standard CIE Illuminants. Staff members also participated in the

determination of transmittance of some fused quartz windows to be

used for the radiometric intercomparison with SURF.

Den si tome try

Development of high optical density (up to approximately 5.8)

standards is under way. Automation of the inverse fourth apparatus

142
Division 534, Technical Activities (cont'd)

is nearing completion. This experiment will be controlled by means of a microcomputer. The sample will be moved step-by-step and inserted into

the beam automatically as well as automation of the photometric measurement. Characterization of the color temperature of the light incident

on the sample has been completed. It was found that the source complies

with ANSI specifications.

Luminescence

The NBS reference photoluminescence spectrometer has been moved

from the Chemistry Building to a laboratory of the Radiometric Physics

Division in the Metrology Building. The process of putting it into

working status is underway. It is anticipated that a new program on fluorescence will be initiated in FY83.

143
Division 534, Technical Activities (cont'd)

ELECTRO-OPTICAL AND QUANTUM RADIOMETRY

The Electro-Optics Group is responsible for (1) providing the

basis for photophysical process characterization in the National

Measurement System, (2) developing a new detector based radiometry

that is different both in conception and execution than the classical

approach based on standard sources of optical radiation, and (3) dedeveloping new electro-optical technology for radiometric application. As was the case last year, the major part of the Group effort

was devoted to studies of silicon junction diode physics as a basis

for accurate radiometry.

The analysis of the silicon quantum yield spectra taken a year

and a half ago in Australia has been completed. The possibility

(mentioned in last year's report) that the prominent feature in

spectra near 4.5 eV was an artifact of the reflectance measurements

has been ruled out. The average of the quantum yields for the three

diodes measured in Australia is shown in fig. 1. Also shown there is

the result of a new calculation done by Geist in collaboration with

C. S. Wang of the University of Maryland and R. C. Alig of RCA,

Princeton. Most of the differences between the two spectra can be

understood in terms of the differences between the band structure of

silicon and the self consistent, first principles band structure used

in the calculation. In connection with these calculations. Gladden

and Geist also completed a study of Kane's random k approximation to

the transition rate for impact ionization that verifies its use- fulness at least for indirect gap semi-conductors.

One possible cause (other than experimental error) of the diodeto-diode differences in quantum yield that were discussed in last

year's report has been discovered. J. R. Lowney of the NBS Center

for Electronic and Electrical Engineering has suggested that the

screening of the electron-electron interaction, which determines the

matrix elements for impact ionization, might depend upon dopant

density and the condition of accumulation or depletion near the

oxide-silicon interface where the ultraviolet radiation is absorbed.

We intend to study this possibility experimental ly and theoretically

next year.

If the quantum yield does turn out to be sensitive either to

doping or to the net charge density near the interface, silicon

photodiodes will not be suitable as high accuracy standards in the

ultraviolet. However, GaP, which has a band gap twice as large as silicon, is being studied as a material for electronic devices that

operate at high temperatures. Devices with very favorable properties

have already been constructed, and high quality GaP photodiodes seem

within the state-of-the-art of current technology.- Because of its

large band gap, the quantum yield of such diodes should be unity

144
Division 534, Technical Activities (cont'd)

below about 6 eV (above about 200 nm). Thus the prospects for a high accuracy absolute detector standard in the near ultraviolet remain

promising.

In this connection, it is of interest that during the last year,

we were able to negotiate a collaborative research grant with Prof. R.

J. Schwartz of the Purdue University School of Electrical Engineering

to develop standards grade Ge photodiodes. If this project succeeds,

we would use these photodiodes to extend self-calibration into the

near infrared. Also, if this project succeeds, Prof. Schwartz has

indicated a desire to continue the joint project with GaP in an attempt to extend self-calibration into the near ultraviolet.

During the last year, Schaefer and Zalewski concluded a study of

minority carrier recombination in the region between the junction and

the rear of the diode, and its role in non linearity, spatial non- uniformity of response, and reduced quantum efficiency When these

occur in the infrared, they are all symptoms of the same problem, a high recombination center count in the region between the junction and

the rear of the diode. Therefore, part of the self-calibration

procedure, the measurement of photoresponse as a function of reverse

bias, turns out to be a simple test with which to screen silicon

photodiodes for linearity and uniformity of response in the red.

During the last year, Booker and Geist studied the physics of new

off-the-shelf inversion layer photodiodes from UDT. These are improved

versions of devices that we investigated during their development by

UDT. We have verified that oxide bias is not needed in order to

obtain above 99.9% collection of the photogenerated minority carriers

in these devices. Reverse bias is still needed with red and infrared

radiation to extend the depletion region toward the rear of the diode

in order to collect all of the minority carriers created by penetrating

radiation, and also at moderately high flux levels in order to keep

the relatively high I-R drop across the inversion layer from forward

biasing the diode. At the sub-tenth percent level, we see effects

that we do not yet understand, but nevertheless, these diodes make a very suitable high accuracy standard for the visible spectral region.

In this connection, Zalewski tested a multiple reflection configuration

of inversion layer photodiodes from UDT that, with sufficient reverse

bias, provides 99.9 ±0.2% external quantum efficiency for low level

laser power measurements throughout the visible. With this type of

standard, self-calibration is not necessary. Reverse bias is applied

and the measurements made. Zalewski has also optimized the design of

the multiple reflection configuration for increased quantum efficiency

while accommodating higher solid angle radiation, and will test it

next year.

145
Division 534, Technical Activities (cont'd)

Also last year, Booker and Geist discovered the mechanism by which

ultraviolet radiation causes the response of the EG&G UV 444A photodiodes

to increase for a period lasting from hours to days after sustained

irradiation. It turns out that ultraviolet radiation photoexcites

electrons from interface traps into the silicon dioxide conduction band.

The electrons then cross the ^30 A thick oxide and are stored on the

oxide surface in the same way as if they had been deposited there by a corona discharge to the surface. Once there, the stored electrons repel

minority carriers from the oxide-silicon interface where they would

recombine. The proof that this was indeed the mechanism was simple once

it had been proposed (by a group at Fort Monmouth, N.J., to explain some anamolous results in electron-spin-resonance studies of the oxidesilicon interface). A drop of ethylene glycol was put on the oxide

surface of the UV 444A diode, and the quantum efficiency of a region of

the diode under the drop was enhanced by ultraviolet irradiation. The

drop was then grounded, and the quantum efficiency was observed to

decrease to the pre-irradiation value within a few minutes. This period

is consistent with the capacitance of the oxide and the resistance of

the ethylene glycol drop, and contrasts strongly with the tens of hours

decay period of an ungrounded surface. The latter period is consistent

with the capacitance and surface resistance of the oxide.

During last year, Zalewski observed the existence of an oxide bias

induced hysteresis effect that was also described to us by Peter Key of

the UK National Physical Laboratory. Figure 2 shows the quantum efficiency

of a photodiode as a function of time while its surface is subjected to

repeated cycles of 0V and - 46 V bias. This effect was also observed at

the PRC National Institute for Metrology by a former NBS guest worker,

Li Tong-Bao. It is as if the passivation (rendering ineffective for

recombination) of surface states involves a complex consisting of a midgap state, an electron and some neutral species, where the complex is

stable even when the Fermi energy is well below the level of the un- occupied surface state. Apparently, the electron can be ejected from

the complex by absorption of a sufficiently energetic photon or by

stimulation by a sufficiently strong field (caused by negative charge on the oxide surface). Once the electron is ejected from the complex, the

neutral species is presumably free to diffuse through the silicon and/or

the oxide, and if the surface state is above the Fermi level, it increases the recombination rate. As a result, the self-calibration

procedure must be carried out after a measurement of radiant flux,

rather than before, if the highest accuracy is desired. This problem

with oxide bias makes the inversion layer diodes all the more desirable

as absolute standards since they require no oxide bias.

The intercomparison between silicon self-calibration and electron

counting on the NBS SURF II finally took place this year. The quantum

efficiencies of two photodiodes with nominal 10 nm band pass filters

centered at 600 nm were calibrated against a self-calibrated photodiode

at ^ 1 a intervals by Schaefer and R. J. Saunders of the Spectroradiometry

Group. The radiation was obtained from an amplitude stabilized dye

laser; the wavelength was measured interferometrically at each wavelength

146
Division 534, Technical Activities (cont'd)

with a wavemeter. The intercomparison between the filtered photodiodes and the SURF monitor diode was conducted with about 100,000

electrons circulating in the ring. The SURF monitor diode was calibrated by counting down from about 400 to about 300 electrons. The

linearity of the monitor diode was tested by comparing its response

when unfiltered to its response when filtered with a V(A) filter.

