Non-thermal advanced fuel fusion: phase space engineering and geometric algorithms

For DT fusion, tritium self-sustainability remains an engineering challenge. Non-thermal advanced fuel fusion replaces high tritium recirculation with high recirculating power needs. We explore phase space engineering using external electromagnetic fields to address this challenge, examining its theoretical and algorithmic aspects [1]. Symplectic dynamics of charged particles constrain phase space engineering. Beyond Liouville's theorem of incompressibility, Gromov's non-squeezing theorem imposes minimum particle footprints in phase space. The Gromov ground state problem is posed as follows [2]: For a given initial particle distribution and a Hamiltonian function, what is the minimum energy state under smooth symplectic transformations? While the analytical solution to this symplectic topology problem is still unknown, newly developed structure-preserving geometric algorithms can be employed to simulate phase space engineering processes (e.g., Maxwell's demon, electromagnetic energy extraction) and calculate minimum phase space footprints. These algorithms conserve symplecticity on discretized spacetime, preserving incompressibility, non-squeezability, and symplectic capacities. This research aims to advance our understanding of non-thermal fusion systems and improve their simulation accuracy, contributing to the development of commercially viable fusion energy technologies. [1] Phys. Plasmas 31, 050601 (2024). [2] N. J. Fisch, private communication (2024).