Destruction rates of metastable helium atoms and molecules in collisions with argon atoms

The destruction rates of metastable helium atoms and molecules due to collisions with argon atoms have been determined at 300°K in mixtures of helium (20 to 60 Torr) and argon (10−5 to 10−1 Torr) in a pulsed afterglow. Those rates are (0.7±0.1) ×10−10 cm3 sec−1 and (1.5±0.3) ×10−10 cm3 sec−1 for the metastable atoms and molecules, respectively. In addition it was possible to confirm the value of 29.5 cm2 V sec−1 for the reduced mobility of Ar2+ in He at 20°C.