Polarization of electron impact radiation 7 S-3 -> 6 P-3(J) from a Hg atom

Polarization of the 7(3)S --> 6(3)P(J) radiation from the Hg atom was obser ved under electron impact with an energy a little above the 6(1)S --> 7(3)S threshold excitation energy. The observing direction was perpendicular to both the incident electron beam and the atomic beam. All of the tripler rad iation (J = 0, 1 and 2) was slightly polarized. The observed degree of frac tional polarization was -3.07, 1.98 and -0.33%, corresponding to J = 0, 1 a nd 2 spectra in the final P-3(J) states of the Hg atom, respectively. These values could be explained by assuming unequal populations in the sublevels M-s = 0 and +/-1 of the 7(3)S states, deviating from an equal mean value o f 1/3 for each sublevel. The deviation value of the fractional population f or the sublevel M-s = 0 was 0.348 +/- 0.004.