Measurements of Electron Drift Velocity in3He Gas

Electron drift velocities in 3He and 4He gases were measured at 0.1 MPa and we compared the results in 3He and 4He under the electric field strength normalized by the number density of helium gas, E/N, from 0.04 to 1.0 Td. This is the first experimental confirmation of the fact that the electron drift velocity in 3He gas is larger than in 4He gas. The difference in the electron drift velocities is attributed to the difference in the atomic masses of 3He and 4He.