Graduate Student Training through Research on Plasma-Based Accelerators

自2009年9月1日以来，美国国家科学基金会合作助学金“通过研究基于等离子体的加速器的研究生培训”资助了七个不同机构的14名研究生的工作。其中8名学生已经毕业，另有6名预计将于2014年9月毕业。这个项目支持这六个学生中的一个，他们的科学目标是在一次拍摄中可视化-在强烈的超短激光脉冲或电子束之后，以光速传播的不断演变的等离子体结构。通过这项研究开发和改进的单次频域全息(FDH)可视化和控制技术可以通过对激光等离子体加速器(LPA)的影响来影响等离子体和加速器科学的广泛领域。在LPA科学中，FDT将从根本上促进LPA向多GeV能源的扩展。紧凑型FDT系统最终可能成为未来激光和质子驱动的等离子体加速器的标准在线计量，这些加速器产生的电子最高可达能量前沿。这些方法还将促进更可靠的基于等离子体的加速器，作为用于生物、化学和医学研究的紧凑、相干的X射线源，用于传统加速器的注射器，以及医疗加速器。学生将把PI实验室开发的频域全息(FDH)尖端可视化方法应用并应用于新的等离子体科学前沿问题：(1)他将在两种机制下实施频域全息成像：(A)由超短太瓦激光脉冲驱动的大气层密度等离子体；(B)由德克萨斯州佩特瓦特激光驱动的0.01大气层等离子体，目的是了解、优化和缩放激光-等离子体加速器(LPA)，该加速器最近将电子加速到2 GeV的世界纪录能量。细胞内粒子模拟和细胞内光子模拟将指导实验。(2)他将开发适合于在一米长的稀薄等离子体中可视化尾迹的方法。这些方法的设计意图是最终在先进的加速器设施中实施它们，例如SLAC的加速器科学和实验测试设施(FEET)。

The NSF Collaborative grant "Graduate Student Training through Research on Plasma-Based Accelerators", has supported the work of 14 graduate students since September 1, 2009 at seven different institutions. Eight of these students have already graduated and another six are expected to graduate by September 2014. This project supports one of these six students, whose scientific goal is to visualize --- in a single shot --- evolving plasma structures that propagate at the speed of light in the wake of intense ultrashort laser pulses or electron bunches. The single-shot Frequency Domain Holography (FDH) visualization and control techniques developed and refined through this research can impact a wide cross section of plasma and accelerator science through the impact on Laser Plasma Accelerators (LPA). In LPA science, FDT will contribute fundamentally to scaling LPAs to multi-GeV energy. Compact FDT systems could ultimately become standard in-line metrology for future laser- and proton-driven plasma accelerators that produce electrons up to the energy frontier. These methods will also promote more reliable plasma-based accelerators, which are useful as compact, coherent x-ray sources for biological, chemical, and medical research, injectors for conventional accelerators, and medical accelerators. The student will apply and adapt the Frequency Domain Holography (FDH) cutting-edge visualization method developed in the PI's laboratory to new frontier plasma science problems: (1) He will implement FDT visualization of evolving laser-driven plasma bubbles in two regimes: (a) atmospheric density plasma driven by an ultrashort terawatt laser pulse; (b) 0.01 atmosphere plasma driven by the Texas Petawatt Laser, with the aim of understanding, optimizing and scaling a laser-plasma accelerator (LPA) that recently accelerated electrons to a world-record-breaking energy of 2 GeV. Particle-in-cell and photon-in-cell simulations will guide the experiments. (2) He will develop methods suitable for visualizing wakes in meter-long tenuous plasma. These methods will be designed with the intention of implementing them ultimately at advanced accelerator facilities such as SLAC's Facility for Accelerator Science and Experimental Tests (FACET).