Operating Results and Improvements on the Zero Gradient Synchrotron (ZGS) Polarized Proton Ion Source

The ANL polarized proton ion source has been operating for almost two years. In that time, the improvements and modifications discussed here have increased the peak current by a factor of 3 and the polarization to 75 to 80%. The beam stability and, spin reversal are no longer problems, and the maintenance requirements have been significantly reduced. Some further increases in the output current of the source may be possible. Adding up all of the current gains discussed above and applying them to a well-tuned source with a clean, efficient dissociator tube; beam currents of 50-60 μA may be possible. A new RF amplifier and a higher voltage electron gun in the ionizer may allow currents in the 75 iA range. However, beam currents beyond this level will probably require a radically new approach to the design of atomic beam sources.