Design and Analysis of the PIXIE CW Radio-Frequency Quadrupole (RFQ)

The Project X Injector Experiment (PXIE) will be aprototype front end of the Project X accelerator proposedby Fermilab [1]. PXIE will consist of an H- ion source, alow-energy beam transport (LEBT), a radio-frequencyquadrupole (RFQ) accelerator, a medium-energy beamtransport (MEBT) and a section of superconductingcryomodules and will accelerate the beam from 30 keV to30 MeV [2]. LBNL has developed an RFQ design forPXIE with fabrication scheduled to begin before the endof CY 2012. The chosen baseline design is a four-vane,4.45 m long CW RFQ with a resonant frequency at 162.5MHz (2.4 wavelengths long). The RFQ will providebunching and acceleration of a nominal 5 mA H- beam to2.1 MeV. The wall power density of less than 0.7 W/cm2results in wall power losses of about 100 kW. The beamdynamics design has been optimized to allow for morethan 99percent beam capture with a longitudinal emittance ofless than 1 keV-nsec. The RFQ mechanical design and asummary of various analyses are presented here