Population of displaced levels of aluminum and copper atoms in plasma jets

Population studies have been made for the displaced levels of aluminum 4s⁴P_{1/2,3/2, 5/2} and copper⁴D_{1/2, 3/2, 5/2, 7/2} in a plasma jet entering an evacuated space. It is found that there is an increase in the relative population (which may exceed the equilibrium value) for unstable levels of high autoionization probability. This is considered to result from accentuated recombination to excited levels in a plasma jet having frozen-in ionization.We are indebted to Academician M. A. El'yashevich (AS Beloruss. SSR) for valuable discussions.