The mobilities of electrons in helium

The electron mobilities in hehum are calculated over the range of Z/ρ from 0.5 to 3.0 v./cm./mm. Hg on the basis of an electron energy distribution formula which has previously been found to be applicable over the electron energy range required for excitation and ionization in the uniform positive column in helium. When the observed variation of atomic cross-section with electron velocity is taken into account, the calculated mobilities show good agreement with the accepted measured values. It is suggested that this agreement may be regarded as evidence in support of the distribution formula considered.