In a typical event, a neutron is captured by a 3He atom, which reacts to produce a proton and triton as shown in Figure 1. The kinetic energies of proton (573 keV) and triton (191 keV) sum to the Q-value of 764 keV for the reaction [3]. The range of these energetic daughter particles is a few millimeters at detector gas pressures of a few atmospheres. The energetic daughter particles ionize atoms creating electron-ion pairs as they slow down. The electrons are attracted to the anode with a drift time of a few microseconds across a typical shell diameter. Motion of the charge carriers produces the measured signal pulse that is sensed by the external electrodes.