Pulsed extraction of ionization from helium buffer gas

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:266

Article

Morrissey, D. J.^1,2  Bollen, G.^1,3  Facina, M.¹  Schwarz, S.¹ 

[1] Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA

[2] Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA

[3] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA

关键词: Nuclear recoils;    Helium buffer gas;    Ion transport by electrostatic fields;    Space charge;    Radioactive ion beams;   

DOI  :  10.1016/j.nimb.2008.07.018

来源: Elsevier

【 摘 要 】

The migration of intense ionization created in helium buffer gas under the influence of applied electric fields is considered. First the chemical evolution of the ionization created by fast heavy-ion beams is described. Straight forward estimates of the lifetimes for charge exchange indicate a clear suppression of charge exchange during ion migration in low pressure helium. Then self-consistent calculations of the migration of the ions in the electric field of a gas-filled cell at the National Superconducting Cyclotron Laboratory (NSCL) using a particle-in-cell computer code are presented. The results of the calculations are compared to measurements of the extracted ion current caused by beam pulses injected into the NSCL gas cell. (C) 2008 Elsevier B.V. All rights reserved.

【 授权许可】

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