Measurements of electron density profile characteristics in various kinds of plasma configurations in the TS-3 plasma merging device

• Published in: Electrical engineering in Japan Vol. 145; no. 2; pp. 35 - 41
• Main Authors: Hayashiya, Hitoshi, Katsurai, Makoto
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.11.2003
• Subjects: compact torus; electron density profile; laser interferometer; spherical torus; TS-3
• ISSN: 0424-7760; 1520-6416
• DOI: 10.1002/eej.10158

Measurements and a comparative study have been performed on electron density profiles, focusing on the electron density gradient near the magnetic separatrix in various kinds of plasma confinements such as the ST, spheromak, and RFP in the TS‐3 device. A CO2 laser interferometer using a glass tube to clear the path for the laser was introduced in order to measure the electron density profile with time resolution. It was shown that ST with a high q value at the plasma edge (q: safety factor) has a larger electron density gradient than low‐q plasma confinements such as the spheromak and RFP. In particular, the ST with edge q value greater than about 2 showed a large electron density gradient at the edge. The idea that the j×B force profile of the higher‐q ST could sustain the higher thermal pressure supports these results. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(2): 35–41, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10158