Gorelov, D.

Paper	Title	Page
MOP71	Advanced Beam-Dynamics Simulation Tools for RIA	186
	T.P. Wangler, R. Garnett LANL, Los Alamos, New Mexico N. Aseev, P.N. Ostroumov ANL/Phys, Argonne, Illinois R. Crandall TechSource, Santa Fe, NM D. Gorelov, R.C. York NSCL, East Lansing, Michigan J. Qiang, R. Ryne LBNL, Berkeley, California
	Understanding beam losses is important for the high-intensity RIA driver linac. Small fractional beam losses can produce radioactivation of the beamline components that can prevent or hinder hands-on maintenance, reducing facility availability. Operational and alignment errors in the RIA driver linac can lead to beam losses caused by irreversible beam-emittance growth and halo formation. We are developing multiparticle beam-dynamics simulation codes for RIA driver-linac simulations extending from the low-energy beam transport (LEBT) line to the end of the linac. These codes run on the NERSC parallel supercomputing platforms at LBNL, which allow us to run simulations with large numbers of macroparticles for the beam-loss calculations. The codes have the physics capabilities needed for RIA, including transport and acceleration of multiple-charge-state beams, and beam-line elements such as high-voltage platforms within the linac, interdigital accelerating structures, charge-stripper foils, and capabilities for handling the effects of machine errors and other off-normal conditions. We will present the status of the work, including examples showing some initial beam-dynamics simulations.
TH302	End-to-End Beam Simulations for the MSU RIA Driver Linac	594
	X. Wu, M. Doleans, D. Gorelov, T.L. Grimm, F. Marti, R.C. York, Q. Zhao NSCL, East Lansing, Michigan
	The Rare Isotope Accelerator (RIA) driver linac proposed by Michigan State University (MSU) will use a 10th sub-harmonic based, superconducting, cw linac to accelerate light and heavy ions to final energies of ≤400 MeV/u with beam powers of 100 to 400 kW. The driver linac uses superconducting quarter-wave, half-wave, and six-cell elliptical cavities with frequencies ranging from 80.5 MHz to 805 MHz for acceleration, and superconducting solenoids and room temperature quadrupoles for transverse focusing. For the heavier ions, two stages of charge-stripping and multiple-charge-state acceleration will be used to meet the beam power requirements and to minimize the requisite accelerating voltage. End-to-end, three-dimensional (3D), beam dynamics simulations from the ECR to the radioactive beam production targets have been performed. These studies include a 3D analysis of multi-charge-state beam acceleration, evaluation of transverse misalignment and rf errors on the machine performance, modeling of the charge-stripping and stripping-chicane performance, and beam switchyard design. The results of these beam dynamics studies will be presented, and further planned beam dynamics studies will be discussed.
	Transparencies
THP03	DESIGN IMPROVEMENT OF THE RIA 80.5 MHZ RFQ	599
	Q. Zhao, V. Andreev, M. Doleans, D. Gorelov, T.L. Grimm, W. Hartung, F. Marti, S.O. Schriber, X. Wu, R.C. York NSCL, East Lansing, Michigan
	An 80.5 MHz, continuous-wave, normal-conducting, radio-frequency quadrupole (RFQ) was designed for the front end of the Rare Isotope Accelerator (RIA) driver linac. It will accelerate various ion beams (hydrogen up to uranium) from 12 keV/u to about 300 keV/u. The 4-meter-long RFQ accepts the pre-bunched beam from the low energy beam transport (LEBT) and captures more than 80% with a current of ~0.3 mA. Beam dynamics simulations show that the longitudinal output emittance is small for both single- and two-charge-state ion beams with an external multi-harmonic buncher. A 4-vane resonator with magnetic coupling windows was employed in the cavity design to provide large mode separation, high shunt impedance, and a small transverse dimension. The results of beam dynamics as well as the electromagnetic simulations are presented.