1. Construction and tests of a Micromegas TPC endplate prototype for the LC
D. Attié, P. Colas, K. Fujii,T. Matsuda,
M. Riallot, A. Sugiyama, W. Wang
Thanks to
M. Dixit, Yun-Ha Shin, S. Turnbull,Yulan Li 1

2. Large prototype TPC Need to make a large prototype to:
Study gases and detector design (both GEM and Micromegas)
Assess technical issues : integration, operability, stability,… at a realistic scale
Since December 2008 we test Micromegas+ resistive foil and GEM modules at the EUDET facility. PCMAG improvement in AIDA.
Theoretical understanding of the point resolution. Present step : study of gain fluctuations.
Electronics developments
Integration
Power pulsing
Software developments
June 15, 2010
P. Colas, K. Fujii - D-RD2

3. Large TPC Prototype for ILC
French-Canadian team : one module was installed in the centre of the large TPC each time. Read out by T2K electronics
Asian+Lund team : 3 GEM modules readout by ALTRO electronics
June 15, 2010
P. Colas, K. Fujii - D-RD2

4. Large TPC Prototype for ILC
ALTRO
readout electronics
Cooling duct
Micromegas
GEM
June 15, 2010
P. Colas, K. Fujii - D-RD2

5. Detector Modules 2 Resistive Kapton Resistive Kapton Standard GEM GEM
Resistive ink
~2(?) MΩ/□
Resistive Kapton
~5 MΩ/□
Standard
2 Resistive Kapton
~3 MΩ/□
GEM
GEM
June 15, 2010
P. Colas, K. Fujii - D-RD2

6. Beijing, 30/03/2010
P. Colas - FJPPL-FCPPL-LCTPC Analysis meeting

7. PRF(Pad Response Functions) for GEMs, z ~ 20 cm
Preliminary Data Analysis Results ( B=1T )
20cm drift
PRF(Pad Response Functions) for GEMs, z ~ 20 cm
June 15, 2010
P. Colas, K. Fujii - D-RD2

8. PRF(Pad Response Functions) fits, z ~ 5 cm
Preliminary Data Analysis Results ( B=1T )
Γ ~ 2.6 mm
Γ ~ 4 mm
δ ~ 10 mm
δ ~ 14 mm
B=1T data : comparison of resistive ink and Carbon-loaded Kapton
PRF(Pad Response Functions) fits, z ~ 5 cm
June 15, 2010
P. Colas, K. Fujii - D-RD2

9. Preliminary Data Analysis Results ( B=1T )
Position residuals xrow-xtrack
June 15, 2010
P. Colas, K. Fujii - D-RD2

10. Preliminary Data Analysis Results ( B=1T )
Mean Residual vs Row Number
Z-independent distortions
Distortions up to 50 microns
for resistive paint (blue points)
Rms 7 microns for CLK film (red points)
Z=5cm
Z=35cm
Z=50cm
June 15, 2010
P. Colas, K. Fujii - D-RD2

11. Dependence of resolution with data taking conditions
Preliminary Data Analysis Results ( B=1T )
Resolution at z=5cm (µm)
Vmesh (V)
Dependence of resolution with data taking conditions
June 15, 2010
P. Colas, K. Fujii - D-RD2

12. Drift velocity measurements ( B=0T )
Vdrift = cm/µs
at E=230 V/cm
(Magboltz : (gas comp.))
The difference is %
June 15, 2010
P. Colas, K. Fujii - D-RD2

13. Drift velocity measurements ( B=0T )
Drift Velocity in Ar/CF4/Iso butane : 95/3/2 compared with Magboltz simulations for
- P=1035 hPa,
- T=19°C
ppm H20
June 15, 2010
P. Colas, K. Fujii - D-RD2

14. Data Analysis Results (B=0T)
Resolution as a function of drift distance. Modules 4 and 5 are identical, except the routing and PCB technique
Module_4
Module_5
c2 / NDOF = 10.6 /10
c2 / NDOF = 13.9 /10
2% uncertainty on Cd : ±1.4 on Neff
June 15, 2010
P. Colas, K. Fujii - D-RD2

15. Preliminary Data Analysis Results ( B=1T )
c2 / NDOF = 29.1 /11
c2 / NDOF = 38.5 /10
Module_CLK
Module_INK
Resolution as a function of drift distance
June 15, 2010
P. Colas, K. Fujii - D-RD2

