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)

2Alexandre Vaniachine Pico-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

3Alexandre Vaniachine Pico-Second Timing Simulation Workshop, University of Chicago, 12/12/2006

1E-16

1E-15

1E-14

1E-13

1E-12

1E-11

1E-10

1E-09

1E-08

1E-07

1E-06

-30 -25 -20 -15 -10 -5 0Reverse Bias Voltage (V)

Cur

rent

(A)

Principle of Operation of SiPMT (credit Claudio Piemonte, ITC-irst)

n+ p-

V

E

V < VAPD => photodiode 1 collected pair/generated pair

VAPD < V <VBD => APD <M> collected pairs/generated pair

V > VBD => Geiger-mode APD inf. collected pairs/generated pair

p

Simulated diode reverse currentIMPACT IONIZATION ONIMPACT IONIZATION OFF

VBD VAPD

diode structure

electric fieldin the reversedbias diode

depletion width

full depletion

4Alexandre Vaniachine Pico-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

5Alexandre Vaniachine Pico-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

constconversionADC

Gpixelsp Si

RADC

SiADC NppN

)(#0

58010 )exp(1

Measurement of saturation gives alternate estimate of gain

6Alexandre Vaniachine Pico-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

7Alexandre Vaniachine Pico-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.

8Alexandre Vaniachine Pico-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