Reference

NBS

Publications

NBSiR 83-2647

The Photodssintegration of the

NAT'L I NST. OF STAND Deuteron, & TECH 1982

1 111 1 1 ] A 1 110b EblSbS

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Radiation Research

Nuclear Radiation Division

Washington, DC 20234

March 1983

J

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C* /

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U S. DEPARTMENT OF COMMERCE

NATIONAL 3U*EAU 0? STANOA^OS

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NBSIR 83-2647

l f

1 THE PHOTODISINTEGRATION OF THE

DEUTERON, 1982

Dr. E. G. Fuller

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Radiation Research

Nuclear Radiation Division

Washington, DC 20234

March 1 983

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

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

The Photodisintegration of the Deuteron, 1982

E.G. Fuller

Center for Radiation Research

National Bureau of Standards

Washington, DC 20234

Measurements of the deuteron' s photodisintegration cross section

made over a thirty year time span are evaluated in terms of the cross section for El and Ml transitions calculated in the effective range approximation. The energy range covered is from

threshold to 44 MeV. Data that do not depend on a knowledge of a bremsstrahl ung spectrum's intensity or spectral distribution are shown to be described very well by the effective-range expressions. The values of the deuteron's electric pol ar i zab i 1 i ty is

shown to be in fair agreement with a value derived from the

observed deviation from Rutherford scattering of deuterons by

208 Pb. A comparison is made of the experimental data with three

recent calculations of the photodisintegreation cross section.

This short analysis of the data available for the deuteron's photodisintegration cross section was instigated both by the recent controversy

regarding the i nterpretation of these data 1 ’ 2

, and by the evaluation of the

deuteron's electric pol ar i zabi 1 i ty from a measurement of the deviation from

Rutherford scattering in the scattering of deuterons by 208Pb. 3 The data

considered for this analysis cover the energy range from the threshold for

the reaction, 2.2246 MeV, to 44 MeV. As well as being the energy region

where the cross section is of most value for technological applications, it

is also the region that establishes the magnitude of the a_ 2 sum rule for

the deuteron, i.e. the magnitude of the integral:

a -2

= I a(Ej

Y

E 2 Y

dE ( 1 )

where a(E ) is the cross section for the absorption of photons by the

deuteron

1
As was first pointed out by Migdal 4 and reemphasized 17 years later by

Levinger 5

, the static electric polarizability of the nucleus is proportional

to the integral a_ 0 of the cross section for electric-dipole transitions.

Sixteen years later, Ericson and HLifner 6 pointed out that in addition to

depending on the electric pol zari zabi 1 ity the low energy photon scattering

and therefore the value of o_

2 should depend on the magnetic susceptibility

of the nucleus. Finally Friar 7 in his complete treatment of the scattering

of photons by nuclei showed that the value of the a_ 2 sum rule depends not

only upon the electric polarizability and the diamagnetic susceptibility of

the nucleus but also on the nuclear paramagnetic susceptibility, the individual nucleon polarizabilities and susceptibilities, and various center of

mass corrections. By far the largest contributions to the a_

2 integral for

the deuteron come from the cross sections for the electric- and magneticdipole transitions, i.e., from the deuteron's electric pol ari zabi 1 i ty and

