Characteristics of S12045(X) photon sensors for GlueX Barrel Calorimeter for GlueX Silicon Photomultiplier Photodetectors Characteristics Operation Summary

BCAL: GlueX Barrel Calorimeter BCAL design modeled after KLOE EMC 48 modules (phi sectors) Readout unit SiPMs Light guides 12 mm Module: 191 layers Pb/Sc/Glue 37/49/14% Immune to magnetic fields!

BCAL Photodetectors Hamamatsu S12045(X) MPPC array: Silicon Photomultiplier (SiPM) Arrays of 16 3x3mm2 cells, pixels 50x50 mm2 Gain ~106, dark rate ~15MHz/array at 250C Insensitivity to magnetic fields! Operation ~ Vbr+1V ~ 75 V Sensitivity to radiation Properties unaffected except for dark rate, which increases proportionally to radiation dose. Lifetime of SiPM in Hall D estimated ~ 9 years at T=5oC 12 mm Qiang NIM A698 (2013) 234 Experience T2K experiment deployed 53,000 1.3x1.3mm2 S10362-13-50C sensors Hall D is the first large-scale application of SiPM arrays Barbosa NIM A695 (2012) 100

S12045(X) Hamamatsu MPPC array Array of 16 cells 3600 pixels/cell Back side can be cooled 16 Pins, one for each cell 4 bias supplied, one per row 12.7 mm GlueX: 1 bias 1 summed output

Lightfoot et al., J. Inst., Oct. 2008 Gain vs Temperature Lightfoot et al., J. Inst., Oct. 2008 T = -196 oC T = 25 oC Vbr as temp. decreases

Photodetectors for GlueX The GlueX experiment requires a total of 4000 arrays All sensors have been delivered and tested. 30% were tested at Jefferson Lab 70% were tested at the Universidad Técnica Federico Santa María (USM), Valparaíso, Chile Four units failed our specifications Good consistency between test results University of Regina 10 units tested using realistic BCAL fiber spectrum Jefferson Lab Tests Measurements performed at 15oC Response measured for each of the 16 cells Five different light input levels USM Tests Measurements performed at 5, 7 and 20oC Response measured for each of the 16 cells Two different light input levels Voltage scan performed for each measurement

Determination of SiPM characteristics ADC (counts) pedestal 1 pixel 2 pixels 3 pixels 4 pixels 5 pixels Spectra for each cell in the array is used to determine gain, cross talk and dark rate at three different temperatures 5, 7 and 200C Photon Detection Efficiency (PDE) is determined using a calibrated light source

Cross talk and afterpulsing ~ 28% Parameters at 15oC <Gain> = 7.5 x 105 <PDE> = 23% <Dark Rate> = 10 MHz/array Cross talk and afterpulsing ~ 28%

Gain dependence on operating voltage

Summary of sensors for GlueX BCAL Testing status 4000 S12045(X) Hamamatsu MPPC arrays have been purchased and tested for use on the GlueX barrel calorimeter The performance of each of the 16 cells in the arrays has been tested at a variety of temperatures, bias voltages and light intensity settings. All sensors exceeded our specifications Next steps Sensors are being incorporated into readout modules that will be mounted on the barrel calorimeter Preparations are being made to deal with the operational challenges of these detectors (narrow voltage operating range and sensitivity to temperature).