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Status of the PSD upgrade. F.Guber, A.Ivashkin, O.Petukhov (INR, Moscow). - Problems with the PSD in Be runs - Modification of cooling system - New temperature control - Upgrade of HV control system - MAPD gain monitoring system - PSD readout upgrade - Nearest plans.
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Status of the PSD upgrade F.Guber, A.Ivashkin, O.Petukhov (INR, Moscow) - Problems with the PSD in Be runs - Modification of cooling system - New temperature control - Upgrade of HV control system - MAPD gain monitoring system - PSD readout upgrade - Nearest plans NA61/SHINEupgrade workshop, CERN6 – 8 November, 2013
Problems with the PSD in Be-runs • No PSD MAPDs and electronics cooling in 2011 Be run; • 2012-13 Be runs - the air flow from underground for cooling; • Not effective cooling system! • The temperature sensors in modules have been not working properly (strange long term behavior of T-sensors). Only 3 normal t-sensors have been used in the last 2013 Be run. • 3. HV control system didnt not readout MAPD voltages. • 4. No monitoring system for the MAPD gains. • 5. The rise time of PSD trigger signal is too slow – problem with the time-amplitude walk and signal delay in trigger box. • 6. Electronics noises are rather small but comparable with MIPs signal. • It makes problem with muon calibration. Energy in PSD Ebeam =30AGeV Temperature MAPD gain ~4 %/0C
Strategy of the PSD upgrade in 2013-2014 • New cooling system. • II. New PSD electronics, including • 1. New temperature control system. • 2. New HV control (readout of real voltages). • 3. Monitoring system for the MAPD gains (LED stabilized source). • 4.. Fast amplifiers and new PSD trigger signal. • III. New readout system should be compatible • with DRS4 and with existing readout. Present status of the rare side of the PSD
First prototype of FEE and slow control system is ready LED source Al-plate+ T-sensor MAPDs SC connector HV channels PCB with amplifiers and adder 10 Analog signals +trigger (adder) Test of prototype has been done
Structure of new PSD electronics in the module and cooling with air flow 60 layers Al plate HV distributor PCB board End cover Plastic tube Lead-scinti, WLS-fibers with 11 optcal 10 SiMs board with with electronics with air inlet from air ~120 cm connectors T sensor (Power 0.5W) distributor box 100 – 160 mm Could be ajust in this range Temperature in this area should be ~20◦±1◦ Air distributorbox Chiller/heater (t~16-20○) Pumped air Valve on each module air tube
Heat sources around photodetectors In PSD module (simulation results - G. Camplone, Enrico Da Riva (CERN)) The total heat transferred from the outer surfaces with the room temperature (T = 28 degrees) is highly inferior to the power which dissipate from the PCB board (0.5 W)
The condensation temperature Optimal stabilized temperature inside modules ~21-22 ◦C
Structure of new PSD electronics in the module with Peltier cooling 60 layers Al plate HV distributor PCB board End cover Plastic tube Lead-scinti, WLS-fibers with 11 optcal 10 SiMs board with with electronics with air inlet from air ~120 cm connectors T sensor (Power 0.5W) distributor box Petlier with sink & controller Temperature in this area should be ~22◦±1◦ Copper sink Chiller/heater (t~16-20○) Air distributorbox Pumped air Valve on each module air tube
PELTIER COOLER We used Peltier element with active area 15 x 30 mm; Umax = +/- 4V Imax = +/- 4A
Scheme of MAPDs temperature stabilization by Peltier element Temperature sensor Copper heat sink To Al plate PELTIER COOLER Heat sink Ts External TEC controller Ts -sink temperature sensor To -object temperature seensor Compressed air PSD module electronics
TEC Controller The TEC-1091 is a specialized TEC controller / power supply able to precision-drive Peltier elements. It features a true bipolar current source for cooling /heating, two temperature monitoring inputs (1x high precision, 1x auxiliary) and intelligent PID control with auto tuning. The TEC-1091 is fully digitally controlled/
Temperature setting by Peltier with TEC controller Cool Room temperature ~19 ○C Heat/cool Object temperature Target object temperature Rump normal temperature Actual output current
Long term temperature stability DCS Room temperature Object temperature Sink temperature Temperature distribution on the MAPD support plate during 24 hours
Cost estimate of the PSD cooling system upgrade based on the Peltier elements • Petlier elements – 50 x 20-30 Euro ~ 2000 CHF • TEC controllers 50 x 180 CHF ~ 9000 CHF • Temperature sensors – 100 pc ~ 2000 CHF • Power supplies -?? • Auxiliary materials and tools ~ 2000 CHF • Total ~15 – 20 KCHF
Many thanks Martin for the help in different mechanical work during tests preparation Petr Gorbounov for very good advices and help with different components, tools and devices needed for tests Gianluca Camplone, Enrico Da Riva for detail simulation of module cooling
First prototype of FEE and slow control system is ready LED source Al-plate+ T-sensor MAPDs SC connector HV channels PCB with amplifiers and adder 10 Analog signals +trigger (adder) Test of prototype has been done
New slow control system. • Originally developed for COMPASS ECAL • Can control up to 127 devices (modules). • Can control the gain monitoring system too (next slide). • Connection with external computer: USB-2.0 or RS-232. • Internal bus: RS485 • Maximum length of bus cables: 50 m Controller for SC Developer - HVSys Co., Dubna. It constructed the slow control for COMPASS EM calorimeter with MAPD readout. New HV distribution system • Extremely low power consumption. • HV stability – 0.01%. • One external power supply ~12 V. • Permanent check of correct HV values within given HV gate - There is feedback to HV values! • Already tested for a few years! !