magnetic susceptibility (diamagnetic). All other terms in the general

expression are negligible compared with these. The objective of these notes

is to show that for energies below 50 MeV the reliable data for the

deuteron's photodisintegration cross section are very well described by the

sum of simple analytic functions giving the cross section for Ml and El

transitions. It is therefore appropriate to use these expressions both for

technological applications as well as to evaluate the o_ 2 integral for the

deuteron

The measurements of the cross section for the photodisintegration of

the deuteron fall into three classes: 1., those in which monoenergetic

photon sources were used, 2., those using accelerators but where it was not

necessary to know either the detailed shape or absolute intensity of a

bremsstrahl una spectrum produced in the laboratory, and 3., those in which

2
the resulting cross section depended directly on the spectral shape and

absolute intensity of a 1 aboratory-produced bremsstr ah 1 ung spectrum. Most of

the measurements made with monoenergetic photon sources were published 30 or

more years ago. In all cases where two or more measurements were made at the

same energy, the data were consistent within the stated uncertainties in the

measurements. At these energies only a single weighted mean value for the

cross section is used in this analysis. In the experimental bibliography at

the end of this report, all of these measurements are designated by a single

reference code, (57Hu80) . The original sources of these data, grouped by

photon energy, are given under this code in the bibl iography . Individual

reference codes are used to indicate the sources of the data for the group 2

and 3 measurements.

The simplest theory for the photodisintegration of the deuteron is that

based on the effective-range approximation. It results in easy to evaluate

analytic functions which give the cross section for Ml and El transitions.

Other than fundamental constants the only parameters of the n-p system that

enter these expressions are the magnetic moments of the neutron and proton,

u

n and Up, the binding energy of the deuteron, B, the very low energy singlet

and triplet scattering lengths for the n-p system, a

$

and a^ respect i vely,

and the related scattering lengths r and r These expressions are:

a(El) = a( Bethe-Peier 1 s)

( 2 )

( 3 )

3
where a^ is the singlet S scattering length, -23.719 ± 0.013 fm, B is the

deuteron binding energy, 2.2246 MeV, y - y = 4.7059, and y

2 = MB/fi 2

. The

P n mass M is the average of the neutron and proton masses, 938.9 MeV. The

approximate effective-range normalization factor N(ER) = 1/(1 - yr is

1.682 ± 0.013. This factor results from using the value of the triplet effective range, r = 1.750 ± 0.005 fm, derived from the measured triplet scattering length, a = 5.414 fm. The approximation used here is that the effectiverange derived directly from the low-energy, neutron-proton scattering data in

a model independent way is the appropriate range to use in normalizing the

deuteron's ground-state wave function, see, e.g., Brown and Jackson. 8 Note

that no effective-range normalization factor apopears in the expression for

the magnetic-dipole cross section. The parameters used here are taken from

the evaluation of neutron-proton scattering by Lomon and Wilson. 9

In the following discussion the experimental data are compared with two

functions for the total photodisintegration cross section based on the

electric- and magnetic-dipole cross sections given by equations (3) and (4).

The two functions were obtained by summing equations (3) and (4) multiplied

by different normalization factors. The first function, F(l), was obtained

by applying a normalization factor only to equation (3). The usual effective

range expression normalization, N ( ER ) = 1.682, was not used. Instead a factor

was determined by fitting the total cross section at 10, 20, and 40 MeV to the

values resulting from the detailed calculation of Partovi. 10 The resulting

normal i zation factor was N(?) = 1.637. With this normalization the total

cross section given by the above expressions differ from the Partovi values

by -1.45, -0.03, and +1.42 percent at 10, 20, and 40 MeV respectively. For

the second function, F(2), the same normalization factor, N(P) = 1.637, was

applied to the electric-dipole cross section. In addition a factor of

4
M = 1.36 was applied to the magnetic-dipole cross section given by equation

(4). The magnitude of this factor was determined by fitting the total cross

section to the low energy points plotted in figure 1. The cross section

given by F(2) differs from the Partovi values at 10, 20, and 40 MeV by

-0.87, +0.46, and +1.86 percent respectively. Only for energies below 4 MeV

is the cross section given by F(2) larger than that given by F(l) by more

than two percent.

The experimental cross section data are compared with the function F(i)

in figures 1 to 4. In figures 1 and 2 the function F(2) is also plotted.

