Numerical optimization of the production of Kr nuclear isomer in laser–cluster interaction

We numerically investigated the optimal conditions for generating nuclear isomers in experiments involving the interaction of intense femtosecond pulses of relativistic intensity with gas–cluster targets. Such experiments are promising as an alternative approach to producing nuclear isomers without the use of accelerators or nuclear reactors. Using three-dimensional particle-in-cell simulations, we investigated the interaction of femtosecond (30 fs) laser radiation with a krypton cluster of 50–100 nm diameter over an intensity range of 1018–1020 W/cm2. It is shown that the main contribution to isomer generation is made by hot electrons propagating from the focal point throughout the gas jet. The laser intensity and cluster size optimal for generating the 83mKr isomer have been determined, and the calculation results have been verified by comparison with recent experiments. The results obtained are of interest for future experiments on the efficient generation of krypton isomers, and the numerical calculation methods developed in this work can be applied to other elements.