Temperature Dependence of Beam on Plasma Stopping Power in the Resonance Regions of Fusion Reactions

TL;DR

This paper calculates how the stopping power of ion beams in plasma varies with temperature in fusion resonance regions, showing it decreases more slowly than classical models predict, especially with quantum corrections.

Contribution

It provides an analytic calculation of the temperature dependence of stopping power in fusion plasmas, incorporating quantum corrections and focusing on resonance regions.

Findings

Stopping power decreases with temperature more slowly than T^{-3/2}.

Quantum corrections significantly affect the temperature dependence.

Results are relevant for accelerator-based fusion reactor designs.

Abstract

A recent proposal of accelerator based fusion reactor considers a scheme where an ion beam from the accelerator hits the target plasma on the resonance of the fusion reaction so that the reactivity ($\sigma v$) can be an order of magnitude larger than that of a thermonuclear reactor. One of the important inputs is the stopping power which is needed to assess the energy loss of the beam in the plasma. In this work, we shall use the analytic formulation of Brown, Preston and Singleton~\cite{Brown:2005ji} to calculate the temperature dependence of the stopping power due to the target $t, {}^3H_e$, and ${}^{11}B$ plasmas in the resonance regions of their respective fusion reactions, i.e., $ d + t \rightarrow n + \alpha, d + {}^3H_e \rightarrow p + \alpha$, and $p + {}^{11}B \rightarrow 3 \alpha$. It is found that the calculated stopping power, especially when the quantum corrections are included, does not go down with temperature as fast at $T^{-3/2}$. Instead it decreases slower, more like $T^{-x}$ with $x \le 1$ in the range of T from $\sim$ 5 to 50 keV for $d$ on $t$ and ${}^3H_e$ plasmas around their resonance energies.