Note that in figures 1 and 2 cross section values are plotted while in

figures 3 and 4 relative cross sections are given, i.e., the ratio of the

measured cross section to that given by F(l) is plotted. The data in

figures 1-3 are all from experiments in which the cross-secti on measurements

did not require a knowledge of either the absolute intensity or the detailed

spectral distribution of a 1 aboratory-produced bremsstrahl ung spectrum,

i.e., they are all from class 1 or 2 experiments as defined above. Note the

good agreement between the measured values and the calculated curves. For

the class 1 and 2 experiments the average deviation of the experimental

points from the values given by F(l) is +1.2 ± 5.5 percent. Based on the 31

data points between 1.504 and 38.7 MeV the chi-square for F(l) is 60. Using

F(2), the average deviation of the points is reduced to +0.4 ± 4.6 percent

and the chi-square is reduced to 12.

The data from the class 3 measurements, i.e., those which required

information on both the spectral distribution as well as the absolute

intensity of a laboratory produced bremsstrahl ung spectrum, are plotted in

figure 4. Note the rather poor agreement with the calculated cross section,

F(l), shown by the points plotted in this figure. Note particularly the

5
different trends with photon energy. Some of the measurements indicate a

positive slope for the relative cross section with increasing photon energy

while other measurements indicate a decreasing slope. The mean deviation

from the calculated cross section for the 43 class 3 measurements is

-9.3 ± 7.8 percent. This result is not surprising in view of the known

problems associated with measurements making use of bremsstrahl ung beams.

Unless considerable care is taken to determine both the absolute intensity

‘and spectral distribution of the bremsstrahl ung beam used in a specific

experimental geometry such experiments can easily have 10 to 20 percent

uncertainties both in the absolute value of a cross section at a specific

energy as well as in the relative cross section obtained by using photons

from different parts of the same bremsstrahl ung spectrum. Taken together

the class 3 experiments give little information on the appropriateness of

using the energy dependence given by the effective-range expressions to

describe the deuteron's photodisintegration cross section below 50 MeV. In

contrast the effective-range cross sections with a slight change in normalization give a very good representation of the data from the class 1 and 2

experiments. The values of a_

2 obtained using the functions F(l) and F(2)

are, respectively, 0.686 ± 0.041 and 0.712 ± 0.036 mb/MeV. These integrals

were carried out to 44 MeV. Since the total cross section peaks at 4.4 MeV

little is lost as a result of this cut off; 97 percent of the integral to

44 MeV is obtained by integrating to only 15 MeV.

The value of a_

2 obtained from the "fit" to the empirical data contains

contributions from all of the multipoles that contribute to the photodisintegration cross section. The quantity required to evaluate the static

electric pol ari zabi 1 ity of the deuteron is a_

2 (El) which while responsible

for most of the observed value does not account for all of it in any of the

6
theories of the deuteron. The measured value of a_

2 given by the total

cross section must then be corrected for the contribution of these other

multipoles. The most important contribution results from magnetic-dipole

transitions. All calculations result in a cross section for Ml transitions

that peaks sharply just above the photodisintegration threshold (2.2246 MeV)

and dominates over the electric-dipole cross section for energies up to

2.4 MeV, see e.g., the Ml cross section given in figure 1. While this cross

section is small, the fact that it peaks so sharply at such a low energy

results in it making a contribution of about 10 percent to the total a_ 2

.

Note that the data plotted in figures 1 and 2 require that there be a

component in the total cross section that peaks strongly in the threshold

region.

In figure 5 the total cross section given by the sum of equations 2 and

4 with N = 1.682, the effect i ve-ranqe value, is compared with the results of

recent calculations as well as the low-energy experimental data points.

Except for the energy region below 2.5 MeV the calculated corss section

using N = 1.637 would be indistinguishable from the curve labeled JOENPER’A'.

The curve labeled LEE results from a calculation to study weak paritynonconservation effects in the disintegration of the deuteron by polarized

low-energy photons and electrons. 11 The calculation makes use of parityadmixed deuteron bound and continuum states. Note that this cross section

curve maintains about the same positive slope above 2.9 MeV, the energy

above which the slopes of the other curves plotted in figure 5 start to

decrease. No multipole decomposition of this cross section is given. Both

electric- and magnetic-dipole cross sections are given by Chetouani,

et al. 12 and by JoenoercT. 13 The main difference between these two

calculations is in the wave functions used for the deuteron 1 s ground state.

