G. Gangopadhyay et al., PULSE-HEIGHT SPECTRUM FROM A PHOTOMULTIPLIER TUBE UNDER DIRECT GAMMA-RAY ILLUMINATION, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 336(1-2), 1993, pp. 186-188
The structure of the tail of a single-photon spectrum measured with a
gamma ray illuminated photomultiplier tube type RCA 8850 has been stud
ied. It is found that the tail shows small but clear two- and three-ph
oton peaks in the presence of a large single-photon peak.