Excitation of heavy rare gases to metastable states by electron impact

The cross sections for electron impact excitation of Ar, Kr and Xe to metastable np 5 (n+1)s 3 P 2.0 states are obtained. It is shown that for heavy rare-gas atoms excitation probability through upper levels with radiative cascade to metastable states is much greater than direct excitation probability. The measurements were made in a gas cell with an electron beam. A new optical absorption method was developed and used.