OBSERVATION OF ANGLE-DEPENDENT POSTCOLLISION INTERACTION IN THE ELECTRON-IMPACT IONIZATION OF XE 4D(5/2)

The angular dependence of postcollision-interaction effects has been studied in the electron impact ionization of the Xe 4d(5/2) orbital at 1000 eV incident energy. The Xe N5O23O23 (S-1(0)) Auger electrons have been measured in coincidence with ejected electrons of 30 eV at two different relative angles, namely, 170 degrees and 25 degrees. At the smallest relative angle, the coincidence spectrum displays a shift towards lower Anger energies and a shape that is consistent with the predictions of angular dependent postcollision-interaction models.