Hi, Pelle. I ran the default Geant4 overlap check on your new detector model and here are the results. http://www.slac.stanford.edu/~jeremym/hps/HPSTracker2014-v0_overlaps.txt You can run the check yourself with a command like slic -g ./detectors/HPSTracker2014-v0.lcdd -m ./overlaps.mac &> HPSTracker2014-v0_overlaps.txt where overlaps.mac is a text file with /geometry/test/run There appear to be some pretty serious overlaps in your detector. You should look into this because these types of problems can cause incorrect/unexpected results in the simulation. --Jeremy ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the HPS-SOFTWARE list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1