The mobility of α particles in helium gas is calculated using the zeroth-order Viehland-Mason theory with interaction potentials recently computed by Cohen and Bardsley. The results show a dependence on field strength similar to the measurements of Johnsen and Biondi but are lower in magnitude by about 5%.
Wadehra JM, Cohen JS, & Bardsley JN. Mobility of α particles in helium. Phys. Rev. A. 1978;18(3):1009-11. doi: 10.1103/PhysRevA.18.1009