1. The Micromegas TPC: achievements and plans for future beam test
Paul Colas, CEA/Irfu, U. Paris-Saclay

2. MM TPC achievements and plans
Achievements so far
PHASE 1 with single modules ( ).
Test various resistive coverlays (not resistive, ink, Carbon loaded kapton, and later Diamond-like Carbon);
measure point resolution.
PHASE 2 multi-module ( ).
Miniaturize electronics, work out the whole chain
demonstrate 0.25 X0 module thickness.
Experience quasi-industrial production of 9 modules +2 more in 2014, and their readout
Begin the study of alignment and distortions
Test CO2 cooling
06/12/2016
MM TPC achievements and plans

3. MM TPC achievements and plans
06/12/2016
MM TPC achievements and plans

4. MM TPC achievements and plans
Z resolution
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MM TPC achievements and plans

5. MM TPC achievements and plans
DISTORTIONS at B=O
Beam test data with alignement
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MM TPC achievements and plans

6. MM TPC achievements and plans
DISTORTIONS at B=1T
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MM TPC achievements and plans

7. MM TPC achievements and plans
PLANS FOR A 3rd PHASE
This must be at minimum cost (no funding before the green light from Japanese gov.) and with cost reduction in mind.
3 or 4 new modules
Solve connection pb
Cooling: 1 loop
‘GEM’ backframes
NEW GROUNDING
SCHEME
Adaptable GEM gate
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MM TPC achievements and plans

8. New voltage distribution to avoid distortions
Grounded mesh
In contact with backframe
Resistive layer
- 380 V
High eR insulator
Pads grounded through electronics
Such a scheme has already been used elsewhere and found to be good for noise suppression
The ‘insulator’ might require R&D
This scheme allows re-using most components (GEM back-frames, AFTER TPC electronics, etc…)
06/12/2016
MM TPC achievements and plans

9. MM TPC achievements and plans
2P CO2 cooling
Go to 1 loop for 3 to 4 modules
(avoids ‘clarinettes’ which were there for robustness in case of leak on one module)
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MM TPC achievements and plans

10. MM TPC achievements and plans
Adapt a GEM gate
Learning from our Japanese colleagues, we plan to adapt a GEM gate on top of the modules Two options : simple frame glued on top of the module (but this gives radial cracks), or two stiff supports tied to the inner and outer circular boundaries of the module (à-la-Saga)
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MM TPC achievements and plans

11. MM TPC achievements and plans
Conclusion
A new phase is starting for MM tests, adapted to continue the developments while expecting the green light for the ILC construction.
We are open to a broad collaboration
Last step before a large module with new electronics
Thanks to D. Attié, S. Ganjour (Saclay), D.S. Bhattacharya, S. Mukhhopadhyay (Kolkata), A. Bellerive, R. Mehdiyev (Carleton)… and many others
Thanks for support from CEFIPRA project 4801 and E-JADE.
06/12/2016
MM TPC achievements and plans