Simulate an LGAD sensor?

I am looking for a good simulation framework to simulate a special variant of an LGAD (Low Gain Avalanche Detector) sensor. In Simon’s CERN Detector Seminar Talk I heard that charge multiplication can be added (Slide 31), but it’s not clear to me if it is included in the code already, or if this has to be coded by the user. Also, the manual makes no mention of charge multiplication or LGAD.

So my questions are:

  1. Can Allpix2 simulate charge multiplication out-of-the-box? E.g. simply by setting a Geant4 flag?
  2. If not, is this an upcoming feature? If so, when will it be availabe?
  3. If it is not planned, can it be easily added by me as a user?

Best regards,

Hi @valentan

Currently charge multiplication is not yet implemented but someone is working on it. There is a basic implementation which needs some more testing though.

  1. Not out-of-the-box currently, and if so it would not be a Geant4 flag because Geant4 is only used to track particles through the material and to calculate energy deposition. Allpix Squared does the charge carrier transport.
  2. Yes, it is. Florian Pitters @ HEPHY is currently working on this.
  3. The implementation is not hard, but to avoid duplicate effort, maybe contact Flo to coordinate.

I’ll send the two of you an e-mail to put you in contact.


Just to say I’m interested in this topic as well. If there is some progess on LGADs please let me know!
Many Thanks,


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