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 mm 2 ) 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 2

Main results (I) NUV-HD-SF: 4x4 mm2, 40 m m 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) 3

Main results (II) NUV-HD-SF: 4x4 mm2, 40 m m cell pitch, tiles produced for DUNE. • Dark count rate at 77 K and 0.75 p.e.: 0.10  0.05 Hz/mm 2 at +3 OV, 0.25 Hz/mm 2 at +4 OV, 0.4 Hz/mm 2 at +5 OV Afterpulse (see Michele’s talk):  10% at +4 OV • Quenching resistance (see Michele’s talk) from 900 k  to 6 M  • 4

Main results (III) Most studies done with a cryogenic amplifier: 5

Main results for the LF sensors NUV-HD-LF: only one sensor available to date: 8x11 mm 2 , 30 m m 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 6

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 ongoing • 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 7