Relativistic Thomson Scattering Investigations with in Situ Electrons in the Focus at the Petawatt Level

能够在短时间内提供极端强度的激光器的发展使我们处于实验研究新时代的门槛。 随着这些工具在未来几年的成熟，它们将能够探索与物质和反物质相关的现象，这可能有助于解释最近的天体物理观测，并揭示各种基本问题，如粒子物理学标准模型和暗物质。 然而，阻碍他们就业的一个主要障碍是衡量强度的可靠方法。 该项目致力于开发一种易于实施并可转移到其他实验室的强度计。 建立合适的强度测量技术是激光界长期以来的愿望。 从产生新光源到探测温暖的致密物质，再到开发基于激光的医学应用，一系列研究也将从该项目中受益匪浅。 在强调国际参与的同时，包括代表性不足的少数民族，并在这一奋进中，该项目提供了一个急需的仪器，同时培养了多样化的学生骨干。短持续时间的多拍瓦激光器的发展使我们处于一个新时代的门槛。 电动力学的非线性方面的关键实验研究-光如何与物质和自身相互作用，-这在很大程度上巩固了我们目前对量子真空的理解，将是可能的。 阻碍实现拍瓦级精确测量进展的主要障碍是直接测量强度的能力。 该项目致力于开发一种强度计，该强度计（i）易于实施，不需要进行重大实验工作，（ii）侵入性最小，允许不受约束地进行主要实验，（iii）对光束特性变化敏感，可以降低焦点能量，从一次到另一次，（iv）能够单次拍摄。 一个有前途的技术，满足这些愿望是基于相对论汤姆逊散射。 汤姆逊散射的细节正在研究（一）监测基波和二次谐波辐射，（二）测量辐射的角分布和（三）测量汤姆逊散射电子的能量和角分布，出生在原地，并由有质动力的激光潜力弹出。 将喷射出的电子与多普勒频移辐射相关联，可以创建汤姆逊散射模型。 该项目将包括与全球高功率激光设施的直接合作，包括捷克共和国和罗马尼亚的极光基础设施（ELI）设施。该奖项反映了NSF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。

The development of lasers capable of delivering extreme intensities in a short time period has placed us at the threshold of a new era for experimental investigation. As these tools mature over the next few years, they will enable exploration of phenomena associated with matter and antimatter that could help with the interpretation of recent astrophysical observations as well as shed light on a variety of fundamental questions such as the Standard Model of Particle Physics and Dark Matter. A major roadblock inhibiting their employment, however, is a reliable way to measure intensities. This project is devoted to developing an intensity gauge that is straightforward to implement and transferable to other laboratories. Establishing suitable techniques for intensity measurement is a long-standing desire of the laser community. A host of studies ranging from generating novel light sources to probing warm dense matter to developing laser-based medical applications will also benefit greatly from this project. Together with the emphasis on international engagement, and including underrepresented minorities and in this endeavor, this project is providing a much-needed instrument while training a diverse cadre of students.The development of multi-petawatt lasers of short duration has placed us at the threshold of a new era. Critical experimental investigations of nonlinear aspects of electrodynamics -- how light interacts with matter and itself, -- which largely undergirds our current understanding of the quantum vacuum, will be possible. A major roadblock inhibiting progress towards realizing precision measurement at the petawatt level is an ability to measure the intensity directly. This project is devoted to developing an intensity gauge that is (i) straightforward to implement, not requiring a major experimental effort to employ, (ii) minimally intrusive, allowing the primary experiment to be performed uninhibited, (iii) sensitive to beam characteristic changes that can degrade the energy in the focus from shot to shot and (iv) single-shot capable. A promising technique meeting these desires is based on relativistic Thomson scattering. Details of Thomson scattering are being investigated by (i) monitoring the fundamental and second-harmonic radiation, (ii) measuring the angular distribution of the radiation and (iii) measuring the energy and angular distribution of the Thomson scattered electrons, born in situ and ejected by the ponderomotive potential of the laser. Correlating the ejected electron with Doppler-shifted radiation is enabling a model of the Thomson scattering to be created. The project will include direct engagement with high-power laser facilities worldwide, including the Extreme Light Infrastructure (ELI) facilities in Czech Republic and Romania.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.