1202.2141 (S. MacMullin et al.)

Partial gamma-ray production cross sections for (n,xng) reactions in
natural argon from 1 - 30 MeV    [PDF]

S. MacMullin, M. Boswell, M. Devlin, S. R. Elliott, N. Fotiades, V. E. Guiseppe, R. Henning, B. LaRoque, R. O. Nelson, J. M. O'Donnell

Background: Neutron-induced backgrounds are a significant concern for
experiments that require extremely low levels of radioactive backgrounds such
as direct dark matter searches and neutrinoless double-beta decay experiments.
Unmeasured neutron scattering cross sections are often accounted for
incorrectly in Monte Carlo simulations. Purpose: Determine partial gamma-ray
production cross sections for (n,xng) reactions in natural argon for incident
neutron energies between 1 and 30 MeV. Methods: The broad spectrum neutron beam
at the Los Alamos Neutron Science Center (LANSCE) was used used for the
measurement. Neutron energies were determined using time-of-flight and
resulting gamma rays from neutron-induced reactions were detected using the
GErmanium Array for Neutron Induced Excitations (GEANIE). Results: Partial
gamma-ray cross sections were measured for six excited states in Ar-40 and two
excited states in Ar-39. Measured (n,xng) cross sections were compared to the
TALYS nuclear reaction code. Conclusions: These new measurements will help to
identify potential backgrounds in neutrinoless double-beta decay and dark
matter experiments that use argon as a detection medium or shielding. The
measurements will also aid in the identification of neutron interactions in
these experiments through the detection of gamma rays produced by (n,xng)
reactions.

View original: http://arxiv.org/abs/1202.2141