On all-FLR order numerical modelling of RF wave propagation and damping

Abstract

Abstract. Determining the fate of waves in hot magnetized plasmas in magnetic confinement fusion machines close to arbitrary cyclotron harmonics retaining finite Larmor radius effects requires solving the relevant integrodifferential wave equation for waves of arbitrary wavelength. Anticipating exploitation in as realistic geometry as possible this requires massive computer resources. Work is ongoing to attempt reducing the required CPU memory and time. As Morlet wavelets are localised in x-space as well as k-space, they potentially offer a means to solve the relevant wave equation at reduced CPU requirement cost. Encouraging first results are obtained.

Summary of the 27th IAEA Fusion Energy Conference in the categories of EX/W, EX/D, and ICC

“…A novel heating scenario using Ion Cyclotron Range of Frequencies (ICRF) heating and Electron Cyclotron Resonance Heating (ECRH) has been developed in tokamak and stellarator. A three-ion species ICRH heating scheme on JET and AUG was reported [19][20][21][22][23]. D-( 3 He)-H threeion ICRH scenario (minority heating of 3 He ions in H-D plasma) was found to be an efficient technique for heating H-D mixed plasma in JET.…”

Optimization of ICRH for core impurity control in JET-ILW

“…A detailed study of the impact of the H concentration on the ICRF performance in JET-ILW baseline H-modes was reported in [26] and a summary is given in figure 7, where various quantities are plotted as function of X[H] = n H /n e . The RF heating efficiency (a) was estimated from the fast changes of the global plasma stored energy (dW MHD /dt) to RF power steps imposed in the discharges (see figure 6 The RF heating efficiency (a) decreases from above 0.9 at low H concentrations to approximately 0.6 at X[H] = 0.25 and is about 10-20% higher than what was observed in L-mode plasmas in earlier JET-ILW experiments [27].…”