Study of activation conditions with the use of 252Cf radionuclide neutron source

Inwestigation into choice of material for moderators for a facility for neutron-activation analysis on the basis of 252Cf used in prospecting and development of gold ore deposits are conducted. Spatial distributions of thermal and resonance neutrons is different types of moderators (water, organic glass, graphite, paraffin) using the method of cadmium difference by activation of gold foils dislocated in the direction at different distances from the source are studied for this purpose. Studies without sample charging have disclosed that in the sphere of the radius up to 10-15 sm hydrogenous materals ensure higher density of thernal and resonance neutrons. It is stated in the case of activation zone charging with samples that a graphite moderator 1.3-1.5 times increases density of thermal neutron flux and twice - density of resonance neutrons. Neutron flux density grows 10 and 3-15 times respectively at a hydrogenous moderator