MRI: Acquisition of Tunable Laser Systems for Laser Induced Fluorescence in Plasmas

激光诱导荧光(LIF)提供了一种非微扰测量等离子体中离子或中性原子沿任意方向的完整速度分布(VDF)函数的方法，具有很高的空间和时间分辨率。对目前使用的激光系统进行升级，将大大增强实验室目前的实验能力。新仪器包括用于Ar II和Xe II LIF的固体激光泵浦环形染料激光器，以及用于Ar II、He I和Ar I LIF的便携式、可调谐、高功率二极管激光器，采用主振荡器功率放大器(MOPA)配置。这些新的激光组件将加强四个正在进行的实验项目，其中包括：研究多离子物种等离子体对致密螺旋源等离子体膨胀区双层形成的影响；对被认为在太阳日冕加热和加速过程中起重要作用的磁流体动力学波的衰减所产生的离子加热和加速的研究；与特罗莫斯大学的合作，将研究多物种等离子体中的切变流的作用；与奥本大学的合作，将研究离子的体积流动，同时测量尘埃复杂的等离子体中的尘埃速度场。除了这些正在进行的合作外，该小组还积极寻求更多基于LIF的合作，涉及等离子体推进器、磁重联过程中离子加热的研究，以及等离子体辅助将煤重整为甲烷。除了拟议的仪器将对正在进行的科学研究产生的影响外，西弗吉尼亚大学的物理计划还吸引了来自美国国内外的合作者；在过去的十年里，超过30名合作者参加了PI实验室的培训或合作LIF实验。该小组有通过出版物、使用便携式激光诱导荧光系统的合作实验以及对来自美国和海外的访问科学家和学生的实践培训来传播他们的激光诱导荧光技术进展的记录。此外，实验室还为研究生、本科生和博士后研究人员提供内部培训和教育机会。拟议的活动将提高妇女和其他代表性不足的群体，如第一代大学生，获得物理学高级学位的比例；增加本科生对前沿科学研究的参与；加强对博士后研究人员的指导，促进国内和国际合作的发展和领导；帮助吸引新的少数族裔物理学教员，并通过在西弗吉尼亚大学使用LIF系统和在其国内机构使用便携式LIF系统，支持目前六个外部用户的等离子体物理学研究

Laser-induced-fluorescence (LIF) provides a means of non-perturbatively determining the complete ion or neutral atom velocity distribution (VDF) function in a plasma along any direction with high spatial and temporal resolution. The upgrade of the laser systems currently in use will significantly enhance the present experimental capabilities of the laboratory. The new instrumentation includes a solid-state-laser pumped ring dye laser for Ar II and Xe II LIF and a portable, tunable, high-power diode laser in a Master Oscillator Power Amplifier (MOPA) configuration for Ar II, He I, and Ar I LIF. These new laser components will enhance four ongoing experimental projects, which include: a study of the effects of multi-ion species plasmas on double layer formation in the expansion region of compact helicon source plasma; an investigation of ion heating and acceleration arising from the damping of magnetohydrodynamic waves thought to play important roles in the heating and acceleration of the solar corona; a collaboration with the University of Tromsø that will examine the role of sheared flows in multi-species plasmas, and a collaboration with Auburn University that will investigate the bulk flow of ions while simultaneously measuring the dust velocity field in a complex, i.e., dusty, plasma. In addition to these ongoing collaborations, this group is actively pursuing additional LIF-based collaborations involving plasma thrusters, studies of ion heating during magnetic reconnection, and plasma-assisted reforming of coal into methane. Beyond the impact that the proposed instrumentation will have on ongoing scientific studies, the WVU physics program attracts collaborators from within and outside the United States; over 30 collaborators have participated in either training or collaborative LIF experiments in the PI's laboratory over the past ten years. This group has a record of disseminating their LIF advances through publications, collaborative experiments involving the portable LIF system, and hands-on training of visiting scientists and students from the United States and abroad. In addition, the laboratory provides internal training and education opportunities for graduate students, undergraduates, and postdoctoral researchers. The proposed activities will improve the percentage of women and other underrepresented groups, such as first generation college students, obtaining advanced degrees in physics; increase involvement of undergraduates in cutting-edge scientific research; enhance the mentoring of postdoctoral researchers in the development and leadership of national and international collaborations; help to attract new minority physics faculty, and support the plasma physics investigations of six current external users through their use of the LIF system at WVU and the use of the portable LIF system at their home institutions