The Influence of Low-$Z$ Impurities on the Ignition Parameters in p6Li Inertial Fusion Plasma

Abstract

The presence of impurities in a high-temperature plasma is one of the major challenges in an inertial fusion reactor. In addition to radiation losses, the impurities affect the ignition parameters of the fusion plasma in the reactor. In this article, the effect of the arbitrary concentration of impurity nuclei carbon, beryllium, and lithium on the ignition properties of the p6Li fusion plasma is investigated. The results show that by increasing the concentration of impurities, the reaction rate decreases and the rate of energy loss self-radiation increases in the p6Li plasma. This effect is considerably stronger than the weak positive effect of reducing the energy lost for matter acceleration and electron heat conduction. With 20% impurity concentration of carbon, beryllium, and lithium, the reaction rate decreases 3.4, 2.7, and 2.2 times, respectively, and the radiation loss rate increases 6.7, 3.5, and 2.4 times, respectively, by more than a factor in comparison to pure p6Li plasma. The factors of energy losses related to material acceleration and electron heat conduction reduce only to 1.1–1.2 in comparison to pure p6Li plasma. The ignition is impossible at any values of the ignition parameter, areal density. The results show that the minimum ignition temperature from 800 keV increases to 1250, 950, and 840 keV with 20% impurity concentration of carbon, beryllium, and lithium, respectively. Also, both areal density and ignition energy parameters increase by increasing the concentration of these impurities. The conclusions show gain decreases in the p6Li plasma due to a decrease in the fusion reaction rate.