טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentSeemann Omri
SubjectImproving Magnetic Mirror Confinement with Radio-Frequency
Modulation
DepartmentDepartment of Physics
Supervisors Professor Ehud Behar
Dr. Amnon Fisher
Full Thesis textFull thesis text - English Version


Abstract

The long standing goal to produce reactor-viable fusion in the laboratory is challenged by the difficulty to confine hot (keV) dense plasma that can sustain fusion reactions. One way to obtain the required thermal isolation is through magnetic confinement. This thesis focuses on magnetic-mirror machines that need to deal with plasma Rayleigh-Taylor instability and loss-cone losses that shorten the plasma lifetime. A scaled down experiment was built to study the interaction of intense RF fields in the MHz range with the plasma, as means to improve its confinement. Plasma heating and rotation was achieved by the RF field. DC magnetic field as well as phase between two antennas were varied in the experiment. The phase was varied in order to control RF polarization (left and right hand rotating magnetic field with respect to the DC field). Plasma reaction is found to depend on these parameters contrary to expectations based on magneto hydrodynamic models. Specifically, plasma radiation power (dependent on temperature and density) is found to increase only for the right hand rotating magnetic field. We also find suggestive evidence for improved stability and compare the results to said models. Although the experiment is scaled down (in temperature to tens of eV and size in accordance), the techniques used are suitable to reactor scale experiments as well. Results might also aid in a design of an innovative toroidal geometry which does not require high plasma currents as is the case for Tokamaks.