EXPERIMENTAL-DETERMINATION OF THE REAL ELEMENTS OF THE DENSITY-MATRIXOF H(N=3) ATOMS PRODUCED IN 20-100-KEV COLLISIONS OF H+ ON KR

In continuation of our previous work, charge transfer processes occurr ing in protons on rare-gas-atom collisions have been investigated. Dia gonal and real off-diagonal coherence elements of the density matrix f or H(n=3) atoms produced in 20-100-keV electron-capture collisions wit h Kr atoms are experimentally determined by analyzing the Balmer-alpha light from the decay of H atoms from the (n=3) state to the (n=2) sta te. The intensity and polarization of the emitted Light are measured a s functions of an axially symmetric electric held in the collision reg ion. These data are fitted to a numerical model of the H atom in an el ectric field in order to extract density-matrix elements. The results are compared to previous studies of H+ on He and Ar. The collisionally produced dipole moment of the H(n=3) atom decreases for increasing at omic number of the rare-gas target atoms, which indicates that the fin al phase of the collision process is not essential for the formation o f the dipole moment. This physical picture is further supported by our alignment data. Absolute cross sections for charge transfer to the 3s , 3p, and 3d levels are presented as well.