Status of HB Phase-1 upgrade hardware at TIFR - Kajari Mazumdar on behalf of TIFR-B - CERN Indico

Status of HB Phase-1 upgrade hardware at TIFR

                                   Kajari Mazumdar
                                  on behalf of TIFR-B

India-CMS meeting, Santiniketan                         August 24 , 2018

Phase-1 upgrades of CMS detector & India

                                                           4th Muon Station

                                                                  Indian
                                                                   contribution
14,000 tons
21 m long
15 m diameter                                    HCAL : New
                                                 Photosensors &
                                                 electronics
                                                                          2

Essentials of CMS Hadron Calorimeter
•  HCAL starts at R ~ 180 cm and Z ~ 400 cm from the interaction point.
•  Sampling calorimeter providing up to 11 interaction lengths (at h=0) for
   hadronically showering particles
• Essentially plastic scintillators with embedded wave-length shifting fibres,
   interleaved with brass in HE, HB regions  ~72000 tiles
• Light read out with photo detectors: HPD Silicon Photomultipliers (SiPM)
Legacy detector with HPDs ~ 10k channels (HB: 2592, HE: 2592, HO: 2160, HF:1728)

Performance directly impacts trigger capabilities through measurements of jets,
missing transverse energy and other kinematic variable, like HT, τ leptons as well
as isolation parameters of e, µ, γ
At offline corrective measures are taken to deliver physics objects (jets and missing
Transverse energy) accurately.

2 hard facts:
1.CMS detector designed in 1990s was not meant for high lumi operation of LHC
2. Radiation damage suffered by HCAL detector during LHC Run1 is worse than
 anticipated.

Upgrade is essential to maintain/improve physics capability for next 20 years 3

Motivation for upgrade of HCAL electronics

• Mitigate radiation damage to scintillator :
  needed photo-detection with high gain and efficiency
  eliminate anomalous signal and increase signal-to-noise ratio
• Longitudinal segmentation for calibration of depth-dependent effects
   Mitigate performance degradation due to high occupancy caused by pile up
• Utilize timing information (with ns resolution) for non-collision backgrounds
  with low energy up to MIP level.

                                                                             4

HB/HE data control path

Eliminate high amplitude noise and drifting response of HPDs by replacing them
with SiPMs (better light detection eff., higher signal-to-noise ration, lower
operating voltage.)

Timeline for HCAL Upgrade

• HE frontend electronics delivered by TIFR during 2016 in operation during 2017-18
 5+50 sets of Calibration unit mechanics + small implements
 5+ 50 Pulser cards and peripheral boards (QIE adapter)
 5+ 190 SiPM control board and bias voltage cards

Block diagram of HB front-end electronics

                                                      •   HE FEE is similar, but varies
                                                          in details

                                                      •   Some of the active
                                                          elements are LHC specific,
                                                          supplied by CERN.

•   Frontend electronics boards MUST be of radiation hard material.

•   Indian industry picked up the technology of producing rad-hard PCBs in the
    context of HE boards.

•   HCAL electronics production helped in being selected for producing frontend
    boards for GEM.                                                             7

HB Phase HB FEE deliverables
Commitment :
 190 SiPM Control Boards : Fabricate and do quality control of the 190 boards
 55 calibration units (CU) : Mechanical casing with various implements and Pulser card 
  Assemble all the components of the CU and test the 55 Units

SiPM Control Board :
 Each card is a 6 layer board with 64 channels that provide accurate Bias Voltage (BV)
   of 65 Volts to 64 SiPMs
 Each SiPM fixed on the mounting board of the HB readout module (RM)
 RM is installed inside the readout box (RBX) .
 This board also monitors the temperature and humidity of the SiPM ambience.
 The SiPM control board also has a mezzanine 4 layer card containing resistance divider
   circuit to provide the necessary BV current

