ALIGNMENT OF KR+(3D(3 2,5/2)) AND XE+(4D(3/2,5/2)) AFTER PROTON IMPACT IONIZATION IN THE ENERGY-RANGE 40-300 KEV/

We have measured the alignment parameter A20 of Kr+(3d3/2,5/2) and Xe(4d3/2,5/2) ions after impact ionization by protons via the non-isotro pic emission of Auger electrons. The energy range of protons was E(H+) = 40-300 keV which corresponds to the ranges of reduced velocity v(H)/v3d = 0.48-1.31 for krypton and v(H+)/v4d = 0.56-1.54 for xenon. In the case of Kr(3d3/2,3d5/2) ionization the A20 values showed a resonan ce-like behaviour with maximUM of A20 = 0.24 at v(H+)/v3d almost-equal -to 0.8. In the case of Xe(4d3/2,4d5/2) ionization the maximum value o f A20 was smaller and shifted to smaller v(H+)/v4d as compared with Kr (3d). The comparison with theoretical A20 values calculated by Berezhk o et al. for the direct (Coulomb) ionization indicated that in both ca ses ionization by electron capture also contributes non-negligibly to the cross section and to the alignment parameter.