Study of Neutron-Induced Ionization in Helium and Argon Chamber Gases

We present studies of Helium- and Argon-filled ionization chambers exposed to intense neutron fluxes from PuBe neutron sources ( E n = 1 − 10 MeV). The sources emit about 10 8 neutrons per second. The number of ion pairs in the chamber gas volume per incident neutron is derived. While limited in precision because of a large gamma ray background from the PuBe sources, our results are consistent with the expectation that the neutrons interact purely elastically in the chamber gas. the response of four parallel plate 8 flux, cross section times the ionization left the recoiling