权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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

电子冷却是原子物理研究和加速器技术中的一种重要方法。实验中的冷却时间和最终精度由电子温度决定，电子温度受阴极温度限制在1000 ℃左右。如果能够进一步降低电子温度，将获得更有效的冷却，电子和离子束质量将得到改善。到目前为止，整个电子系统已经沉浸在一个均匀的螺线管场和电子束的大小是不变的整个束线。然而，通过在逐渐减小的螺线管场中膨胀电子束，可以将电子温度降低到小于阴极温度的水平。基于这一原理，我们将现有的电子系统修改为这样的绝热膨胀型。我们在电子束的横截面积中选择了12.7的膨胀因子，其目的是获得最大分辨率。这种扩张 ...更多信息是世界上现有电子冷却器中最大的。1994年度，经过精心设计、建造和在储存环中安装，完成了整个系统。由于这一领域的研究竞争激烈，我们在1994年底完成装置后立即开始了原子物理实验。因此，在第一个实验中，我们发现了分子离子HD^+的解离复合光谱中的精细结构。这些数据很好地与基于多通道量子亏损理论的理论预测进行了比较。这是第一次在解离复合过程中理论与实验符合得很好。研究结果发表在《物理评论快报》上，这是物理学中最著名的期刊，以其高度快速的传播而闻名。此外，在^4HeH^+、^3HeH^+、^4HeD^+和^3HeD^+与超冷电子束的解离复合中，发现了很强的同位素效应。这些结果得到了国内外原子物理学家的赞赏，并在以色列、加拿大和日本的会议上发表。目前，我们也在设计一个超导电子冷却器，目标是达到超导精度。少