The population kinetics of metastable electron states

Yu. A. Kulagin, Leonid A. Shelepin

A I Didyukov, Iu. A. Kulagin, S. A. Reshetnyak +1 more

T. K. Razumova, G. M. Rubanova

D. A. Myshkis, E. G. Luzan

The kinetics of oriented metastable states is examined in a helium plasma afterglow at T ≈ 10 °K and in superfliud helium. The initial conditions given by preliminary optical orientation under total mixing conditions are extended for both the cases under consideration. Their total spin is conserved in bulk processes of destruction of metastable states and the orientation reaches unity. Results are presented for a computation of the kinetics on an electronic computer. The time to achieve complete orientation is less than 10 msec for concentrations of He(23S1) and He2(23Σu+) ≈ 1012 cm3. In the gas phase, the behavior of the inverse concentration is linear in time for a zero initial orientation. In a liquid the features of the kinetics and the optical orientation are related to the formation of microbubbles around the metastable states and electrons. This results in nonmonotonic behavior of the concentration components with zero spin projection.

L. M. Biberman, V. S. Vorob’ev, I. T. Yakubov

Vladimir Leonardovich Derbov, Leonid A. Melnikov, И. М. Уманский +1 more

Numerical study of the kinetics in metastable antiprotonic helium molecules driven by a sequence of laser \ensuremath{\pi} pulses resonant to the adjacent transitions is carried out. The phenomena taking place are shown to be useful for checking the mechanisms of the depopulation of high-n states, for measuring the populations of the individual energy levels, and for slowing down the decay by means of \ensuremath{\pi}-pulse-induced inversion.