METHOD FOR DETERMINING MODERATION LENGTH OF FAST NEUTRONS IN WELL-BROKEN ROCK

摘要

FIELD: determining moderation length of fast neutrons. SUBSTANCE: method involves irradiation of medium being analyzed by stationary neutron flux and recording of flux of epithermal neutrons N_et at recorded distance from neutron source followed by calculation of moderation length L using experimentally derived equation including well diameter. In addition, epithermal neutron flux is measured by means of same instrument in well fluid; measurements are also made of rock clayness K_cl and density ρ their values being used to distinguish hydrogen containing and non-containing strata. Mathematical models for hydrogen containing and non-containing strata are used to calculate moderation length of fast neutrons in rock. Prior to analyzing unknown media N_et is measured in standard media with known moderation lengths and well diameter, and measurement data are used to calculate constants for mathematical models. EFFECT: improved neutron moderation length measurement accuracy. 4 cl, 1 tbl