Evaluation of Non-Thermal Fusion Probability in Dense p¹¹B Plasmas Using Newly-Reported Fusion Cross Section*

It has been reported that in p¹¹B fuel, energetic protons recoiled by alpha particles produced from p¹¹B fusion reactions cause non-thermal fusion reactions with ¹¹B in the bulk plasma during their slowing down, which results in chain (or avalanche) reactions [1], being expected to contribute to the realization of p¹¹B inertial fusion. The earlier numerical study [2] showed 5 ~ 10% enhancement in the fusion reaction rate due to the chain reactions at temperature of 150 – 350 keV and density of 10¹⁶ – 10²⁶ cm^-3. The recently-reported p¹¹B fusion cross section [3] is larger than the previously reported one [4], which will enhance the chain reaction probability. So, we have performed transport calculations of alpha particles generated by the thermal p¹¹B fusion reactions and protons recoiled by the alpha-particles in dense p¹¹B plasmas using newly reported fusion cross section in order to evaluate the probability of non-thermal fusion reactions relative to thermal fusion reactions. We perform the calculations by changing plasma temperature and concentrations of proton and boron. In the meeting, we will report the p¹¹B non-thermal fusion probability and clarify its contribution to p¹¹B inertial fusion.

 

[1] S. Eliezer, et al., Phys. Plasmas 23, 050704 (2016).

[2] T. Weaver et al., UCRL-74938 (LLNL, Livermore, CA, 1973).

[3] A. Tentori et al., Nucl. Fusion 63, 086001 (2023).

[4] W. M. Nevins et al., Nucl. Fusion 40, 865 (2000).