Testbeam Requirements for LC Calorimetry S. R. Magill for the Calorimetry Working Group...
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Transcript of Testbeam Requirements for LC Calorimetry S. R. Magill for the Calorimetry Working Group...
Testbeam Requirements for LC CalorimetryTestbeam Requirements for LC Calorimetry
S. R. Magill for theCalorimetry Working Group
Physics/Detector Goals for LC Calorimetry
E-flow implications for CAL Design/Testing
Optimization for E-flow Testbeam Goals
Hardware/Readout mode tests
E-flow/Detector simulation validation/verification
Test Beam Programs and Venues
Summary
Physics/Detector Goals for LC CalorimetryPhysics/Detector Goals for LC Calorimetry
Physics Requirement : separately id W, Z using dijet mass in hadronic decay mode (~70% BR) -> higher statistics physics -> higher statistics physics analysesanalyses
Detector Goal : measure jets with energyresolution -> -> /E ~ 30%//E ~ 30%/EE
Calorimeter challenge : match tracksto charged hadrons – requires separationof charged/neutral hadron showers in Cal,and isolation of photons –> E-flow approach
-> high granularity, both transverse and -> high granularity, both transverse and longitudinal, to reconstruct showers in 3-Dlongitudinal, to reconstruct showers in 3-D
W, Z
30%/M
75%/M
For example, explore EWSB thru the interactions : e+e- -> WW and e+e- -> ZZ
-> Requires Z,W ID-> Can’t always use (traditional) constrained fits
E-Flow Implications for CalorimetryE-Flow Implications for Calorimetry
Traditional Standards
HermeticityUniformity
CompensationSingle Particle E measurementOutside “thin” magnet (~1 T)
E-Flow Modification
HermeticityOptimize ECAL/HCAL
separatelyLongitudinal Segmentation
Particle shower reconstruction
Inside “thick” coil (~4 T)Optimized for best single particle E resolution
Optimized for best particle shower separation/reconstruction
ECAL E-flow ECAL E-flow OptimizationOptimization
For good isolation of photon showers :-> small rM (Moliere radius) – dense calorimeter-> If the transverse segmentation is of size rM, get optimal transverse separation of electromagnetic clusters-> If X0/I is small, then the longitudinal separation between starting points of electromagnetic and hadronic showers is large
All of the above help to separate hadron showers as wellSome examples :Material Z A X0/I
Fe 26 56 0.0133Cu 29 64 0.0106W 74 184 0.0019Pb 82 207 0.0029U 92 238 0.0016
Priorities :1) Measure (isolated) photon energy2) Separate charged/neutral hadron showers
A dense ECAL with high granularity (small transverse size cells), high segmentation (many thin absorber layers), and with X0/I small is optimal for E-Flow.
-> 3-D shower reconstruction
HCAL E-flow OptimizationHCAL E-flow Optimization
To optimize the HCAL for E-Flow requires : full containment of (neutral) hadronic showers good precision on energy measurement high segmentation in transverse and longitudinal directions inorder to separate in 3-D close-by clusters in jets
Integrated approach including other detector sub-components in the design phase, with E-Flow algorithms
Assume a tracking system optimized for, e.g., di-leptonmeasurements Assume a dense ECAL optimized for photon reconstruction Vary HCAL parameters, e.g., absorber material, thickness, size ofreadout cells in both transverse and longitudinal directions, to determine optimal performance in an E-Flow Algorithm.
Priorities :1) Measure neutral hadron energy2) Separate charged/neutral hadron showers
Testbeam Goals for CalorimetryTestbeam Goals for Calorimetry
Test detector hardware technologies and readout configurations
-> flexible configurations of absorber type and thickness, active media types-> linearity, uniformity, signal response, energy resolution, analog/digital readout schemes
Study reconstruction algorithms-> flexible configurations of transverse granularity, longitudinal segmentation-> E-flow properties, particle shower shapes-> beam particle tracking?
