Possibilities for stochastic cooling at RHIC

Intra-Beam Scattering (IBS) is the fundamental performance limitation for RHIC. The emittance growth from IBS determines the ultimate luminosity lifetime and the only cure is cooling. Full-energy electron cooling will be installed to not only control emittance growth but also reduce emittances during a store. Before that, stochastic cooling could increase integrated luminosity by momentum cooling.Two significant benefits would follow; the average luminosity in a 10 h store would double, and the problem of coasting beam in the abort gap would be solved. Of course high-frequency bunched beam stochastic cooling is required and previous attempts at this at the TEVATRON and SPS were not successful. It appears that the conditions in the heavy ion collider are more favorable. First, the high charge state of ions gives better signal to noise ratio in the Schottky signal. Second, the anomalous coherent components in the pick up signals that caused saturation in the electronics in previous attempts are greatly reduced. Measurements of Schottky signals from gold beam in RHIC at 100 GeV and longitudinal beam transfer functions are presented to illustrate these points.