/
Chetouani et al . derived two ground-state wave functions by solving the

Schrddinger equation resulting from two different "realistic", nonlocal,

separable, nucleon-nucleon interactions that gave "equivalent satisfactory

fits to the deuteron data and to the phase shifts up to 350 MeV". Except

for a slight difference in the magnitude of the El cross section between 4

and 15 MeV these two wave functions gave equivalent results for the photodisintegration cross section. The maximum difference between the two cross

sections was less than 4 percent at about 5 MeV. The ground-state wave

function used by Joenpera was that derived by McGee. 14 Both calculations

used plane-wave continuum states except for the L S

0 state where the singlet

phase shift, 6

0

, was taken into account. Joenpera included the "shapedependent" term in the expansion for ctg 6

0 (see, e.g., ref. 8). The total

cross section calculated by Chetouani, et al . remains about 8 percent higher

than the cross section F(l) plotted in figures 1 and 2 up to 10 MeV and then

falls to join this curve at about 20 MeV. At 2.23 MeV the total cross

section calculated by Joenpera is 1.4 times that given by F(l) but falls

rapidly so that between 2.7 and 6 MeV it is higher than that given by F(l)

in figures 1 and 2 by less than 1.5 percent. Above 6 MeV it rises again and

is hiaher than the plotted curve by a factor of 1.14 at 8 MeV, the highest

energy cal cul ated

.

While the cross-section expressions given by F(l) and F(2) result in a

total cross section that agrees very well with the empirical values of the

photodisintegration cross section it does not necessarily follow that the

break up of the total cross section into its El and Ml components is

correctly given by these expressions. While there is theoretical and some

weak experimental evidence that the magnetic-dipole contribution to the

total cross section is correctly given by equation (4), there is no evidence

8
that this component could be larger by a factor of 1.36 as was necessary to

obtain the cross section given by F ( 2) which fits the low energy data. There

have been eight photoproton angul ar-di str i buti on measurements made at five

photon energies between 2.5 an 2.89 MeV which indicate that the ratio

a(Ml)/a(El) is not given correctly by any of the expressions used to describe

the total cross section. In table 1 these data are compared with the ratios

given by several calculations of the magnetic- and electric-dipole cross

sections. The ratios of the values listed for a(Ml)/a(El) at 2.89 MeV to the

values at 2.504 MeV is the same for all of the calculations to within 1.5

percent, i.e., to a good approximation the functional dependence on photon

energy for the Ml and El cross sections is essentially the same for all

calculations, e.g., that given by equations 3 and 4 above. The ratio given

by these equations is 0.263, a much smaller value than the ratio of

0.45 ± 0.10 given by the experimental data. As was first pointed out by

Hulth£n and Nagel 15 it is difficult to simultaneously resolve the discrepancies between theory and experiment for both the angular distribution and

total cross section data at these low energies. It is interesting to note

that if the difference between the total cross sections F(2) and F(l),

A a = 0.36 a(Ml), is assumed to be due to electric-dipole rather than

magnetic-dipole transitions, a somewhat better agreement can be obtained

between the calculated and experimental values for the ratio a(Ml)/a(El).

Based on the five measured values of a(Ml)/a(El) the chi-square is reduced

from 93.5 for F(l) to 27.4 for a total cross section given by F(l) + Aa(El).

