Study of parametrized plasma response and regime for consistent stopping power models of α particles in D-T and p-11 B fusion scenarios

This work develops a systematic parameterization of plasma response regimes in deuterium–tritium ($D$-$T$) and proton–boron ($p$–$^{11}$B) fusion plasmas using a set of dimensionless plasma parameters. These parameters describe the thermodynamic state of the plasma, its collective response properties, as well as the kinetic properties of energetic fusion-born alpha particles in terms of dimensionless ratios of characteristic velocities, collision/oscillation frequencies, and relevant interaction length scales. Special emphasis is put on $\alpha$-electron and $\alpha$-ion interaction metrics, which define the main energy-loss channels. By determining these dimensionless parameters across representative fusion-relevant density-temperature domains, the numerical analysis identifies the plasma regime controlling alpha-particle transport in ($D$-$T$) and ($p$–$^{11}$B) plasmas. The results show that, under typical conditions for inertial confinement fusion, the plasmas are weakly to moderately coupled, weakly perturbed, and in a weakly non-degenerate regime, implying a consistent physical description where the energy exchange is governed by the collective response of the plasma. This study allows the identification of the operational domains in which reduced-stopping-power descriptions, such as the binary collision or dielectric response approaches, remain physically justifiable and numerically stable. This allows for the development of a physics-based framework in which to validate reduced transport models without the need for kinetic or quantum-level complexities. The parameterization aims at facilitating the integration of validated stopping models into advanced particle simulation toolboxes that include Monte Carlo approaches, such as GEANT4, for more valid virtual experiments in the study of fusion plasmas.