Three-channel electronic instrument for the measurement of metastable level excitation functions

A three-channel electronic instrument for the measurement of the excitation function f₁₂(U₁) of forbidden transitions is described. The instrument consists of two electron guns in antiparallel arrangement and a mobile metallic detector. It is shown that in order to determine f₁₂(U¹), it is sufficient to measure either the current from collisions of the second kind of excited atoms with slow electrons, the current of secondary electrons being emitted during the bombardment of the detector surface by metastable atoms, or the radiation intensity of the spectral line emitted during step-by-step excitation. Formulas are also proposed for the determination of the absolute magnitudes of the effective cross sections of step-by-step excitation and collisions of the second kind.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 61–65, December, 1977.The author wishes to thank N. I. Petrov for valuable assistance in the preparation of the instrument.