|hicks_icc2006_snib_extra.pdf||2006-02-23 19:25:59||Nathanie Hicks|
Production and Acceleration of a Symmetric Neutralized Ion Beam Using a Radio Frequency Quadrupole Accelerator
Author: Nathanie K Hicks
Submitted: 2005-12-15 08:41:12
University of California, Los Angeles
1040 Veteran Avenue
Los Angeles, CA 90024
A symmetric neutralized ion beam is composed of positive and negative ions having the same charge-to-mass ratio, like H+ and H-. Such a beam can propagate across magnetic fields due to the formation of a polarization electric field in the beam, and may therefore be applicable to injection into magnetic confinement fusion devices. Acceleration of this kind of beam can be efficiently accomplished by a radio frequency quadruople (RFQ) accelerator. The RFQ is capable in principle of simultaneous acceleration of positive and negative ions in alternating bunches. This research aims to demonstrate the first experimental confirmation of this property. A compact (15 cm long), 200 MHz RFQ is used to accelerate a beam consisting of approximately 50 microAmps each of H+ and H- ions from 1 keV to 20 keV. The output beam is measured with a beam collector that separates the positive and negative species and discriminates energies. The results are compared to simulations using the standard RFQ code PARMTEQ, which has been modified for this research to accommodate an arbitrary number of different particle species. Scaling of such beams and accelerators to various energies and powers is discussed. The work is supported by DOE Grant DE-FG02-04ER54760.