At the time of this writing, the two filtered photodiodes agree

to within about 1% in their assessment of the radiant power per

electron from SURF II, but differ by about 6 % from the power assessment based on electron counting. Because they differ by the same

amount in their assessment of the spectral irradiance from a calibrated standard lamp, it is clear that the fault lies with the calibration

of the filtered photodiodes. Since this type of calibration has been

carried out successfully in the past, the 6 % discrepancy does not

indicate a fundamental problem with the procedure for calibrating the

filtered photodiodes, but rather seems to be the result of an isolated,

non-essential error. Currently, we suspect deterioration of the

interference filters between the time of the filtered diode calibration

(late May) and the time of the SURF II intercomparison (late August).

There is a brighter side. Consider the filtered photodiodes as transfer standards used to measure the irradiance from SURF II one week and the irradiance from the standard lamps the next. The result

is that the blackbody theory based standard agrees with the synchrotron

theory based standard at the 1% level, which is the precision of the

comparison. As pointed out below in connection with the silicon

detector based calibration of FASCAL, we also know that the quantum

yield theory based and blackbody theory based standards agree to at

the 1% level. The demonstration of this level of agreement between

the three scales is in itself useful.

In connection with the SURF II intercomparison, Fowler developed

a detector-op-amp configuration that provides greater immunity to

pick-up noise than those that we used previously. He also tested the

feasibility of digital measurement and control of an electrically calibrated pyroelectric radiometer with an 8 bit microcomputer. However,

to get sufficient precision and dynamic range, it was necessary to use

a 16 bit A-to-D converter. The overhead in reading and processing the

16 bit words on an 8 bit machine slowed the system too much to be

practical. He will test the concept with a 16 bit computer when one

becomes available to us. Also this year, Fowler has designed and

prototyped a versatile, dual channel, current-to-vol tage converter/ratio

meter with variable voltage supplies that is specifically designed to

facilitate silicon based radiometry. Next year he will have a number

of units built for routine application in various Division projects.

The first full recalibration of the DRIP radiometers since their

initial distribution was completed this year by Gladden and Zalewski.

147
Division 534, Technical Activities (cont'd)

They measured both spectral response and the reflectance of the

radiometers at several of the laser lines readily accessible in the

detector characterization facility. They showed that reflectance

interpolation based on published optical constants worked reasonably

well over the visible, but was a more severe problem in the ultraviolet.

They also continued their detector based measurement of spectral

irradiance, repeating both the silicon spectral response recal ibration

of FASCAL and the measurement of lamp irradiance with FASCAL. At the

time of this writing there appears to be a 1% discrepancy between the

source based and detector based measurement of spectral irradiance.

However, the source based recal ibration of the lamps used in this

intercomparison is not yet complete.

Zalewski also assembled and characterized several detectordiffuser assemblies for the self-calibration intercompari son that he

is coordinating for the CIE. He tested the feasibility of measuring

the quantum yield of the luminol chemical fluorescence against silicon

photodiode standards of spectral response in collaboration with Ian

Matheson of the University of Georgia. The preliminary results were

very promising and we expect the chemistry, rather than the radiometry,

to limit the accuracy of the final results.

Finally, Cohen has completed his review of noise in general and

noise in photodiodes in particular, and has written up his findings

in three reports which have stimulated considerable thought and

discussion about these topics. During the last year he started a study of infrared thermography for non-destructive testing under the

sponsorship of the NBS NDE program.

148
Division 534, Technical Activities (cont'd)

PHOTOMETRIC-RADIOMETRIC CALIBRATIONS AND MAP

This group provides a firm measurement base for the Nation's

optical radiation community (defense and aerospace, instrument manufacturers and commercial calibration laboratories, lighting and

photographic industries, research institutions, etc.). To accomplish

this objective, the group:

(1) maintains the U.S. photometric and radiometric scales

and provides, improves and extends the NBS calibration

services for the basic photometric and radiometric

quantities—radiance temperature, spectral radiance,

spectral irradiance, detector spectral responsivity

,

luminous intensity, luminous flux and color temperature.

(2) engages in activities such as intercomparisons , measurement assurance programs, consultations and ad hoc

experiments that will insure that measurements made in

laboratories outside NBS are being made at acceptable

levels of accuracy.

As in the past, much of the group's activity has been devoted to

the calibration program during FY 1982. Calibration volume increased

about 10 percent during the year and now consumes about 50 percent of

the group's effort. Several improvements were made in the facilities

devoted to calibration services. New microcomputers have been

installed on the Facility for Automatic Spectral Calibrations (FASCAL)

and the software conversion is substantially complete. A FASCAL

compatible, variable high temperature blackbody for pyrometric calibrations has been designed and construction is about 50 percent

complete.

Improved documentation of the routine calibration services

received considerable attention. New write-ups describing the calibration procedures have been prepared and issued for the spectral

radiance and the luminous flux standards. The availability of appropriate personnel outside the Division's regular staff permitted

additional effort toward meeting the documentation guidelines of the

NBS Calibration Advisory Group. As a result of this additional effort

an NBS Technical Note describing the realization of the spectral

radiance scale is now in draft form.

International acceptance and compatibility of the NBS radiometric

and photometric scales is a concern of the group. A considerable

effort was devoted to preparations for the September 1982 meeting on the Consultative Committee on Photometry and Radiometry (CCPR). The

CCPR, an advisory committee functioning under the Treaty of the Meter,

addresses optical radiation measurement problems at the international

level, primarily by organizing intercomparisons. Of particular note

149
Division 534, Technical Activities (cont'd)

in the NBS preparations for this meeting was a bilateral spectral

radiance intercomparison conducted with the National Physical Laboratory, England. Two specially built British tungsten strip lamps have

been evaluated and proposals for their use in an international intercomparison will be presented to the CCPR.

The calibration program of the Radiometric Physics Division is

constantly being updated. At the beginning of this year, the luminous

directional transmittance standards were identified for possible

phase-out. The availability of an alternative standards base (the NBS

scale of spectral radiance) and the low volume in recent years (approximately 5 items per year) suggested this action. Input from the user

community has been solicited through articles and talks. A decision

will be made shortly as to whether to begin a three-year phase-out

period.

The technical opportunities offered by the development of silicon

cell technology have continued to receive attention, particularly in

the area of the realization, maintenance, and dissemination of photometric scales. Mosaical ly-fil tered, photopically-corrected silicon

cells have been examined for V(A) response at several laser wavelengths

(maximum deviation observed: 1.25 percent) and for linearity (maximum

deviation observed: less than 0.2 percent). Testing, particularly

with respect to long-term stability will continue into the coming

year. An experiment designed to realize photometric scales through

silicon cells and filter radiometry has been planned and procurement

begun. It will be carried out next year in collaboration with a guest

worker from Egypt.

A major expansion of the infrared activities of the group has

been initiated. Optical systems operating in the 2 to 25 micrometer,

long wave infrared (LWIR) spectral region are becoming increasingly

important to the nation's defense effort. Such systems are used for

weapons guidance and surveillance. The low signal levels involved

pose extremely severe calibration problems. LWIR calibrations and

other agency projects totaling more than $75K were performed during

the year. A five-year program to upgrade the NBS calibration

facilities, investigate error mechanisms, and extend the capabilities

of the NBS equipment to lower input signal levels has been formulated.

A major attempt to obtain other agency funding for this program is now underway.

150
SPONSORED CONFERENCES

Division 534, Radiometric Physics

Council for Optical Radiation Measurements, NBS Gaithersburg, May 11-12, 1982.

151
INVITED TALKS

Division 534, Radiometric Physics

D. A. McSparron, "The Future of Luminance Standards", Electronics Industries

Association, Committee on Optical Characteristics of Display Devices,

Washington, D. C., March 5, 1982.

D. A. McSparron, "DoD and the NBS Optical Radiation Program", 1982

Measurement Science Conference, San Diego, California, January 22, 1982.

A. R. Schaefer, Invited Lecture Tour of People's Republic of China,

State Bureau of Metrology - Beijing, Chengdu, Wuhan, and Shanghai, June

17 -July 4, 1982.

A. R Schaefer, "Characterization of a Silicon Filter Radiometer and

Intercomparison with NBS SURF", Electro Technical Laboratory, Tsukuba

City, Japan, July 5, 1982.

