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Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 1/16
Optimisation Studies for the BeamCal Design
Lucia Bortko, DESY โ Zeuthen
ILD Meeting | IFJ PAN - Krakow | 24-26 Sep 2013
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 2/16
The Aim and ContentThe Aim: โข compare 2 types of segmentation of calorimeter โข investigate the characteristics
Content: โข Introduction โข Simulation studies - SNR - efficiency of reconstruction of showers - range of charge deposited into the pads - dependence vs - energy resolution - spatial resolution โข Conclusion
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 3/16
Beam Calorimeter for ILC
30 layersโข Tungsten absorberโข Diamond sensorโข Readout plane/air gap
1
Graphite absorber
BeamCal aimed:- Detect sHEe - Determine Beam Parameters - Masking backscattered low
energetic particles
Beam parameters from the ILC Technical Design Report (November 2012)- Nominal parameter set- Center-of-mass energy 1 TeV
FE
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 4/16
BeamCal Segmentation
UniformSegmentation (US)
pads size are the same
ProportionalSegmentation (PS)
pads size are proportional to the radius
Similar number of channels
Y, c
m
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 5/16
Energy Deposition due to Beamstrahlung
US
RMS
PS
Beamstrahlung (BS) pairs generated with Guinea Pig
Energy deposition in sensors from BS simulated with BeCaS (Geant4)
โ considered as Background (BG)
RMS of the averaged BG
โ considered as noise (for SNR)
is the same, but /pad is different!
Average10 BX
Figures show sum of all layers
Average10 BX
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 6/16
Shower from Single High Energy Electron
- Showers are simulated with BeCaS (Geant4)
- Investigated energies: 10, 20, 50, 100, 200, 500 GeV
Shower from 100- GeV electron
Maximum in10th layer
(average over 10 showers)
= 100 GeV
Longitudinal shower profile
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 7/16
ProportionalSegmentation
UniformSegmentation
The average energy in the pad of the core of shower
RMS of the averaged Background
Signal and RMS for both Segmentations
20 bunch crossings were given
Signal nearly segmentation-independent!
Different distributions!
ProportionalSegmentation
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 8/16
SNR in cell with maximum _ ๐ ๐๐๐ฉ
SNR =
= 50 GeV
= 100 GeV PS US
PS US
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 9/16
Efficiency of Showers Reconstruction
PS US
= 200 GeV
Radius, cm
PS US
= 50 GeV
Efficiency =
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 10/16
Charge Range Estimate
DiamondPS
USPS
US
Distribution of the collected charge per pad from
Background for DiamondDistribution of the collected charge per pad from
500Gev electron for Diamond
Showers Background
Diamond GaAs
Charge collected from MIP 2.44 fC 4.29 fC
Maximum collected charge from 500GeV electron
12 214 fC 21 497 fC
Correspond to about 5 000 MIPs
For sensor pad thickness 300 ยตm:
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 11/16
Deposited Energy vs Energy of Electron
Energy deposition (GeV)
Num
ber o
f eve
nts
๐ธ๐=๐ดโ๐ธ๐๐๐โ๐ต๐ด=58.66 ยฑ0.03974 ;๐ต=โ0.2972ยฑ0.1183
y = 0,017x + 0,0051
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 12/16
Energy Resolution vs Energy of ElectronEn
ergy
Res
olut
ion
Energy of Electron (GeV)
๐ ๐ฌ๐ฌ =โ๐ .๐๐๐๐๐
๐ฌ +๐ .๐๐๐๐๐๐๐
๐ ๐ฌ๐ฌ =โ๐๐
๐
๐ฌ +๐๐๐
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 13/16
Spatial Resolution ( In Process)
Estimation
PSUS
COG
= 2.9%
= 1.65 deg
= 2.21 mm
= 2.16 mm
๐๐ ๐๐๐๐๐๐
๐๐๐
๐๐๐
๐๐๐๐ ๐๐
๐๐
๐๐
๐๐
๐ ๐ถ๐๐บ=๐ 1๐ธ๐ 1+๐ 2๐ธ2+๐ 3๐ธ๐ 3
๐ธ๐ 1+๐ธ2+๐ธ๐ 3
0
4 5
2 1
3 6
x
y
๐๐ถ๐๐บ=โ๐=0
6
๐ ๐๐ธ๐
โ๐=0
6
๐ธ๐
= 0.609 mm
= 3.97 mm
= 5.14 deg
= 0.848 deg
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 14/16
Spatial Resolution ( In Process)
Corrected COG
Energy of Electron
๐๐
Gaussian fit
- 0
๐๐
๐น๐ช๐ถ๐ฎ
๐น๐๐๐๐
โR
โR
Parameters
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 15/16
Conclusion> Performance of BeamCal for two different sensor segmentations is
compared Number of readout channels is kept similar Signal from sHEe nearly independent of the segmentation Energy deposition per pad from Beamstrahlung differs significantly Proportional segmentation improves the signal-to-noise ratio Proportional segmentation gives better reconstruction efficiency
> The charge range has been estimated Collected charge per pad from sHEe nearly independent of the
segmentation Collected charge per pad from BS for US in 6 times bigger than for PS
> Energy deposition was investigated Dependence between energy of electron and deposited in calorimeter
energy is linear. Deposited in sensors energy is 1,7% from the original energy of electron. Dependence energy resolution vs energy of electron is calculated and
parameterized. Calorimeter gives good energy resolution: 2% for 100GeV electron.
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 16/16
Thank you for your attention!
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 17/16
Backup slides
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 18/16
Layer 7 Layer 11
Shower maximum โ Layer 9
PS US
PS US
PS US
SNR for 50 GeV ElectronSNR in cell with maximum
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 19/16
Layer 6 Layer 10
Shower maximum โ Layer 8
PS US
PS US
PS US
SNR for 20 GeV Electron
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 20/16
Layer 5 Layer 9
SNR for 10 GeV Electron
PS US
PS US
PS US
Shower maximum โ Layer 7
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 21/16
Charge range estimate
For Diamond sensor pad thickness 300 ยตm:
- Charge collected from MIP: 2.44 fC - Maximum charge collected โ for shower from 500 GeV electron: 12214 fC(correspond to about 5000 MIPs)
Diamond GaAs
Distribution of the collected charge per pad for 500Gev electron showers
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 22/16
Diamond
GaAs
Blue โ Uniform SegmentationOrange - Proportional
Green โ Uniform SegmentationBlue - Proportional
Distribution of the collected charge per pad for 500Gev electron showers
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 23/16
Efficiency of Showers Reconstruction
Efficiency for 50 GeV
= 200 GeV PS US
Efficiency =
Lucia Bortko | Optimisation Studies for the BeamCal Design | 2013-09-25 | IFJ PAN Krakow | Page 24/16
ProportionalSegmentation
UniformSegmentation
The average energy in the pad of the core of shower
RMS of the averaged Background
UniformSegmentation
Signal and RMS for both Segmentations
20 bunch crossings were given
Signal nearly segmentation-independent!
Different distributions!
ProportionalSegmentation