EFFECTS OF TARGET TEMPERATURE ON ANALYTICAL SENSITIVITIES OF COLD-NEUTRON CAPTURE PROMPT GAMMA-RAY ACTIVATION-ANALYSIS

Cold-neutron prompt gamma-ray activation analysis sensitivities are often decreased because of an increase in the average neutron energy on scattering within room temperature targets. Experiments were performed to determine whether target cooling would alleviate these effects. Cooling the targets to 77 K increased hydrogen sensitivity by as much as 25%. Target cooling decreases those effects of neutron scattering on CNPGAA sensitivities that are the result of an increased average neutron energy. However, cold-neutron scattering may also change the average path length traveled, and this effect on sensitivity is not alleviated by controlling temperature.