Abstract

Measurements of the transfer of angular momentum to rubidium and sodium atoms in collisions with electrons are reported. For excitation of the rubidium 5²S_1/2–5² P_3/2 transition, it is found that existing first order distorted wave Born approximation calculations show poor agreement with the data and that a model which includes the relativistic interaction between the electrons and the atoms in the potential is needed. For the de-excitation of the sodium 4²S_1/2 –3² P_3/2 transition, a long standing proposal relating to the sign of the transferred angular momentum is not supported except at small scattering angles. A convergent close coupling calculation displays excellent agreement with the measured data.