NEUTRON-ACTIVATION ANALYSIS OF REFRACTORY COMPOUNDS

Instrumental neutron activation techniques for the determination of 26 -36 impurities in MoSi2, WSi2, TiB2, NbB2, TiC, NbC and SiC with detec tion limit of 0.1-0.000001 ppm in the range of contents of 100-0.001 p pm have been developed. The determination of this large number of elem ents was achieved with using complex conditions of irradiation, includ ing varying neutron energy and choosing optimal time parameters. The c ontents of short-lived radionuclides also have been determined. Self-s hielding and disturbance of neutron flux, absorption of gamma-rays wer e taken into account both with the help of literature data and prelimi narily obtained experimental results.