PSD upgrade: concept and plans - Why the PSD upgrade is necessary? - Concept and status of the PSD temperature control - Concept of the PSD analog part upgrade - Upgrade of HV control system - PSD upgrade schedule F.Guber & A.Ivashkin, (INR, Moscow) 1

Why the PSD upgrade is necessary? 1. Existing HV control system sets the MAPD voltages but does not readout HV. No information about real HV at MAPDs. 2. The temperature stabilization of MAPDs is not working properly. 3. The temperature control system is not working properly; 4. No monitoring system for the MAPD gains. 5. The PSD trigger signal is rather 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. Upgrade of all items, excluding 5 and 6, doesn’t depend on the choice of PSD readout - TRB3, DRS4, …., and can be done even if the old PSD readout electronics would be used in 2014 run 2

Energy in PSD – – Temperature Temperature dependence of 7 Be peak position MAPD gain ~4 %/ 0 C Position of Be peak for 13 AGeV for 1 small (left) and 2 large modules. E beam =30AGeV 3

60 layers Al plate HV distributor PCB board End cover Plastic tube Lead-scinti, WLS-fibers with 11 optcal 11 SiMs board with with electronics with air inlet f rom air ~120 cm connectors T sensor (Power mWt) distributor box 100 – 160 mm Could be ajust in this range Temperature in this area should be 25 ◦ ±1 ◦ New structure of the PSD electronics and temperature control system Heater (t~25 ○ ) Air distributor box Pumped air Valve on each module air tube T sensor 4

Originally developed for COMPAS ECAL modules with 9 MAPDs/module Can be easy adopted to 10 MAPDs/PSD module. Compact design. Extremely low power consumption. HV stability – 0.01%. One external power supply ~12 V. Permanent check of correct HV values within given HV gate! Slow control exists! Already tested for a few years! Production by HV systems, Dubna New HV distribution system There is feedback to HV values! 5

New Slow control system. Originally developed for COMPAS 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 6

MAPDs gain monitoring system Stabilized light pulses of LED is provided by PIN-diode inside with very low temperature dependence. Controlled by SC (the same as HV) Control of MAPD gain at ~1% level 1 device in one module. Gain monitoring system is based on 7

The PSD trigger signal 60 ns 300 ns MAPD signal M~5x10 4 integrated signal M~10 7 ADC signal At present: 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. Plans: trigger signal after MAPD amplifier – fast signal, no problem with time walk and delay. To have fast trigger new amplifiers and new adders are needed. This action requires the replacement of present FEE by new readout electronics – DRS4, TRB3,…. 8

New fast amplifiers. New development is needed. The technical parameters are fixed for a while: Gain~ Bandwidth ~20 MHz Dynamical range 1 mV-2.5V One analog adder in each module for PSD trigger. Needs additional inputs: connectors, types of cables… (depends on used readout system –DRS4, TRB3?? 9

Different scenarios for PSD upgrade a)The PSD (as well as TOF) readout is completely new: All items above (temperature stabilization, MAPD temperature control, MAPD gain monitoring, new HV control system, trigger signal and new amplifiers) can be performed. b) The PSD readout is old: Some items (temperature stabilization, MAPD temperature control, MAPD gain monitoring, new HV control system) can be performed. Trigger signal and readout part is unchanged. 10

Preliminary PSD electronics upgrade plan: April (CERN) Dismount of existing PSD electronics and MAPDs, preparations to MAPDs mounting on the same plate in each module - done - May-June (Moscow) Preparation the technical task for production of the PSD FEE, HV and SC systems - in progress -July – September (Moscow) Production of FEE prototype and test at test-bench. -October-November Assembling and test of new electronics for one module at CERN -November – February 2014 Mass production of new PSD electronics. -March – April 2014 Installation and test of the PSD electronics and temperature control system at NA61. -It is quite urgent to sign NA61-INR agreement to start the PSD electronics upgrade 11

Thank YOU 12