Modular calibration/monitor system for the GlueX BCAL +FCAL

1. Modular calibration/monitor system for the GlueX BCAL +FCAL University of Athens * G.Voulgaris E.G.Anassontzis P.Ioannou E.Kappos C.Kourkoumelis *with lots of help from Elton, Zisis, George L. and Matt UoA calibration system 1 UoA calibration system

2. The main philosophy behind : The main idea is that we need continuous monitoring and relative calibration info (absolute will be done by physics channels) from the above systems. BCAL involves novel readout elements (the SiPM’s) and their performance as well as the possible ageing of the detector elements etc has to be monitored and studied extensively (gain shifts etc). • GENERAL QUIDELINES • The calibration system should be: • Modular-> applicable to both detectors • Simple (avoid optical benches and high power lasers, exploit available technology) • The light->readout part: small in size->since readout elements are closely packed • Reasonably priced UoA calibration system

3. OUR PROPOSED SOLUTION: After a study of the various options (Laser +light distributions with fibers, low cost splitters etc) we converged to light generated by LED’s close to the calorimeters APPLICABLE TO BOTHCALORIMETERS LED Pulser Control Module (LPCM) and Fan out to LED boards LED board UoA calibration system

4. BCAL UoA calibration system

5. Possible considerations for BCAL +SiPM • LED board size • new design • Board height (components + PCB thickness • = 1.4mm + 0.8mm ≤ 2.5mm • Positioning the board: on the tapering of the Winston cone (can illuminate the other side SiPM) • LED ageing: for output 20ns at 1kHZ expect 620sec • “on”/year 7% deterioration/year for DC operation UoA calibration system UoA calibration system

6. Light guides with LED board UoA calibration system

7. Near and far side pulses for Baby Cal Near side P.H.=1.03 V Far side P.H=118 mV Add attenuation through full module -> Far/Near ~ 3% too large dynamic range UoA calibration system

8. Regina proposal/solution: Inject the light into the light guide via short green-blue fiber (optimal injection angle ~15o ) Far/Near 5:1 Mounting 3,000 boards is tricky Fiber will be much shorter Possibility to mount LED on the board at an angle New idea fiber on board UoA calibration system

9. LED Board 25mmx 7mm , 2 layer, 2.4mm thick, blue LED Daisy chained to 10 light guides and wired to control PCB UoA calibration system

10. Control PCB 90mmx50mm, 2 layer Receives 4 triggers and drives 4 different daisy chains of LED boards. UoA calibration system

11. After lots of discussions we converge to article one: Construction of two control Boards and 80 LED Boards which will be used for BOTH BCAL and FCAL with minor modifications (on small boards) • Control board • QUANTITY = 2 • DIMENSIONS (approx.) : 90mm x 50mm, 2-layer PCB • CONNECTORS • 1 x 2-row (5+5 pins) pin header for ribbon cable connector to provide: • T1, T2, T3, T4 (triggers), +5V supply, GND_digital, V_bias (0 to 25V), GND_bias • Standard 2.54mm pitch for pin header and ribbon cable to be used • 4x4-pin connectors (pin headers) for the 4 daisy chains • TOTAL POWER DISSIPATION: 200 μW (for 1kHz) • -------------------------------------------------------------- • LED boards • QUANTITY = 80 • DIMENSIONS (approx.): 25mm x 7mm, 2-layer PCB • Board thickness = 2.4mm • LED choice: KINGBRIGHT LED, BLUE, KP-3216MBC, 1206 size (or other) • TOTAL POWER DISSIPATION: 80 μW/board • -------------------------------------------------------- • Ribbon cable assemblies (daisy chains) • QUANTITY = 8 • 4-wire ribbon cable (daisy chain) with 10 LED boards per chain • Lengths and spacing to be agreed upon • -------------------------------------------------------------- UoA calibration system

12. In the near future To test, as soon as : 1)the Article one (new boards) arrives 2)the light guides from USM arrive 3) some SiPM’s ??? 4)unfortunately the new Baby Cal arrived unpolished (so we have to use the old rectangular one) • Test a “full” size read out chain from both sides • Check space in between guides • Extrapolate to real size • Check functioning of different triggers • Cross talk of different triggers UoA calibration system

13. FCAL UoA calibration system

14. Four different colour LED’s will be used 410,470,525,590 nm UoA calibration system

15. Full size plexiglas proposed by J.Fye for illumination of Pb glass four quadrants ~2.6 x 2.6 m2 “Protype” measured UoA calibration system

16. Configuration • Lucite 117x 95x 1.24 cm pane [instead of 1.3x1.3m] (already existed in the lab, but non polished) placed horizontal in the black box. • Define a grid on the Plexiglas where a square grid of 10x10 cm was marked • Few blue LED’s (V=17V) mounted on the two long (free) sides of the pane • A Pb-block in contact with the pane fixed but scaned different positions in the grid vertically. HV of the PM was 1700 V • Studied number and position of LED’s UoA calibration system

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18. Control board LED board mounted on the pane UoA calibration system

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20. One LED only used UoA calibration system

21. Please note: Uncertainty +/-30% Six LED’s used UoA calibration system

22. Normarized to mean value Please note: Uncertainty +/-30% Six LED’s used on the same side 9/10/2014 UoA calibration system UoA calibration system 23

23. Conclusions • The LED option has progressed well and it is at the final design and testing stage • The position and signals, number of boards etc for BCAL have been defined and will be verified by final testing. • The light injection from the LED to the light guides has to be finalized. • The number of boards, colours, positions etc for FCAL have been also defined for the FCAL, subject to testing with the first article. UoA calibration system

24. BACK UP 9/10/2014 UoA calibration system 25 UoA calibration system

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26. VOLTAGES FOR LED CONTROL BOARD:       A. All signals can be supplied by ribbon cable       B. Vbias will preferably have its own return wire (GND_B)       C. Wires needed (8):             T1, T2, T3, T4, +5V, GND, Vbias, GND_B CALCULATION OF VOLTAGE DROP IN CASE ALL LED’s FIRE AT ONCE In any case, assuming 25V operation, 1km of ribbon cable (250 Ohm/km), AWG 28  a pessimistic 10000  MOhms insulation resistance for each cap we have 2.5nA/cap leakage, i.e. 100nA per box of 40 caps which on a 1km cable gives a drop of 25 uV. If the insulation resistance drops to 1000 MOhms, say due to humidity, the drop over 1km cable will be 0.25 mV. If I add protection to the Vbias wire against overvoltage or   electrostatic build-up, this is expected to add some microamps of leakage, depending on the device chosen. This may result in a few mV of voltage drop for 1km wire. UoA calibration system

27. Rough schematic UoA calibration system

28. Monitoring System Connector- Fischer Series 102 (up to 9 pins for this connector) Monitoring System PCB can extend into this section if more space is needed (avoiding 2” mounting plate) Monitoring System Connector- mounting to end plate allows for modular cooling plate- electronics assembly (i.e. monitoring system stays with BCAL 2” mounting plate Monitoring System control PCB- shown as 4.5”x2” (114x51mm) UoA calibration system

29. Emerald LED, Temperature dependence for different driver voltages Vd~0.5%/oC Temperature dependence for different supply voltages. Emerald InGaN LED. UoA calibration system

30. Part Number: KPTD-1608QBC-G Blue UoA calibration system