E. F Ea'lewski, "The Quantum Yield of Silicon Photodiodes - A New Basis

for Absolute Photon Fluv Measurements and Spectrofluorimetry", Dept, of

Chemistry, University of Maryland, College Park, MD, March 5, 1982.

i F Zalewski, "Calibrations and Corrected Spectra - Tried, True and

New", ASTm Symposium on Ne* Direction in Molecular Luminescence, Atlantic

Cit\, NJ, March ID, 1982.
PUBLICATIONS

Division 534* Radiometric Physics

Apel , C. T. , Keller, R. A. and Zalewski, E. F., "Optogal vanic Effect in a Hollow Cathode Discharge with Non Laser Sources", Appl . Opt. 21_, 146

5 (1982).

Baltes, H. P. and Geist, J., "Kirchhoff's and Planck's Radiation Laws for

Small Particles", J. Quant. Spect. and Rad. Trans. 26_, 535 (1981 ).

Booker, R. L., "Specular UV Reflectance Measurements for Cavity Radiometer

Design", Appl. Opt. 21_, 153 (1982).

Booker, R. L. and Geist, J., "Photodiode Quantum Efficiency Enhancement at

365 nm: Optical and Electrical", Appl. Opt. (Accepted for Publication).

Budde, W., Erb, W. and Hsia, J. J., "International Intercomparison of

Absolute Reflectance Scales", Color Research and Application _7, 24 (1982).

Demas, J. N., Bowman, E. D., Zalewski, E. F. and Velapoldi, R. A., "Determination

of the Quantum Yield of the Ferrioxalate Actinometer with Electrically

Calibrated Radiometers", J. Phys. Chem 8j>_, 2766 (1981 ).

Eckerle, K. L. and Hsia, J. J., "Proposed Standards for NBS Retroreflection MAP", Color Research and Applications 7_, 235 (1981 ).

Geist, J., Liang, E. and Schaefer, A. R. , "Complete Collection of Minority

Carriers from the Inversion Layer in Induced Junction Diodes", J. Appl.

Phys. 52, 4879 (1981).

Geist, J., Farmer, A. J. D., Martin, P. J., Wilkinson, F. J., and Collocott,

S+ J., "Elimination of Interface Recombination in Oxide Passivated Silicon

p n Photodiodes by Storage cf Negative Charge on the Oxide Surface", Appl.

Opt. 21_, 1130 (1 982).

Geist, J., Gladden, W. K. , and Zalewski, E. F., "Physics of Photon-Flux

Measurements with Silicon Photodiodes", J. Opt. Soc. Am. 72_, 1068 (1982).

Hsia, J. J. and Weidner, V. R. , "NBS 45°/Normal Refl ectometer for Absolute

Reflectance Factors", Metrologia 1_7, 97 (1981 ).

Hughey, L. R. and Schaefer, A. R., "Reduced Absolute Uncertainty in the

Irradiance of SURF-II and Instrumentation for Measuring Linearity of X-ray,

xuv and uv Detectors", Nuclear Instruments and Methods 1 95 , 367 (1982).

Kostkowski , H. J., Saunders, R. D. , Ward, J. F., Popenoe, C. H., and

Green, A. E. S., "Self-Study Manual on Optical Radiation Measurements,

Part III --Applications, Chapter I, Measurement of Solar Terrestrial

Spectral Irradiance in the Ozone Cut-Off Region", to be published as an NBS Tech Note in the 910-series.

153
Division 534. Publications (cont'd)

Mielenz, K. D., Weidner, V. R., and Burke, R. W., "Heterochromatic Stray

Light in UV Absorption Spectrometry: A New Test Method", Appl . Opt.

21, 3354 (1982).

Mielenz, K. D., "Measurement of Photoluminescence", in Optical Radiation

Measurements, Vol . 3, (K. D. Mielenz, editor), Academic Press, NY, 1982.

Mielenz, K. D., "Photoluminescence Spectrometry" , in Optical Radiation

Measurements, Vol. 3 (K. D. Mielenz, editor), Academic Press, NY, 1982.

Mielenz, K. D., Costa, L. F. and Grum, F., "Correction of Emission

Spectra", in Optical Radiation Measurements, Vol. 3 (K. D. Mielenz,

editor), Academic Press, NY, 1982.

Shumaker, J. B., "Self-Study Manual on Optical Radiation Measurements,

Part I--Concepts, Chapter 10, Introduction to Coherence in Radiometry",

to be published as an NBS Tech Note in the 910-series.

Weidner, V. R. and Hsia, J. J., "Standard Reference Materials: Preparation

and Calibration of First-Surface Aluminum Mirror Specular Reflectance

Standards", NBS Special Publication 260-75 (May 1982).

Zalewski, E. F., "Radiometry: New Developments Relating to Spectrofluorimetry

and Photon Yield Measurements", in Optical Radiation Measurements,

Vol. 3, (K. D. Mielenz, editor), Academic Press, NY, 1982.

154
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 534, Radiometric Physics

Robert L. Booker

Member and Secretary, U.S. Panel of CIE TC-1.6 on Fundamentals of

Visual Signalling.

Member, U.S. Panel of CIE TC-1.4 on Vision: Photopic, Mesopic,

and Scotopic.

Member, U.S. National Committee of the CIE.

Robert J. Bruening

Secretary, National Capital Section of the Optical Society of

America.

Jon C. Geist

U.S. Representative of TC-2 - Photon Detectors Committee of the

International Measurement Confederation (IMEKO).

Member, Program Committee for the 1982 International Electron Devices

Meetings (iedm).

Jack J. Hsia

Chairman, International Subcommittee on Standards and Techniques

of CIE TC-2. 3 on Properties of Materials.

Member, U.S. Panel of CIE TC-2. 3 on Properties of Materials.

Member, ASTM D- 1.26 Subcommittee on Optical Properties of Paint,

Varnish, Lacquer and Related Products.

Member, ASTM E-12 Committee on Appearance of Materials.

Member, ASTM E- 37 Committee on Thermal Measurements.

Delegate from ASTM to ISCC.

NBS Representative, ANSI Committee PH2 on Sensitometry and Subcommittee

PH2-28 on Densitometry.

155
Division 534, Technical Professional Committee Participation and

Leadership (cont'd)

Donald A. McSparron

Member, ANSI Z311 on Photobiological Safety of Lamps.

Member, Lamp Testing Engineers Conference.

Member, Illuminating Engineering Society (IES) on Testing Procedures.

Member, U.S. Panel of CIE TC-1.2 on Photometry and Radiometry.

Klaus D. Mielenz

Secretary, U.S. National Committee of the CIE.

Chairman, CIE International Technical Committee TC-2.3 on Properties of Materials.

Member, ASTM E-13 on Molecular Spectroscopy

Member, ASTM E-13. 06 on Luminescence.

Member, Comite Consultatif de Photometrie et Radiometrie

Board of Directors (ex officio). Council on Optical Radiation

Measurements.

Robert D. Saunders

Member, IES Committee on Photobiology.

Member, Illuminating Engineering Research Institute (IERI) Committee

on Extra Visual Effects.

A. Russell Schaefer

Member, U.S. Panel of CIE TC-2.2 on Detectors and Photometric

Instruments.

Member, Teller's Committee of Optical Society of America

John B. Shumaker

Member and U.S. Coordinator of U.S. Panel of CIE TC-2.3 on

Pol arization.

Edward F. Zalewski

Chairman, U.S. Panel of CIE TC-2.2 on Detectors.

Member, U.S. Panel of CIE TC-1.2 on Photometry and Radiometry.

156
MAJOR CONSULTING AND ADVISORY SERVICES

Division 534, Radiometric Physics

1. R. L. Booker assisted the NBS Center for Building Technology and the

Naval Coastal Systems Center in planning and conducting a field experiment

to determine the difference at sea in the visual range of surfaces

illuminated by known amounts of either low pressure sodium (LPS) or

red light. Recommendations were also made regarding a land-based

experiment, with observations over water, that offers better control

over the experimental variables.

2. K. L. Eckerle provided consultation to ASTM Committee E-12 on statistical analysis and precision statement for ASTM method on retroreflectance measurements.

3. K. L. Eckerle provided consultation to Ellen Gerrity and Prof. Fred

Billmeyer, Jr. on spectral transmittance measurements of liquid filters.

4. J. B. Fowler provides ongoing consultation in the area of microcomputer

hardware and software to other divisions within NBS.

5. J. B. Fowler is a member of the Microprocessor subcommittee of the

NBS Electronics Storeroom Committee.

6. J. J. Hsia provided consultation to EPA-ESRL Peer Review Program on "Evaluation of Trained (Method 9) VE Observers for Fugitive. Emission

Opacity Measurements" (Contact: Barbara Framer, Jeffalyn Johnson

and Associates, Inc., Falls Church, VA.) January 15, 1982.

