* if an error occurs while saving the log file
*/
private void createLog(Properties props, MonteCarloSS mcss)
throws IOException {
// Beam
ElectronGun beam = mcss.getElectronGun();
props.setProperty("beam.energy",
Double.toString(FromSI.eV(beam.getBeamEnergy())));
props.setProperty("beam.center.x", Double.toString(beam.getCenter()[0]));
props.setProperty("beam.center.y", Double.toString(beam.getCenter()[1]));
props.setProperty("beam.center.z", Double.toString(beam.getCenter()[2]));
if (beam instanceof PencilBeam) {
props.setProperty("beam.direction.x",
Double.toString(((PencilBeam) beam).getDirection()[0]));
props.setProperty("beam.direction.y",