Prompt Gamma Rays Emitted in Thermal-neutron Capture Reaction by 99Tc and Its Reaction Cross Section

Abstract

We have studied the primary and secondary rays (a total of $1;100) in 100 Tc following thermal-neutron capture by the radioactive 99 Tc isotope. A fraction of these rays have been incorporated into the corresponding level scheme consisting of 36 levels in 100 Tc. The determined neutron separation energy (S n) for 100 Tc is 6;765:20AE0:04 keV. By summing the cross sections of all ground-state transitions, we have obtained 21:37AE0:68 b as a lower limit of the thermal-neutron capture cross section for 99 Tc. We have also determined the capture cross section by examining the 540and 591-keV rays in 100 Ru emitted following the À decay of 100 Tc. The inferred thermal-neutron capture cross section for 99 Tc is 22:8AE1:8 b.

Thermal Neutron Capture Cross Section of Palladium-107

“…Because the 107 Pd(n th , ) reaction leads to the stable nuclide 108 Pd, it is not possible to measure this cross section using an activation method. However, the more difficult technique of measuring intensities 10) of prompt rays following thermal neutron capture can be employed to determine 0 in this case. Therefore, this work was undertaken to obtain 0 for 107 Pd by the analysis of prompt rays emitted from the 107 Pd (n th , ) 108 Pd reaction in comparison with a wellstudied reference nuclide.…”

Nuclear Level Densities with Microscopic Statistical Method Using a Consistent Residual Interaction

“…One of the essential data is the nuclear level density (NLD), which is defined as the number of levels per energy. The number of levels is obtained by several experimental approaches, for example, analysis of prompt gamma ray 9) and counting of resonances observed at the neutron separation energy. 10) There exists several techniques to extract information on NLDs, such as the Ericson fluctuation measurement and an approximate theoretical analysis of charged particle reactions.…”