Measurement of the 241Am (n, 2n) reaction cross section, by the activation method

The measurement of the cross section of the reaction 241Am (n, 2n)240Am, has been performed, for the first time at neutron energies from 8.8, to 11.1MeV, by the activation method. The neutron beam was produced at the TANDEM accelerator of NCSR “Demokritos”, by the 2H (d,n)3 He reaction, using a deuterium gas target. During the 5‐day long irradiation, the neutron beam fluctuations were monitored in 100 sec intervals by a BF3 counter connected with a multi‐scaling unit. The radioactive target consisted of a 37GBq 241Am source enclosed in a Pb container. A natural Au foil, a 27Al foil and a 93Nb foil were used as reference materials for the neutron flux determination. After the end of the irradiation the activity induced at the target and the reference foils, was measured off‐line by a 56 % HPGe detector.