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Title: L-changing depopulation of Na s and p Rydberg states by ion impact

Journal Article · · Phys. Rev. A; (United States)

Ar/sup +/ and Na/sup +/ ion beams bombarding Na ns and np Rydberg-state targets at impact velocities near the Bohr-orbital velocity of the target atoms (i.e., v-italic-tildeapprox. =1) induce transitions to (n-1)l states (lgreater than or equal to2) with larger-than-geometric cross sections. Depopulation of ns states proceeds directly into the full n-1, lgreater than or equal to2 manifold rather than populating the np or (n-1)p states as the first of a sequence of dipole-allowed steps. Depopulation of np states leads to a distribution of final states that is dominated by the nearer or high-l part of the n-1 manifold. n dependences of the cross section for ns depopulation are given at several energies for n = 32--41 and at a single energy for np, n = 26--32. The absolute cross section for Na(36s) depopulation falls gradually but steadily for reduced velocities v-italic-tilde increasing from 0.3 to 1.35. Bombardment of Na 39s and 39p states in applied fields 0--18.5 V/cm reveals that the final-state distributions become narrower as manifold states are Stark shifted close to the initial states. No theoretical results are available for direct comparison with these experiments, but the method of coupled channels seems to be the most suitable candidate.

Research Organization:
Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055
OSTI ID:
5437704
Journal Information:
Phys. Rev. A; (United States), Vol. 37:7
Country of Publication:
United States
Language:
English