Parity Nonconservation in Neutron Resonances in 232Th,

Authors

Sharon L. Stephenson, Gettysburg CollegeFollow
J D. Bowman, Los Alamos National LaboratoryFollow
Bret E. Crawford, Gettysburg CollegeFollow
P P J. Delheij, TRIUMFFollow
C M. Frankle, Los Alamos National LaboratoryFollow
M IInuma, Kyoto UniversityFollow
J N. Knudsen, Los Alamos National LaboratoryFollow
L Y. Lowie, North Carolina State UniversityFollow
A Masaike, Kyoto UniversityFollow
Y Matsuda, Kyoto UniversityFollow
G E. Mitchell, North Carolina State UniversityFollow
S I. Penttila, Los Alamos National LaboratoryFollow
H Postma, Delft University of TechnologyFollow
N R. Roberson, Duke UniversityFollow
S J. Seestrom, Los Alamos National LaboratoryFollow
E I. Sharapov, Joint Institute for Nuclear ResearchFollow
Y-F Yen, Los Alamos National LaboratoryFollow
V W. Yuan, Los Alamos National LaboratoryFollow

Document Type

Article

Publication Date

8-1998

Department 1

Physics

Abstract

Parity nonconservation (PNC) was measured for 24 p-wave resonances from 8 to 300 eV in ²³²Th by measuring the helicity dependence of the total neutron cross section for epithermal neutrons with an improved experimental system. Ten resonances show statistically significant parity violation. For these ten resonances the analyzing powers are all positive, thus confirming the previously observed sign correlation. The data are fit to the sum of two terms, a constant asymmetry and a fluctuating asymmetry. With this ansatz the root-mean-square PNC matrix element M=1.12 meV, which corresponds to a weak spreading widthΓ_w=4.7×10^-7 eV. For the neighboring nuclide ²³⁸U there is no constant offset, suggesting that the sign correlation is specific to ²³²Th.

Copyright Note

This is the publisher's version of the work. This publication appears in Gettysburg College's institutional repository by permission of the copyright owner for personal use, not for redistribution.

Recommended Citation

Stephenson, S., Bowman, J. D., Crawford, B .E., Delheij, P. P. J., Frankle, C. M., IInuma, M., Knudsen, J. N., Lowie, L. Y., Masaike, A., Matsuda, Y., Mitchell, G. E., Penttila, S. I., Postma, H., Roberson, N. R., Seestrom, S. J., Sharapov, E. I., Yen, Y.-F., and Yuan, V. W. (1998). Parity Nonconservation in Neutron Resonances in 232Th. Physical Review C, 58(2), 1236–1246. http://dx.doi.org/10.1103/PhysRevC.58.1236

Required Publisher's Statement

Copyright held by American Physical Society. First published as SL Stephenson et al, Parity nonconservation in neutron resonances in 232Th, Physical Review C, 58:2, 1236–1246, doi: 10.1103/PhysRevC.58.1236.