Cold Highly Ionized Ions: Comparison of Energies of Recoil Ions Produced by Heavy Ions and by Synchrotron Radiation X-rays

Abstract

The energies of highly excited, high-charge-state recoil ions produced by fast heavy-ion impact on target atoms ("hammer" method) have been compared with the energies of similar-charge-state recoil ions produced by vacancy cascades subsequent to inner-shell photoabsorption of tuned synchrotron radiation X-rays ("scalpel" method). These comparisons show that the "hammer" method leads to recoil ion temperatures typically 4 orders of magnitude lower than those which occur in plasma sources in which ions of similar ionization and excitation states have comparable abundance, while the "scalpel" method leads to temperatures up to 6 orders of magnitude lower. Advantages and drawbacks of each method for potential precision spectroscopy of stored or trapped high charge state ions, and for production of extracted beams of low emittance for use in secondary ion-atom collison studies at eV to keV energies are discussed.