Orientational dependence of luminescence yield excited by fast electrons in NaCl crystals

An investigation is made of the orientational dependence of the integral luminescence yield when NaCl(T1) single crystals are irradiated by electrons of energy 0.8–2.5 MeV in the direction 100. It is shown that the luminescence yield at small excitation densities depends linearly on the specific ionizational energy losses of the bombarding particles. The ionizational energy losses are calculated for the case when electrons of energy E=1.0 MeV pass through an NaCl single crystal in the direction 100. The minimum observed in the luminescence yield is due to electron capture in canalization conditions and decrease in energy losses. The maximum in the calculated curve at small angles of disorientation is due to the focusing of fast electrons by atomic chains.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 75–79, March, 1979.It remains to thank A. M. Taratin for performing the computer calculations and S. A. Vorob'ev for supervising the work.