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Determination of the meniscus shape of a negative ion beam from experimentally obtained beam profile
https://repo.qst.go.jp/records/48724
https://repo.qst.go.jp/records/487246e28dfd1-2d4f-4696-99fe-8fd0dabb8843
| Item type | 学術雑誌論文 / Journal Article(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2018-04-15 | |||||
| タイトル | ||||||
| タイトル | Determination of the meniscus shape of a negative ion beam from experimentally obtained beam profile | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | journal article | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Ichikawa, Masahiro
× Ichikawa, Masahiro× Kojima, Atsushi× Chitarin, G.× Agostinetti, P.× Aprile, D.× Bartador, C.× Barbisan, M.× Delogu, R.× Hiratsuka, Junichi× Marconato, N.× Nishikiori, Ryo× Pimazzoni, A.× Sartori, E.× Serianni, G.× Tobari, Hiroyuki× Umeda, Naotaka× Veltri, P.× Watanabe, Kazuhiro× 吉田, 雅史× Antoni, V.× Kashiwagi, Mieko× 市川 雅浩× 小島 有志× 平塚 淳一× 錦織 良× 戸張 博之× 梅田 尚孝× 渡邊 和弘× 柏木 美恵子 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | In order to understand the physics mechanism of a negative ion extraction in negative ion sources, an emission surface of the negative ions around an aperture at a plasma grid, so-called a meniscus, has been analyzed by an inverse calculation of the negative ion trajectory in a two dimensional beam analysis code. In this method, the meniscus is defined as the final position of the negative ion trajectories which are inversely calculated from the measured beam profile to the plasma grid. In a case of the volume-produced negative ions, the calculated meniscus by the inverse calculation was similar to that obtained in conventional beam simulation codes for positive ion extractions such as BEAMORBT and SLACCAD. The negative ion current density was uniform along the meniscus. This indicates that the negative ions produced in the plasma are transported to the plasma grid uniformly as considered in the transportation of the positive ions. However, in a surface production case of negative ions, where the negative ions are generated near the plasma grid with lower work function by seeding cesium, the current density in the peripheral region of the meniscus close to the plasma grid surface was estimated to be 2 times larger than the center region, which suggested that the extraction process of the surface-produced negative ions was much different with that for the positive ions. Because this non-uniform profile of the current density made the meniscus shape strongly concave, the beam extracted from the peripheral region could have a large divergence angle, which might be one of origins of so-called beam halo. This is the first results of the determination of the meniscus based on the experiment, which is useful to improve the prediction of the meniscus shape and heat loads based on the beam trajectories including beam halo. | |||||
| 書誌情報 |
AIP Conference Proceedings 巻 1869, p. 030024-1-030024-9, 発行日 2017-08 |
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| 出版者 | ||||||
| 出版者 | American Institute of Physics | |||||
| DOI | ||||||
| 識別子タイプ | DOI | |||||
| 関連識別子 | 10.1063/1.4995744 | |||||
| 関連サイト | ||||||
| 識別子タイプ | DOI | |||||
| 関連識別子 | http://dx.doi.org/10.1063/1.4995744 | |||||
| 関連名称 | http://dx.doi.org/10.1063/1.4995744 | |||||