7. E. Lewis and J. H. Walker provided consultation and a special

calibration of a novel prototype optical pyrometer operating in

the near infrared to personnel from Leeds and Northrup Corporation.

8. D. A. McSparron provided consultation to NASA (Goddard) and to the

Aerospace Division of Ball Brothers (Prime Contractor) on the calibration

of a Solar Backscatter Ultraviolet Radiometer (SBUV) for use in the

NASA/NOAA solar monitoring program.

9. D. A. McSparron provided consultation to Jerry Terrell of the Naval

Avionics Facility (Indianapolis) on traceability and measurement

consistency to meet photometric and colorimetric Mil specs.

10. D. A. McSparron provided consultation to Frank F. Koblitz of AMP

Corporation on optical characterization of the photo-polymerization

of dental materials.

157
Major Consulting and Advisory Services (cont'd)

11. D. A. McSparron and K. D. Mielenz consulted with Charles Showalter and

Robert Landry of the Bureau of Radiological Health on the calibration

of sensi tometers as a control method for limiting x-ray dosage in

medical diagnosis.

12. K. D. Mielenz visited the National Institute for Standards (NIS)

in Cairo, Egypt, from May 15 to 21, 1982, to assist the Photometry

Laboratory of NIS in establishing a standards base traceable to NBS.

13. C. H. Popenoe, Member of Microprocessor Subcommittee of the NBS

Electronics Storeroom Committee.

14. J. H. Walker and D. A. McSparron provided consultation and a special

calibration of the Faint Object Spectrograph for the Space Telescope

to John McCoy of Martin Marietta Corporation.

15. V. R. Weidner provided consultation to Dr. Elian Greenbaum of the

Oakridge National Laboratory regarding the design of instrument and

measurements of absorption for liquid with particles.

16. C. R. Yokley consulted with Todd Gilmore of Lockheed and Willard

Birtley of Rockwell International on the design, construction and

calibration of cryogenic blackbodies for long wave infrared DoD

research program.

17. E. F. Zalewski is providing consultation on the measurement of absolute

photon yields of chemi-luminescence reactions to members of the

Department of Biochemistry of the University of Georgia.

18. E. F. Zalewski is providing consultation on the optogalvanic effect

to staff members of the Los Alamos National Laboratory.

158
TRIPS SPONSORED BY OTHERS

Division 534, Radiometric Physics

R. 1. Booker, airfare and per diem supplied by the Naval Sea Systems

Comnand through the Center for Building Technology to plan and conduct

a visual range experiment, Panama City, FLorida, Oct. 21-22 and

Dec. 14-19, 1981.

A. R. Schaefer, Lecture Tour of the People's Republic of China,

sponsored by Protocol Agreement between NBS and Chinese State Bureau

of Metrology, National Institute of Metrology, Beijing; Institute of

Measurement and Test Laboratories , Dayi County and Chengdu, Sichuan

Province; Hupei Provincial Bureau of Metrology, Wuhan; and Shanghai

Bureau of Metrology, Shanghai.

159
STANDARD REFERENCE MATERIALS

Division 534, Radiometric Physics

1. SRM 1001, X-Ray Film Step Tablet

Used in the 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

Used in the calibration of optical densitometers and similar

equipment used in the photographic and graphic arts fields.

Certified for Optical Densities from 0 to 4.

2. SRM 1008, Photographic Step Tablets

Used in the 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, Microcopy Resolution Tests Charts

Used for determining the resolving power of microcopy systems.

4. SRM 2061, Reflection Step Tablets

Used in the calibration of reflection densitometers and similar

equipment used in the photographic and graphic arts fields.

Certified for optical density from 0 to 2.

5. SRM 2019 and 2020, White Ceramic Tile for Directional-Hemispherical Reflectance from 250 to 2500 nm,

SRM 2021 and 2022, Black Porcelain Enamel for DirectionalHemispherical Reflectance from 250 to 2500 nm.

For use in calibrating the reflectance scale of integrating sphere

reflectometer.

6. SRM 2003a, First Surface Aluminum Mirror for Specular Reflectance

from 250 to 2500 nm.

SRM 2023, Second Surface Aluminum Mirror for Specular Reflectance

Specular Reflectance from 250 to 2500 nm.

For use in calibrating the photometric scale of specular reflectometers

7. SRM 2009, 2010, 2013, and 2014 Didymium-Oxide glass as Wavelength

Standards between 400 and 760 nm.

160
CALIBRATION SERVICES PERFORMED

Division 534, Radiometric Physics

Type of Service Customer SP 250 Number of Income

tests

Pyrometry 7=4 A 30 $30K

thru G

Defense & Aerospace 13

Instrument & Cal labs 6

Lighting & Photography 3

Foreign 1 Electrical & Materials 7

Spectroradiometry 7=5 A 38

thru H

Defense & Aerospace

Instrument & Cal labs

Lighting & Photography

Foreign

Photometry • 7=6 A

thru M

& 7.7 B thru F

Defense & Aerospace

Instrument & Cal labs

Lighting & Photography

Foreign

Spectrophotometry 7.8 A

thru I

12

13

4

9

16

6

53

2

25

$1 2K

$ 5K

$ 4K

$ IK

$ 8K

$88K

$46K

$1 7K

$ 6K

$1 9K

$25 K

$ 7K

$ 3K

$ 6K

$ 9K

$1 7K

Defense & Aerospace 7 Instrument & Cal labs 5 Lighting & Photography 5 Foreign 1 Electrical & Materials 7

$ 7K

$ 2K

$ 3K

$ 2K

$ 3K

109 $1 60K

161
TECHNICAL ACTIVITIES

Division 535, Radiation Source and Instrumentation

Task No. 11252 (new task no. 15252) - Provide linac beam

Task No. 11253 (new task no. 15253) - FASTBUS instrumentation specification

Task No. 11254 (new task no. 15254) - Design, install and test microtron

components

CW Microtron Project

This project, sponsored by the Division of Nuclear Physics of the

Department of Energy is a joint effort of the Radiation Source and

Instrumentation Division of CRR and the Accelerator Technology Division

of the Los Alamos National Laboratory. The goal of this project is to

determine the feasibility of building a 1 to 2 GeV, 100% duty factor

electron accelerator with a beam current in excess of 100 yA using beam

recirculation and room temperature rf technology. An accelerator with

these operating parameters has been identified as a major need of the

national nuclear physics community by serveral high level committees

charged with determining future needs and priorities of the national

effort in nuclear physics.

An essential part of the program is the design, construction and

operation of a demonstration racetrack microtron (RTM) of sufficient

size to provide a meaningful test of components and beam performance.

The RTM will be built and operated at NBS . Its design calls for a beam

energy of 185 MeV and a current of 550 yA. This machine, in addition

to demonstrating the feasibility of building a 1 to 2 GeV machine using

the same technology, will be a powerful tool in its own right for nuclear

physics research and several other NBS programs.

The total estimated cost of this project is $10.4 million for the

5-1/2 years needed to design, build, and demonstrate the operation of

the accelerator. The collaboration between NBS and Los Alamos brings

together the unique expertise of Los Alamos in the area of rf accelerator

structures and systems with the expertise at NBS in particle beam dynamics

and accelerator technology.

At the end of the third year of this project most systems of the RTM are well into the construction and/or installation phase. Thus far, no insurmountable technical problems have arisen. Operation of the 100 keV

injector beam has begun, as has construction of the end magnets. An

important but unexpected result during the past year was the discovery

by Los Alamos that the disc and washer accelerating structure is unsuit162
Division 535, Accelerator Research (cont'cL)

able for cw electron accelerators. An alternative structure (sidecoupled) is being developed by Los Alamos for the RTM with no relaxation

of performance specifications. A one-year delay of the project completion date to May 1985 will be necessary to accomodate the extra rf

structure development work.

Planning for New Facility

We are designing a 800 MeV CW microtron. This accelerator is a scaled up version of the present 200 MeV RTM design. The two accelerators used in combination would then produce a 1000 MeV continuous duty

electron beam of up to 300 yA for use in nuclear reaction studies of the

type (e,e'x) and (y, x) with tagged photons. We are also designing a building to house the 800 MeV accelerator and two new experimental halls.

Together with the nuclear research group (532), who are designing the

experimental equipment for a 1000 MeV resarch program, we will make a proposal to the DoE and NSF for construction and operation of a national

user facility for electromagnetic nuclear research.

