Parametric Study of Ultrashort Pulse Laser-Driven Neutron Production with Particle-In-Cell Simulations

Recent experimental advances in tabletop laser-driven neutron generation raise a number of questions regarding how the neutron yield can be further improved by novel target configurations and increased laser intensity. This work uses the WarpX Particle-In-Cell (PIC) code to model high-intensity ultrashort laser pulses interacting with thin deuterated targets in bulk and 'pitcher-catcher' configurations. A pairwise fusion algorithm [Higginson et al. Journal of Computational Physics 388 (2019)] directly calculates neutron generation and standard PIC algorithms model the subsequent motion of the new fusion products within the simulation. We evaluate this method by systematically exploring how predicted neutron yield depends on laser intensity and target thickness. Additional parameters tested include the separation between the 'pitcher' and 'catcher' and the influence of initial target heating on neutron production. We also highlight important convergence considerations and effects of simulation dimensionality. In conjunction with experimental efforts, PIC simulations provide a pathway for evaluating the viability of laser-driven neutron sources for applications including neutron imaging, radiation hardening, and fusion energy.