Self-focusing of a high current density ion beam extracted with concave electrodes in a low energy region around 150 eV.
Rev Sci Instrum
; 85(2): 02A728, 2014 Feb.
Article
em En
| MEDLINE
| ID: mdl-24593462
ABSTRACT
Spontaneous self-focusing of ion beam with high current density (Jc â¼ 2 mA/cm(2), Ib â¼ 65 mA) in low energy region (â¼150 eV) is observed in a hydrogen ion beam extracted from an ordinary bucket type ion source with three electrodes having concave shape (acceleration, deceleration, and grounded electrodes). The focusing appears abruptly in the beam energy region over â¼135-150 eV, and the Jc jumps up from 0.7 to 2 mA/cm(2). Simultaneously a strong electron flow also appears in the beam region. The electron flow has almost the same current density. Probably these electrons compensate the ion space charge and suppress the beam divergence.
Texto completo:
1
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article