Calibration Unit (CU) :
 Each Calibration Unit houses 1 optics box, 2 LEDs ,3PINDIODE boards, 1 Puslerboard
 Pulser Board has MicroSemi FPGA, 1 QIE Card, LC-LC optical cable, 6 SMA connectors (for
   laser light from the tiles) & 1 fiber splitter assembly .
 Each CU primarily provided the controlled LED light which is made to shine on the SiPMs for
   the calibration monitoring of the SiPM gain and calibration for single photo electron

HB Calibration Units & HB SiPM Control cards: status
HB Calibration Units
 HB CU to be delivered at CERN in batches (QIE Cards, and Fiber splitter unit , being
  fabricated at FNAL, to be assembled later at CERN)
 4 Pulser cards of batch1 were re-worked after modification of design for additional capacitor at CERN for
  remote JTAG programming
 The initial batch of 4 CUs then reassembled at CERN and retested to be ok.
 The QIE card and the fiber splitter to come from Fermilab .
 HB CU Mechanics in TIFR workshop going at slow pace
 Batch 1 (2) of 4 (6) CU assembled and has reached CERN by July 12 (Aug 16th )

SiPM Control cards
 Batch 1 : Eight SiPM control cards tested at TIFR and carried to CERN
 Batch 2 : Twenty four SiPM control cards being assembled at Peninsula Electronics and will
  be tested and then have to be in CERN by at least 2nd week of September

Fabrication of CU box and other mechanical implements done at TIFR workshop.
 Each CU box (12’’ X 4’) consists of 13 pieces, mostly done in CNC machine

Mandakini: in charge of the complete hardware fabrication and quality control of electronics
 QC setup has been built at TIFR indigenously.

HB Calibration Units fabricated at TIFR workshop
                                     HB CU closed
                    HB CU Top View

HB CU inside

 Pulser Board

Part of the workforce at TIFR

HB FEE Boards fabricated in India

                               HB Mezzanine board

                 Capacitor

Pulser Board

        Pulser Board

                                HB SiPM
                                Control
                                Board

SiPM Control Cards Batch1 testing
 Test at TIFR :
 Eight Boards carried to CERN by 17th July.

 All boards tested with NO load using Flex Mount Board at TIFR and all were
  found OK (no channels goes into saturation) .

Test at CERN :
 Duplicated the TIFR stand alone test stand setup using the Raspberry Pi setup at
   CERN.

 Tests performed with full load (75Kohms x64 ) of 2 boards at cern
    design modified slightly

 One SiPM Control Board assembled inside a production HB Readout Module.

 After mounting the Petliers etc , installed in the Burn-in readout Box (RBX) at CERN
  and again tested.
   design subsequently modified (one resistor value changed) slightly

8 Boards tested without load at TIFR

                                       TIFR test stand

Test Setup at B28 for SiPM control cards testing
                                                   GUI Interface

             Test Board connected               External Power
             to SIPMCC                          supply for -
                                                100V BV

                                    Testboard

Load Resistors
Bank (75K)

Automated the Test stand for SiPMCC at CERN
 Used the Keithley 7001 Switch Box and Keithley, Voltmeter GPIB interface
  card
 Designed, wired and tested the interface test boards, for the connecting of
  Load resistor Bank to the SiPMCC channels via switch box to the Voltmeter
 Code in Lab Windows was modified to close the connection of switch box to
  appropriate Channel loads
 This automatic switch box and test board saves the manual measurements
  of 200x64x3 =38400 readings!!!

                                                 Interface test
                                                 boards

                                                        Switch Box
   CERN test stand

Summary
 Batch 1 : 8 SiPM control cards at CERN
  - tests showed trivial modifications required both on the SiPM control card
   and the Mezzanine boards  steps taken

   Batch 2 : SiPM control boards and mezzanine boards : 24 cards to be tested
   at TIFR and sent to CERN by Sept 1st week .

 Automatic standalone Test stand for SiPM Control Card & Bias Voltage cards.
   Calibration procedure developed and fully functional

 Batch 1 and batch 2 Calibration units : 10 in total at CERN now after the Quality
  Control of the Pulser Boards inside the CU.

HB hardware fabrication related activities are in full swing, both at TIFR and CERN .
Will continye for next 2-3 months.