Exploring the Limits in Ultrafast High Brightness Electron Beam Generation

探索超快高亮度电子束产生的极限

• 批准号: 1415583
• 负责人: Pietro Musumeci
• 金额: $ 55.77万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1415583&HistoricalAwards=false
• 关键词: Exploring; Limits; Ultrafast; Brightness; Electron

Accelerators are important instruments for the advancement of scientific research, for their broad application in medicine and industry, and as a research area in their own right. Accelerators typically accelerate protons, antiprotons, electrons and positrons (anti-electrons). Powerful accelerators have lead to the discoveries of the Higgs Boson and the top quark, intermediate sized accelerators have been used as sources of x-rays to study properties of materials, and smaller machines are used to provide cancer therapy or for electron beam microscopy. A recent novel trend in accelerator and beam physics is the development of precise electron beams for diverse applications in the study of ultrafast structural dynamics, and as the drivers for Free Electron Lasers or laser-based accelerators. This award to UCLA aims to develop a new electron source capable of generating electron beams with an order of magnitude higher brightness than has been previously achievable using state-of-the-art radiofrequency photoinjectors. By pushing for lower beam charges, the design choices of a photoinjector cavity can be reevaluated, incorporating recent advances in cathode surface engineering and adopting different solutions for the beam dynamics. Technically, the development of a novel electron source with extreme beam parameters will have important impact on compact x-ray free-electron lasers and ultrafast electron diffraction and microscopy. These technologies have the prospect to provide real time atomic scale images of matter with the potential for profound impact in a variety of scientific fields such as condensed matter physics, chemistry, biology and material sciences. Educationally, the work with be intrinsically interdisciplinary and will provide full hands-on experience for students with a broad preparation in photoemission physics, laser and accelerator technology, and high brightness beam and beam diagnostic development.In the program as awarded, the UCLA group plans to study some of the most pressing unanswered questions in electron-source physics, such as the growth of the longitudinal emittance and uncorrelated energy spread and the limit in the cathode thermal emittance.

加速器是推进科学研究的重要工具，在医学和工业中有着广泛的应用，本身也是一个研究领域。加速器通常加速质子、反质子、电子和正电子(反电子)。强大的加速器导致了希格斯玻色子和顶夸克的发现，中型加速器被用作X射线源来研究材料的性质，较小的机器被用于癌症治疗或电子束显微镜。最近加速器和束流物理学的一个新趋势是发展精密电子束，用于研究超快结构动力学，并作为自由电子激光或基于激光的加速器的驱动器。授予加州大学洛杉矶分校的这一奖项旨在开发一种新的电子源，能够产生比以前使用最先进的射频光注入器实现的亮度高一个数量级的电子束。通过推动更低的束流电荷，可以重新评估光注入器腔的设计选择，结合阴极表面工程的最新进展，并采用不同的束流动力学解决方案。在技术上，具有极端束流参数的新型电子源的发展将对紧凑型X射线自由电子激光器、超快电子衍射和显微技术产生重要影响。这些技术有望提供物质的实时原子尺度图像，可能对凝聚态物理、化学、生物和材料科学等各种科学领域产生深远影响。在教育方面，加州大学洛杉矶分校的工作本质上是跨学科的，将为学生提供全面的实践经验，他们在光电子物理、激光和加速器技术以及高亮度光束和光束诊断开发方面都有广泛的准备。在获奖的项目中，加州大学洛杉矶分校的小组计划研究电子源物理学中一些最紧迫的悬而未决的问题，例如纵向发射度和不相关能量扩散的增长以及阴极热发射度的限制。