Development of Magnetic Flux Surface Measurement Method on TOKASTAR-2

抄録

The measurement method of magnetic flux surfaces on TOKASTAR-2 was developed. The electron gun was designed and fabricated. Calculation of the orbit of electrons showed that low energy of injected electrons, typically less than 50 eV, was proper for the measurement to suppress large deviation of the electron orbits from the magnetic flux surfaces. The preliminary experiment for the method using a fluorescent screen showed that the acceleration voltage of 80 V was required and we need significant improvement of the electron gun to apply the method using a fluorescent screen to TOKASTAR-2. The experiment for the method using a probe showed that the required acceleration voltage was 10 V so we found that the method using a probe was proper for a small plasma confinement device with weak magnetic field like TOKASTAR-2.