Post on 19-Dec-2015
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