Turbulent transport of MeV range cyclotron heated minorities as compared to alpha particles

TL;DR

This paper compares the turbulent transport of high-energy minority ions heated by ion cyclotron resonance in tokamaks with that of fusion alpha particles, highlighting differences due to their distribution functions and generation processes.

Contribution

It provides a theoretical comparison of turbulent transport between ICRH-heated minorities and alpha particles, emphasizing the impact of their distribution functions.

Findings

Transport coefficients are similar for both particle types.

Differences in distribution functions lead to different turbulent fluxes.

Caution is needed when interpreting experimental results involving these particles.

Abstract

We study the turbulent transport of an ion cyclotron resonance heated (ICRH), MeV range minority ion species in tokamak plasmas. Such highly energetic minorities, which can be produced in the three ion minority heating scheme [Ye. O. Kazakov et al. (2015) Nucl. Fusion 55, 032001], have been proposed to be used to experimentally study the confinement properties of fast ions without the generation of fusion alphas. We compare the turbulent transport properties of ICRH ions with that of fusion born alpha particles. Our theoretical predictions indicate that care must be taken when conclusions are drawn from experimental results: While the effect of turbulence on these particles is similar in terms of transport coefficients, differences in their distribution functions - ultimately their generation processes - make the resulting turbulent fluxes different.