Numerical investigation of a new ICRF heating scenario in D-T plasma on CFETR

Abstract

For a fusion device, plasma pre-heating is required before the self-sustaining burning-state reactions of deuterium (D) and tritium (T) commence. Plasma heating with waves in the ion-cyclotron range of frequencies (ICRF) is effective in tokamaks. A new three-ion ICRF heating scheme for plasmas in the Chinese Fusion Engineering Test Reactor (CFETR) that require an increase in the bulk ion temperature via heating the lithium impurities in the D–T plasmas, was studied numerically. Our simulations show that the radio-frequency wave power is strongly absorbed by very few 7Li ions with concentrations of 0.01%–0.2% in a suitable mixture of D–T plasmas, the enhanced minority ion heating is related to that the 7Li fundamental resonance layer is very close to the two mode conversion layers. In adjusting the mixtures over a wide range of composition, an oscillatory behaviour in the 7Li absorption efficiency arises because of interference. Moreover, from estimates of the 7Li ion tail energy, most of the tail energy of the minority ions is found to be transferred to background ions via collisions. Compared with the routine (3He)-D–T scheme, the ICRF power is absorbed more effectively by the 7Li ions in the (7Li)-D–T heating scenario, and after the Fokker–Planck equations were solved, a large fraction of bulk ion heating was evident in the (7Li)-D–T heating scenario. The new three-ion scenario may therefore be an attractive proposition for bulk ion heating during the activated phase of the reactor.

Progress with applications of three-ion ICRF scenarios for fusion research: A review

“…Note that off-axis plasma heating with the similar T-( 7 Li)-D ICRF scenario was already observed in the past D-T experiments on TFTR, but was considered as a parasitic 7 Li impurity absorption [49]. Recently, the application of this ICRF scenario was revisited and the three-ion T-( 7 Li)-D ICRF scenario was proposed for bulk ion heating in CFETR [50].…”

Influences of plasma density perturbations on ion cyclotron resonance heating

“…Ion cyclotron resonance heating (ICRH) is an efficient auxiliary heating scheme [1,2] which can heat target ions directly at any desired specific position in tokamaks with controllable parameter settings. This method is expected to play an important role in ion heating for future magnetic confinement fusion demonstration reactors [3,4]. In the ICRH scenario, fast waves are often launched from antennas at the low-field * Authors to whom any correspondence should be addressed.…”

Finite elements method-based ICRF wave heating simulation integrating with SOL plasma for EAST tokamak

“…Ion cyclotron range of frequency (ICRF) wave heating has proved to be an efficient method for heating magnetically confined fusion plasma on the EAST [1,2] and other tokamaks. The method is also expected to be important in future magnetic confinement fusion demonstration reactors such as ITER [3] and CFETR [4]. The predictions of magnetosonic wave (fast wave) propagation and absorption based on numerical calculations are of great significance and have drawn physicists' attention in the past few decades.…”