Angular distribution of L3M2,3M2,3(1S0) Auger electrons of argon

The angular distribution of L 3 M 2,3 M 2,3 ( 1 S 0 ) Auger electrons of argon has been measured by impact ionization with electrons of primary energy E p =497 eV, 994 eV and 3976 eV corresponding to the two-, four- and sixteen-fold of the L 3 binding energy of argon. The anisotropy coefficient A 2 of the theoretical angular distribution function W( theta )=1+A 2 P 2 (cos theta ) of the L 3 M 2,3 M 2,3 ( 1 S 0 ) Auger electrons of argon has been deduced to be 0.05+or-0.01 for E p =2E(L 3 ) and 4E(L 3 ), and 0.01+or-0.01 for E p =16E(L 3 ). In the first two cases the Auger electrons are emitted with nonisotropic distribution whereas in the latter case the distribution is isotropic within the experimental error. These results agree well with theoretical results.