1. A.C.Eckerbeth and F.S.Owen, Rev.Sci.Instrum. 43, 995 (1972).
2. Yu. Khait and O.Biblarz,J.Appl.Phys. 50, 4692 (1979).
3. O.Biblarz and R.E.Nelson,J.Appl.Phys. 45, 633 (1974).
4. J.Shwartz and Y.Lavie, AIAA Jornal 13, 447, 1975.
5. J.L.Barto, M.S.Thesis, US Naval Postgraduate School, Monterey, USA, 1976.