| Popis: |
Distorted-wave Born approximation calculations for Ps formation in positron impact on He, Ne, Ar, Kr and Xe are reported for the energy range up to 200 eV. Capture into the n=1, 2 and 3 states of Ps is calculated explicitly and 1/n3 scaling is used to estimate capture into states with n>3. The calculations for the heavier noble gases allow for capture not only from the outer np6 shell of the atom but also from the first inner ns2 shell. However, the inner shell capture is found to be very small. Although by no means unambiguous, the calculations provide some support to the conjecture of Larrichia et al. [J. Phys. B 35 (2002) 2525] that the double peak and shoulder structures observed experimentally for Ps formation in Ar, Kr and Xe arise from formation in excited states. |
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