Liverpool Group presentation 22/07/2009 SiPM response: experimental results In collaboration with LSN-University of Catania and STMicroelectronics-Catania SiPM response: experimental results In collaboration with the University of Catania Liverpool Group presentation 22/07/2009 Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org angela.intermite@quasar-group.org

Overview SiPMs and beam loss monitor From a single SPAD to a SiPM (1) SiPM models Realization of the amplifiers and SiPMs signal readout board Dark count SiPM to a pulsed laser signal Measurements of rise time and recovery time Conclusions Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 2/14

SiPMs and beam loss monitor Multimode step index fibers SiPM directly coupled to the fibers Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 3/14

From a single SPAD to a SiPM (1) Semiconductor junction with a reverse bias few Volts above VBD. Depletion layer E higher than 3x105 V/cm: a single carrier can trigger a self-sustaining avalanche. A few mA current pulse with sub-nanosecond rise time is sharply produced. The voltage is restored to the bias value and the device is ready to detect another photon quenched the avalanche by using a large resistor (passive quenching) or a suitable circuit (active quenching). OXIDE METAL N+ Gettering P+ Sinker S P A D Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 4/14

From a single SPAD to a SiPM (2) Matrix of n pixels in parallel Every pixel gives the same signal when it is hit by a photon but the output charge is proportional to the number of triggered cells, i.e the number of injected photons: Qout=C(VR – VBR) Nfired Analog device S I P M Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 5/14

SiPM models STMicroelectronics (Catania) Photonique SA-Switzerland Blue range Visible range Active surface 1mm2 Number of cells ~500 Fill factor > 70% Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 6/14

Realization of the amplifiers and the signal readout board High gain amplifier (Photonique AMP_0604) Signal rise time ~5ns (5000ps), Amplification 20x...60x High Rise Time amplifier (Photonique AMP_0611) Signal rise time ~700ps, amplification 10x...20x Catania very high gain amplifier Amplification 10x...200x Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 7/14

Dark count amplitude (mV) Dark count measurements : repetition frequency and dark peak amplitude Dark noise rate originates from the carriers thermically created in sensitive volume and also due to the effects of high electric fields. The SiPM dark rate increases with temperature. SiPM Dark count amplitude (mV) Blue Phot 20 Vis Phot ST modF 25 ST mod H 30 1 ph 2 ph Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 8/14

SiPM response to a pulsed laser signal Laser features: Wavelength: 408 ± 10 nm Spectral width (Δλ) <7nm Pulse width <60 ps Peak power in collimated beam (mW) >140 Tune: [0,100] % Repetition frequency: 10Hz-1MHz Experiments: Fixed tune and variable rep frequency Fixed rep frequency and variable tune Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 9/14

SiPM response to a pulsed laser signal: fixed tune 1 kHz: a signal every 1ms f= 5kHz: a signal every 200μs 1 MHz: a signal every 1μs f=100 kHz: a signal every 10 μs We have a coherent signal for every repetiton frequency between 10 Hz and 1 MHz Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 10/14

SiPM response to a pulsed laser signal: fixed repetition frequency Tune 100% Tune 50% Tune 4.4% Tune 20% The SiPM response is proportional to the injected photons until the Nph< Ncells : saturation Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 11/14

SiPM response to a pulsed laser signal: rise time and recovery time Rise time: time useful for triggering the avalanche Recovery time: time useful for quenching the avalanche (dependent on the quenching circuitry used) Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 12/14

Conclusions We mounted the read-out electronics of SiPM and we tested the SiPMs for observing their response to: Different amplifiers Dark count Timing response between 10 Hz and 1 MHz with a pulsed laser signal Rise time and recovery time Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 13/14

Thank you very much for your attention Liverpool Group presentation 22/07/2009 angela.intermite@quasar-group.org 14/14