York R.C.

Paper	Title	Page
MO304	MSU Re-accelerator - the re-acceleration of low energy RIBS at the NSCL	28
	X. Wu, G. Bollen, M. Doleans, T. L. Grimm, W. Hartung, F. Marti, S. Schwarz, R. C. York, Q. Zhao MSU/NSCL
	The in-flight Particle Fragmentation (PF) method for producing Rare Isotope Beams (RIBs) has been used at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) since 1989. The upgraded Coupled Cyclotron Facility (CCF) has been in operation for nuclear physics research since 2001 with the experimental program largely utilizing PF produced RIBs. To provide new research opportunities for an experimental program ranging from low-energy coulomb excitation to transfer reaction studies of astrophysical reactions, a novel system is proposed at the NSCL to first stop the high energy RIBs in a helium filled gas system, then increase their charge state with an Electron Beam Ion Trap (EBIT) charge breeder, and finally re-accelerate them to about 3 MeV/u using a radio frequency quadrupole (RFQ) followed by a superconducting linac. The superconducting linac will use quarter-wave resonators with optimum beta (beta_opt = beta value for which the cavity delivers the maximum accelerating voltage) of 0.041 and 0.085 for acceleration, and superconducting solenoid magnets for transverse focusing. An upgrade option to achieve a beam energy up to ~12 MeV/u with additional accelerating cryomodules is also possible. This paper will discuss the accelerator system design and beam dynamics simulations for the MSU Re-accelerator project.
	Slides(PDF)
TUP55	Fine Grain and Large Grain Niobium Cavity Prototyping for a Proton Linac	255
	W. Hartung, J. Bierwagen, S. Bricker, C. Compton, T. Grimm, M. Johnson, D. Meidlinger, J. Popielarski, L. Saxton, R. C. York Michigan State University G. W. Foster, I. Gonin, T. Khabiboulline, N. Solyak, R. Wagner, V. Yarba Fermilab P. Kneisel JLab
	A superconducting cavity has been designed and prototyped for acceleration of particles travelling at 81% the speed of light (beta = 0.81). The application of interest is an 8 GeV proton linac proposed as an upgrade to the Fermilab accelerator complex, although the cavity would also be suitable for other ion accelerators. The cell shape is similar to that of the 805 MHz high-beta cavity developed for the Spallation Neutron Source Linac, but the resonant frequency is 1.3 GHz and the beam tube diameter matches that of the 1.3 GHz cavity for the TeSLA Test Facility. Four single-cell prototypes have been fabricated and tested before and after post-purification. Two of the cavities were formed from standard high purity fine grain niobium sheet; the other two were fabricated from large grain niobium, following up on the work at Jefferson Lab to investigate the potential of large grain material for cost savings and/or improved RF performance. Two 7-cell cavity prototypes (one fine grain, one large grain) have also been fabricated. The single-cell results are presented in this paper, and the status of the prototyping effort is reported.
TUP67	Niobium Quarter-Wave Resonator Development for a Heavy Ion Re-accelerator	296
	W. Hartung, J. Bierwagen, S. Bricker, C. Compton, T. Grimm, M. Johnson, F. Marti, J. Popielarski, L. Saxton, R. C. York Michigan State University A. Facco INFN-LNL E. Zaplatin FZ Juelich
	A superconducting linac is being designed for reacceleration of exotic ions produced by the Coupled Cyclotron Facility at Michigan State University (MSU). The re-accelerator beam line will include a cyclotron gas stopper, a charge breeder, a normal conducting radio-frequency quadrupole, and two types of superconducting quarterwave resonators (QWRs) for re-acceleration to energies of up to 3 MeV per nucleon, with the option of additional acceleration to 12 MeV per nucleon as a future upgrade. Both QWR types are based on existing cavities that are presently used at INFN-Legnaro. The second QWR (optimum beta = 0.085, 80.5 MHz) was previously designed and prototyped as a collaborative effort between Legnaro and MSU. The first QWR (optimum beta = 0.041, 80.5 MHz) is very similar to the corresponding QWR in use at Legnaro, but with a larger beam aperture. Separation between the cavity vacuum and the cryostat insulation vacuum is also implemented to reduce the risk of particulate contamination. Structural analysis of the QWRs is being done in collaboration with FZ Juelich. The beta = 0.041 QWR design and prototyping effort is discussed in this paper.