Analysis of the Thermonuclear Instability including Low-Power ICRH Minority Heating in IGNITOR

TL;DR

This paper investigates the stability and temperature equilibrium of plasma in the IGNITOR fusion experiment, emphasizing the role of low-power ICRH minority heating in triggering thermonuclear instability.

Contribution

It provides an analytical and numerical analysis of plasma stability considering ICRH power, highlighting its potential to induce thermonuclear instability in IGNITOR.

Findings

ICRH heating can trigger thermonuclear instability in IGNITOR.

Minority heating with ${}^3He$ can increase plasma temperature.

The study estimates confinement time and stability conditions.

Abstract

The nonlinear thermal balance equation for classical plasma in a toroidal geometry is analytically and numerically investigated including ICRH power. The determination of the equilibrium temperature and the analysis of the stability of the solution are performed by solving the energy balance equation that includes the transport relations obtained by the classical kinetic theory. An estimation of the confinement time is also provided. We show that the ICRH heating in the IGNITOR experiment, among other applications, is expected to be used to trigger the thermonuclear instability. Here a scenario is considered where IGNITOR is led to operate in a slightly sub-critical regime by adding a small fraction of ${}^3He$ to the nominal $50$$\%$-$50$$\%$ Deuterium-Tritium mixture. The difference between power lost and alpha heating is compensated by additional ICRH heating, which should be able to increase the global plasma temperature via collisions between ${}^3He$ minority and the background $D-T$ ions.