While not directly giving a quantitative confirmation of the magnitude

of the Ml strength concentrated just above the photodisintegration threshold,

the early 41.5 MeV, 180 degree el ectrcn-scattering data 16 tend to support an

Ml strength that is consistent with that given by ^equation 4. While

9
differing considerably in the magnitude of the magnetic-dipole cross section

they give at 2.23 MeV, ranging from 0.6 (ref. 15) to 1.4 (ref. 13) times the

value given by equation 3, the values for the integral a_ 2 up to 27 MeV given

by various calculations range only from 0.0702 (ref. 15) to 0.0773 (ref. 12)

mb/MeV. The value resulting from using equation 3 for the Ml cross section

is 0.0721 mb/MeV. This value, with a conservative estimate of ±10 percent

for its uncertainty has been used to obtain a value for a_

2 (El):

o_

2 (E1) = a_

2 (tot) - o_2 (M1)

= 0.686 ± 0.041 - 0.0713 ± 0.0072

= 0.615 ± 0.042 mb/MeV

The most this integral could be increased by is 0.026 mb/MeV. This would

involve making the unlikely assumption that the entire difference between the

functions F(l) and F(2) is due to electric dipole transitions. The relationship between the polarizability a and a_ 2 is

a = a_ 2 ( El) or , 2tt 2

a(fm 3

) = .9995 a_

2 (mb/MeV)

The value of the polarizability derived in a rather direct manner from the

photodisintegration cross ection, a(pd) = 0.62 ± 0.04 fm 3 is in fair agreement

with the value obtained by Rodning, et al

.

3 from the scattering of deuterons

by 203 Pb , a( sc ) = 0.70 ± 0.05 fm 3

.

10
The weakest points in the above discussion are all associated with

questions concerning the magnitude and energy dependence of the magnetic- and

eiectric-dipole photd i s i ntegrat ion cross sections between threshold and

10 MeV. The available data all come from measurements made at only eight

energies with monoenerget ic photon sources over 30 years ago. Both total

cross section and angular distribution measurements making use of modern

photon-source calibration and cross-section measurement technologies would

be extremely valuable. In order to firmly establish the magnitude of both

the empirical a_ 2 integral as well as the contribution of magnetic-dipole

transitions to it, careful total cross section and angular distribution

measurements at as many photon energies as feasible between threshold and

5 MeV are required. The energy region up to 3 MeV is particularly important.

11
57HU80 - + o

rO

Fig. 1

The

low

energy

photodisintegration

cross

section

for

the

deuteron.

The

data

points

were

obtained

from

measurements

made

with

monoenerget

ic

photon

sources.

The

total

cross

section

functions

F(l)

and F

(2)

are

defined

in

the

text.

The

lower

curve

is

the

magnetic-dipole

cross

section

given

by

equation

4.

References

for

the

data

points

are

given

in

the

Bibliography

of

Experimental

Data.
( m) NO 1103 s SSONO

13

PHOTON

ENERGY

(MEV)

Fig.

2

Cross

section

for

the

photodisintegration

of

the

deuteron.

The

data

shown

did

not

require

a

knowledge

of

either

the

intensity

or

shape

of

a

breinsstrahl

ung

spectrum.

The

curves

give

the

total

cross

section

given

by

expressions

F(l)

and

F(2)

described

in

the

text.

See

Bibliography

of

Experimental

Data

for

sources

of

data

indicated

by

reference

codes

given

in

the

upper

right

corner

of

figure.
\ o

CD

CD

CM

rO

CO

CM

CM

O

CM

CD

CM

CO

M"

O LO O

CM ^ ^

lO O O Q

LD O

O') CD

Oli|/d N0I133S SSOdO

ik

M

PHOTON

ENERGY

(MEV)

Fig.

3

Ratio

of

experimental

cross

section

values

for

the

photodisintegration

of

the

deuteron

to

the

cross

section

given

by

F(l).

The

data

shown

did

not

require

a

knowledge

of

either

the

intensity

or

shape

of

a

bremsstrahl

ung

spectrum.

