Observation of wide rf induced synchrotron sideband depolarizing resonances.

In a recent experiment with a stored 104.1 MeV vertically polarized proton beam at the IUCF Cooler Ring, we depolarized the beam using an rf solenoid with a magnetic field of about 1.3\cdot10^-3T\cdotm. We observed the two expected rf depolarizing resonances centered around the protons' 1.5 MHz circulation frequency as in previous experiments. Near each of these resonances, we also found synchrotron sidebands which are caused by the proton's energy oscillations. The strengths and widths of the synchrotron resonances were quite different for the sidebands above and below the circulation frequency.