Improvement of beam uniformity by magnetic filter optimization in a Cs-seeded large negative-ion source
Improvement of beam uniformity by magnetic filter optimization in a Cs-seeded large negative-ion source
复制标题
通过在 Cs 种子大型负离子源中磁过滤器优化来提高束流均匀性
DOI：
10.1063/1.2165768
复制
发表时间：
2006
影响因子：
1.6
通讯作者：
K. Watanabe
中科院分区：
文献类型：
--
作者：
M. Hanada;T. Seki;N. Takado;T. Inoue;H. Tobari;T. Mizuno;A. Hatayama;M. Dairaku;M. Kashiwagi;K. Sakamoto;M. Taniguchi;K. Watanabe
为了改善大规模铯籽源的束流均匀性，研究了磁过滤结构对束流均匀性的影响。通过降低负离子源中横向磁场的滤波强度，在保持束流强度基本不变的情况下，随着等离子体均匀性的提高，束流均匀性得到了很大的改善。然而，共提取的电子电流大大增加。为了抑制coextracted电子电流，帐篷形的磁过滤器一起施加在尖磁铁的修改，形成一个典型的多尖正离子源的安排。纵向束流分布的均匀性得到改善，局部束流强度的偏差在16%以内，这几乎等于在50Gcm的横向滤波强度的偏差。与此同时，共提取的电子电流保持与H−离子电流相同。目前的结果表明，H−离子束的均匀性…
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 50Gcm 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...