Fully stripped heavy ion yield vs energy for XE and AU ions

Synchrotrons designed originally for proton acceleration are now being modified for heavy ion acceleration. Their vacuum which is suitable for good proton operation is usually too poor for the acceleration of fractionally charged heavy ions and, consequently, they can only be used to accelerate fully stripped or bare ions. Some kind of injector accelerator must provide the necessary fully stripped ions with adequate intensity for the planned research program which means that the yields of fully stripped ions from various kinds of stripping foils must be known as a function of energy. The Bevalac is now capable of accelerating 238U ions to approximately 1 GeV/amu and measurements have shown that fully stripped 238U ions are produced with good yield at these energies.1 However, knowing the stripping yields at different energies for 238U does not allow an accurate prediction for other, lower Z projectiles. Consequently, extensive stripping yield measurements were made for 19779Au and 12954Xe ions. In addition to the stripping measurements from the direct Bevalac beam, pickup measurements were also made with specially prepared bare, one electron, and two electron ions. Since many research groups are considering heavy ion storage rings and/or synchrotrons, the pickup cross section for bare ions is important to estimate beam lifetime in terms of the average machine vacuum. Since the Mylar target provides a pickup probability similar to air, a preliminary analysis of the Xe54+ and U92+ data is presented along with predictions for other ions ranging down to Fe26+