See

Bibliography

of

Experimental

Data

for

sources

of

data

indicated

by

reference

codes

given

in

the

upper

right

corner

of

figure.
GO

ro

LO

CNJ O

CM

lO o O

O

lO O

CO CO

lO O

go co

OliVO NOiiOHS SSOdO

5

PHOTON

ENERGY

(MEV)

Fig.

4

Ratio

of

experimental

cross

section

values

for

the

photodisintegration

of

the

deuteron

to

those

given

by

equations

2

and

4

with

N=1

.

637

.

The

experimental

data

points

all

required

a

knowledge

of

both

the

intensity

and

shape

of

a

bremsstrahl

ung

spectrum.

See

Bibliography

of

Experimental

Data

for

sources

of

data

indicated

by

reference

codes

given

in

the

upper

right

corner

of

figure.
o in

rO CN

m

O LO

NOI103S SSOdO

Qr\]

4- > o CD 3 2: o 0) 1— 3 in i— • s_ 03 CM • o >

<+- CD r—

-a > CD c 0) o > o 4-) sz —- •r— <o 03 4-1 4-1 u CD u •f— 1/1 <d <v -a CD CL

</) c •r— 1/1 •>— oz <D to i_ i1/1 CD CD o .c C ro

i. 4-1 CD >—i u

SZ i- -a c 4-1 O c o p* 4- 03

4-1 :< «N 03 ^3" q; CM x LU i-H CD -a a_

CD

C *

4-> 03 LU t—1 C o t—H • r— C\J ro

of) l/l •r— co a CD T3 c CD U O o r— c

4-> r— CD CD o 4-1 SZ 4- -C <13 03 CD Q. 3 r— 4- C CD r— a> 4-> 03 03

4-> >>-C != O sz 4—1 o

4-J i_ c S= 4-

(-0 CD o - > i- CD c i— 4- S- o CD. 03

s- CD

0) 4-5 i

:<c

4-J 03 -O a;

13 JZ 03 '_U a; 4-> -C o_

“C 00 s:

oo •r— LU

(D •r— Z3

O

sz an 4-> C\J c

cc •<— c <4- oo 4-> c o • l/l 03

r—H •r— 00 II a •> C c i—

o 1—

•r— C£ < 4-> LU CD =3

03 sz o r— T3 1—

13 <D -a LU U r— i

sz i— <D a c_> o3

-Q o u 03 3 * i

LU

U— r-» LU C a; m> Lc c s_ • "O c 33 i—* CD

00

U

n (

•r- CD a> p

03 c

i. 03 o f— o r— £ 4- O l/l o • CD CD

00 > >

<D S- LO • r— a 3

cd

a CD cr. CD CD CD • r— i— >7" Ll. CD 1— 1

16
Table 1. Ratio of magnetic-dipole to electric-dipole cross sections

Energy Hu 1 then Eqs . 2+4

(MeV) Nagel 15 N=1 .637

Table 7

2.504 .660 .722

2.618 .395 .415

2.71 .286 .303

2.757 .250 .266

2.89 .175 .190

aG . R . Bi shop, et al • 9 Phys. Rev. 83

b

W. M. Woodward and I. Hal pern, Phys

r Weighted mean: G . R. Bi shop. et al

E. P. Mei ners

,

Jr.,

N. 0 . Lassen, Phys.

B. Hammermesh and A

Chetouani Joenpera 1Data

et al

12

.693 .750

<T3 UD oo +1 OOJ

.395 .431 .360 ± .008

.293 .322 .49 ± .07

b

.257 .285 .265 ± .006'

.185 .200 .27 ± .06

b

1052 (1951).

Rev. 76, 107 (1949)

, Phys. Rev. 83, 1052 (1951)

Phys. Rev. 76, 259 (1949);

Rev. 75, 1099 (1949);

Wattenberg, Phys. Rev. 76 1408 (1949).
BIBLIOGRAPHY OF EXPERIMENTAL DATA

Ref. Code —Enerqy Ranqe

(fevy^-

57Hu80 L. Hulthgn, M. Sugawara; Encyclopedia of Physics 39, 1, 2.504 - 17.6

edited by S. Flugge (Springer, Berlin, Germany, 13137)

Most of the monoenergetic photon-beam measurements reported

in the following papers are listed in table 4 of this review.

