Improved Performance of BF3 Neutron Counters in High Gamma Fluxes

A method is described for maintaining good operational characteristics of BF3 counters operating in gamma fluxes of 1000 R/hr or more. Loss of good counting ability, due to accumulation of chemical dissociation products of ionization, is counteracted by placing within the counter an absorbing agent capable of removing the impurities from the gas phase. Data is presented showing pulse height resolution of several counters exposed to various levels of gamma flux. Standard type counters are compared to those containing an absorbing agent. A marked improvement in neutron counting ability in gamma fluxes is shown.