From Phase Space Manipulation to First Light from a Laser Plasma Accelerator Powered Free Electron Laser

该项目的目标是开发一个桌面X射线源。 高亮度X射线光源是探测化学、生物和物理系统不可或缺的工具。 X射线源由加速器中产生的电子束驱动，加速器依赖于非常强的激光束来激发电离气体云（等离子体）中的波，电子可以在等离子体上冲浪以达到高能量。这项技术已经表明，与使用传统技术的几个足球场长的加速器相比，电子束可以从只有几英寸长的设备中产生。 为了产生大量的X射线，电子束的质量必须非常好，这个项目将证明这样的光束实际上是可以产生的。该项目的成功将大大减小X射线源的尺寸，并将这一工具带到各个实验室和研究人员手中，促进科学的进步。 该项目还支持三名研究生的教育，他们将接受超短光束物理学、激光-等离子体相互作用和先进加速器概念的培训。该项目旨在利用激光-等离子体加速器（LPA）产生的光束开发一种紧凑、超快（飞秒）、软X射线辐射源。通过将超短激光等离子体加速电子束耦合到传统的磁波荡器中，可以通过波荡器辐射机制产生强辐射。电子束的传输将通过两个磁透镜进行，其中包括最近开发的超强活性等离子体透镜和一个用于能量分散的弯道。后者是关键，以减少束切片的能量扩散，使自由电子激光增益的观察。通过部署基于波动器的辐射诊断，将在每次发射时测量电子束质量，并提供必要的反馈，以了解和控制对激光等离子体加速器和传输晶格的要求，以提供高质量的束流。该项目包括三个阶段：（1）使用新的100 TW级激光系统以稳定和高电荷模式运行LPA。(2)实施和演示LPA源到波荡器传输系统，并调试嵌入强聚焦的波荡器。预期在10-100 eV范围内具有每次发射10^8个光子数量级的超短非相干波荡器辐射。(3)通过调谐弯道，将追求波荡器辐射的相干增强。该光源与激光驱动器本质上同步，使这种紧凑型光源成为超快科学中泵浦探测应用的理想选择。

The goal of this project is to develop a table-top x-ray source. High-brightness x-ray light sources are indispensible tools to probe chemical, biological, and physical systems. The x-ray source is driven by electron beams generated in an accelerator that relies on very intense laser beams to excite waves in a cloud of ionized gas, a plasma, on which electrons can surf to reach high energies. This technology has already shown that electron beams can be produced from devices that are only a few inches long compared to several-football-field-long accelerators using conventional technology. In order for a lot of x-rays to be generated, the electron beam quality has to be excellent, and this project will demonstrate that such beams can, in fact, be produced. Success of this project will greatly reduce the size of x-ray sources and bring this tool to individual laboratories and investigators, promoting the advancement of science. This project also supports the education of three graduate students, to be trained in the physics of ultra-short beams, laser-plasma interactions, and advanced accelerator concepts.The project aims at developing a compact, ultra-fast (femtosecond), soft X-ray radiation source using beams produced by a laser-plasma accelerator (LPA). Intense radiation can be generated via the undulator radiation mechanism by coupling the ultra-short laser-plasma-accelerated electron beam into a conventional magnetic undulator. Transport of the electron beams will be performed with two magnetic lenses, incorporating recently-developed ultra-strong active plasma lenses, and a chicane for energy dispersion. The latter is critical to reduce the beam slice energy spread, enabling the observation of free-electron laser gain. By fielding undulator-based radiation diagnostics, the electron beam quality will be measured on every shot and will provide the necessary feedback to understand and control the requirements imposed on the laser plasma accelerator and transport lattice to deliver high quality beams. The project consists of three phases: (1) Operate the LPA in a stable and high-charge mode with the new 100-TW-class laser system. (2) Implement and demonstrate the LPA source-to-undulator transport system, and commission an undulator embedded with strong focusing. Ultra-short incoherent undulator radiation with on the order of 10^8 photons per shot in the 10-100 eV range is expected. (3) By tuning the chicane, coherent enhancement of the undulator radiation will be pursued. This light source is intrinsically synchronized to the laser driver, making such a compact source ideal for pump-probe applications in ultrafast science.