Comparison of Gabor lens, gas focusing, and electrostatic quadrupole focusing for low-energy ion beams

Author

Reiser, M.

Author_Institution

Lab. for Plasma Res., Maryland Univ., College Park, MD, USA

fYear

1989

fDate

20-23 Mar 1989

Firstpage

1744

Abstract

A theoretical reevaluation of the Gabor lens and a comparison with an electrostatic quadrupole (ESQ) doublet are presented. It is shown that the focusing strength of the Gabor lens depends on the electron trapping efficiency and is significantly higher than that of the ESQ doublet when the trapping efficiency is close to the theoretical Brillouin limit. However, an ESQ doublet with equivalent geometry and voltage parameters performs better than the Gabor lens if the trapping efficiency is below a certain threshold, as appears to be the case in experiments so far. For the present analysis, an H⁺ beam and electrons for charge neutralization are assumed. Application to H^- beams is also discussed. The results presented are of interest in connection with the problem of focusing high-brightness, low-energy ion beams such as H⁺ and H^- in the range of 10 kV to 2 MV, 10 mA to 200 mA

Keywords

beam handling equipment; beam handling techniques; focusing; ion accelerators; Brillouin limit; Gabor lens; H⁺ beam; H^- beams; electron trapping efficiency; electrons; electrostatic quadrupole focusing; focusing strength; gas focusing; low-energy ion beams; Electron beams; Electron traps; Electrostatics; Ion beams; Laboratories; Lenses; Magnetic confinement; Particle beams; Plasma confinement; Plasma transport processes;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1989. Accelerator Science and Technology., Proceedings of the 1989 IEEE

Conference_Location

Chicago, IL

Type

conf

DOI

10.1109/PAC.1989.72912

Filename

72912