Neutron Cross Sections. Neutron Resonance Parameters and Thermal Cross Sections, Part B: Z=61–100

654 Pages·1984·8.894 MB·English

by  Said F. Mughabghab (Auth.)

NEUTRON CROSS SECTIONS
Volume 1 Neutron Resonance Parameters
and Thermal Cross Sections
Part A Ζ = 1 - 60
S. F. Mughabghab, M. Divadeenam, and Ν. E. Holden
Part Β Ζ = 61 - 100
S. F. Mughabghab
Volume 2 Neutron Cross Section Curves
Neutron Cross Sections
Volume 1
NEUTRON RESONANCE PARAMETERS
AND THERMAL CROSS SECTIONS
Part Β
Ζ = 61 - 100
S. F. MUGHABGHAB
National Nuclear Data Center
Brookhaven National Laboratory
Upton, New York
1984
ACADEMIC PRESS, INC.
(Harcourt Brace Jovanovich, Publishers)
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United Kingdom Edition published by
ACADEMIC PRESS, INC. (LONDON) LTD.
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Library of Congress Cataloging in Publication Data
Mughabghab, S. F., Date
Neutron cross sections.
Contents: v. 1, pt. Α. Ζ = 1-60 — pt. Β. Ζ * 61-100.
1. Neutron cross sections—Tables. I. Oivadeenam, M.
II. Holden, Ν. Ε. III. Title.
QC793.5.N462N47 539.7*213 s [539.7'213] 82-110824
ISBN 0-12-509701-8 (set)
ISBN 0-12-5097Π-5 (v.l, pt. B)
PRINTED IN THE UNITED STATES OF AMERICA
84 85 86 87 9 8 7 6 5 4 3 2 1
PREFACE
This book represents the fourth edition of what was previously known as
BNL-325, Neutron Cross Sections, Volume 1,* Resonance Parameters (Third
Edition, 1973) by S. F. Mughabghab and D. I. Garber. The first edition of the
BNL-325 reports which appeared in 1955 was prepared by Donald J. Hughes and
John A. Harvey. Because of the vast amount of data included, this fourth edition
of Volume 1 is published in parts A and Β covering the mass regions represented
by Ζ = 1-60 and 61 - 100, respectively. As with the third edition, only
recommended parameters are presented.
In addition to the extensive list of detailed individual resonance parameters for
each isotope, this book contains thermal cross sections and average resonance
parameters as well as a short survey of the physics of thermal and resonance
neutrons with emphasis on evaluation methods. The introduction to the third
edition has been expanded in this edition (Part A) to include commonly used
nuclear physics formulas and topics of current interest such as direct or valence
capture and the Brink-Axel treatment of electric dipole radiation. The introduc­
tion to Volume 1, Part B, covers the topics of paramagnetic scattering, alpha
widths of resonances, and sub-threshold fission, which were not discussed pre­
viously in Part A, as well as the systematics of the average resonance parameters
for the whole mass range. New additional features have been added to appeal to a
wider spectrum of users. These include (1) spin-dependent scattering lengths that
are of interest to solid state as well as nuclear physicists and evaluators, (2)
Maxwellian 30-keV capture cross sections that are of importance to astrophysi­
cists in their studies of nucleosynthesis and the age of the universe, and (3) s- and
p-wave average radiative widths and 7-ray strength functions that are required in
capture cross section measurements by neutron physicists.
The figures describing the systematics of the potential scattering lengths, s-,
ρ-, and d-wave neutron strength functions, and average radiative widths have
been enlarged for easy readability for those users requiring an interpolated value.
Of particular interest is the determination of potential scattering lengths for light
nuclides and the comparison of the behavior of this quantity with mass number in
terms of the optical model.
* Volume 2: Neutron Cross Section Curves, in preparation.
vii
viii PREFACE
In the present edition, an attempt has been made to achieve, where possible,
a consistency between the individual resonance parameters and the various ther­
mal cross sections. To meet this objective, the parameters of negative energy
resonances are postulated where required. Immediately preceding the resonance
parameter tables, one can find the contribution to the thermal capture and fission
cross sections from positive energy resonances of each spin state (for odd target
nuclides) as well as the direct capture component calculated within the
framework of the Lane-Lynn theory. This information is required in nuclear
structure studies carried out by thermal neutron capture 7-ray spectra
measurements.
An errata to Volume 1, Part A is included in this volume. The author would
appreciate being notified by the users of any errors found in the text.
Previous editions of BNL-325 have been widely used and frequently refer­
enced. We hope that this new edition continues to be a prime source book that
will satisfy the needs of the casual and serious user of neutron cross sections as
well as the student interested in this exciting and rich field.
