SiPM calibration Tagir Aushev (ITEP)

Proposal There 18 000 SiPM’s must be calibrated SiPM’s properties vary from one to another some SiPM’s can be bad to optimize total efficiency, all SiPM are preferable to have similar gain/efficiency/etc. and to reject the bad one Some tests are already done in both, ITEP and U of Tabuk using small number of SiPM’s calibrated simultaneously New device will calibrate a large amount of SiPM’s reduces the total calibration time to reasonable level (1-2 months) The proposal is to develop such a device with combined efforts of ITEP and U of Tabuk groups, who have some experience in it

Testing SiPMs at the U Tabuk done for Large Angle Beamstrahlung Monitor(LABM) by R. Ayad, C. Boulahouche, J. Madani to detect synchrotron radiation at large angle (beamstrahlung) to study beam-beam effect Later SiPMs from Advansid(Italy) to be used to save size in the optical Box and for robustness Optical Box: First we use PMs

SiPM tests at U of Tabuk Lab DAQ Dark Pulses and baseline change With temperature Channel by Channel Threshold Finding

Plans & schedule First step is to develop the principal scheme of the device 3 person x month Build a low channel prototype 4 person x month Develop DAQ system to collect, store and manage data Write a software to automatically analyze data from SiPM’s The building of the prototype can start now there is an available funding of about $25k We (ITEP & U of Tabuk) submit soon application for Grants in SA the decision will be made around June, 2013 The man power for the calibration will be provided by U of Tabuk

Backup

SiPM operation ΔHV = 1.4 V ~ 70 V 1 – 1.5 V HV = HVbreak down + ΔHV HVbreak down strongly depends on temperature: ~ 57mV/°C; all important for us SiPM characteristics (gain, efficiency, xtalk, noise) depends only on ΔHV – independently of temperature! choose working point: efficiency < saturation noise (at 0.5 p.e.) < 1 MHz xtalk < 20% to have maximum efficiency but staying in the linear region (robustness against temperature changes) SiPM noise (@ 8 p.e. threshold) < 1kHz << neutron bg rate To stay at the operation point it is sufficient to adjust HV to keep gain constant at chosen value ΔHV = 1.4 V

SiPM data base & distributions For 200 SiPMs available at ITEP we measured main characteristics and put them to SiPM db No big spread! Do we need calibration for the rest 18000 SiPMs?