Simulation Status and Problems for SiPM/APD Pico-Second Timing Simulation Workshop University of Chicago, Chicago, USA December 12, 2006 Alexandre Vaniachine, Robert Wagner (Argonne)

2 Alexandre VaniachinePico-Second Timing Simulation Workshop, University of Chicago, 12/12/2006 Excellent Idea I like the idea to develop SiPM simulations code very much Indeed, these new devices does not have any commonly adopted simulations tools in the public domain

3 Alexandre VaniachinePico-Second Timing Simulation Workshop, University of Chicago, 12/12/2006 Principle of Operation of SiPMT (credit Claudio Piemonte, ITC-irst) n+ p- V E V photodiode 1 collected pair/generated pair V APD APD collected pairs/generated pair V > V BD => Geiger-mode APD inf. collected pairs/generated pair p Simulated diode reverse current IMPACT IONIZATION ON IMPACT IONIZATION OFF V BD V APD diode structure electric field in the reversed bias diode depletion width full depletion

4 Alexandre VaniachinePico-Second Timing Simulation Workshop, University of Chicago, 12/12/2006 Simple SiPM Features to be Reproduced by Simulations Start with the single SiPM cell model –Reproduce the measured separated peaks Depending on the temperature, integration (S/H) time, etc. Room temperature response Pulse height for ~1-2 pe expected SiPM cooled by dry ice Pulse height for ~1-2 pe expected

5 Alexandre VaniachinePico-Second Timing Simulation Workshop, University of Chicago, 12/12/2006 Simple SiPM Features to be Reproduced by Our SiPM Model (2) Reproduce the saturation measurements Line is a two parameter fit to Measurement of saturation gives alternate estimate of gain

6 Alexandre VaniachinePico-Second Timing Simulation Workshop, University of Chicago, 12/12/2006 Advanced SiPM Features to be Reproduced by Our SiPM Model Reproduce the cross-talk measurements

7 Alexandre VaniachinePico-Second Timing Simulation Workshop, University of Chicago, 12/12/2006 Advanced SiPM Features to be Reproduced by Our SiPM Model (2) Reproduce high-rate behavior affected by the dead-time in fired cells Reproduce the gain measurements from the current measurement Simulate the efficiency Simulate the timing performance (vs. number of photons) etc.

8 Alexandre VaniachinePico-Second Timing Simulation Workshop, University of Chicago, 12/12/2006 Conclusions If we will develop common SiPM simulations tools – the SiPM Model - we could become the first who grabbed that growing research area