Validate/verify MC simulation-> shower libraries
Calorimeter Hardware/Readout Calorimeter Hardware/Readout SchemesSchemes
ECAL
Si pixel/W sandwich Analog “SD Detector”Scin Tile/W sandwich Analog Si-Scin/W hybrid AnalogDense Crystals AnalogCerenkov compensated AnalogHCAL
Scin Tile/SS sandwich Analog “CALICE”Scin “pixels”/SS DigitalRPC/SS DigitalGEM/SS Digital
Same absorber – hanging file configuration at Testbeam?
E-flow/Simulation validation Testbeam E-flow/Simulation validation Testbeam RequirementsRequirements
Design of CAL relies on simulation for E-flow algorithm applications
Simulations need to be verified in testbeam at particle shower level
Ultimate goal is jet energy/particle mass resolution - not possible in test beam
So, since EFAs require separation/id of photons, charged hadrons, and neutrals -
Verify photon shower shape in ECAL prototype (Si/W with fine granularity - 1X1 cm**2 or better – see plot)
Verify pion shower probability in ECAL as function of longitudinal layer
Verify pion shower shapes in ECAL/HCAL prototype (must be able to contain the hadron shower both transverse and longitudinally – see plot)
Try to get beams with particle energies as in Z jets from e+e- -> ZZ at 500 GeV ->
3 GeV e- in SD Cal3 GeV e- in SD Cal
LayerSh
ow
er
Rad
ius
(bla
ck)
Am
pl. F
ract
ion
(re
d)
70% of e- energy in layers 3-9
2.6,3.1
13,15.5
5.2,6.2
cm(front,back)
ECAL
ECAL/HCAL Boundary
10 GeV 10 GeV -- in SD Cal in SD Cal
Need all 34 layers
20 cm X 20 cm X 30 layer ECAL
80 cm X 80 cm (min.) X 34 layer HCAL
Sh
ow
er
Rad
ius
(red
) A
mp
l. F
ract
ion
(b
lue)
3.1,5.2
7.8,12.6
15.5,26
cm(front,back)
HCAL
Summary of SD Calorimeter Properties Summary of SD Calorimeter Properties On average, 94% of pion energy is contained within an ECAL area of 20 X 20 cm2
-> 20% of 10 GeV pions appear as MIPS throughout the entire ECAL volume, therefore are 100% contained
In the SD CAL, 95% of pion energy is contained for 35% of 10 GeV pions in a 20 X 20 cm2 ECAL coupled with an 80 X 80 cm2 HCAL (90% containment for 66% of these pions)
-> important to tag leakage from ECAL/HCAL in all directions
In a digital SD HCAL, 90% of pion hits are contained in a 90 X 90 cm2 area
-> again, important to tag leakage from ECAL/HCAL in all directions
Readout Channels for Testbeam CAL :30 X 30 cm2 SD ECAL (0.5 cm X 0.5 cm pixels in 30 layers)
-> 108K channels!!!1 X 1 m2 SD HCAL (1 cm X 1 cm cells in 40 layers)
-> 400K channels!!!
Tagging scintillator paddles surround CAL modules
HCAL
ECAL
Beam halo veto scintillator paddles
Beam
Wire Chambers (3-views)
Scintillator hodoscopes
Dead material
LC CAL Testbeam ConfigurationLC CAL Testbeam Configuration
HCAL : 1 X 1 X 1 m3
Testbeam requirements :a. Electron and photon beamb. Pion and other hadron beamc. Energies of EM and Hadrons: 5 - 150 ~ 250 GeV (If possible as low energies as possible, down to 1~2 GeV)d. Muon beam at energies 1-100 GeV or so --> This is for calorimeter tracking algorithm studies.
Testbeam VenuesTestbeam Venues
SummarySummary
The Calorimeter Working Group has begun to think about testbeam programs – first working document written which addresses :
-> Compatibility of various hardware configurations in the same testbeam area-> Challenge of testbeam programs for E-flow calorimetry-> Challenge of several readout configurations, large number of channels-> First look at possible venues-> Cooperation with European (CALICE) colleagues