ON THE THE THEORY OF BETA-RADIOACTIV ITY I I I INFLUENCE OF ELECTRIC AND MAGNETIC F IELDS ON POLARIZED ELECTRON BEAMS *)

The influence of electric and magnet ic fields on the spin or ientat ion (polarization) of electrons in a beam is calculated according to the P a u I i spin theory and the D i r a c theory. For the cases, where the field is per-pendicular or parallel to a polarized electron beam, the following results are found. Transverse lectric field. In the non-relat ivist ic approx imat ion the spin or ientat ion remains constant in space, even if the beam is deflected; the relat ivist ic formula gives for the ratio of the rotat ion of the spin or ientat ion and the angle of deflection of the beam: Eki,,/E (ratio of kinetic energy and tota l energy, i.e., including the rest mass). Transverse magnetic field. The spin or ientat ion does not change in rela-t ion to the direction of propagation. Longitudinal electric field. Though the beam is accelerated (or retarded) the spin or ientat ion remains constant in space. Longitudinal magnetic]idd. The spin or ientat ion rotates about the direc-t ion of propagation. I t is shown that longitudinal polarization of electron beams (spins parallel or antiparal lel to the direction of propagation) can be observed by means of an electric deflection of the beam and a scatter ing exper iment in succession