Consulting and Advisory Services

The application of accelerators and accelerator technology is growing at a tremendous rate, as evidenced by the fact that there is at

present a severe nationwide shortage of trained accelerator physicists

and engineers. Older applications of accelerators in fields such as cancer therapy, medical diagnostics, curing of paints and plastics,

nuclear and high energy physics research, and many others are well

known. Newer applications in such areas as fusion energy sources (both

magnetic and inertial confinement fusion schemes do or might employ

particle accelerators), weapons, weapon effects simulation, and materials

research demand new types of accelerators with performance characteristics

far beyond what was thought possible a few years ago. NBS has an excellent

reputation in the accelerator community, based largely on important

contributions made in the past, and therefore we are constantly being

called on to provide consulting and advisory services, as well as specific

research work. Requests for our services in this area have come from

many agencies including DoD, DoE, NSF, NASA, as well as a number of

universities and industrial organizations. In the past year, P. Debenham

has served as a consultant to the University of Maryland on the design of

a magnetic spectrometer to be installed at the University of Indiana.

He has also advised the University of Illinois on the design of end

magnets for a racetrack microtron. Although our in-house research

programs on DoD accelerator needs have been phased out, both M. Wilson

and S. Penner will continue to provide consulting services as requested.

163
LINAC OPERATIONS

Division 535, Radiation Source and Instrumentation

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. Major users of the linac in FY 1982 included programs in neutron

cross section standards and radiography, high energy electron scattering,

electron activation, photonuclear research, and activation analysis.

The last is an activity of the Center for Analytical Chemistry. In

addition, a number of outside collaborators and guest workers participated in the above mentioned programs.

The Linac Operations staff normally consists of three engineers

and seven technicians. At present the staff consists of only two

engineers and four technicians. In spite of its relatively small size

this group has achieved 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, construction,

and installing mechanical components. Table I shows the distribution

of the total Linac Operations staffing time in the operation of the

facility for FY 1982 (through August 1982). The facility is staffed

from 7:30 am Monday morning and runs for experiments until 6:30 am Saturday. Scheduled maintenance hours have varied throughout the year.

Experiment time on the facility was requested by and allocated to users at scheduling meetings, which were held every four weeks. Time

requested by experimenters has continued to run over 150% of that which

is available. Table II shows the distribution of time by experiment for

the fiscal year.

The unscheduled maintenance of 837.5 hours, through September 1, is

broken down and summarized by system in Table III. The large amount of

unscheduled maintenance is due, in the main, to three factors: (1) the

facility is old, having begun operation for experiments in 1965, (2) the

lack of resources, especially in FY 1981 and 1982, both financial and

personnel wise, and (3) due to #2 we were unable to have a scheduled

shut down for annual preventive maintenance.

164
Division 535, Linac Operations (cont'd.)

TABLE I

LINAC OPERATIONS

Month/Year Scheduled Actual

FY82 Hours Hours

Maintenance 396.0 396.0

Unscheduled Maintenance \ — — 837 .6^

Beam Time 4066.5 3203.5

Set-up* 165.5 186.5

Experimental Down-Time** — 5.5

Instal 1 ation 32.0 32.0

Inventory --- ---

Total Hours*** 4660.0 4660.0

*Includes lock-up after scheduled maintenance.

**Linac available for operation, but experiment either not ready or breaks down during scheduled run.

***Total staffing hours.

^Includes 65 hours of Plant down time.

165
Linac

Operations

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166

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1982
Division 535 s linac Operations (cont'd.)

TABLE III

LINAC OPERATIONS

FY 82

LINAC: Total unscheduled maintenance 380.0 hours.

System

Modulators 115.0 hours 30.8%

R. F. Drive 49 hours 12.9%

Injector 65 hours 17.1%

M.G. Sets 73 hours 19.2%

Vacuum 56.5 hours 14.9%

No other system or item

BHS: Total unscheduled

over 2%.

maintenance 382 .!5 hours.

System

BHS Mag. 170.0 hours 44.4%

Magnet P.S. '12.5 hours 3.3%

Vacuum 142 hours 37.1%

Water 47.5 hours 12.4%

No other system or item over 2%.

Balance of total unscheduled maintenance, 65.0 hours, due to air

conditioning and power outage.

167
SURF OPERATIONS

Division 535, Radiation Source and Instrumentation

SURF-II is a dedicated synchrotron radiation facility, consisting

of the recently upgraded 280 MeV electron synchrotron storage ring, a 10

MeV microtron injector and associated synchrotron radiation beamlines.

It produces light in a narrow, intense, highly polarized beam with a continuous and accurately known spectrum from the infrared through the

visible and into the extreme ultraviolet. SURF-II is unique among

synchrotron light sources by virtue of its uniform and precisely known

electron orbit.

SURF-II serves users from the Radiation Physics Division (533) as well as from other NBS divisions and outside users, in radiometric

standards and calibration work, optical physics research, surface science,

biochemistry, spectroscopy and other areas involving ultraviolet radiation.

It fills a growing demand for radiation in the ultraviolet and soft x- ray region of the electromagnetic spectrum. The multiple ports at SURF

now serve eight active experimental stations of which seven can run simultaneously. Three beamlines are especially active, with several

research groups using them on a rotating basis. The Optical Calibration

Facility on beamline 2 is also operating on a full schedule for outside

user groups. Three additional beamlines are in the planning stage.

The project to upgrade SURF operating energy _ from 240 to 280 MeV has

been successfully completed. Electrons were accelerated in the

reassembled machine on February 9, 1982 and limited operation for users resumed on February 17, although at a slightly reduced energy. After

optimization of the magnetic field profile and ramping program, as well

as a 25% boost in RF power, regular operation at 282 MeV commenced on May 3.

In the course of the shutdown, detailed mechanical and magnetic

measurements were performed on the magnet to verify pole circularity

and gap uniformity, and to map the magnetic field radially and azimuthally. An inherent azimuthal non-uniformity of the field on orbit of up

to + 0.5% was discovered. These field variations would be expected to

cause local variations in bending radius of about the same magnitude,

and a corresponding variation in the synchrotron radiation spectrum from

port to port. The detailed field maps will now permit appropriate

corrections to be made in the calculation of the photon flux at any

port, if necessary.

Field measurements and thermal calculations predicted that the new correction coils and power supplies should enable the magnet to support

a circulating beam of up to 300 MeV. This has been demonstrated. However the available RF power is insufficient to maintain the beam with

168
Division 535, SURF Operations (cont'cL)

reasonable lifetime. Operation at 300 MeV would necessitate a major

modification of the RF system to increase its power capability by a factor of two.

Electron counting is now a routine procedure for calibrating the

beam current monitor and for calculating the photon flux in the calibration beamline. This technique provides the basis for intercomparison

between SURF and the self-calibrated silicon diode standards, as reported elsewhere.

Other improvements and enhancements are still in the works, having

been delayed by lack of manpower, lack of funds, and/or late vendor

delivery. These include the second harmonic RF system, the optimization

of flight apertures in the microtron accelerating cavity, and microcomputer control of the correction coil system. The first two should be

completed in FY 83; the last item will require six months of software

development, by an experienced programmer.

Operational statistics for FY 82 reflect the shutdown which lasted

nearly six months. The second half of FY 82 saw nearly normal operation

again. Beam hours to users averaged 141 hours per month, peaking at

187 hours for the month of July. On the other hand downtime was up too,

due as much to understaffing as to normal bugs in the newly installed

systems

.

A number of challenging opportunities exist for further enhancing

SURF performance and exploiting its known potential, such as:

o operation at up to 300 MeV;

o beam currents of up to 50 mA, with the present injector;

o beam currents in excess of 50 mA, using a higher-energy injector

system;

o computer control of machine parameters.

Efforts will be made to implement these improvements which would benefit

current users and would make possible experiments currently deemed

impractical or marginal.

SURF serves a large user community, as shown in the list below. It

provides essential services and resources which, in many instances, are

not available anywhere else. The facility represents a sizable investment by NBS and other agencies. The responsibilities of the SURF Operations

Group include supporting full and efficient utilization of this investment, and maintaining its performance and capabilities at the current

169
Division 535, SURF Operations (cont'd.)

state of the art. Without additional engineering and technical staff

and appropriate funding, these responsibilities cannot be adequately

met.

