Beam Dynamics Simulation During Longitudinal Bunch Compression with Focusing Field Errors

In heavy ion inertial fusion (HIF), the intense heavyion beam (HIB) is one of the influential candidates as the energy driver, and the physics of space-charge-dominated beams is crucial in the HIF and High Energy Density Physics studies. Required parameter values of HIB are several GeV particle energy, ∼100 kA total current, and ∼10 ns short pulse duration, and the beam parameters are far from those of conventional particle accelerator system. Therefore the beam dynamics and control are important research issues in HIF. At the final stage, the beam pulse must be longitudinally compressed from ∼100 to ∼10 ns. In our studies [1, 2, 3], the beam instability excited by the strong space charge effect was observed using multi-particle numerical simulations during the final beam bunching. The final beam bunching was carried out by the beam transport using the continuous and alternating focusing lattice system. We also investigate the beam dynamics during the bunch compression with the focusing error field. Transverse particle-in-cell simulation with a longitudinal bunch compression model is carried out to investigate transverse particle behaviors. For the particle positions xp and yp of index p, the equations of motion along the transport distance s are written as[1]