The Experimental Study of the Hot Electron Interchange Instability in a Magnetic Cusp

热电子交换不稳定性是一种常见的观察现象，与低密度、无碰撞等离子体中产生的热电子有关。在这个实验中，一对高温超导磁体悬浮在一个18英寸的球形真空室中，用液氮低温冷却，并排列成一个轴对称的磁尖。利用2.45 GHz微波源，利用电子回旋共振加热在低密度等离子体中产生热电子居群，观察到热电子交换的不稳定性。使用一组高阻抗浮动探针观察低频波动，使用一组粒子探测器观察电子输运。特别注意磁尖对热电子交换不稳定性的作用和低频波动稳定的条件。其主要目标是支持一所高中实验室实验等离子体物理研究的发展计划。该项目的资金将用于采购2kW 2.45 GHz微波功率系统，以增强斯图伊文森高中的现有设施。学生将有机会学习和应用现代等离子体物理实验室的实验技术进行真正的科学研究。研究机会是研究电子回旋共振加热和磁尖中热电子交换的不稳定性。学生将学习使用一系列的诊断方法，包括：朗缪尔探针、离子饱和探针、法拉第杯、粒子阵列、光电二极管阵列和高增益运算放大器，并将使用光谱仪和示波器来研究热电子交换的不稳定性及其输运。PI将协调学生团队，鼓励他们设计、制造和安装研究组件，利用一系列诊断来研究等离子体的特性，并撰写并向各种科学竞赛提交以学生为中心的研究论文。

The Hot Electron Interchange Instability is a commonly observed phenomenon associated with the creation of a hot population of electrons in a low density, collisionless plasma. In this experiment, a pair of high temperature superconducting magnets are suspended inside an 18" spherical vacuum chamber, cryogenically cooled using liquid nitrogen and arranged to form an axisymmetric magnetic cusp. A 2.45 GHz microwave source is used to create a hot population of electrons in a low density plasma using electron cyclotron resonance heating leading to the observation of the hot electron interchange instability. Low frequency fluctuations will be observed using an array of high impedence floating probes and electron transport will be observed using an array of particle detectors. Special attention will be given to the role of the magnetic cusp on the hot electron interchange instability and the conditions for stabilization of the low frequency fluctuations.The primary goal is to support a developing program of experimental plasma physics research in a high-school laboratory. Funds from this project would be used to procure a 2kW 2.45 GHz microwave power system to augment an existing facility at Stuyvesant High School. Students would have the opportunity to learn and apply the experimental techniques used in a modern plasma physics laboratory to conduct real scientific research.The research opportunities are to study electron cyclotron resonance heating and the hot electron interchange instability in a magnetic cusp. Students would learn to use an array of diagnostics including: langmuir probes, ion saturation probes, faraday cups, particle arrays, photodiode arrays and high gain op-amps and will use spectrometers and oscilloscopes to study the hot electron interchange instability and its transport. The PI would coordinate teams of students who would be encouraged to design, fabricate and install research components, to utilize an array of diagnostics to study the properties of plasma and to write and submit student-centered research papers to various scientific competitions.