Fuel-ion velocity distribution functions can be distorted from a Maxwellian by Alfvén eigenmodes when the mode amplitudes are large, and the fusion reaction rate coefficient can be enhanced by the distortion. Assuming an ITER-like deuterium-tritium plasma containing an excited Alfvén eigenmode, we have investigated the modified deuteron and triton velocity distribution functions and the resulting fusion reaction rate coefficient. It is found that the non-Maxwellian components in the distribution functions form in directions parallel and antiparallel to the magnetic field lines due to the toroidal Alfvén eigenmodes or the ellipticity-induced Alfvén eigenmodes. Focusing on the effect of the distortion of the distribution functions, we discuss the dependence of the enhancement of the fusion reaction rate coefficient on the mode amplitudes and determine the threshold amplitude necessary to enhance the rate coefficient.
All Science Journal Classification (ASJC) codes
- Nuclear Energy and Engineering
- Condensed Matter Physics