CAREER: An Integrated Research/Educational Plan for Advancing RF Superconductivity for Particle Accelerators

提案号：0841213机构：康奈尔大学nsf项目：PHY ？基本粒子加速器用户主要研究者：Liepe， Matthias U.职称：职业：推进粒子加速器射频超导性的综合研究/教育计划本提案要求部分支持一项研究计划，该计划旨在系统地表征超导体的射频（RF）表面电阻，以推进粒子加速器的超导微波腔，并支持一项涉及社区大学教职员工和学生的教育和推广计划。这项研究将在康奈尔大学的基于加速器的科学和教育实验室进行。超导射频（SRF）加速腔的最终性能由两个因素决定：在没有电击穿的情况下可以实现的最大加速梯度，以及在该最大梯度附近工作时的腔Q（或质量因子）。Q越高，实现最大梯度所需的功率越小，因此建造和操作加速器的成本越低。在给定的激发水平下，腔体的最佳Q与腔壁材料的射频表面电阻有关，而这种表面电阻又与表面的最大射频磁场有关，这种方式既依赖于样品，又在理论上很难理解。提出的研究计划的重点将是研究限制SRF腔内固有Q的机制，以及提高Q的方法。研究这些主题的主要重点将放在超导体铌上，这是当今SRF腔的首选材料。作为附属课题，将探讨a -15超导体Nb3Sn提供最高内在品质因子空腔的潜力。在研究这些主题时，获得统计上显著的数据将是至关重要的。该提案通过开发用于快速周转测试小材料样品的宿主腔来解决这一挑战。新一代改进的超导射频腔将通过改善未来粒子加速器的能量范围、性能和科学潜力，对基于加速器的科学和工程产生变革性的广泛影响。这些下一代加速器将满足粒子物理、核物理、中子科学、x射线科学和自由电子激光器的需求。此外，这项研究提供了未来几代加速器科学家和工程师的教育，这是高需求的。最后，该提案还包括一个专门为社区大学学生提供物理科学研究机会的项目，以鼓励他们从事科学、技术或科学教育方面的职业。这个庞大而关键的学生群体通常很少或根本没有机会获得尖端的研究机会，而拟议的试点项目解决了这个众所周知但大多未解决的问题。

PROPOSAL NUMBER: 0841213INSTITUTION: Cornell UniversityNSF PROGRAM: PHY ? ELEMENTARY PARTICLE ACCEL USERPRINCIPAL INVESTIGATOR: Liepe, Matthias U..TITLE: CAREER: An Integrated Research/Educational Plan for Advancing RF Superconductivity for Particle AcceleratorsThis proposal requests partial support for a program of research to systematically characterize the radio-frequency(RF) surface resistance of superconductors to advance superconducting microwave cavities for particle accelerators and for an education and outreach program involving community college faculty and students in the research. This will be carried out at the Cornell Laboratory for Accelerator-based Sciences and Education at Cornell University.The ultimate performance of a superconducting radio-frequency (SRF) accelerating cavity is governed by two factors: the maximum accelerating gradient that can be achieved without electrical breakdown, and the cavity Q (or Quality factor) when operating near this maximum gradient. The higher the Q, the less power required to achieve the maximum gradient, and therefore the less cost to both construct and operate the accelerator. The optimal Q of a cavity at a given level of excitation is related to the RF surface resistance of the cavity wall material, and this surface resistance is in turn related to the maximum RF magnetic field at the surface in a way that is both very sample dependent and theoretically poorly understood. The focus of the proposed research program will be on studying the mechanisms that limit the intrinsic Q in SRF cavities, and ways to improve Q. The primary attention in studying these topics will be on the superconductor niobium, which is the material of choice today for SRF cavities. As a subsidiary topic the potential of the A-15 superconductor Nb3Sn for providing highest intrinsic quality factor cavities will be explored. In studying these topics it will be of critical importance to get statistically significant data. This proposal addresses this challenge by developing a host cavity for testing small material samples with fast turnaround. A new generation of improved superconducting rf cavities would have transformative, broad impact across accelerator-based sciences and engineering by improving the energy reach, performance and scientific potential of future particle accelerators. These next generation accelerators will fulfill the needs for particle physics, nuclear physics, neutron science, X-ray science and free-electron lasers. In addition, this research provides for the education of future generations of accelerator scientists and engineers, which are in high demand. Finally, this proposal includes a program to provide research opportunities in the physical sciences specifically for community college students to encourage them to pursue careers in science, technology, or science education. This large and critical group of students usually has very limited or no access to cutting-edge research opportunities and the proposed pilot program addresses this well-recognized, but mostly unaddressed issue.