Gamma spectrometry on SIRIO R277 gamma scan wires

The influence of the boron shielding on the thermal neutron fluence can be noticed from the nuclides representing the thermal neutron fluence 51Cr and 60Co. Without the boron shielding the 51Cr activity increases with a factor of about 83.3 and the 60Co activity increases with a factor of about 11.1. The 58Co activity decreases with a factor 0.45 due to burn out of 58Co by thermal neutrons. The absorption of the fast neutrons in the sample holders is shown by the decrease of 54Mn, this is the difference between GSW3 and GSW1 which is 0.95. (orig.)