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

Stuyvesant High School, New York NY

Investigators

Abstract

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.