BIC
The BIC code is a particle-in-cell (PIC) code designed to model the propagation of an ion beam from the wall of the fusion chamber to the target. It was developed at LLNL in 1990 and has been significantly upgraded since that time. There are two code modules, the transverse-slice model BICxy and the axisymmetric model BICrz.
BICxy follows a cross-sectional sllice of a beam or bundle of beamlets. The calculation is done in the moving frame of the slice, so that fields are predominately electrostatic. BICxy has been used to assess the importance of photoionization of beam ions by thermal x rays from a heated target, the interaction of beamlets as they merge and overlap at the target, and other topics.
The axisymmetric model BICrz follows a finite-length beam on a mesh that is stationary in the laboratory frame. The code is fully electromagnetic and uses a spatially tapered mesh that maintains accuracy as the beam converges radially. The code has Monte-Carlo models of collisional ionization and photoionization of the beam and the background gas to allow detailed examination of these processes, and a suite of diagnostics allows various beam quantities to be viewed at a chosen time or as functions of time at chosen axial locations. BICrz has been used to study the effects of collisional ionization and photoionization, the scaling of the focal spot with beam perveance and background-gas pressure, and the transport of the long-duration pulses used to heat the shell of an indirect-drive target.
BIC runs under the Basis code-steering system, allowing a user great flexibility in setting up and running jobs. Most parts of the code are written in Fortran77, but the ionization subroutines use Fortran90. The code runs on UNIX workstations, DEC-alphas, and on Cray vector machines, but the Basis interface makes BIC unsuited for parallel processors.
references
D. A. Callahan-Miller, "Chamber Propagation Physics for Heavy Ion Fusion," Fus. Eng. & Des. 32-33, 441 (1996).
W. M. Sharp, D. A. Callahan-Miller, A. B. Langdon,
M. S. Armel, and J.-L. Vay, "Improved Modeling of Chamber
Transport for Heavy-Ion Fusion," Nucl. Instr. Meth. in
Phys. Res. A 464, 284 (2001).
For comments or questions contact WMSharp@lbl.gov or DPGrote@lbl.gov. Work described here was supported by the Office of Fusion Energy at the US Department of Energy under contracts DE-AC03-76SF00098 and W-7405-ENG-48. This document was last revised June, 2002.