State changing collisions with ions

State changing collisions between singly charged positive ions and Rydberg atoms of Na have been studied extensively using crossed beams of atoms and ions, the approach shown in Fig. 13.1.1 The Na atoms in a thermal beam are excited to a 

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There have been many experimental studies on fine structure changing collisions with argon ions, most of which have been performed at collision energies high in comparison to the excitation energy of the Pi/2 state. With the exception of the following unpublished data, which are from the PhD thesis of E. Haufler there have been so far no experimental studies determining the fine structure relaxation... 

The most easily observed process with ionic, as with neutral, collisions partners is mixing. When the Na nd states are exposed to an ion beam, the field ionization signal changes from one which is predominantly adiabatic to one which is predominantly diabatic. By measuring the fraction R of signal transferred from the adiabatic to the diabatic peak of the field ionization signal MacAdam et al. measured the depopulation cross section of the Na nd states by He+ ions.1 In the limit of small values of R the depopulation cross section is given by1... 

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