Recent progress in the simulation of heavy ion beams

Abstract

Production of electric power by using a beam of heavy ions to ignite an inertially-confined fusion target requires the focusing of high-power beams onto a small spot several meters distant from the final lens system. Beams with the necessary intensity generally behave like warm nonneutral bounded plasmas where beam kinetic temperatures are sufficiently high that a cold-plasma description can be inadequate for describing the collective space-charge modes. In view of the complexity of the self-consistent nonlinear dynamics, analytic study has largely been limited to the singular Kapchinskij–Vladimirskij (K–V) distribution. Numerical simulations, primarily using the WARP [D. P. Grote, A. Friedman, I. Haber, W. Fawley, and J. L. Vay, Nucl. Instrum. Methods Phys. Res. A 415, 428 (1998)] particle-in-cell (PIC)/accelerator code, have been employed to identify the degree to which the analytic results, especially the predictions of unstable modes, are applicable to realistic beam distributions. During extensive benchmarking of the code against experiments at Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, and the University of Maryland, a particular feature of the beam which has been seen in both experiment and simulation is the launching, in the source region, of collective warm-plasma oscillations similar to those predicted on the basis of the K–V analysis.

Survey of collective instabilities and beam–plasma interactions in intense heavy ion beams

“…during the acceleration of the charge bunch [10], and can provide the free energy to drive both the electrostatic Harris instability [32][33][34][35][36][37][38][39][40][41][42] and the electromagnetic Weibel instability [39,[43][44][45][46][47][48].…”

Thermodynamic bounds on nonlinear electrostatic perturbations in intense charged particle beams

“…Thus, much effort has been devoted to understanding the underlying physics of the nonlinear processes occurring in these beams. An important, tractable approach to solving the detailed dynamics of such systems is often to rely on advanced numerical tools such as particle-in-cell (PIC) simulations [6][7][8] , eigenmode codes 9,10 , and Monte-Carlo codes [11][12][13][14] which can simulate the linear and nonlinear phases of instabilities that may cause a degradation of beam quality.…”

Weibel and Two-Stream Instabilities for Intense Charged Particle Beam Propagation through Neutralizing Background Plasma

“…Nonetheless, often with the aid of numerical simulations, there has been considerable recent analytical progress in applying the Vlasov-Maxwell equations to investigate the detailed equilibrium and stability properties of intense charged particle beams. These investigations include a wide variety of collective interaction processes ranging from the electrostatic Harris instability [29][30][31][32][33][34][35] and electromagnetic Weibel instability [36][37][38][39][40][41] driven by large temperature anisotropy with T ⊥b T b in a one-component nonneutral ion beam, to wall-impedance-driven collective instabilities [42][43][44][45], to the dipole-mode two-stream instability for an intense ion beam propagating through a partially neutralizing electron background [45][46][47][48][49][50][51][52][53][54][55][56], to the resistive hose instability [57][58][59][60][61][62][63] and the sausage and hollowing instabilities [64][65][66] for an intense ion beam propagating through a background plasma [67][68][69]…”