S. F. Mughabghab
Brookhaven National Laboratory
ACKNOWLEDGMENTS
A project of this magnitude is not the work of one individual. The list of
people whose help must be acknowledged is necessarily quite long. Four people
must be specially thanked. These are Dr. C. L. Dunford, Dr. R. R. Kinsey, F. M.
Scheffel, and V. McLane.
The scope of the project consists of four parts: (1) preparation of the pertinent
up-to-date body of data; (2) computer coding; (3) evaluation and recommenda­
tions; and (4) production and checking.
(1) Production of this volume demanded an accurate and complete body of the
world's resonance parameter and thermal data. For this publication, the com­
puterized files of the CSISRS library of the National Nuclear Data Center
(NNDC) were used. In addition, the other three international neutron data cen­
ters, CCDN (Ν. Ε. Α.), NDS (I. Α. Ε. Α.), and CJD (USSR), compiled and
transmitted to us data collected from their areas of responsibility.
(2) To operate on the CSISRS library files and produce resonance parameter
listings in a usable form for evaluation, computer coding was necessary. This
was ably carried out by V. McLane.
(3) As an aid in the evaluation stage, computer codes for physics checking
and calculations of quantities from the voluminous amount of resonance param­
eters were required. Many people readily extended their help in this regard. The
author wishes to express his deep gratitude to Dr. C. L. Dunford, Dr. R. R.
Kinsey, and V. McLane. The author also acknowledges the help of B. A. Magur-
no in calculating the Westcott factors using ENDF data base.
(4) This volume was produced from computer-generated film on an FR80.
The program to compose pages, including upper and lowercase symbols and
Greek letters, was written by Dr. R. R. Kinsey and afforded very substantial
savings of money and of errors.
The checking at various stages of this task was diligently done by F. Scheffel
and the checking of the final results was carried out by Dr. S. Pearlstein and
Dr. M. R. Bhat. The author gratefully acknowledges their suggestions and
criticisms.
In addition, the author wishes to thank M. Blennau, P. Dixon, J. Roys, S.
Santos, Τ Dawson, and A. Fuoco for their diligent, tireless effort in providing
the necessary computer services, and D. Faivre for typing the introduction.
ix
χ ACKNOWLEDGMENTS
Many physicists outside the NNDC have aided in this publication. We are
grateful to the many experimentalists throughout the world who made special
efforts to provide us with their very recent resonance parameter and thermal data
prior to publication. In particular, special mention goes to Drs. R. Macklin and
J. A. Harvey, J. Dabbs, and D. Horen of Oak Ridge National Laboratory;
Professor J. B. Garg of the State University of New York at Albany; Professors
R. C. Block and R. W. Hockenbury of Rensselaer Polytechnic Institute; Drs. H.
Jackson and R. Holt of Argonne National Laboratory; Professor R. O. Lane and
Dr. H. Knox of Ohio State University; Dr. W. R. Kane of Brookhaven National
Laboratory; Drs. H. Weigmann, G. Rohr, F. Poortmans, F. Corvi, and Κ. H.
Bockoff of Central Bureau of Nuclear Measurements, Belgium; Drs. B.J. Allen,
J. W. Boldeman, G. C. Hicks, and A. R. de L. Musgrove of Australian Atomic
Energy Commission Research Establishment; Professor F. Firk of Yale Univer­
sity; Dr. D. B. Syme of Harwell; Drs. Yu. Popov and A. B. Popov of Joint
Institute of Nuclear Research (DUBNA); Dr. S. M. Kalebin of Research Institute
Atom Reactors (USSR); Drs. J. C. Browne, B. Berman, and R. M. White of the
University of California Lawrence Livermore Laboratory; Dr. R. W. Benjamin
of Savannah River Laboratory; Dr. R. F. Carlton of Middle Tennessee State
University; Dr. R. Winters of Denison University; Drs. D. M. Drake, F. O.
Purser, and J. A. Farrell of Los Alamos National Laboratory; Dr. V. P. Vertebnyi
of the Ukranian SSR Academy of Sciences; Dr. H. G. Priesmeyer of Institut fur
Reine und Angewandte Kernphysik der Universitat Kiel; and Dr. M. Ohkubo of
Japan Atomic Energy Research Institute. In addition, we are grateful to the
physicists who communicated their thermal data prior to publication. These
include Professor Dr. L. Koester of Physik Department der Technischen Univer­
sitat Munchen; Drs. H. Glaettli and A. Abragam of Saclay; Drs. F. DeCorte and
L. Moens of the Institute for Nuclear Sciences, Belgium; Dr. E. Steiness of
Institutt for Atomenergi, Norway; Dr. B. Ryves of National Physical Laboratory,
Great Britain; Dr. Ε. T. Jurney of Los Alamos National Laboratory; Dr. Ε. T.
