Extreme Value Statistics Suggest Enhanced Fuel Implosion Efficiency Using Seven Sequential Sets of 26 Lasers Compared to Simultaneous Firing of 192 Lasers at NIF

Abstract

Power generation from hydrogen fusion is the ultimate benefit for humanity. The achievement by National Ignition Facility (NIF) in 2022 of producing energy exceeding the input energy using lasers was a great step forward. However, since the laser was applied indirectly, only 14.2% of its total thermal output was delivered to the fuel. Therefore, the purpose of this study is to identify improvements that would enable the total laser output to more efficiently induce nuclear fusion. One such improvement is to irradiate the fuel uniformly with the lasers so as to avoid imbalance in implosion. In this study, we define the range in implosion velocity as an indicator of imbalance, assuming it to be the difference between the maximum and minimum velocities among the n -laser-induced implosion measures. It is then found, based on extreme value statistics commonly used in probability theory, that with 26 lasers the range decreases by 27.6% compared to the 192 lasers used at NIF. A set of 26 laser devices is arranged along a long cylinder, with seven such sets positioned in sequence. A spherical fuel pellet is then allowed to free-fall from the top of the cylinder, and at the moment it passes through each set, the lasers are fired simultaneously. This method enables the fuel to be irradiated directly and continuously. It is estimated that ignition will be achieved if 182 ( i.e ., 26 × 7) of the 192 lasers used at NIF are arranged around the cylinder.