Simulation of nuclear isomer production in laser-induced plasma

Abstract

Nuclear isomers play essential roles in various fields, including stellar nucleosynthesis, nuclear clocks, nuclear batteries, clean nuclear energy, and γ-ray lasers. Recent technological advances in high-intensity lasers have made it possible to excite or de-excite nuclear isomers using table-top laser equipment. Utilizing a particle-in-cell code, we investigate the interaction of a laser with a nanowire array and calculate the production rates of the 73mGe (E1 = 13.3 keV) and 107mAg (E1 = 93.1 keV) isomers. For 73m1Ge, production by Coulomb excitation is found to contribute a peak efficiency of 1.0 × 1019 particles s−1 J−1, while nuclear excitation by electron capture (NEEC) contributes a peak of 1.65 × 1011 particles s−1 J−1. These results indicate a high isomeric production ratio, as well as demonstrating the potential for confirming the existence of NEEC, a long-expected but so far experimentally unobserved fundamental process.