Kennett of McMaster University; Dr. F. Kropff of Centre Atomics Bariloche,
Argentina; Drs. V. F. Sears and M. A. Lone of Chalk River Nuclear Laborator­
ies, Canada; Dr. K. Abrahams of Reactor Centrum Netherlands; Dr. C. Coceva
of CNEN Centre, Bologna, Italy; and Dr. M. Asghar of Institute Max Von
Laue-Paul Langevin, Grenoble, France.
The criticism and suggestions of the reviewers have been essential. Our thanks
go to Dr. R. E. Chrien of Brookhaven National Laboratory; Drs. J. A. Harvey,
L. Weston, and R. Macklin of Oak Ridge National Laboratory; Professor R. C.
Block of Rensselaer Polytechnic Institute; Professor R. O. Lane and Dr. H. Knox
of Ohio State University; and Professor F. Firk of Yale University. Valuable
discussions with Drs. G. F. Auchampaugh and M. Moore of Los Alamos Na­
tional Laboratory about their sub-threshold fission results are gratefully
acknowledged.
ACKNOWLEDGMENTS xi
The tabulation of an energy-ordered listing of strong resonances as an aid to
experimentalists for identifying impurities in samples was motivated by a sug­
gestion from the late Dr. E. R. Rae. We also gratefully acknowledge Dr. G. D.
James for the tabulation of neutron energy standards. These tables appear in
Volume 1, Part B.
We would like to recognize the past and present members of the NNDC
Advisory Committee, Drs. R. Ehrlich, A. B. Smith, H. Goldstein, M. S. Moore,
G. Hanna, P. Lazarus, P. Greebler, R. A. Dannels, J. Robertson, and M. Duret
and Professors R. O. Lane and C. Maynard for their valuable suggestions and
encouragement.
The author would like to gratefully acknowledge the financial support of the
United States Department of Energy.
Neutron Physics of Thermal Cross-Sections
and Resonance Parameters
In a previous publication, the compilations and evaluations of the
thermal cross sections, average resonance properties and resonance param­
eters for elements Ζ = 1-60 were reported. In addition, a short survey of basic
neutron physics was presented with emphasis on the systematics of s- and
p-wave neutron strength functions, So and Si radiative widths, Γ ο and Γ ι
7 7
and potential scattering lengths, R'. A comparison of optical model calcula­
tions of So, Si, and R' with the relevant experimental data was made for the
purpose of testing the reliability of interpolating and extrapolating values
in mass regions where experimental data are lacking. Because of the
success of the direct capture mechanism in the thermal region and the
valence neutron model in the resonance region, these interesting aspects of
the capture reaction mechanism were discussed previously in some depth.
In this volume, we conclude the evaluations of the thermal cross sec­
tions and neutron resonance parameters of the remaining isotopes covering
the mass region Ζ = 61-100. A summary of the systematics for the whole
mass region Ζ = 1-100 is illustrated in different graphical forms. Further­
more, some interesting and exciting developments in sub-threshold neutron
induced fission and their interpretation 2 3 in terms of Strutinsky's4 double
humped fission barrier are briefly covered. For details, the interested reader
is referred to the excellent detailed review articles by Bjornholm and Lynn, 5
-
6 78
Lynn and Michaudon.
In the appendices, neutron and gamma-ray energy standards, as well as
the ten strongest resonances of each isotope are included.
To avoid repetition, this introduction is to be viewed as a supplement to
Vol. 1, part A. This volume basically follows the same format and approach
as that of Vol. 1, part A.
I. THERMAL CROSS-SECTIONS
In ref. 1, the scattering cross sections, coherent scattering amplitudes
and capture cross sections were discussed in some detail. In the present
section, the paramagnetic scattering cross sections, the generalized ex­
pression for the direct capture cross^section, and the 2200 m/sec thermal
constants for 23U3 , 23U5 , 23P9 u, and 24P1u are presented.
A. Paramagnetic Scattering
In the rare earth region and for elements in the ionic state such as oxide
samples, the interaction between the magnetic moment of the neutron and
that of the ion must be taken into account. Such an interaction gives rise to a
paramagnetic cross section which has the form: 9
1
40 Ί—ι—ι—ι—ι—ι—ι—ι—ι—ι—ι ι—ι Γ Ί—I—Γ
PARAMAGNETIC SCATTERING
OF RARE EARTH IONS
(E = 0.0253 eV)
n
EXPERIMENTAL VALUES
30 CALCULATED VALUES
20
oh
J L J L
55 65 70 75
ATOMIC NUMBER Ζ
Figure 1. Comparison of the paramagnetic scattering cross sections measured at a
neutron energy of 0.0253 eV with the theoretical calculations of Mattos .
The solid curve is an eyeguide to the theoretical values.
2