40Ca(n, a) 37Ar Reaction at 14.1 MeV

Alpha particles produced by the interaction of 14.1MeV neutrons with
Ca have been studied by using counter telescope technique.
The well resolved groups of the alpha particles leading to 37Ar*=0,
1.41-1.61 and 2.22-3.52 MeV states were obtained. The strong forward peak in
the angular distributions of these groups suggests a large contribution from
direct reaction process, in contrast with the earlier investigations. The angular
distribution of the ground state was analyzed with the incoherent combination
of direct reaction process using DWBA method, and compound nucleus process
by Hauser-Feshbach theory. The cross section of the ground state transition
was found to be 1.7f0.2 mb, in which the contribution due to compound nucleus
process was less than 1274.
For the unresolved groups of the alpha particles, corresponding to the
highly excited states of 37Ar the angular distribution is approximately symmetrical
with respect to 90 , and is agreeable with the prediction of compound
nucleus process. From the analysis of these groups, the level density parameter,
nuclear temperature and spin cut-off parameter are evaluated.