The Ultimate Limit of Rescattering in Strong Laser Fields

强激光场中再散射的极限

• 批准号: 1607321
• 负责人: Barry Walker
• 金额: $ 32.05万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1607321&HistoricalAwards=false
• 关键词: Ultimate; Limit; Rescattering; Strong; Laser

When a material is in an intense laser, the laser removes electrons from the matter in a process known as ionization. A second step in the laser-matter interaction was discovered where, after the electron is removed in ionization, the laser accelerates the electron and forces it back to "re-collide" and excite the original material. These re-collisions are a primary way that lasers transfer energy and create new light and particles. Using laser re-collisions, the principal investigator has observed the emission of x-ray radiation, multiple additional electrons, and recently the shortest pulses of light ever achieved, which can measure reaction dynamics down to the level of an electron or nucleus. The impact of the laser re-collision mechanism now stretches far into the fields of atomic and molecular physics, physical chemistry, and plasma physics. Advances in laser technology, including science planned at 1,000 Trillion Watt High Intensity Laser Facilities worldwide, have pushed laser intensities to the limit where the recollision process breaks down. Broad questions addressed by the research that will promote the progress of science include "What is the ultimate limit for high energy radiation and particles emitted from laser interactions?" and, "With the breakdown of traditional laser-matter rescattering, can we learn to generate high energy radiation and particles efficiently using lasers?" This grant is co-funded by the Atomic, Molecular & Optical Physics program in the Physics Division and the Chemical Measurements and Imaging (CMI) program in the Chemistry division. The research will use high peak power lasers to understand the end of the rescattering mechanism as a function of the laser intensity, laser light color (wavelength), and material species being excited. The experiments are done in ultrahigh vacuum on individual atoms and molecules in a laser focus. The particles and radiation from the laser excited matter are analyzed with high resolution spectrometers specifically designed to handle the extreme energy of the products. The research involves intensive, hands-on training for graduate and undergraduate students in experiment and theory on applied and fundamental topics including: high intensity laser technology, optical system alignment and design, advanced computer programming, and data acquisition and processing. Students from the group have found significant positions across science and technology disciplines from national defense contracting to medical physics to laser material processing industry. The Principle Investigator will be chairing a conference to help students from the populous Mid-Atlantic region share research results. This section meeting is an excellent opportunity for the physics STEM students at the more than thirty universities and colleges within 100 miles of the conference site. The conference will be cohosted by the University of Delaware and Delaware State University (a historically black university).

当材料处于激光激光器中时，激光在称为电离的过程中从物质中去除电子。在激光 - 物质相互作用的第二步中发现了在电离中去除电子后，激光加速了电子并将其迫使其恢复“重新扣”并激发原始材料。这些重新收集是激光传递能量并创造新的光和颗粒的主要方式。使用激光重新收集，主要研究者已经观察到X射线辐射的发射，多个其他电子以及最近达到的光的最短脉冲，这可以测量反应动力学至电子或核的水平。现在，激光重新收缩机制的影响延伸到原子和分子物理，物理化学和血浆物理学的领域。激光技术的进步，包括计划在全球范围内采用1,000万亿瓦的高强度激光设施的科学，将激光强度推向了回忆过程破裂的极限。研究将促进科学进步的研究提出的广泛问题包括“高能辐射和激光相互作用发出的颗粒的最终限制是什么？”而且，“随着传统激光脱落的分解，我们可以学会使用激光有效地产生高能量辐射和颗粒吗？” 该赠款是由化学部门的物理部门的原子，分子和光学物理计划以及化学测量与成像计划（CMI）共同资助的。该研究将使用高峰值激光器来理解脱落机制的末端，这是激光强度，激光浅色（波长）和材料物种被激发的函数。实验是在激光焦点中对单个原子和分子的超高真空中进行的。使用专门设计用于处理产品的极端能量的高分辨率光谱仪分析激光激发物的颗粒和辐射。这项研究涉及针对应用和基本主题的实验和理论的研究生和本科生进行深入的动手培训，包括：高强度激光技术，光学系统对齐和设计，高级计算机编程以及数据获取和处理。该小组的学生发现，从国防合同到医学物理学再到激光材料加工行业的科学和技术学科的重要职位。主要调查员将主持会议，以帮助来自人口众多的中大西洋地区的学生分享研究结果。对于会议地点100英里以内的三十多个大学和大学，本节会议是物理茎学生的绝佳机会。该会议将由特拉华大学和特拉华州立大学（历史悠久的黑人大学）共同主持。