EXCITATION OF K-ASTERISK(3P(5)4S(2)-P-2(3 2), P-2(1/2)) BY ELECTRON-IMPACT IN THE RANGE FROM NEAR-THRESHOLD TO 500-EV - ALIGNMENT AND CROSS-SECTION RATIOS/

We have measured the alignment A(20) of K(3p(5)4S(2 2)P(3/2)) and the ratio of cross sections R(0) = sigma(3/2)/sigma(1/2) of fine structur e states K(3p(5)4s(2 2)P(3/2), P-2(1/2)) for electron impact excitati on in the range of incident energy E(0) = 31.4-500 eV. We have also ca lculated these quantities in the distorted wave Born approximation (DW BA) and the plane wave Born approximation (PWBA). There is good agreem ent between experiment and the present DWBA and PWBA values for the al ignment A(20) whereas earlier DWBA values by Pangantiwar and Srivastav a deviate systematically from experiment for E(0) < 100 eV. For the ra tio of cross sections R(0) the present DWBA values agree only qualitat ively with the experiment for E(0) < 100 eV.