16. Resistive ink very non-uniform.
Uncertainties :
Use CD=94.2 ±1.8 at B=1T
and B field (± 0.02 T) ->±1.6
Resistive ink very non-uniform.
All Carbon-loaded kapton very consistent : average them
Neff = 38 ± 2
Expected : Neff = 47.7 * <G>2 / <G2>
This implies rather low gain fluctuations.
June 15, 2010
P. Colas, K. Fujii - D-RD2

17. Advanced TPC endplate (2010-2012)
Small pads (1 x 4 mm) for high double-track separation and high resolution:
Thin endplate for PFA (15% radiation length + low voltage power cables)
 Light mechanical structure of TPC endplate (Cornel/Saclay/DESY)
 High density readout electronics S-ALTRO for MPGD detectors (CERN/Saclay/Lund/TPC Japan)
ALICE TPC (LHC)
LC (ILD) TPC
 (a) Development of S-ALTRO:
A 64ch analog-digital mixed chip mount directly on the backside of pad plane of MPGD detector.
 (b) Issues of power switching, power delivery and cooling (2P-CO2)
 (c) Issue of mechanical stability in high magnetic field
 A 16ch S-ALTRO prototype in fall (CERN)
 A test board with ADC/FPGA in preparation
One of 12 sections of the test board (TPC Japan/CERN) 
(c)  A test module (Bulk MicroMEGAS) in preparation
to be tested in DESY 5T magnet (Scalay)
June 15, 2010
P. Colas, K. Fujii - D-RD2

18. Intermediate step : new T2K electronics
NEW ELECTRONICS – FLAT ON THE BACK OF THE MODULE
Goal: Fully equip 7 modules with more integrated electronics, still based on the T2K AFTER chip: use naked Silicon, wire-bounded on small cards, ADC on the mezzanine, remove/optimize protections,…
First prototype basically ready, tests at fall 2010
Then production and characterization of 9 modules in 2011 at the CERN T2K clean room
June 15, 2010
P. Colas, K. Fujii - D-RD2

19. New T2K Electronics
Backend ready. Gain of factors of 2 in evt rate and thruput
2 Mezzanine prototypes under test
FECs : in the process of choosing between tenders. More complicated, but no show stopper
Detector PCB ready to be ordered, process under study
June 15, 2010
P. Colas, K. Fujii - D-RD2

20. June 15, 2010
P. Colas, K. Fujii - D-RD2

21. Tracking Software development
Current Status : test beam data with different readout modules have been analyzed with different tracking programs developed independently by different groups.
Desired Environment
A common tracking framework (MarlinTPC) to compare different readout technologies on the same software test bench.
In order to realize this we need the implementation of
a) multi-module handling
b) non-uniform B field
The developed software is to be fed back to the LC-TPC tracking.
Two packages being developed in the FJPPL activities
1) Topological track finding
+ kalman filter based track fitting
2) Combinatorial Kalman filter in which track finding and fitting proceed simultaneously
Common Tracking
Hits
Tracks
Track = subset of hits
Hit Point Making
Readout Technology Dependent
Multi-module handling: almost finished
Non-uniform B field under development
Set of Pulses
Set of Hits
Set of Tracks
Set of Track Param. Vectors
June 15, 2010
P. Colas, K. Fujii - D-RD2
Hit Making
Tracking = Track Finding x Track Fitting

22. SC solenoid modification
PCMAG
Originally built for a balloon experiment
Used in TPC small prototype beam tests at KEK/PS in
Being used for LC TPC Large Prototype beam test at DESY (LC TPC/EUDET).
Open solenoid of 1T.
Thin coil and cryostat (20% radiation length).
Require 1,000L Liq. He for an initial cooling and ～200L in a refilling for 6-7 days
PCMAG at DESY with GEM/ALTRO TPC
Modification funded in AIDA
Safe/easy operation by TPC R&D groups.
Portability to any beams lines in the world
Save Liquid He cost
Remove Liq. He reservoir
Add two 4KGM refrigerators
Schedule: in 2011 (6 months)
(Thanks for full cooperation s
of the KEK cryogenic group and Toshiba)
Modified PCMAG with 4K GM refrigerators
June 15, 2010
P. Colas, K. Fujii - D-RD2

23. Conclusions and outlook
Since 2005, common analysis work led to deep understanding of the resolution of a GEM or a Micromegas.
Next steps: 7 Micromegas modules to fully equip the present endplate and work on improvement of the common testing facility, endplate, electronics and multi-module software.
June 15, 2010
P. Colas, K. Fujii - D-RD2

24. Thank you
June 15, 2010
P. Colas, K. Fujii - D-RD2