1. MicroMegas DHCAL : Résultat des tests en faisceau et simulation
Catherine ADLOFF
Laboratoire d’Annecy-le-Vieux de Physique des Particules
Catherine Adloff
Jan Blaha
Sébastien Cap
Maximilien Chefdeville
Alexandre Dalmaz
Cyril Drancourt
Ambroise Espagilière Raphael Gallet Nicolas Geffroy
Claude Girard Richard Hermel Kostas Karakostas (invité) Yannis Karyotakis
Inocencio Monteiro Fabrice Peltier Julie Prast Jean Tassan
Guillaume Vouters
09 Décembre 2008
SOCLE

2. Outline MicroMegas R&D for DHCAL Simulation Conclusion Why MicroMegas?
Analog Readout
Long source run with 55Fe
Test Beam
Digital readout
Simulation
Conclusion
09 Décembre 2008
SOCLE

3. MicroMegas Micro mesh gaseous structure Description: Readout:
or pads
Description:
Gas mix: Argon+Isobutane
Drift and Mesh HV < 500 V
High detection rate
Robust, cheap (industrial process)
Thickness: 3,2 mm
Delicate functioning: sparks
Readout:
Analog for characterisation GASSIPLEX + CENTAURE DAQ
Digital HARDROC or DIRAC + Digital InterFace (DIF) board + EUDET DAQ2 or CrossDAQ
cell = 1cm2 PCB pad
Steel top is part of the absorber
12x32 cm pads
325 LPI mesh
spacers : 120 m heigh m diameter
Bulk technology from R. De Oliveira & O. Pizzirusso
09 Décembre 2008
SOCLE

4. X-ray Response Set-up: 55Fe source (5.9 keV) Trigger on mesh
analog readout
FWHM (%)
Mean (ADC Counts)
VMesh (V)
Gain : up to
Energy resolution : down to 8.5 % (FWHM = 19.6)%
VDrift = VMesh + 70 V
EDrift = 233 V/cm
K. Karakostas
VMesh (V)
VMesh = 420 V EMesh = 35 kV/cm
VDrift = 470 V EDrift = 167 V/cm
Entries
ADC Counts
escape peak
A. Espargilière
pedestal
X-ray peak
Slope = ADC/mbar
= - 2 fC/mbar
K. Karakostas
Mean (ADC Counts)
Pressure (mbar)
09 Décembre 2008
SOCLE

5. Test Beam 2008 From dream to reality
H2 line at SPS-CERN (August 2008)
With the IRFU team (P. Colas, D. Attié,
S. Turnbull)
The data
200k 200 GeV
200k ~200 GeV
250k Pions with 1 steel block + absorbers
T9 line at PS-CERN (November 2008 TB)
The data
200k ~7 GeV
Characterisation of the prototypes:
efficiency and multiplicity
pads / prototypes uniformity
X-talk studies
behaviour in hadronic shower
A. Espargilière Preliminary
Results
09 Décembre 2008
SOCLE

6. Test Beam Setup Trigger: 3 scintillators in coincidence
3 MicroMegas 6x16 pads
1 MicroMegas 12x32 pads
Steel absorber option
analog readout
09 Décembre 2008
SOCLE

7. Preliminary Results MIP Signal observed on every Single Channel MPV
E (ADC counts)
MIP MPV ~ 45 fC
E Nb of Events
all triggers
platinum events
Pedestal:
aligned online (0.2 fC RMS)
constant over time
average sigma = 0.6 fC
 Good noise conditions!
MPV variation under study:
Electronics channels disparity
Drift space homogeneity
Y (cm)
X (cm)
MPV
HV Pad
Normalised MPV
Number of Pads
09 Décembre 2008
SOCLE

8. Preliminary Results Efficiency Measurements: Threshold :
gold events
Efficiency
Chamber 0
97,05 ± 0,07%
Chamber 1
98,54 ± 0,05%
Chamber 2
92,99 ± 0,10%
Chamber 3
96,17 ± 0,07%
Threshold :
2.8 fC = 0.06 MIP MPV x Y
09 Décembre 2008
SOCLE

9. Preliminary Results Multiplicity < 1.1 2 chambers
~ 75k gold events / chamber
threshold : 2.8 fC = 0.06 MIP MPV
gold events
gold events
09 Décembre 2008
SOCLE

10. MicroMegas with Digital Readout
PCB with DIRAC1 64 channels ASIC (R. Gaglione, IPNL)
3 thresholds on 8 bits each, 8 events memory
2 Gains  6 fC to 200 fC or 100 fC to 10 pC
Digital link to DAQ (possibility to chain detectors)
Bulk from R. De Oliveira & O. Pizzirusso
First operational Bulk MicroMegas
with embedded readout electronics !
DIRAC
Sparks protections
mask for bulk laying
8x8 pads with bulk
09 Décembre 2008
SOCLE

11. MicroMegas with Digital Readout
Tested during the August 2008 TB
Very promising results!
Beam Profile
when moving
the X-Y table
MicroMegas
Lower Threshold = 19 fC
ethernet
readout
Future test beam: Need a stack of chambers to check efficiencies
09 Décembre 2008
SOCLE

12. MicroMegas with Digital Readout
PCB with 4 HARDROC1 64 channels ASIC 3 layers of 8x32 cm2
HARDROC1
sparks protections
Mesh side
bulk
09 Décembre 2008
SOCLE