SURF Operations Statistics

FY 81 FY 82

Beam to users 1872 hours 855 hours

Standby (beam available) 267 81

Studies and Maintenance 216 136

Unscheduled downtime 126 159

Total hours 2481 1262 (6 mos

SURF Users During FY 82

R.P. Madden,* D.L. Ederer, L.R. Hughey, A.C. Parr, E. Saloman, N. Swanson

(533 Radiation Physics Division, Far UV Physics Group)

*Principal Scientist

J. Cooper (520 Center for Absolute Physics Qunatities)

J. Geist, R. Schaeffer (534 Radiometric Physics Division)

T. Madey (541 Surface Sciences Division)

R. Stockbauer (543 Chemical Thermodynamics Division)

D. Holland (Reading University, England)

E. Bertel (Innsbruck University, Austria)

G. Leroi , '82 SURF Fellow (Michigan State University)

R. M. Catchings (Howard University)

C. Mehlman (CNRS, France)

S. Donnelly (University Notre Dame de la Paix, Belgium)

G. Carruthers, J. Rife, M. VanHoosier (Naval Research Lab)

170
Division 535, SURF Operations (cont'ch)

M. O. Krause (Oak Ridge National Lab)

R. Day, R.J. Bartlett, D. Lear (Los Alamos National Lab)

E. Poliakoff (Argonne National Lab)

B. Guenther, J. Mentall , D. Williams (NASA Goddard)

W. Hodge, J. Castracane, S.T. Durrance, T.N. Woods, T. Yu (Johns Hopkins

University)

G. Mount, R. Jakoubek (LASP, Colorado)

D. Hwang (Princeton University)

N. V. Richardson (Liverpool University, England)

171
INSTRUMENTATION SERVICES

Division 535, Radiation Source and Instrumentation

Electronic Instrumentation Maintenance and Construction

Provision of electronics instrumentation maintenance and construction services for the experimental program of the Center for Radiation

Research is a continuing responsibi 1 i ty of the Division. Instruments

designed and constructed during 1982 number about 105 and maintenance

has involved about 225 instruments. Increasing complexity of the instruments requires increasing amounts of highly-trained technicians time.

More advanced support instrumentation is still urgently needed for use

in this maintenance although some instruments have been purchased through

FY 1982.

Although the Center has almost doubled in size over the past few

years due to internal reorganization , technician support manpower has

remained static at a lower level than in 1980. It is presently impossible to provide all the services required by Center personnel for

presently instituted programs.

Control Instrumentation Design and Construction

Design and construction of many types of Control Instrumentation

has been undertaken for the Division of the Center for Radiation

Research. Typical examples of instrumentation included; a control and

data acquisition system for pulse radiolysis measurements using the NBS

2 MeV flash electron accelerator; a CAMAC target control system for an electron spectrometer used with the NBS linac; a neutron beam scanner;

a controller and data acquisition system for temperature and humidity

measurements

.

Instrumentation Support for Physics and Chemistry Projects

Consulting and systems instrumentation has been provided to

scientists in programs relating to neutron physics, electron physics,

surface electron physics. X-ray dosimetry, radiation chemistry, vacuum

ultraviolet physics (SURF), analytical chemistry, physical chemistry and

photometry.

Instrumentation also has been provided for the States Regional

Calibration Centers. Instrumentation supplied includes; a novel track

and hold pulse amplifier for pulsed radiolysis measurements, neutron

dosimetry instrumentation, low-noise current amplifiers, analog signalprocessing circuits, pulse detection, counting and processing devices,

microcomputer circuits, complex NIM modules.

172
Division 535, Instrumentation Services (cont'd.)

An important, continuing and growing problem is the lack of adequate modern instrumentation to complement and support the efforts of

the electronic instrumentation design engineering staff. This concern

has been noted in previous years but sufficient funds have not been

available to overcome the problems. At present, as last year, the

Radiation Instrumentation Laboratory is ill -equipped to provide adequate

support to the Center in the following areas; radio-frequency circuit

characterization and systems measurement, transient analysis, measurement of very short time intervals, microcomputer development and

microcomputer software development, CAMAC development and clibration.

This lack of instrumentation affects the innovation, efficiency and

productivity of the Instrumentation Group. When coupled with a severe

staff shortage, this combination adversely affects the programs of

the Center on a continuing basis.

Consultation continues to be provided to the Center for Chemical

Physics (ozone measurements, ion cyclotron resonance), the Center for

Analytical Chemistry (metal sampling techniques, ion time-of-fl ight mass spectrometry , low-level counting measurements), Center for Building

Research (humidity measurements) . One staff member (Whittaker) continues the joint project with the Chemistry Department of the University

of Maryland on air particulate measurements supervising the work of a graduate student. A new AID sponsored cooperative project with the

Eqyptian National Institute of Standards has been started and presently

two Egyptian scientists are studying electronic repair and maintenance

techniques in the Instrumentation Laboratory.

The Radiation Instrumentation Group has provided a large amount of

support to the racetrack microtron project relating to the design of

sensitive current amplifiers, pulse data acquisition, high-voltage

terminal design, test instrumentation, wiring and interlock support and

general instrumentation consultation.

Mechanical Instrumentation Services

Mechanical instrumentation services were provided for the Center

for Radiation Research in connection with the particle accelerators of

the CRR and the experimental programs of the Center. The services

provided consist of design and construction of new equipment and

facilities as well as maintenance, and modification of existing equipment. This past year the major effort was the NBS-Los Alamos racetrack

microtron accelerator. The viewscreens, wire scanners and water cooled

chopping aperature were designed and prototype assemblies built and

tested. The precision, moveable "turn around" magnet support design

has been completed.

173
RADIATION INSTRUMENTATION STANDARDS

Division 535, Radiation Source and Instrumentation

Standards work falls into three categories as follows:

(a) 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 US and is the predominant system in nuclear laboratories throughout the world. There is

a continuous coordination requirement involving contact with numerous

laboratories and manufacturers. Similar management, direction and

maintenance are provided in the US 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

now being developed and 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 and preparation of the final specifications is now underway.

The preparation of reports for the above systems involves a number

of individuals and laboratories. Coordination and processing, as well

as writing of some sections, is handled by the National Bureau of

Standards. The documents are usually issued initially 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). There are currently sevel CAMAC standards. These

have been updated and the updated documents issued in FY 82. Some

additions to the basic NIM standard, such as specifying the "IEEE

Standard Interface for Programmable Instrumentation" (IEEE Std 488) as

a digital data bus for NIM instruments, are now in process.

(b) National Voluntary Standards - The Division plays an active

role in IEEE and ANSI Standards activities with L. Costrell serving 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 several ANSI And IEEE standards in FY 1982.

J. Whittaker serves on ASTM Committee D-22 on Methods of Sampling and

Analysis of Atmospheres.

(c) International Electrotechnical Commission - L . Costrell serves

as Technical Advisor to the US National Committee of the IEC for IEC

174
Division 535 9 Radiation Instrumentation Standards (cont'd.)

Committee TC45 on Nuclear Instruments. He serves as Chief US 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 published and others that are to be published in FY 1983.

175
INVITED TALKS

Division 535, Radiation Source and Instrumentation

Ayres, R. L., Lecture on "Practical Gamma Counting in our course Rad

Sci 230 Radioimmunoassay," George Washington University Medical Center,

Washington, DC, October 19, 1981.

Ayres, R. L. , "Microcomputers - How They Function and How They are Used,"

Winston Churchill High School, Potomac, Maryland, December 4, 1981.

Costrell , L. , "FASTBUS Modular High Speed Data Acquisition System,"

Franklin Plaza Hotel, Philadelphia, Pennsylvania, June 16, 1982.

Penner, S. , "NBS-LANL Racetrack Microtron Project," Triangle Universities

Nuclear Laboratory Seminar, Durham, North Carolina, November 5, 1981.

Penner, S. , "Next Generation Accelerators - An Overview," Conference on New Horizons in Electromagnetic Physics, Charlottesville, Virginia,

April 22, 1982.

Wilson, M. A. D. , "The Induction Linac - A New Concept in High Current

Charged Particle Accelerators," Electrophysics Physics Seminar, College

Park, Maryland, December 4, 1981.

176
PUBLICATIONS

Division 535, Radiation Source and Instrumentation

Ayres, R.L., Radioactivity Standardization of TC and Mo, International Journal Applied Radiation and Istopic (in press).

Costrell, L. and Dawson, W.K. , "FASTBUS Modular High Speed Data

Acquisition Systems, published in Conference Records of 1982 IEEE

International Conference on Communications, ISSN 0536-1486, IEEE Catalog

Number 82CH1 766-5, June 1982.

Debenham, P.H., Homogenizing the Field in a Picture-Frame Magnet,

Proceedings of Workshop of High-Resolution, Large-Acceptance Spectrometers, Argonne, Illinois, September 8-11, 1981.

Debenham, P.H., Understanding the Purcell Filter, Proceedings of

Workshop on High-Resolution, Large-Acceptance Spectrometers , Argonne,

Illinois, September 8-11 , 1981.

