Tech-X, Boulder, Colorado
LBNL, Berkeley, California
Brown University, Providence, Rhode Island
Electromagnetic particle-in-cell (PIC) simulations of laser wakefield accelerator (LWFA) experiments have shown great success recently, qualitatively capturing many exciting features, like the production of ~1 GeV electron beams with significant charge, moderate energy spread and remarkably small emittance. Such simulations require large clusters or supercomputers for full-scale 3D runs, and all state-of-the art codes are using similar algorithms, with 2nd-order accuracy in space and time. Very high grid resolution and, hence, a very large number of time steps are required to obtain converged results. We present preliminary results from the implementation and testing of 4th-order algorithms, which hold promise for dramatically improving the accuracy of future LWFA simulations.
Tech-X, Boulder, Colorado
High-energy electron cooling requires co-propagation of relativistic electrons over many meters with the recirculating bunches of an ion collider ring. The expected increase of ion beam luminosity makes such systems a key component for proposed efforts like the RHIC luminosity upgrade* and the FAIR project**. Correctly simulating the dynamical friction of heavy ions, during brief interactions with low-density electron populations, in the presence of arbitrary electric and magnetic fields, requires a molecular dynamics approach that resolves close Coulomb collisions. Effective use of clusters and supercomputers is required to make such computations practical. Previous work*** will be reviewed. Recent algorithmic developments**** and future plans will be emphasized.
* http://www.bnl.gov/cad/ecooling
** http://www.gsi.de/GSI-Future/cdr
*** A. V. Fedotov et al., Phys. Rev. ST/AB (2006), in press.
**** G. I. Bell et al., AIP Conf. Proc. 821 (2006), p. 329.
