Open AccessOperation of {sup 3}He Proportional Chambers in High Gamma Radiation Fields
Author(s) -
N.W. Hill,
V.C. Miller,
T.E. Valentine,
J.A. Williams
Publication year - 1999
Language(s) - English
Resource type - Reports
DOI - 10.2172/15042
Subject(s) - amplifier , preamplifier , physics , radiation , nuclear physics , analytical chemistry (journal) , irradiation , linearity , atomic physics , fissile material , radiochemistry , optics , materials science , chemistry , optoelectronics , neutron , chromatography , quantum mechanics , cmos
Operation of {sup 3}He proportional chambers with irradiated fissile materials is limited because of the sensitivity of these chambers to gamma ray events. The optimum performance of these chambers is achieved with proper selection of an additive gas to the chambers and with proper choice of preamplifier and linear amplifier time constants. The counting efficiency of a 4-atm, {sup 3}He-CO2 chamber is improved from 35% to 43% in a 200 R/hr gamma radiation field by decreasing the linear amplifier time constant. Likewise, the counting efficiency of a 1-atm, {sup 3}He-CF4 is improved from 11% to 14% in a 200 R/hr gamma radiation field by decreasing the linear amplifier time constant. The 4-atm, {sup 3}He-CO2 1-in.-OD chamber has a higher efficiency than the 1-atm, {sup 3}He-CF4 1-in.-OD chamber although the energy resolution of the 3 He-CF4 chamber is better than that for the {sup 3}He-CO2 chamber