PK-4: Self-Ordering of Interacting Complex Plasma Particles in Microgravity

该项目将利用国际空间站上的等离子体晶体-4(PK-4)设备进行微重力实验，调查相互作用的复杂等离子体尘埃粒子自排序背后的基本物理。复杂的等离子体，也被称为尘埃等离子体，由离子、电子和带电的纳米到微米大小的固体颗粒组成，称为尘埃。尘埃等离子体长期以来一直是天体物理学界感兴趣的对象。例如，恒星和行星形成的物质、星际云，甚至行星环都是由尘埃等离子体组成的。尘埃等离子体也存在于地球上，特别是在工业等离子体应用中，而实验室环境中尘埃晶体的受控形成为原子和分子系统提供了有用的模拟，使我们对相关物理的理解取得了根本进展。因此，尘埃等离子体的研究促进了科学的进步，同时也使人们能够深入了解半导体制造中的成品率的实际问题。该奖项还将通过吸引学生参与进来，影响STEM员工队伍，这些学生将发展计算和建模技能，获得仪器设备的实际经验，并提高他们的技术写作和演示技能。由于大多数研究是在引力环境中(即在地球上)进行的，要正确理解尘埃等离子体研究领域的物理基础是很复杂的。该项目直接解决了这一问题，利用多国合作，将在地球上收集的相互作用的复杂等离子体尘埃颗粒的自序研究与使用PK-4设施在微重力下的实验结果进行了比较。所获得的数据将与两个不同地面实验的数据进行比较，并与使用一整套分析技术对等离子体/尘埃环境进行数值模拟所提供的结果进行比较。这种组合将被用来定义可以存在特定波模的参数空间，并发展关于粒子间势和颗粒-等离子体相互作用的全面理论，确定复杂等离子体的微观和宏观性质。所取得的成果将直接影响以下领域的研究：天体物理和行星科学(例如，原行星盘中的尘埃、无气态物体表面的带电尘埃，例如月球和小行星、行星环系)、大气物理(例如，夜光云)、聚变研究(例如，尘埃污染)、材料物理(例如，软物质、亚稳态、复杂流体、颗粒物质)和先进制造(例如，半导体、蚀刻和沉积系统)。该奖项是根据“NASA/NSF尘埃等离子体科学伙伴关系：利用国际空间站上的PK-4设备”颁发的；根据联合计划，NASA正在为一名本科生提供补充奖励。

This project will utilize a facility called Plasma Krystal-4 (PK-4) on the International Space Station to conduct experiments in microgravity investigating the underlying physics behind self-ordering of interacting complex plasma dust particles. Complex plasma, also known as dusty plasma, consist of ions, electrons and charged nanometer to micron sized solid particles known as dust. Dusty plasmas have long been of interest in the astrophysics community. For example, the material from which stars and planets form, interstellar clouds, and even planetary rings all consist of dusty plasma. Dusty plasmas are also present on the Earth, particularly in industrial plasma applications, while the controlled formation of dust crystals in a laboratory setting provides a useful analog for both atomic and molecular systems, allowing fundamental progress in our understanding of the physics involved. As such, dusty plasma research enables the progress of science while allowing insight into practical issues of yield efficiency in semiconductor manufacturing. This award will also impact the STEM workforce through engagement of students who will develop computation and modeling skills, obtain practical experience with instrumentation, and improve their technical writing and presentation skills. A proper understanding of the physics underlying the field of dusty plasma research is complicated by the fact that the majority of research conducted occurs in a gravitational environment (i.e., on the Earth). This project directly addresses this issue, utilizing a multinational collaboration to compare studies on self-ordering of interacting complex plasma dust particles collected on the Earth to experimental results employing the PK-4 facility under microgravity. Data obtained will be compared with data from two different ground-based experiments as well as to results provided by numerical modeling of the plasma / dust environment using a comprehensive set of analysis techniques. This combination will be used to define the parameter space where particular wave modes can exist, and to develop comprehensive theories on interparticle potential and grain-plasma interactions, determining the microscopic and macroscopic properties of the complex plasma. The results obtained will directly impact research in astrophysics and planetary science (e.g., dust in protoplanetary disks, charged dust on the surface of airless bodies, such as the moon and asteroids, planetary ring systems), atmospheric physics (e.g., noctilucent clouds), fusion research (e.g., dust contamination), materials physics (e.g., soft matter, metastable states, complex fluids, granular matter), and advanced manufacturing (e.g., semiconductor, etching, and deposition systems). This award is made under a "NASA/NSF Partnership on Science of Dusty Plasmas: Utilizing the PK-4 Facility on board the International Space Station"; a complementary NASA award to support an undergraduate student is being made under the joint program.