Secondary Electron Emission Type Neutral Particle Detector

Experimental studies have been made on the secondary electron emission yields from metal surfaces bombarded by H 1 0 , H 1 + , and H 2 0 with energies ranging by 10 to 40 KeV. The yields increase with the incident beam energy. The yield from H 1 0 is smaller than that by H 1 + and is proportional to the cosecant of the incidence angle. The yield by H 2 0 is larger by a factor of two than that by H 1 0 with the same velocity. The mechanism of the secondary electron emission is discussed by comparing the yield by H 1 0 with that by H 1 + and by considering the observed angular dependence. The observed difference in the yields by H 1 0 and H 1 + is considered to originate essentially from the difference between the ionization cross-sections of the two particles within the shallow layer below the surface. A neutral particle detector has been made on the basis of the angular dependence results.