TIMING RESOLUTION OF ACTIVE GANGING OF 48 SiPMs

ESTEBAN CRISTALDOJORGE MOLINA

Laboratorio de Mecánica y Energía (LME)Facultad de Ingeniería de la Universidad Nacional de Asunción (FIUNA)

Brief description◦ I will present the preliminary results of the simulations of timing resolution of

the amplified signals of 48 SiPMs by the transimpedance active gangingconfiguration.

◦ I will try to establish a relationship between the signal’s dynamiccharacteristics and the arrival time separation of photons hitting the detectorin order to distinguish individual photon hits at the output.

Active Ganging scheme

Transimpedance

Output

Hamamatsu S13360-6050

Simulation outline

Dynamic characteristics of the simulated signal:Rise Time (tr) : 97 nsFall Time (tf) : 619.5 nsTime to begin Fall (tbf) : ~200ns

The time to begin the fall is measured from t(Vp10%) at the rising edge to t(Vp90%) at the falling edge.

tbf

tr tf

1 PE

3 PESimulated event where 10 photon hitthe detector with exponential distribution ofarrival time. The first peak is the fast component withτ = 6 ns followed by photons arriving with τ = 1,6 us.

1 PE

3 PE

~260 ns ~300 ns

Single photon peaks can be clearly seen with a time separation of 300 ns and above 200 ns.

Peaks below 200 ns of time separation start mergin in each other and blend as a fast arriving photon.

𝑡𝑠 > 𝑡𝑏𝑓

The signal peak is distinguishablebecause it has time to fall

𝑡𝑠

~110 ns

Two photons arriving with a separation of 110 nsproduce a single double peak.

The signal peak merge as one because:

𝑡𝑠 < 𝑡𝑏𝑓

𝑡𝑠

Increasing the number of hits in one detector to 100illustrates the limits of the timing resolution of the active ganging amplifier.

Increasing the number of hits in one detector to 100illustrates the limits of the timing resolution of the active ganging amplifier.

Multiple photon hits blending in one peak. Multiple photons arriving under the time resolutionare packed in one peak.

◦ Apparently, the time resolution of this configuration is around 200 ns,meaning it cannot distinguish photons arriving less than 200 ns apart.

◦ To have a better view of the time resolution, photon hits can be simulatedarriving at fixed time rate of:◦ 300 ns

◦ 200 ns

◦ 150 ns

◦ 100 ns

With 300 ns arrival time, the peaks are clearlydistinguishable.

With 200 ns arrival time, the peaks are still clearlydistinguishable, but single photon peaks arrivingnearly can be missed.

With 150 ns arrival time, peak amplitude is nearlycompletely attenuated for single photon hits.

With 100 ns arrival time, the peaks are completelyundistinguishable.

Conclusions◦ Based on observations of this simulations, I conclude that for a signal with a

rise time of 97 ns it may be posible to distinguish photons arriving 200 nsappart, down to 150 ns if good SNR is achieved.

◦ By extrapolation, to be able to obtain a timing resolution of 100 ns the risetime of the signal must be 60 ns or less and a time to begin the fall of ~100 ns.

◦ Statistical data on based on this kind of simulation can be produced todetermine the signal parameters more accurately.

Thanks for your attention.