We have observed spin-exchange collisions between the singly ionized
2P23 ground state of Xe and the
3P2 metastable state of neutral Xe, both formed and aligned by electronic-impact excitation under space-charge neutralization. Extension to the rf spectroscopy of the ionized ground state of other noble-gas atoms seems promising.
The radio-frequency paramagnetic-resonance method was used to observe the exchange collisions between the singly ionized Xe ground state
2P23 and the neutral metastable state
3P2. The ionic ground-state and metastable-state atoms are both formed and aligned by unidirectional low-energy high-flux electron-beam impact. The magnetic resonances of even and odd ionic ground-state atoms were observed by monitoring changes in the transparency of the resonance radiation absorbed by the metastable-state atoms. Phenomenological theories are presented which explain the sign of the magnetic-resonance signal of the ionic ground state relative to that of the neutral metastable state, together with independent experimental evidence to support the theories. Conclusive experimental evidence is presented supporting our original assumptions that the ionic ground-state
Xe+(2P23) is aligned by low-energy electron-impact ionization and that such alignment is detectable through the results of exchange collisions with the metastable state.