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The collimators in OPAL 2.0.0 show a strange behavior. When a particle hits the collimator, it is not removed from the simulation, but it's scattered and leaves the Cyclotron in a straight line. The particle also doesn't appear in the COLL.loss file.

This is a minimal example, which reproduces the error: comet_min_example.in The LINE should be the one with the collimator (coll), the distribution is dist1 and NPART=1. The magnetic map: BMap_Dummy_m.txt The distribution file: dist_single_part.dat

The plotted particle track looks like this: gnuplot

If I use dist2 in the example and simulate with e.g. NPART=100, then the particles are correctly stopped by the collimator and written to the COLL.loss file. But in that case in the terminal output from OPAL, the number of 'Live Particles', always stays at 100, even though clearly the particles hit the collimator.