Improvement of beam uniformity by magnetic filter optimization in a Cs-seeded large negative-ion source

M. Hanada, T. Seki, N. Takado, T. Inoue, H. Tobari, T. Mizuno, Akiyoshi Hatayama, M. Dairaku, M. Kashiwagi, K. Sakamoto, M. Taniguchi, K. Watanabe

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

The influence of magnetic filter configuration on the beam uniformity was examined to improve beam uniformity in a large Cs-seeded negative-ion source. By reducing the filter strength of the transverse magnetic field used in a typical negative-ion source, the beam uniformity was largely improved with the improvement of the plasma uniformity while the beam intensity was kept to be nearly constant. However, the coextracted electron current greatly increased. To suppress the coextracted electron current, a tent-shaped magnetic filter was applied together with modifications in the cusp magnets to form a typical multicusp positive-ion source arrangement. The uniformity in longitudinal beam profile was improved with the deviation of local beam intensity within 16% that was nearly equal to the deviation obtained at 50 G cm of the transverse filter strength. In the meantime, the coextracted electron current was kept to be the same as the H- ion current. The present result suggests that the uniformity of H- ion-beam profile is affected by the uniformity of atoms or protons in the source plasma, which are the primary species of negative ions under Cs-seeded surface production.

Original languageEnglish
Article number03A515
JournalReview of Scientific Instruments
Volume77
Issue number3
DOIs
Publication statusPublished - 2006 Mar

Fingerprint

Magnetic filters
Ion sources
Heavy ions
negative ions
ion sources
Negative ions
filters
optimization
Electrons
Plasma sources
Ion beams
Magnets
Protons
Positive ions
Magnetic fields
deviation
Plasmas
Atoms
electrons
Ions

ASJC Scopus subject areas

  • Instrumentation
  • Physics and Astronomy (miscellaneous)

Cite this

Hanada, M., Seki, T., Takado, N., Inoue, T., Tobari, H., Mizuno, T., ... Watanabe, K. (2006). Improvement of beam uniformity by magnetic filter optimization in a Cs-seeded large negative-ion source. Review of Scientific Instruments, 77(3), [03A515]. https://doi.org/10.1063/1.2165768

Improvement of beam uniformity by magnetic filter optimization in a Cs-seeded large negative-ion source. / Hanada, M.; Seki, T.; Takado, N.; Inoue, T.; Tobari, H.; Mizuno, T.; Hatayama, Akiyoshi; Dairaku, M.; Kashiwagi, M.; Sakamoto, K.; Taniguchi, M.; Watanabe, K.

In: Review of Scientific Instruments, Vol. 77, No. 3, 03A515, 03.2006.

Research output: Contribution to journalArticle

Hanada, M, Seki, T, Takado, N, Inoue, T, Tobari, H, Mizuno, T, Hatayama, A, Dairaku, M, Kashiwagi, M, Sakamoto, K, Taniguchi, M & Watanabe, K 2006, 'Improvement of beam uniformity by magnetic filter optimization in a Cs-seeded large negative-ion source', Review of Scientific Instruments, vol. 77, no. 3, 03A515. https://doi.org/10.1063/1.2165768
Hanada, M. ; Seki, T. ; Takado, N. ; Inoue, T. ; Tobari, H. ; Mizuno, T. ; Hatayama, Akiyoshi ; Dairaku, M. ; Kashiwagi, M. ; Sakamoto, K. ; Taniguchi, M. ; Watanabe, K. / Improvement of beam uniformity by magnetic filter optimization in a Cs-seeded large negative-ion source. In: Review of Scientific Instruments. 2006 ; Vol. 77, No. 3.
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