Strong-field ionization and acceleration of heavy ions in the interaction of ultraintense laser pulses with targets

A strong-field ionization model is developed and implemented to accurately characterize the ionization process of heavy ions. Using one- and two-dimensional particle-in-cell simulations that incorporate both the developed and conventional ionization models, we investigate the interaction dynamics of intense lasers with Xe gas targets. It is found that at high laser intensities, both the maximum energy and acceleration efficiency of Xe ions are significantly enhanced due to the higher ionization rate provided by the developed model. However, the discrepancy in heavy ion acceleration between the two models is weakened in ultra-high-intensity laser fields since strong γ-photon radiation will result in massive laser energy loss. Furthermore, we observe the absence of Xe ions in certain charge states, which can be attributed to the high ionization barriers of electron orbitals with magnetic quantum number equal to ±2. Our results should be helpful for understanding ultraintense lasers interacting with high-Z targets and the generation of heavy ions with different charge states.