CALICE Status

1
CALICE Status

• Paul Dauncey
• Imperial College London
• For the CALICE-UK groups Birmingham, Cambridge,
  Imperial, Manchester, RAL, UCL

2
The CALICE collaboration

• Study calorimetry for a future linear collider
• Both electromagnetic (ECAL) and hadronic (HCAL)
• ECAL studies are for Si-W tracking calorimeter
• HCAL studies are for analogue scintillating tile
  or digital (small cell) made with RPCs,
  scintillating tiles or GEMs
• Big collaboration already
• 150 people, 24 institutes, 8 countries (including
  Europe, US and Asia)
• DESY is a member (CALICE grew out of TESLA TDR
  studies)
• and still expanding
• 6 institutes have joined since the last LCUK
  meeting
• FNAL have also approached the collaboration
• Informal agreement on collaboration with
  SLAC/Oregon
• Recent summary of status written for DESY PRC in
  October
• Can find from CALICE-UK page http//www.hep.ph.i
  mperial.ac.uk/calice/

3
CALICE beam test

• Major aim is beam test
• ECAL 20?20?20cm3
• 30 layers of tungsten
• 9720 Si diode pads with analogue readout
• HCAL 1?1?1m3
• 38 layers of iron
• 15000 5?5cm2 scintillator pads with analogue
  readout, OR
• 350000 1?1cm2 RPC, scintillator or GEM pads with
  digital readout
• Timescale is short
• mid 2004 mid 2005

4
CALICE-UK approval

• UK project (finally!) approved in Dec 2002
• Funding only for two full FYs, not the three
  requested
• Funds up to March 2005 cannot complete beam test
  or do analysis!
• Can reapply to extend in 18 months
• Equipment fund sufficient to build ECAL
  electronics
• We will design and build VME boards and DAQ
  system for beam test
• Hope to use same boards for HCAL readout
  (analogue and digital)
• Full effort request granted for engineering from
  Rutherford Laboratory
• New engineer (Adam Baird, RAL) has now joined the
  project
• One RA post for two years at Cambridge
• For simulation work, the other part of the UK
  involvement
• Travel money for the two FYs

5
CALICE-UK simulation studies

• Two sets of studies going on
• Jet resolution is major driver for fine-grained
  calorimetry
• Simulation indicates required 30/?E is
  achievable using energy flow
• but simulation needs to be verified
• Hadronic interactions known to be difficult to
  model
• Compare Geant3/Geant4/Fluka predictions
• Birmingham and Cambridge groups
• Beam energy spread will be significant
• Luminosity will need to be known as a function of
  ?s
• Bhabha rate is high and (obviously) depends
  directly on luminosity
• Measure ?s for each event from acollinearity
  angle of e and e
• Could use tracker only but need very high
  efficiency at low angles
• UCL group

6
Geant3/Geant4 electron comparisons

• Expect EM response to be modelled well
• Use beam test configuration for studies
• Direct comparison to data when available
• Agreement is reasonable after tuning
• Low energy cut-offs
• Production of ?-rays

7
Geant3/Geant4 pion comparisons

• Did not expect hadronic response to be as good
• Pion beam agreement also pretty reasonable after
  same tuning
• Comparable to (better than?) electrons

8
Geant3/Geant4 proton comparisons

• Protons show much worse agreement
• Small nucleon component in all jets
• Causes almost all of small discrepancy in pion
  jets
• Importance of using proton test beam
• Not previously recognised
• Data may be different from both models!

9
CALICE-UK electronics work

• Effort from several groups in ECAL readout
  electronics
• Imperial, Manchester, UCL
• Following approval, RAL TD became involved
  brought experience of CMS tracker
• Significant knowledge of design of Front End
  Driver (FED)
• Readout board for CMS silicon tracker
• Around 500 boards needed for whole tracking
  system
• FED architecture close to proposed CALICE board
• Data gathering and control almost identical
• Actual data input technology very different CMS
  use fibre
• FED design is quite advanced
• Physical board layout complete, firmware designs
  in progress
• Two final-specification prototypes received two
  weeks ago and currently undergoing tests
• Will now use FED as a starting point
  for CALICE

10
Original proposed system

• Readout board most complex part
• Each cable handled by slave FPGA
• Whole board controlled by master FPGA

• 15 readout boards
• Each handles digitisation of 2 layers
• 1 trigger board
• Holds off further triggers until readout complete
• 1 test board (not shown)
• For testing cable connections of readout board

11
FED board compared to readout board
12
FED layout

• Ideally
• Keep everything to the right
• Redo everything to the left
• FED is bigger
• More per board
• More channels per board also
• Total cost approximately the same
• Saving is on schedule and effort

13
ECAL electronics schedule
2003 2004
J F M A M J J A S O N D J F M A M
Prototype 2 boards Design
Layout
Fabrication and assembly
Testing, including VFE prototype tests
Production 9 boards Redesign
Layout
Fabrication and assembly
Testing
14
CALICE summary

• CALICE as a whole is still growing
• Dominating the LC calorimetry community
• CALICE-UK is finally approved
• Not everything we wanted (yet)
• Will keep us going for the next two years
• Simulation studies producing useful results
• Indicating the importance of proton beams
• Ensures beam test will be sensitive to most
  critical issues
• Electronics getting close to producing hardware
• Now based on CMS FED board cost neutral but less
  effort needed
• Should have prototypes this summer, final boards
  early in 2004