The influence of non-standard orbits on ICRH power deposition in tokamaks

The distribution function and power deposition during ICRH in a tokamak pla sma are analysed. The importance of self-consistent calculations and the fo rmation of son-standard drift orbits are addressed. It is found that for hi gh power ICRH, the presence of non-standard orbits are crucial for describi ng the distribution function. For a standard minority heating scenario with the ion cyclotron resonance located at the high field side, the absorption of the wave power is shifted to the low field side (LFS) because of the or bit topology and the evolving wave field profile. The high energy tail of t he distribution function of the resonating ions is found to be dominated by ions in passing orbits, of which some reside completely on the LFS of the tokamak.