Cooled rf stacking injection in the IUCF Cooler

The Indiana University Cooler is an electron-cooled storage ring and synchrotron designed primarily for internal target nuclear physics experiments. The Cooler is injected by a two-stage cyclotron which delivers 300 nA of polarized proton beam at kinetic energies up to 200 MeV. The desired luminosity of multipass internal target experiments in the Cooler requires that the ring current be increased by 10;A difficulty of multiturn injection of the Cooler involves the small design aperture of the ring: the transverse acceptance and momentum acceptance of the Cooler are both only about an order of magnitude larger than that of the injected beam. The smaller aperture design was an essential feature to bring down the construction and operating cost.;Use of the electron cooling technology, on the other hand, makes the phase space density of the stored beam compressible in the Cooler. The total longitudinal emittance of the tightly bunched cyclotron beam is quite small, making phase space density-conserved longitudinal stacking possible. A good combination of longitudinal stacking and electron cooling has the potential to avoid both the accumulation rate limit imposed by cooling and the phase space saturation limit imposed by incompressibility of phase space volume.;This thesis addresses development of longitudinal stacking with electron cooling at the IUCF Cooler. Effort was concentrated on circumventing the difficulties caused by the aperture limitation while maximizing the benefit of electron cooling phase space density compression. Aside from the general design and beam experiments on multiturn accumulation, much of the discussion focuses on special considerations for Cooler stacking. They include beam momentum spread reduction by synchrotron phase space rotation, stack phase displacement reduction by deceleration in a small bucket and electron cooling, longitudinal debunching stack heating reduction by adiabatic and precursor rf manipulations, and transverse kicker stack heating reduction by fundamental frequency rf bunching and electron cooling.