Flux normalization for d-T sources

Summary form only given, as follows. A technique for measuring the source strength of d-T neutron generators used in well logging has been developed. The ¹⁶O(n,p)¹⁶N reaction was chosen to monitor the 14-MeV flux because of the high (11-MeV) threshold for this reaction. An oxygen-containing scintillator, cerium-activated yttrium orthosilicate, is used as both oxygen target and detector for the decay products of ¹⁶N. All signals are counted between accelerator pulses to reduce interference with the 7-s half-life signal from ¹⁶N. Only those events which deposit greater than 7.7 MeV in the scintillator are counted, in order to avoid interference from external oxygen background reactions and from backgrounds arising from thermal neutron capture in steel casing pipe. Gain stabilization is achieved by observing the double-escape peak from an external gamma source. The cerium-activated scintillator performs well at the elevated temperatures found downhole