Electron Cooling with and Ultracold Electron Beam and Related Applications

电子冷却和超冷电子束及相关应用

基本信息

批准号：
06402005
负责人：
TANABE Tetsumi
金额：
$ 22.66万
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：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06402005/
关键词：
Accelerator Electron cooling Atomic phisics Atomic collisions Dissociative Recombination

项目摘要

Electron cooling is now becoming a very important method in atomic physics research as well as accelerator technology. The cooling time and the final accuracy in experiments are determined by the electron temperature which is limited by the cathode temperature at around 1000 ﾟC.If one can further reduce the electron temperature, more efficient cooling will be attained and the electron and ion beam quality will be improved. So far, the whole electron system had been immersed in a uniform solenoid field and the electron beam size was unchaged throughout the beam line. However, electron temperature can be reduced to a level less than the cathode temperature by expanding the electron beam adiabatically in a gradually decreasing solenoid field. Based on this principle, we modified the existing electron system to such adiabatic expansion type. We have chosen an expansion factor of 12.7 in the cross sectional area of the electron beam which was aimed at the maximum resolution. This expansion … More factor is the biggest in the existing electron coolers in the world. In the fiscal 1994, we completed the entire system after the deliberate disign, construction and installation in the storage ring.As the research competition in this area is furious, we started atomic physics experiments immediately after the completion of the device in the late 1994. Consequently, at the first experiment, we have discovered a fine structure in the dissociate recombination spectrum of the molecular ion HD^+. These data nicely compared with the theoretical predictions based on a multi-channel quantum defect theory. This is the first time for the good agreements between theory and experiment in dissociative recombination process. The results were published in the Physical Review Letters which is the most famous journal in physics and is well known for its highly rapid communication. Furthermore, strong isotope effects have been found in the dissociative recombinations of ^4HeH^+, ^3HeH^+, ^4HeD^+ and ^3HeD^+ with the ultracold electron beam. These results have been appreciated by domestic and foreign atomic physicists and were presented at the conferences in Israel, Canada and Japan. Now we are also designing a superconducting electron cooler aiming at ultrahigh accuracy. Less

电子冷却现在已成为原子物理学研究和加速器技术中非常重要的方法。实验中的冷却时间和最终准确性取决于电子温度，该电子温度受阴极温度限制在1000 ﾟ的情况下。如果可以进一步降低电子温度，将获得更有效的冷却，并且将提高电子和离子光束质量。到目前为止，整个电子系统都浸入了均匀的电磁阀场中，并且在整个梁线上都没有结盟电子束尺寸。但是，通过在逐渐降低的电磁阀场中，电子温度可以降低到低于阴极温度的水平。基于这一原则，我们将现有的电子系统修改为这种绝热膨胀类型。我们选择了电子束的横截面区域的膨胀系数为12.7，这是这个扩展的……更多的因子是世界上现有电子冷却器中最大的因子。在1994财年，我们在储存环中进行了故意调度，施工和安装后完成了整个系统。由于该领域的研究竞赛是愤怒的，我们在1994年底完成该设备后立即开始了原子物理实验。因此，在第一个实验中，我们在第一个实验中发现了分离性重组的良好结构，该结构是分离的谱系谱的分离谱。这些数据与基于多通道量子缺陷理论的理论预测很好地比较。这是分离重组过程中理论与实验之间达成良好协议的第一次。结果发表在《物理评论信》中，该信件是物理学上最著名的期刊，并以其高度快速的沟通而闻名。此外，在 ^4heh ^+， ^3heh ^+， ^4Hed ^+ and ^3hed ^+的分离重组中发现了强的同位素效应。这些结果得到了国内和外国原子物理学家的赞赏，并在以色列，加拿大和日本的会议上介绍了这些结果。现在，我们还设计了针对超高准确性的超导电子冷却器。较少的