After downloading the distribution file unpack this file in the PEPC install directory. Each demo contains a complete directory structure necessary for running the code (up to a certain number of CPUs, which can be increased if necessary), one or more input parameter files (.h) and corresponding run scripts. The following demos are currently included:

Coulomb explosion of cluster - demo_cluster

Starts with ionized spherical cluster with equal numbers of ions and electron Laser is uniform field in the x-direction (beam_config_in=3), sinusoidal in time, amplitude vosc. Can also be switched on by visualisation, if steering=.true. switch set.

Two input sets:

 cluster.h - small system for viewing particle orbits
 cluster_big.h - large system with particles switched off, density and temperature fields only

Associated run scripts are: cluster.sh, cluster_big.sh

Ion crystal generation - demo_crystal

Runs in 'crystal' mode, creating config with equidistant ions. Sets:

cube.h - cubic box
shell.h - hollow shell

Electron + Ion acceleration (laser+ wire target) - demo_wire

Laser hits middle of wire near x=0 and starts heating electrons, pushing them through the wire. Charge cloud on rear surface and sides starts to pull ions away. Laser also 'drills' through front surface, pushing on ions there. Sets:

  wire.h + wire.sh
  wire_big.h + wire.job

Visualisation tips for XNBODY:

• Set ivis > # timesteps (too many particles to display and selective shipping isn't implemented yet). Pick laser intensity and electron density fields initially.
• Select isosurface and adust cut for laser to about half-way down wire.
• Selecting lowest value for electron density will pick out single electrons.
• User right mouse button to adjust the colour maps (make val=0 transparent).
• After simulation has developed, switch to ion density to see ion motion.

Laser wakefield accelerator

Short laser pulse passes through thin, uniform plasma column, exciting plasma waves in its wake (speedboat effect). Electrons trapped in the wake get accelerated to high (many MeV) energies and trail behind the laser pulse at nearly the speed of light. Radial forces in front of the pulse cause electrons to make complex orbits away from the propagation axis, rejoining the wake behind the pulse.

Sets:

  shoot_200k.h + shoot.sh
  shoot_2m.h + wake_big.job

Vis tips:

• smaller run designed to display particles, BUT can only run until rezoning starts (XNBODY currently crashes if # particles not constant/labels change).
• use longer column for big run if necessary (currently no rezoning)