Obtaining Slow Beam Spills at the Ssc Collider

There is substantial interest in providing slow-spill external proton beams in parallel with “interaction running” at the 20 TeV SSC collider. The proposal is to cause a flux of particles to impinge on a target consisting of a bent crystal extraction ‘channel.13 Additionally, a slow spill onto a conventional internal target could be used as a source of secondary beams for physics or test purposes and might also be used for B-physics as proposed for HERA. The “natural” beam loss rates from elastic and diffractive beam gas scattering and IP collisions are not sufficient to provide suitably intense external proton beams. The presently favored scheme for providing sufficient spill intensity is to increase the emittance of the beam via rf noise excitation of the longitudinal synchrotron oscillations.‘3