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Monitoring system for the HCAL prototype. Preparation of the test beam for HCAL LED monitoring system - monitor stability of tile-fiber system + SiPM - cover the dynamic range of data taking maybe monitor the saturation of SiPM Temperature monitoring system.
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Monitoring system for the HCAL prototype • Preparation of the test beam for HCAL • LED monitoring system • - monitor stability of tile-fiber system + SiPM • - cover the dynamic range of data taking • maybe monitor the saturation of SiPM • Temperature monitoring system Erika Garutti
Requests for LED monitoring system Monitoring: stability of MIP calibration during run, in between spills, 1Hz measurement low gain, MIP-like LED light need to take 2 pedestals: one for LED (in between spills) one for data (during spills) Calibration: determination of SiPM gain at the beginning of every run, 100Hz measurement ~10k events, high gain, low LED light (single pe) ~10k events, high gain, MIP-like LED ~10k events, low gain, MIP-like LED Monitoring: saturation curve parameters daily/weekly ~10k events x 5 points, high gain, min-3MIP LED light ~10k events x 20 points, low gain, ½ MIP-max LED light ~5 min ~30 min Erika Garutti
SiPM readout cards 18 clear fiber 10 - 100 cm Photodiode monitoring fiber UV-LED Photodiode LED monitor design 18 pairs LED+Photodiode • Present status of design • LED + PD board easy to exchange • Light-tight connection of the board l on cassette frame • Connections: • 1 LED voltage supply ~ 30-60V • 1 Photodiode voltage supply • 1 PD-preamp V supply • 1 Trigger input (NIM, neg.) • 18 signal outputs from the PDs, pos., ~ 500 ns shape • 1-2 Temp. sensors on board Erika Garutti
LED choice: Blue vs UV UV LED: to monitor scintillator + WLS fiber + SiPM - several types tested - best one 30% above the others - small LY spread over many fibers ±15% - all of them very slow: ~20ns to max LY NEW LED from NIU ~30% more LY Blue LED: monitor only WLS fiber + SiPM - slightly less LY than UV (~20 %) when shining on tile LED from: www.roithner-laser.com and www.led-shop24.de Best choice UV LED: LED405-02V (405 nm, 10mV @ 20mA, 12o) Erika Garutti
Status of LED monitoring system • Chosen LED monitoring setup: 1 LED + 20 clear fibers + 1 PD • 18 tiles monitored by each LED • Fiber inserted in a 0.5cm hole on the G10 board, fixed with reflector foil • Max LY achieved with our best LED & 0.5mm Luminous fiber 60 MIP • Improvements: • 0.75mm Luminous fiber ~ factor 2 • new LED from NIU ~ factor 30% (3mm Ø, 30o,UV) • Still to check (on LED side): • > LY spread form new LED (smaller diameter) • > LY spread on new mock-up • > UV light attenuation on clear fiber • > ageing of clear fiber with UV light • > comparison of LED signal to MIP signal Erika Garutti
Test setup 30 fibers, 0.5 mm UV LED LY spread on bundle output ±15% 0-11 V, 20ns pulse 100 Hz LED signal rise time ~ MIP rise time MIP : rise 11 ns fall 46 ns LED : rise 11 ns fall 45 ns Erika Garutti
Driving & monitoring the LED -LED pulser: -LY @ 30V with Petr pulser = LY @ 11V on standard pulser -saturation of LED light @ 30 V in Petr pulser is 60 V needed? -LED frequency: -during beam data taking 1 Hz -during special calibration 100Hz -PIN diode signal (with present preamp): -rise ~50ns, fall ~80ns -noise ~factor 10 larger than SiPM noise -S/N ~factor 2-3 larger than PM Erika Garutti
More about the system stability -long term LED stability checked (~1 month of data analyzed by Evgeni) -often jumps observed in LED LY -after correction stability of ~1% for SiPM (~3% on APD dominated by noise) APD/PD APD PD Erika Garutti ~15days
Temperature stability Warm up LED directly Warm up LED in water Preliminary check 27oC? oC 26oC41oC Consistent response of PM and PIN diode Direct warm up is too fast and T cannot be controlled LED variation < 0.5% / oC Erika Garutti
LED Stability in the lab Almost stable temperature over ~15h Study the spectral changes of LED light emission ~2% deviation of PM and PD measurement can be related to sensitivity to different light spectra maybe use WLS-fiber to connect PD ? PM PD First look Erika Garutti
LED/SiPM cross talk • measured SiPM signal with LED off • compared to LED on but light screened • 0.25pC cross talk on SiPM with LED at < 1cm distance • (MIP ~10mV ~2.5pC) LED off LED ~ MIP max LED LY Peak to peak 2.8 mV 5.8 mV Erika Garutti
SiPM saturation curve • Response function of SiPM obtained with 3 LED fibers perpendicular to the tile • good reproducibility • good agreement with saturation curve with: Npixel =1500 , geom. eff. = 0.12 , xtalk = 0.15 [a.u.] Erika Garutti
Temperature monitoring • Platinum resistors • interpolate 5 readout points • 2 r/o on LED board • 2 r/o on mother board • Total > 300 readout signals • Multiplexed r/o Project in collaboration between Prague-DESY Erika Garutti
MUX(MC14051) PT100n PT1001 PT1002 IB IL TEMP 2 RTD-PAC + CAN-bus IL CAN BK-TC-PAC Temperature monitoring(scalable system) no time constrain all ch. can be multiplexed AD590 Current RO Erika Garutti from Sven Karstensen + Milan
Slow control schematic Temperaturemonitoring(Phoenix contact) Motor control and monitoring(Siemens S7) Power Supply control and monitoring(W-ie-ne-r) CAN-bus CAN-bus Linux PCwith PVSS TCPIP Connection to the world:ORACLE, ODBC, TCPIP, HTTP, WAP Erika Garutti from Sven Karstensen