Basic research of high-brightness positron and x-ray sources utilizing single crystal

利用单晶的高亮度正电子和X射线源的基础研究

• 批准号: 17540377
• 负责人: SUWADA Tsuyoshi
• 金额: $ 1.98万
• 依托单位: High Energy Accelerator Research Organization
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17540377/
• 关键词: Channeling radiation; Coherent bremsstrahlung; Positron source; Tungsten single crystal; Electron; positron linear accelerator; Positron generation; Single crystal target; 高輝度陽電子源; 高輝度X線源; タングステン結晶標的; 電子線形加速器; 電子陽電子対生成

A new tungsten monocrystalline positron target has been successtully employed for generation of the intense positron beam at the KEKB injector linac in September 2006. The target is composed of a tungsten monocrystal with a thickness of 10.5 mm. Tungsten crystals of various thicknesses were developed at collaborating Tomsk POLYTECHNIC University. A series of experimental studies at KEK have been carried out to find out the optimum crystal thickness as a function of the incident electron energy. Several technological issues were studied concerning the mounting of the tungsten crystal into the positron production station at KEK, because the crystal axis<111> must be oriented to the direction of the incident electrons to within a few mrad. To achieve this precise orientation without any alignment devices, the target assembly was carefully fabricated based on X-ray Bragg-reflection measurements in terms of the crystal axis orientation. After establishing these techniques, the crystal target was installed at the operational positron source of the KEKB injector linac. A conventional tungsten plate with a thickness of 14 mm has been used previously, and the conversion efficiency (Nei^+ Ne^-), the ratio between the number of positrons captured in the positron capture section and the number of the incident electrons, was 0.20 (mean). By replacing the tungsten plate with the tungsten crystal, it increased to 0.25 ( mean). The increase of the conversion efficiency has boosted the positron intensity to its maximum since the beginning of KEKB operation in 1999. The crystal target has been used for the first time at a high-energy electron/positron linac, and thus, useful information on radiation damage and stability of the crystal target will be obtained through KEKB operation. We believe that this new method could be applied in the next generation of B-factories and e^+ e^- linear colliders.

2006年9月，已成功地用于在Kekb注射器Linac在KEKB注射剂的强烈正电子束生成一个新的钨单晶正电子靶标。该靶标由钨单晶体组成，厚度为10.5 mm。汤姆斯克理工大学合作开发了各种厚度的钨晶体。已经在KEK进行了一系列实验研究，以找出最佳的晶体厚度，这是入射电子能量的函数。研究了几个技术问题，这些问题是关于将钨晶体安装到Kek的正电子生产站，因为必须将晶体轴<111>定向到几个MRAD内的入射电子方向。为了实现这种确切的方向而无需任何对齐设备，基于X射线布拉格反射测量值仔细地制造了目标组件，以晶体轴方向进行。建立这些技术后，将晶体目标安装在KEKB喷油器Linac的操作正电子源。以前已经使用了厚度为14 mm的常规钨板，转化效率（nei^+ ne^ - ），在正电子捕获部分中捕获的正上子数量与入射电子数量为0.20（平均值）之间的比率。通过用钨晶体代替钨板，它增加到0.25（平均值）。自1999年KEKB操作开始以来，转化效率的提高已将正电子强度提高到了最大。晶体目标已首次以高能量电子/正电子linac的高度使用，因此，将通过KEKBB Operation获得有关晶体靶标的辐射损伤和稳定性的有用信息。我们认为，这种新方法可以应用于下一代的B因子和E^+ E^ - 线性相撞器。

项目成果

Experimental study of positron production from silicon at high-bunch charges

高束电荷硅产生正电子的实验研究

• 发表时间: 2005
• 期刊: Proceedings of the 2nd Annual Meeting of Particle Accelerator Society of Japan and the 30th Linear Accelerator Meeting in Japan
• 作者: T.Suwada;et al.
• 通讯作者: et al.

単結晶を利用した加速器陽電子源の開発

单晶加速器正电子源的开发

• 发表时间: 2008
• 期刊: 日本物理学会 (印刷中)
• 作者: S.;Tanimura;諏訪田 剛
• 通讯作者: 諏訪田 剛

New Positron Source with Tungsten Single-Crystal

新型钨单晶正电子源

• 发表时间: 2007
• 期刊: Journal of the Particle Accelerator Society of Japan (KASOKUKI) Vol. 4 No. 1
• 作者: Tsuyoshi Suwada;et al.;Tsuyoshi Suwada
• 通讯作者: Tsuyoshi Suwada

Experimental Study of Positron Production from Monocrystalline Targets at the KEKB Injector Linac

KEKB 喷射器直线加速器单晶靶产生正电子的实验研究

• 发表时间: 2006
• 期刊: Proceedings of the 2006 International Linac Conference(LINAC'06)
• 作者: Tsuyoshi Suwada;et al.
• 通讯作者: et al.

Tungsten-crystal target boosts positron intensity at KEKB linac

钨晶靶提高 KEKB 直线加速器的正电子强度

• 发表时间: 2006
• 期刊: CERN Courier 46・10
• 作者: Tsuyoshi Suwada;et. al.;Tsuyoshi Suwada
• 通讯作者: Tsuyoshi Suwada