177
TECHNICAL AND PROFESSIONAL COMMITTEE PARTICIPATION AND LEADERSHIP

Division 535, Radiation Source and Instrumentation

Louis Costrell

Chairman, ANSI Technical Committee N42, Nuclear Instruments.

Member, ANSI Technical Committee N41 , Controls, Instrumentation,

and Electrical Systems for Nuclear Power Generating Stations.

Chief U.S. Delegate, International Electrotechnical Commission

(IEC), Technical Committee on Nuclear Instruments (IEC/TC45).

Chairman, IEC/TC45 Working Group-9 on Radiation Detectors.

Member, IEC/TC45 Working Group-3 on Interchangeability.

Member, IEC/TC45 Working Group-1 on Classification and Terminology.

Technical Advisor, U.S. National Committee of IEC.

Secretary, Institute of Electrical and Electronics Engineers

( IEEE ) / NPSS Nuclear Instruments and Detectors Committee of IEEE

Nuclear and Plasma Sciences Society.

Member, IEEE Standards Review Committee.

Member, U.S. National Committee of International Electrotechnical

Commission (IEC).

Chairman, U.S. Department of Energy National Instrumentation

Methods (NIM) Committee.

Chairman, NBS Microprocessor Standards Action Group.

Philip H. Debenham

Member, 1983 Particle Accelerator Conference Program Committee.

Samuel Penner

Member, 1983 Particle Accelerator Conference Program and Organizing

Committees.

178
Division 535, Technical and Professional Committee Participation and

Leadership (Cont'd.)

Julian K. Whittaker

Member, ASTM Committee D-22 on Methods of Sampling and Analysis

of Atmospheres.

Member, U.S. Department of Commerce, Industry and Trade Administration, Electronic Instrumentation Technical Advisory Committee.

Chairman, Electronics Storeroom Committee, NBS.

Chairman, Electronics Storeroom Committee Microprocessor Subcommittee, NBS.

179
MAJOR CONSULTING AND ADVISORY SERVICES

Division 535, Radiation Source and Instrumentation

1. R. L. Ayres serves as a consultant on the design and development of a microprocessor based automated humidity calibration system

for the NBS Thermal Processor Division.

2. P. Debenham serves as a consultant to the University of

Maryland on the design of a magnetic spectrometer to be installed at

the University of Indiana.

3. P. Debenham serves as an advisor to the University of

Illinois on the design of end magnets.

4. S. Penner serves as a member of the DoE-sponsored Nuclear

Physics Major Facilities Review Panel.

5. S. Penner and M. Wilson continue to provide Accelerator

Technology and Assessment and Oversight for DARPA.

6. J. Whittaker serves as a consultant on instrumentation and

instrumentation maintenance and repair to AID for the Egyptian Government Standards Laboratories.

7. J. Whittaker serves as an advisor to two Eqyptian visiting

scientists in the field of repair and maintenance services.

8. J. Whittaker serves as an advisor to a graduate student in the

Department of Chemistry, University of Maryland.

9. J. Whittaker serves as a consultant on electronics instrumentation and instrumentation repair and maintenance to the University of

Petroleum and Minerals, Dhahran, Saudi Arabia.

180
I

I STANDARD REFERENCE MATERIALS

I Division 535 s Radiation Source and Instrumentation

1. SRM 4949B 9 Preparation of 1-129 Radioactivity

I

181
SPONSORED SEMINARS & COLLOQUIA

CENTER FOR RADIATION RESEARCH

F. Wuilleumier, Universite Paris-Sud, Orsay, France, "New X-Ray Sources

and New Experimental Studies Involving Synchrotron and Laser Radiation,"

October 8, 1981.

H. G. Ebert, Biology, Radiation Protection and Medical Research, Commission of the European Communities, Brussels, Belgium, "Radiation Protection

Research Program of the Commission of the European Communities,"

October 8, 1981.

Michael Danos, Nuclear Radiation Division, Center for Radiation Research,

NBS , "Nuclear Quarks According to Versailles," October 15, 1981.

Kurt Behringer, Max Plank Institut fur Plasma Physik, Garching, Germany,

"VUV and X Ray Spectroscopy of Impurity Ions in the ASDEX Tokamak,"

October 19, 1981.

Samuel Penner, Radiation Source Instrumentation Division, Center for

Radiation Research, NBS, "The Future of Nuclear Physics Research at NBS,"

October 22, 1981.

A. Carillon, University of Paris-Sud, Orsay, France, "Some Aspects of the

Production of Multicharged Ions in Dense Laser Produced Plasma,"

November 12, 1981.

S. J. Wallace, Guest Worker, Center for Radiation Research (on leave from

the University of Maryland,) "Bright Spots in High Energy Proton Scattering," November 12, 1981.

Stephen W. Lovesey, Neutron Division, Rutherford Appleton Laboratory,

England, "Dynamic Properties of Electrons in Materials by Neutron Scattering," November 19, 1981.

R. R. Silbar, Nuclear Physics Division, Department of Energy, "The Nucleon

Nucleon Interaction at Medium Energies," December 3, 1981.

Martin Lingare, Princeton University, "Photoproduction of Spin Polarized

Hydrogen Atoms in Mixtures of Cs Vapor and Hydrogen Gas," December 8, 1981

Michael Simic, Radiation Physics Division, Center for Radiation Research,

NBS, "Radiation Biological Mechanisms," December 10, 1981.

Arthur Charlesby, Professor Emeritus, Royal Military College of Science,

Shrivenham, Great Britain, "The Use of Pulsed NMR for Characterization of

Polymers," December 14, 1981.

182
John Leonard Holmes, University of Ottawa, "Phenomenology of Slow Ion

Fragmentation Processes," December 14, 1981c

S. J. Wallace, Guest Worker, Center for Radiation Research (on leave from

the University of Maryland,) "Dynamics of High Energy Proton Scattering,"

December 17, 1981.

W. R. Cooke, University of Southern California, Los Angeles, California,

Multi-channel Quantum Defect Theory on the Back of an Envelope,"

December 18, 1981.

J. Tersoff, University of California, Berkeley, "Substrate Effects in

Thin N-j Films," December 28, 1981.

Walter Johnson, Dept, of Physics, University of Notre Dame, Notre Dame,

IN, "New Theoretical Insights into the Photoionization Process,"

January 8, 1982.

Emanuel Riklis, Nuclear Research Center, Negev, Israel, "Mechanisms of

DNA Repair as a Probe to Radiation Sensitivity," January 15, 1982.

Santos Alvarado, Inst. Sol. State, Res., KFA, Julich, Germany, "Surface

Magnetism of Ni(100) Near the Critical Region by Spin Polarized Electron

Scattering," January 26, 1982.

Peter Smith, Harvard Smithsonian Center for Astrophysics, Cambridge, MA,

"Measurements of f-values of Intersystem Lines Used in Astrophysi cal

Plasma Diagnostics," January 27, 1982.

Carl Bigging, Uppsala University, Sweden, "Solar Selective Properties

of Oxidized Steel and Copper," February 4, 1982.

Gary Prinz, Naval Research Laboratory, Washington, DC, "Properties of

Single Crystal Fe Films Grown on GaAs by Molecular Beam Epitaxy,"

February 9, 1982.

Kamil V. Ettinger, Department of Biomedical Physics and Bioengineering,

University of Aberdeen, Scotland, "Free Radical Dosimetry Using Organic

Systems," February 12, 1982.

Klaus W. Geiger, National Research Council of Canada, "Electron Dosimetry," February 18, 1982.

Donald Lehman, George Washington University, Washington, DC, "What Do

We Learn About the Structure of ^He and ^Li from Three-Body Models?"

February 23, 1982.

Richard Ellis, University of Maryland, Laboratory for Plasma and Fusion

Energy, "Synchrotron Emission as a Diagnostic for Magnetic Mirror Machine

Plasmas," March 9, 1982.

183
Wilfrid B. Mann, Nuclear Radiation Division, Center for Radiation

Research, NBS, "Radio- (and other) Activities in China," March 11, 1982.

David Holland, Radiation Physics Division, Center for Radiation

Research, NBS, "Photoionization of Atoms and Molecules,"

March 15, 1982.

K. G. W. Inn, W. S. Liggett, Jr., Nucear Radiation Division, Center for

Radiation Research, NBS," NBS Natural Matrix Radioactivity Standards,"

March 18, 1982.

H.P. Baltes, Landis and Gyr Central Research Laboratory, Zug,

Switzerland, "Magnetic Field Microsensor Based on a Magnetoresistive

Comparator," March 22, 1982.

H.P. Baltes, Swiss Federal Institute of Technology, Laussanne,

Switzerland, "Multiplex Version of the Generalized Van Cittert-Zernike

Theorem," March 23, 1982.

