The drift velocities of positrons in rare gases, He, Ne and Ar have been calculated at various temperatures. The drift velocity depends quite sensitively on the strength of the electric field and temperature.

We have performed a computer-aided analysis of position behaviour in atomic hydrogen. Effect of electric, magnetic and temperature fields on the diffusion and annihilation of positrons has been studied. Electric field is varied over a wide range of 0–200 V cm⁻¹ amagat⁻¹, magnetic field over 0–30 kG while the temperature range considered is 300–10,000°K. The position decay rate decreases with electric and temperature fields but increases with magnetic fields. However, the effect of these fields is reversed on the diffusion coefficient.

Positron annihilation and average energy in argon have been investigated in the presence of external high frequency electric and steady magnetic fields. The effect of temperature has also been studied. Two models of positron atom interaction have been employed and compared with experimental results wherever possible.