55A11

58 Wh 1

71 We 2

73Ba3

7 4Ah 9

74Skl

79Bol0

G. R. Bishop, et al . , Phys. Rev. 80, 211 ( 1950) 2.504

A. H. Snell, et al . , Phys. Rev. 8U7 637 (1950)

S. A. Colgate, Phys. Rev. 83, 1262 (1951) 2.62

K. Shinohara, et al . , J. PTTys. Soc . Japan _4, 77 (1949)

P. Marin, et al., Proc. Phys. Soc. London A67 , 1113 (1954)

G. R. Bishop, et. al . , Phys. Rev . 80 , 211 TT950)

A. H. Snell, Phys. Rev. 80, 632 (1950) 2.757

G. R. Bishop, et al . , Phys. Ref. 80, 211 (1950)

C. A. Barnes, et al . , Phys. Rev.

C. A. Barnes, et al . , Phys. Rev.

C. A. Barnes, et al . , Phys. Rev.

C. A. Barnes, et al . , Phys. Rev.

C. A. 3arnes, et al . , Phys. Rev.

86, 359 (1952) 4.45 ± .04

80, 326 (1950) 6.14 ± .01

86, 359 (1952) 7.39 ± .15

86, 359 (1952) 8.14 ± .08

80, 326 (1950) 12.5 ± .21

C. A. Barnes, et al . , Phys. Rev. 80, 1069 (1950) 17.6 ± .2

P.V.C. Hough, Phys. Rev. 80, 1069^1950)

W. Waffler and S. Younis, Helv. Phys. Acta 24, 483 (1951)

L. Allen, Jr., Phys. Rev. 98, 705 (1955)

B. Weissman and H. L. Schultz, Nucl. Phys. A174,

129 (1971)

H. E. E. Baglin, et. al . , Nucl. Phys. A201 , 593 (1973) 17.

J. Ahrens, et al . , Phys. Lett. 52B , 49 ( 1974)

D. M. Skopik, et al . , Phys. Rev. C9, 531 ( 1974)

M. 3osman, et al .

,

Phys. Lett. 82B, 212 (1979)

22.7 - 64.0

9.5 - 22.5

22. - 55

.

17. - 25.

15. - 25.

12. - 28.

20.8 - 38.6

13
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19

N BS-1I4A < r E v. 2-ec) U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

1. PUBLICATION OR

REPORT NO.

2. Performing Organ. Report No. 3. Publication Date

SHEET (See instructions) . NBSIR 83-2647 March 1983

4. TITLE AND SUBTITLE

THE PHOTODISINTEGRATION OF THE DEUTERON, 1982

5. AUTHOR(S)

E.G. Fuller

6. PERFORMING ORGANI ZATION (If joint or other than N 8S, see in struction s) 7. Contract/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)

10. SUPPLEMENTARY NOTES

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)

Measurements of the deuteron's photodisintegration cross section made over a thirty

year time span are evaluated in terms of the cross section for El and Ml transitions

calculated in the effective range approximation. The energy range covered is from

threshold to 44 MeV . Data that do not depend on a knowledge of a bremsstrahl ung

spectrum's intensity or spectral distribution are shown to be described very well by

the effective-range expressions. The values of the deuteron's electric polarizability

is shown to be in fair agreement with a value derived from the observed deviation from

Rutherford scattering of deuterons by 208 Pb. A comparison is made of the experimental

data with three recent calculations of the photodisintegration cross section.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s)

cross section, deuteron, dipole, electric, magnetic, nuclear, photodisintegration,

polarizability

13. AVAILABILITY

I j Unlimited For Official Distribution. Do Not Release to NTIS

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