Speaker
Description
SiPM (Silicon PhotoMultiplier) sensors are one of the technologies under study for the outer timing layer of ALICE 3, a next-generation multipurpose detector at the LHC which will replace the present ALICE experiment for Run 5 and beyond.
SiPMs are usually coupled to scintillators or Cherenkov radiators. Nonetheless, in recent studies it has been shown that SiPMs can directly detect charged particles due to the emission of Cherenkov light in the standard protection layer placed on top of the SiPM.
NUV-HD-LFv2 SiPMs, produced by Fondazione Bruno Kessler with 3.20 x 3.12 mm$^2$ area and with different thickness of protection layers, have been tested in a beam-test setup at CERN PS. The telescope is made of four sensors: two SiPMs under test and two LGAD detectors (1x1 mm$^2$ 25 um and 35 um thick sensors). The latter are used as timing reference and the coincidence of the two defines the trigger for the beam particles. The main results, obtained with a 4 GHz digital oscilloscope, confirm a very high efficiency above 99% and a noise below 1% for a threshold over 6-10 photoelectrons.
In addition, the performances after irradiation in terms of timing response and Dark Count Rate will be presented. They have been evaluated for NUV-HD-RH SiPMs of 1 x 1 mm$^2$ area, proving the possibility to maintain excellent timing performance close to 20 ps and low level of dark counts once an appropriate threshold is applied to the signal.
In the last beam test, SiPMs were also studied in a new and complete front-end and readout electronics chain made by a LIROC discriminator and a picoTDC with 3.05 ps bin size. In this poster, the efficiency with this setup will be reported for matrices made of 9 SiPMs, confirming to be above 95% at the lowest threshold achievable.
| Category | Experiment |
|---|---|
| Collaboration (if applicable) | ALICE |
