Capture of intense heavy ion beams with RFQ electrodes

使用 RFQ 电极捕获强重离子束

• 批准号: 15360041
• 负责人: OKAMURA Masahiro
• 金额: $ 9.73万
• 依托单位: RIKEN
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15360041/
• 关键词: RFQ; space charge effect; ion source; plasma; laser; highly charged ion beam; 重イオンビーム; 四重極共振器; 高周波

To capture intense heavy ions in laser plasmas up to a limit of space charge effect in RFQ electrode, experimental and simulation studies have been done. The results enabled us to design a new RFQ electrode which can handle intense carbon 4+ beam and an ion extraction devise from a laser plasma. We are currently in optimization process of the extraction devise and are still improving a maximum current of the highly charged heavy ion production. The latest result shows 65 mA of carbon beam. Our achievements was reported at "linear accelerator conference 2004" in Lubeck, Geramany last August. Our report was focused as new technique of high current heavy ion production at the summary talk in the conference.In the experiments, we examined the relationship between the strength of RFQ field and the captured ion current. This results were well explained by the simulations which took the space charge effect and the confinement force of the RFQ field into account. Both the experiment and the simulation showed that the carbon 4+ beam was captured by an inter-vane voltage of 120 kV most efficiently. Also it was found that the inter-vane voltage of 63 kV could only accelerated fully stripped carbon 6+ beam. We established the technique which could induce intense highly charged heavy ions at high purity.We also succeeded to extend pulse length of the beam from 1 micro s to 10 micro s using a variation of expanding velocities in the RFQ channel. The longer pulse length will fit to a large size synchrotron accelerators.

为了捕获激光等离子体中的强重离子，使其达到RFQ电极的空间电荷效应极限，进行了实验和模拟研究。这些结果使我们能够设计一种新的RFQ电极，它可以处理强C4+束流和从激光等离子体中提取离子的装置。我们目前正在优化引出装置，并仍在改进高电荷态重离子产生的最大电流。最新结果显示，碳束的能量为65 mA。我们的成果于去年8月在德国吕贝克举行的“2004年直线加速器会议”上公布。在会议的总结发言中，我们的报告集中在强流重离子产生的新技术上。在实验中，我们研究了RFQ场强与俘获离子流的关系。考虑到空间电荷效应和RFQ场的禁闭力的模拟很好地解释了这一结果。实验和模拟结果都表明，当叶片间电压为120kV时，C4+束流的捕获效率最高。研究还发现，63千伏的叶片间电压只能加速完全剥离的碳6+束流。我们建立了诱导高纯强高电荷态重离子的技术，并利用RFQ通道中膨胀速度的变化，成功地将束流脉冲长度从1微米S扩展到10微米S。较长的脉冲长度将适合大尺寸的同步加速器。

项目成果

High current RFQ using laser ion source

• 发表时间: 2004
• 作者: M. Okamura;R. Jameson;J. Takano;K. Yamamoto

A Comparison of High Current Ion Beam Matching from an Ion Source to a RFQ by Electrostatic and by Magnetic Lenses

通过静电透镜和磁透镜从离子源到 RFQ 的高电流离子束匹配比较

• 发表时间: 2005
• 期刊: Proc.9th European Particle Accelerator Conference 1
• 作者: R;Becker;M.Okamura;et al.
• 通讯作者: et al.

直接プラズマ入射法によるRFQ線形加速器で.炭素イオン50mA加速に成功

使用直接等离子体注入法的RFQ直线加速器成功将碳离子加速50mA。

• 发表时间: 2004
• 期刊: 日本加速器学会誌 1
• 作者: 服部俊幸;岡村昌宏;柏木啓次;岩田佳之
• 通讯作者: 岩田佳之

Compact ion source for intense heavy ion production

用于强重离子产生的紧凑型离子源

• 发表时间: 2005
• 期刊: Parity 20-3
• 作者: 福永 久雄;Y.Saito;M.Okamura
• 通讯作者: M.Okamura

Nd–YAG laser ion source for direct injection scheme

• DOI: 10.1063/1.1691513
• 发表时间: 2004-05
• 期刊: Review of Scientific Instruments
• 影响因子: 1.6
• 作者: H. Kashiwagi;T. Hattori;N. Hayashizaki;K. Yamamoto;Y. Takahashi;T. Hata;M. Okamura;R. Jameson;T. Katayama;N. Mescheryakov