A simple drift-diffusion model for calculating the neutralization time of H- in xe gas for choppers placed in the LEBT

Tan, Cheng-Yan

Fermi National Accelerator Laboratory

关键词: Accelerators;    43 Particle Accelerators;    Xenon Accelerators;    Electric Fields;    Beam Transport;   

DOI  :  10.2172/974354
RP-ID  :  FERMILAB-TM-2452-AD
RP-ID  :  AC02-07CH11359
RP-ID  :  974354

美国|英语

来源: UNT Digital Library

【 摘 要 】

The neutralization of H{sup -} beam with a gas like Xe is an important part of low energy beam transport (LEBT). It is well known that choppers which use an electric field when placed in the LEBT strongly affects the neutralization of H{sup -}. The question then naturally arises as to whether a magnetic chopper has a better neutralization time than an electric chopper. To answer this question, a simple 1-space, 1 time drift-diffusion model of H{sup -} beam in Xe gas has been used to calculate the neutralization times for the following scenarios: (a) a region initially cleared of Xe+ ions with an electric field but partially neutralized outside, (b) a region within and outside the chopper which is initially partially neutralized.