CERN Accelerating science

Article
Title	DESIGN IMPROVEMENT OF THE RIA 80.5 MHZ RFQ
Author(s)	Zhao, Q ; Andreev, V ; Doleans, M ; Gorelov, D ; Grimm, T L ; Hartung, W ; Marti, F ; Schriber, Stanley O ; Wu, X ; York, R C
Affiliation	(NSCL, East Lansing, Michigan)
Publication	2004
In:	22nd International Linear Accelerator Conference, Lubeck, Germany, 16 - 20 Aug 2004, pp.599
Subject category	Accelerators and Storage Rings
Abstract	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<sup>-</sup> 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.