MAPDs gain monitoring system Based on stabilized LED source. Light amplitude is controlled by PIN-diode inside with very low temperature dependence. Control of MAPD gain at <1% level Digitized LED signal A, ch Time, bin sE/E~2% LED amplitude spectra Time amplitude stability ~1%
300 ns 60 ns The PSD trigger signal MAPD signal M~5x104 ADC signal integrated signal M~107 2011-2013 Be runs: the PSD trigger signal comes after integrators with rise time ~60 ns: rather slow and large time-amplitude walk. Needs careful adjustment for each beam energy and each beam ion. In 2014 - :…. trigger signal after MAPD – fast signal, no problem with time walk and delay.
Trigger problem is solved Fast Amp. G=30 Present scheme: MAPD Adder Signal shape after adder. Rise time ~10 ns No time walk! No extra delay of trigger signals!
Matching with readout electronics (present and future variants) Fast Amp. G=30 Signal adapter Slow amp.-integrator CB Present variant : MAPD Low gain output G=30 (for high energy deposition) DRS Future variant : MAPD or/and High gain output G=30x4 (for low energy deposition + muon calibration) DRS Shape and amplitude of MAPD signal after amplifier are PMT like ones. Easy to adapt to any readout scheme.
How many DRS channels are needed? • 440 MAPDs in PSD. • 440 DRS readout channels for individual MAPD readout. • If to use both low/high outputs 440x2=880 DRS readout channels. But the amplifiers are saturated at 2.5 V, while DRS are at 1 V. Attenuator (x2.5) in each channel will match the A-range of amplifiers and DRS by preserving the dynamical range somehow. • Is the use of only one (low or high) gain output enough for lead? • For pile-up identification the adder signals must be digitized in the time window ~10 ms. • How many adders must be digitized: in each module (44)? separately for central and outer parts (2) ? only one adder for full PSD? Cables, connectors, patch-panel?
PSD trigger(only central modules in trigger) 7Be + 9Be Spectator spots at PSD surface Significant part of T2 triggers has no interactions because of exclusion of first section from trigger. 40A GeV 75A GeV T1 T1 T2 T2 15 40 GeV/c 80 GeV/c
PSD trigger for 7Be+9Be reaction Spectator spots at PSD surface 20 AGeV 13 AGeV 30 AGeV T1 T1 T1 T2 T2 T2 All PSD modules must be in trigger. Gain of all MAPDs and amplifiers must be the same.
PSD upgrade plan: • July – September (Moscow) • Production of FEE prototype and test at test-bench. - DONE • October-November (CERN) • Assembling and test of new electronics for one module at CERN - DONE • November – December (Moscow) • Mass production of new PSD electronics. - IN PROGRESS • -December (CERN) • Test cooling system in one module with real TEC controller and Peltier. • Test module readout by CAEN DRS module. • January – April 2014 (CERN) • Installation and test of the PSD electronics and cooling system at NA61. • Summer 2014 –the PSD test with cosmic rays. • October 2014 – test/calibration of the PSD with proton (better with muon beam!) • Estimated beam time ~ 3-4 days.