Temperature dependence of the rate constants for deexcitation of He(2 1P) by SF6 and Ar

The temperature dependence of the rate constants for deexcitation of He(2 1P) by SF6 and Ar has been measured in the temperature range from 133 to 300 K using a pulse radiolysis method, thus obtaining the collisional energy dependence of the deexcitation cross sections. The results agree well with the calculations of the Penning ionization cross sections based on a long-range dipole--dipole interaction. It is also suggested that bent trajectory due to an attractive potential is important, which influences greatly the absolute value and the collisional energy dependence of the cross sections