Combined ICRF heating and adiabatic compression in Tuman-3

Major and minor-radius adiabatic compression and minority-ion ICRF heating have been studied in the small aspect ratio TUMAN-3 tokamak. During the minor-radius adiabatic compression, the density profile becomes narrower and the ion temperature increases adiabatically. In the combined major and minor-radius compression, an effective electron density compression, electron heating and ion heating close to adiabatic are observed. The ICRF heating is mainly in the mode conversion regime but the ion heating by absorption of the Bernstein wave at the second harmonic of the light impurity (N+6, O+7) ions is observed. When the adiabatic compression follows by ICRF heating, the bulk ion temperature rises from 110 eV (in ohmic) to 250 eV after compression. (Author)