U.S.-Federal Republic of Germany Cooperative Research in High-Temperature Superconductivity

美德意志联邦共和国高温超导合作研究

• 批准号: 8922344
• 负责人: Alan Portis
• 金额: $ 0.27万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-10-01 至 1991-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8922344&HistoricalAwards=false
• 关键词: U.S.; Federal; Republic; Germany; Cooperative

This award supports Professor Alan M. Portis of the University of California at Berkeley for collaborative research on high temperature superconductivity with Professor Helmut Piel, Department of Physics, University of Wuppertal. They share an interest in the development of high quality films and coatings of high temperature superconductors for a variety of applications including particle accelerator cavities operating at microwave frequency. The quality of these materials deteriorates at high microwave power levels. Together with Dr. D. W. Cooke of the Los Alamos National Laboratory, they are developing a detailed theoretical model of microwave flux penetration and surface resistance and are also undertaking careful measurements of both phenomena. The development of microwave cavities for particle accelerators has largely been led by Dr. Piel and his students. There is no comparable experience anywhere else. Dr. Portis brings to the collaboration outstanding expertise in the microwave properties of high temperature superconductors. Their goal is to identify the loss processes and to work for their elimination, so as to obtain materials that maintain their quality at high microwave power levels. Verification of a microwave critical state in superconductors would have important scientific and technological benefits. It would indicate that microwave processes in superconductors are much faster than has been thought possible, requiring reexamination of some of our ideas of flux penetration into type II superconductors. It would also improve surface quality at high power by identifying the origin of the observed power dependence in surface resistance in high temperature superconductors. If the loss mechanism does persist into the microwave frequency range, there may well be opportunities for using these materials for high frequency signal- processing. Thus a mechanism that creates a problem for particle accelerators may provide opportunities in an entirely different domain.

该奖项支持加州大学伯克利分校的艾伦·M·波蒂斯教授与伍珀塔尔大学物理系赫尔穆特·皮尔教授在高温超导方面的合作研究。他们都有兴趣开发高质量的高温超导体薄膜和涂层，用于各种应用，包括在微波频率下运行的粒子加速器腔。在高微波功率水平下，这些材料的质量会恶化。他们与洛斯阿拉莫斯国家实验室的D·W·库克博士一起，正在开发微波通量穿透和表面阻力的详细理论模型，并对这两种现象进行了仔细的测量。用于粒子加速器的微波腔的开发在很大程度上是由Piel博士和他的学生领导的。在其他任何地方都没有类似的经历。波蒂斯博士为此次合作带来了高温超导体微波特性方面的杰出专业知识。他们的目标是识别损耗过程并努力消除它们，以便获得在高微波功率水平下保持其质量的材料。验证超导体中的微波临界状态将具有重要的科学和技术好处。这将表明超导体中的微波过程比人们认为的可能的速度要快得多，这需要重新审视我们关于磁通渗透到第二类超导体的一些想法。它还将通过确定高温超导体表面电阻中观察到的功率依赖的来源来改善高功率下的表面质量。如果损耗机制确实持续到微波频率范围，则很可能有机会使用这些材料进行高频信号处理。因此，一种给粒子加速器制造问题的机制可能会在完全不同的领域提供机会。