13. MicroMegas with Digital Readout
Tested during the November 2008 TB
PCB
with ASICs
Readout : DIF board
Separated from the slab
For large number of ASICs HARDROC, DIRAC and also SPIROC and SKYROC
DIF task force interface USB or DAQ2
Excellent work from Guillaume Vouters (DIF) and Christophe Combaret (CrossDaQ)
Difficulties to get the bulk stable
Data currently under study
09 Décembre 2008
SOCLE

14. Simulation (J. Blaha) Simulation tools
SLIC full simulation (Geant 4)‏
Analysis using JAS3
2008 Test beam setup is being simulated
Comparison with real data
Better understanding of our detector
Preparation for next test beam
200 GeV Pions
Simulation
Test beam
30 cm iron absorber in front
09 Décembre 2008
SOCLE

15. Simulation DHCAL with MicroMegas HCAL dimensions:
1m3 HCAL prototype (40 planes of 1m2, 4.5 I, 1m3)‏
Large HCAL (80 planes of 2m2, 9 I, 8m3)
‏1.9 cm thick steel absorber
Thickness of active layer: 6 mm
3 mm Gas: 95 % Argon + 5 % Isobutane
2.8 mm PCB + ASICs‏
Different readout cell size:
0.5 x 0.5 cm2
1 x 1 cm2
2 x 2 cm2
4 x 4 cm2
09 Décembre 2008
SOCLE

16. 8 m3 Energy spectrum: example 100 GeV pions
1 particle/pad
Contribution
normalised to 1
2 particles/pad
# Pads
3 particles/pad
# Pads
4 particles/pad
5 particles/pad
6 particles/pad
Energy per Pad (GeV)
Energy per Pad (GeV)
Number of Particle contributing to a Hit (E > 0 GeV)
3 GeV
10 GeV
50 GeV
100 GeV
Fraction of Pads
Number of particles per pad
09 Décembre 2008
SOCLE

17. 8 m3 Energy resolution : example 10 GeV pions Digital : Analog
Hit Threshold = 0 GeV
Analog
# Events
# Events
# Hits
Energy (GeV)
09 Décembre 2008
SOCLE

18. From 8 m3 HCAL to 1 m3 Prototype
Analog
Analog
Digital
Digital
Hit Threshold = 0 GeV
Hit Threshold = 0 GeV
example :
10 GeV pions
Digital
Digital
Hit Threshold = 1 MIP MPV
Hit Threshold = MIP MPV
09 Décembre 2008
SOCLE

19. 1 m3 Threshold studies : Correlation Digital : Digital : Digital :
Hit Threshold = 0 GeV
Digital :
Hit Threshold = 1 MIP MPV
Digital :
Hit Threshold = 4.5 MIP MPV
# hits
Energy (GeV)
09 Décembre 2008
SOCLE

20. 1 m3 Threshold studies : Energy Resolution Analog : 0.054 + 58%/√E
Threshold (MIP MPV)
E/E
Pion Energy (GeV)
E/E
Analog : %/√E
Digital : %/√E
E  50 GeV
09 Décembre 2008
SOCLE

21. Conclusion MicroMegas R&D for DHCAL very active! Towards In parallel
ASIC developments
Optimised prototypes, first digital readout prototypes
Tests Beam: very promising results (still a lot to analyse)
Future Test Beam in 2009 …
Towards
1m2 prototype
Calorimeter prototype of 1m3
In parallel
Work on simulation of TB prototypes, future 1m3 and leakage less 8m3 Future : Different concept geometry, pads size…
09 Décembre 2008
SOCLE

22. HCAL Dimension Parameters
SiD Example
Barrel
Dimension (mm)
End-Cap
Inner Radius
1420
200
Outer Radius
2370
1410
Z length
± 2780 ± ±
Absorber Thickness 18
Active Media
Thickness
< 8
 Large active media surfaces (eg 1.8x3.5 m2) Total surface ~ 3000 m2
09 Décembre 2008
SOCLE

23. ILC: High Precision Measurements
Most widespread approach for calorimetry: Particle Flow Algorithms where jet resolution depends on
cluster separation
track-cluster matching
HCAL choice of active media
ANALOG HCAL: Scintillators+SiPM
DIGITAL HCAL: Gaseous Detectors RPC or GEM or MicroMegas
Imaging calorimeters: Compact showers High granularity
09 Décembre 2008
SOCLE

24. “semi-digital” (2bits) readout with 1cm2 cells
Analog or Digital?
Hadronic energy resolution
Jet energy resolution (perfect PFA)
KEK for GLD
H MATSUNAGA
Pramana J. Phys., Vol 69, No 6, p
dec 2007
Optimal for PFA:
“semi-digital” (2bits) readout with 1cm2 cells
09 Décembre 2008
SOCLE

25. DHCAL: Gaseous Detectors
Performance studies
MIP efficiency
Hit multiplicity
Ease of calibration (30 M cells  30 M elect. channels)
Recovery time (RPC)
Discharge rate (GEM, MicroMegas)
Behaviour in hadronic shower
Operating in high magnetic field
Technological challenges
Large surfaces
Thickness < 8 mm
Low cost and industrial process
Aging: no performances degradation
 Uniformity /detector /cell
09 Décembre 2008
SOCLE