Development of Ultrashort Relativistic Electron Beams as a Plasma Diagnostic

一个非常强大的激光可以通过与一种被称为等离子体的物质状态相互作用来将电子加速到高能量，等离子体是一种带电粒子的电离气体。激光通过在等离子体中产生波来实现这一点，就像船在水中推进一样，电子可以在上面冲浪并被加速到高能量。在这个项目中，用激光加速的电子将被用来成像，从而更好地理解等离子体本身的行为。在这项研究中获得的技术和理解将进一步帮助紧凑粒子加速器的发展，它可以影响从癌症治疗到飞机机翼成像应力的各个方面。由激光驱动的等离子体波产生的电子束持续时间特别短且聚焦紧密，因此它们可用于非常快速变化现象的成像。在这个项目中，世界上最强大的激光器之一，由美国国家科学基金会资助的密歇根大学的HERCULES激光器，将被用来制造电子束来探测激光与固体材料相互作用时产生的电磁场结构。其中包括表面磁场、重联磁场和维贝尔不稳定细丝。强电子束也将用于加热和产生高能量密度等离子体，这可以用来更好地理解实验室环境中的天体物理相关现象。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

A very powerful laser can be used to accelerate electrons to high energies by interacting with a state of matter known as a plasma, an ionized gas of charged particles. The laser achieves this by creating waves in the plasma, like a boat pushing through water, on which the electrons can surf and be accelerated to high energies. In this project, electrons accelerated with lasers will be used to image and, in turn, better understand the behavior of the plasma itself. The techniques and understanding obtained in this study will further help the development of compact particle accelerators, which can impact everything from cancer therapy to imaging stresses in aircraft wings. Electron beams produced by laser driven plasma waves are especially brief in duration and tightly focused, so they may be used for imaging of very rapidly changing phenomena. In this project, one of the most powerful lasers in the world, the NSF funded HERCULES laser at the University of Michigan, will be used to create electron beams to probe electromagnetic field structures that are produced when lasers interact with solid materials. In particular, these include surface magnetic fields, reconnecting magnetic fields and Weibel instability filaments. An intense electron beam will also be used to heat and produce high energy density plasmas which can be used to better understand astrophysically relevant phenomena in a laboratory setting.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.