Study of Heavy-Ion Beam Cooling using the Electron Cooling Method

利用电子冷却法进行重离子束冷却的研究

• 批准号: 59420006
• 负责人: TANABE Tetsumi
• 金额: $ 24.51万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1984
• 资助国家: 日本
• 起止时间: 1984 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-59420006/
• 关键词: Electron Cooling; Heavy Ion; 蓄積リング; 電子ビーム; ビーム冷却

Electron cooling is very attractive subject of physics as well as accelerator technology. This research project aims primarily at the study of the cooling process itself and is intended to extend the technology of proton cooling to heavier ions.A device to cool light to heavy ions up to the energy of 200 MeV/u was designed and constructed. The maximum electron energy is 120 keV, which is equivalent to 200 MeV/u ion beam energy. The length of interaction region between electrons and ions is 1.5 m. The electron beam diameter is 50 mm and maximum current density is 0.5 A/ <cm^2> . Electron optics consists of a Pierce electrode, an anode and accelerating electrodes. A flat cathode is immersed in a uniform solenoid. Computer simulation studies show that transverse electron temperature of around 0.1 eV can be realized at the solenoid field less than 1.2 kG. Electron gun and collector were carefully designed taking account of the vacuum, high voltage and high temperature. The main parts of th … More e electron guiding coil consists of three solenoids and two 45゜-toroids. A good homogeneity of the magnetic field than <+!-> 2x <10^(-4)> was realized at the central solenoid. The high voltage system to accelerate electrons consists of 120 kV high voltage power supply and some other power supplies. A good stability is required for this HVPS since the longitudinal temperature of electron beam is mainly determined by the variation of the acceleration voltage. A good stability of <+!-> 1x <10^(-5)> was achieved at 120 kV. A vacuum chamber made of SUS316L stainless steel can attain the vacuum pressure of <10^(-11)> Torr. Inside the chamber we have drift tubes, position monitors and antenna to pick up microwave. Electron orbit was studied using a small electron beam. The electron path starting from the gun and ending in the collector was visually observed by viewing the light emitted from fluorescent plates. The fraction of deveation of electron trajectory at the cooling solenoid was less than <+!-> 2x <10^(-4)> , which is consistent with the result of the magnetic field measurements. Electron cooling process was studied by simulation and it was found that the cooling time of the order of second can be realized. A microparticle internal target for the electron cooler was developed. A flow of charged microparticles was produced by a simple method of contact-charging and accelerating fine metal powder. The obtained thickness between <10^(14)> and <10^(16)> atoms/ <cm^2> is just the desirable value for an internal target for a cooler ring.The construction of the ion beam storage ring to execute the beam cooling is now under construction. Im-mediately after the first beam, we intend to start the electron cooling studies, firstly for proton and then for heavy ions. The balance between target heating and electron cooling is also our important theme in future. Less

电子冷却是物理学和加速器技术中非常有吸引力的课题。本研究项目主要针对质子冷却过程本身进行研究，旨在将质子冷却技术推广到重离子，设计并建造了一台能将能量达到200 MeV/u的轻离子冷却为重离子的装置。最大电子能量为120 keV，相当于200 MeV/u离子束能量。电子与离子相互作用区的长度为1.5m。电子束直径为50 mm，最大电流密度为0.5 A/ <cm^2>。电子光学由皮尔斯电极、阳极和加速电极组成。将一个平板阴极浸入均匀螺线管中。计算机模拟研究表明，在小于1.2kG的螺线管磁场下，可以实现0.1eV左右的横向电子温度。考虑到真空、高压和高温的要求，对电子枪和收集极进行了精心设计。主要部分 ...更多信息 电子导引线圈由三个45 °和两个45 °环形线圈组成。磁场的均匀性比<+！->在中心螺线管处实现了2x <10^（-4）>。加速电子的高压系统由120 kV高压电源和其他电源组成。由于电子束纵向温度主要由加速电压的变化决定，因此对这种高压电源要求有良好的稳定性。良好的稳定性<+！->在120 kV下达到1x <10^（-5）>。用SUS 316L不锈钢制成的真空室可达到<10^（-11）> Torr的真空压力。在室内，我们有漂移管，位置监视器和天线来接收微波。使用小电子束研究了电子轨道。通过观察从荧光板发出的光，目视观察从电子枪开始并在收集器中结束的电子路径。电子轨迹在冷却螺线管处的偏离分数小于<+！-> 2x <10^（-4）>，这与磁场测量结果一致。对电子冷却过程进行了模拟研究，发现可以实现秒级的冷却时间。研制了一种用于电子冷却器的微粒子内靶。通过一种简单的接触充电和加速细金属粉末的方法产生带电微粒流。得到的厚度在<10^（14）>和<10^（16）> atoms/ <cm ^2>之间，正好是冷却环内靶的理想厚度。在第一束流之后，我们打算立即开始电子冷却的研究，首先是质子，然后是重离子。靶材加热与电子冷却的平衡也是我们未来的重要课题。少

项目成果

田邊徹美: Institute for Nuclear Study report. INS-T-454. (1986)

田边哲美：核研究所报告。INS-T-454（1986）。

田邊徹美: "ビーム電子冷却(フィジクス第6巻1号)" 海洋出版, 7 (1985)

田边哲美：“束电子冷却（物理学第 6 卷第 1 期）” Kaiyo Publishing，7（1985）

Tetsumi Tanabe: Kaiyo Shuppan Co., Ltd.Electron Beam Cooling (Physics Monthly Vol. 6, No. 1), 13-19 (1985)

Tetsumi Tanabe：Kaiyo Shuppan Co., Ltd.Electron Beam Cooling（《物理月刊》第 6 卷第 1 期），13-19（1985 年）

Tetsumi Tanabe: "ELECTRON COOLING PROJECT AT INS" Proceedings of the Workshop on Electron Cooling and Related Applications, (Karlsruhe, 1984). 3846. 127-135 (1984)

Tetsumi Tanabe：“INS 的电子冷却项目”电子冷却及相关应用研讨会论文集，（卡尔斯鲁厄，1984 年）。

Tetsumi Tanabe: "STATUS OF THE TARN <II> PROJECT" Proceedings of the 13th Int. Conf. on High Energy Accelerators, (Novosibirsk, 1986). (1987)

田边哲美：“TARN <II> 项目的状态”第 13 届国际会议论文集。