A summary of FBK tests in view of the TDR Francesco Terranova DUNE - - PowerPoint PPT Presentation

A summary of FBK tests in view of the TDR

Francesco Terranova DUNE Photosensor Meeting (DUNE-SP-PDS) 9 Apr 2019

Main items

We have been testing two technologies from FBK:

• NUV-HD-SF: lower breakdown voltage, higher DCS
• NUV-HD-LF: higher breakdown voltage, lower DCS, developed

for dark matter We are procuring sensors with the optimal dimensions for DUNE (6x6 mm2) and SMD package We are setting up a schedule for down-selecting once we have all technical information on the SF and LF:

• Production of a batch of several hundreds of sensors to test

uniformity, reliability, thermal behaviour

• Production of some X-Arapuca cells to be tested at the PDS

test-stand in Italy and a module in Protodune-SP Run II

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Main results (I)

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NUV-HD-SF: 4x4 mm2, 40 mm cell pitch, tiles produced for DUNE.

• Thermal tests: 38 SiPMs OK (>20 cycles for 6 of them, >5 for

all others). 1 SiPM not working after the first thermal cycle

• Breakdown voltage at 77 K: 21 ± 0.5 V
• Max overvoltage: 21- 31 V (+10 V)

Main results (II)

NUV-HD-SF: 4x4 mm2, 40 mm cell pitch, tiles produced for DUNE.

• Dark count rate at 77 K and 0.75 p.e.: 0.10  0.05 Hz/mm2 at

+3 OV, 0.25 Hz/mm2 at +4 OV, 0.4 Hz/mm2 at +5 OV

• Afterpulse (see Michele’s talk): 10% at +4 OV
• Quenching resistance (see Michele’s talk) from 900 k to 6 M

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Main results (III)

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Most studies done with a cryogenic amplifier:

Main results for the LF sensors

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NUV-HD-LF: only one sensor available to date: 8x11 mm2, 30 mm cell pitch, sensor produced for DarkSide.

• Thermal cycles: OK (>20)
• Equivalent resistance at 77 K: 64.2 Ohm (Rq about 5 M )
• Quenching resistance at room temperature: Rq about 1 M
• Equivalent capacitance at 77 K: 6.5 nF

TDR

Main message:

• The FBK SF and LF technologies are interesting candidates for

the DUNE photosensors

• The tests on NUV-HD-SF performed in DUNE are consistent

with the specs provided by FBK while tests on NUV-HD-LF are

• ngoing
• We have set up a schedule for validation and down-selection of

the sensors Choose a subset of the results presented above for more technical details

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