Temperature dependence of the deexcitation of He(2 3S) by atoms and molecules as studied by pulse radiolysis method

Abstract

The temperature dependence of the rate constants for deexcitation of He(2 3S) by Ar, Kr, N2, O2, CO, NO, CO2, and C2H4 has been measured in the temperature range from 133 to 300 K by a pulse radiolysis method, and thus the collisional energy dependence of the deexcitation cross sections is obtained. The results are interpreted in terms of an electron exchange mechanism. The value of α/β, the ratio of the exponential factor of the potential width Γ(R)=A exp(−αR) to that of the interaction potential V*(R)=B exp(−βR), is obtained for each target molecule. It is found that the value of α/β decreases with the increase of the deexcitation probability.