James E. Lawler, Department of Physics, University of Wisconsin,

"Applications of Hollow-Cathode Discharges in Laser Spectroscopy,"

March 24, 1982.

Roger Falcone, Ginzton Laboratory, Stanford University, Stanford, CA,

"XUV Spectroscopy and Source Development at Stanford University,"

March 26, 1982.

Jeff Linsky, JILA, University of Colorado, Boulder, CO, "UV Observation

of Stars with the International UV Explorer Spacecraft," March 29, 1982.

V. I. Mishin, Institute for Spectroscopy, Moscow, USSR, "Laser Photoionization Detection of Impurities in Solids and Studies of Hyperfine

and Isotope Structures of Radioactive Atoms," April 5, 1982.

Kwok Tsang Cheng, Department of Physics, Argonne National Laboratory,

Photochannel Quantum Defect Analysis of the Absorption Spectrum of Ba,"

April 5, 1982.

Aryeh Frimer, Department of Chemistry, Bar-Ilan University, Israel,

"Autoxidation by Superoxide Radical Anion," April 12, 1982.

Claude Fleurier, University of Orleans, Cedex, France, "Some Aspects of

the Atomic and Plasma Physic Research at the University of Orleans,"

April 12, 1982.

S. C. Roy, Department of Enmgineering and Applied Science, Yale

University, New Haven, CT, "Neutron Detection Using Superheated Liquids,"

April 16, 1982.

184
Helmut Hermi nghaus, Institut fur Kernphysik dur Johannes, GutenbergUniversitat, Mainz, W. Germany, "The Mainz CW Racetrack Microtron,"

April 20, 1982.

C. von Sonntag, Max Planck Institut fur Strahl enhemi e, Mulheim, Germany,

"Mechanisms of Radiation Induced DNA Strand Breaks," April 30, 1982.

David Herrick, University of Oregon, "Approximate Symmetries in Doubly

Excited States of Helium," April 27, 1982.

Stephen M. Younger, Atomic and Plasma Radiation Division, Center for

Radiation Research, NBS, "Dividing the Indivisible: Selected Topics in

Modern Atomic Physics," May 4, 1982.

John R. Calarco, Department of Physics, University of New Hampshire,

Burham, New Hampshire, "238u(e s e'f) Cross Section Measurements at 80,

120 and 160 MeV," May 4, 1982.

Jurio Avoitinsh, Department of Physical Chemistry, Latvian State

University Chemistry Department, University of Colorado, Boulder,

Colorado, "Lyolumi nescence Alkali Halides," May 11, 1982.

H. Zacharias, Universitat Bielefeld, Bielefeld, West Germany, "Spectroscopy of Hydrogen Atoms with VUV Lasers," May 11, 1982.

Susumu Namba, Osaka University, Toyonaka, Osaka, Japan, "X-Ray Lithography at the Toyko Synchrotron Radiation Source," May 17, 1982.

Charles Clark, Atomic and Plasma Radiation Division, Center for

Radiation Research, NBS, "Atomic Diamagnetism," May 18, 1982.

W. Timothy Elam, Physics Dept., University of Washington, Seattle, WA,

"EXAFS Measurements of the Oxygen - Transport Protein Hemerythrin,"

May 21, 1982.

John F. Ward, Professor of Radiology, Chief of Radiobiology, School of

Medicine, University of California, San Diego M027, La Jolla CA, "Does

Rate of DNA Repair Affect Cell Survival?" May 21, 1982.

Peter Rosen, National Science Foundation, "Double Beta Decay and

Marjorana Neutrinos," May 25, 1982.

Sydney Meshkov, Nuclear Radiation Division, Center for Radiation

Research, NBS, "An Update on the Status of Glueballs and Oddballs,"

May 26, 1982.

Michele Crance, Laboratory Aime Cotton, Orsay, France, "Fluorescence

Induced by Resonant Multiphoton Ionization Near an Autoionizing State,"

May 26, 1982.

185
D. E. Murnick, Bell Laboratories, Murray Hill, NJ, "Laser Optical

Pumping in Nuclear Physics," June 3, 1982.

Josh Halpern, Chemistry Department, Howard University, "Photodissociation of Cyanogen," June 9, 1982.

Donald Schran, Eidenhoven University of Technology, Eidenhoven, Holland

(on sabbatical leave at the University of Montreal,) "Non-Equilibrium

in Pulsed Cascaded Arcs and Medium Density Cathode Discharges,"

June 10, 1982.

Leonard Maximon, Nuclear Radiation Division, Center for Radiation

Research, NBS, "Radiative Tail from Elastic Eletron Scattering,"

June 23, 1982.

K. T. Lu, Argonne National Laboratory, Argonne, Illinois, "Chemical

Physics of Highly Excited States," June 24, 1982.

Gian-Paulo Tozzi , Institute fur Astronomie, ETH, Zurich, Switzerland,

"Measurements of UV Branching Ratios at ETH," June 30, 1982.

Nikola Konjevic, Institute of Applied Physics, Belgrad, Yugoslavia,

"Stark Broadening of Non-hydrogeni c Atom and Ion Lines in PI asmas-Cri ti cal

Review of Experimental Data for the Period 1976-1981," July 8, 1982.

Goran Pichler, University of Zagreb, Yugoslavia, "Spectroscopy of Alkali

Metal Vapors," July 9, 1982.

Johann Rafelski, Institute for Theoretical Physics, University of

Frankfurt, Frankfurt, Germany, "Quark-Gluon Plasma," July 15, 1982.

Volkmar Helbig, Institut fur Experimental physi k , Universitat Kiel, West

Germany, "Atomic Transition Probability Studies on Rare Gases,"

July 20, 1982.

Johann Rafelski, Institute for Theoretical Physics, University of

Frankfurt, Frankfurt, Germany, "Strange Particle Production in High

Energy Nuclear Collisions," July 22, 1982.

Erhard Kisker, Institute fur Festkorperforschung , Julicn, West Germany,

"Ennancement of the Spin Polarization of Secondary Electrons from Ferromagnets," August 2, 1982.

Takeshi Namioka, Research Institute for Scientific Measurements, Tohoku

University, Japan, "High Resolution Spectrometers for Synchrotron

Radiation," August 3, 1982.

John Umbarger, Bruce Erkilla, Los Alamos National Laboratory, Los Alamos,

New Mexico, "Radiac Instrumentation - New Directions for the '80s,"

August 12, 1982.

186
Walter Greiner, University of Frankfurt, Germany and Yale University,

Connecticut, "Evidence for Giant Nuclei from Supercritical Field Positron

Emission Spectra," August 19, 1982.

Gerhard Wiech, Sektion Physik der ludwi g-Maximi 1 ian-Uni versitat Munchen,

Munich, FRG, "Angular-Resolved X-Ray Emission Spectroscopy,"

September 7, 1982.

Gunter Baum, Fakultat fur Physik, Universitat Bielefeld, Bielefeld, West

Germany, "Ionization and Excitation of Atoms with Polarized Electrons,"

September 24, 1982.

Andrew C. Tam, IBM Research Laboratory, San Jose, CA, "Laser-Induced

Plasmas and Shock Waves in Atomic Vapors," September 25, 1982.

Sybille Krummacher, National Synchrotron Light Source, Brookhaven

National Laboratory, Upton, NY, "News from the National Synchrotron Light

Source Facility at Brookhaven," September 27, 1982.

\

187

NBS-114A (rev. 2-80

U.S. DEPT. OF COMM.

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BIBLIOGRAPHIC DATA

SHEET (See instructions

1. PUBLICATION OR

REPORT NO.

2. Performing Organ. Report No. 3. Publication Date

NBSIR 83-2654

4. TITLE AND SUBTITLE

Technical Activities 1982

Center for Radiation Research

5. AUTHOR(S)

Prepared by: Chris E. Kuyatt

6. PERFORMING ORGANIZATION (If joint or other than N 6 S, see instructions) 7. Con tract/ Grant No. NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered

WASHINGTON, D.C. 20234

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City „ State, ZIP)

| | 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

bibliography or literature survey, mention it here)

This report summarizes research projects, measurement method development,

testing and data evaluation activities, carried out during Fiscal Year 1982 in

the NBS Center for Radiation Research. These activities fall in the areas of

radiation measurements, atomic and plasma radiation, nuclear radiation, radiation

physics, radiometric physics, and radiation sources and instrumentation.

\

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) Atomic radiation; nuclear radiation; plasma radiation; radiation instrumentation;

radiation measurement; radiation physics; radiation sources; radiometric physics.

13. AVAILABILITY

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