11

Micromegas TPC R&DMicromegas TPC R&D

P. ColasP. Colas

22

R&D in progress and to be planned R&D in progress and to be planned forfor

Present collaborations NIKHEF, CERN Present collaborations NIKHEF, CERN workshop, CERN electronics, workshop, CERN electronics, Carleton, etc…Carleton, etc…

Existing and planned infrastructuresExisting and planned infrastructures(viewed from Saclay)

33

The contextThe context 3 out of 4 ILC detector concepts feature a 3 out of 4 ILC detector concepts feature a

TPCTPC All worldwide R&D for ILC TPC is carried out All worldwide R&D for ILC TPC is carried out

in the framework of LC-TPC (41 institutes, in the framework of LC-TPC (41 institutes, 120 physicists)120 physicists)

LC-TPC carries out in parallel R&D and LC-TPC carries out in parallel R&D and common realization of a large prototype common realization of a large prototype

Mainly GEM and Micromegas technologies Mainly GEM and Micromegas technologies are consideredare considered

A large Micromegas TPC is being built for the A large Micromegas TPC is being built for the T2K experiment : fully engineered project to T2K experiment : fully engineered project to be delivered in 2009be delivered in 2009

44

HistoryHistory1992 Garmich-Partenkirchen proposition of a TPC for the LC (R. Settles)

1996-97 Conceptual Design Report of TESLA. Proposition of Micromegas and GEM readout

1999-2004 TPC Berkeley-Orsay-Saclay

June 2005: MP-TPC in a KEK beam

2006 development of the theory of the resolution in a Micropattern detector ; T2K builds a large mM TPC

2002-2005: development of the ‘resistive foil’ at Carleton U.

October 2005 : 50 micron at small drift distance in a KEK beam

Nov. 2006 : Record resolution: 50 microns at all distances in a 5T field at DESY

2007 towards a collab. for a resistive bulk

January-April 2004 : principle demo of gas+pixel (digital TPC)

July 2005 : first InGrids (grid on silicon)

January 2006 : EUDET start

October 2007 first TimePix operational

55

1999-2004 : construction of a large TPC (50cm, 1000 chanels) in a 2T magnet NIM A 535 (2004) 181

Gas studies NIM A (2002), resolution studies

Ion backflow suppression NIM A 535 (2004) 226

66

Beam tests at KEK in June and October 2005, cosmic tests in 2006

384 ‘pads partout’ TPC

Multi-Prototype TPC (wires, GEM and Micromegas)

77

88

Mesure de résolution à B=0.5 et 1TMesure de résolution à B=0.5 et 1T

99

Analytical theory of the Analytical theory of the resolutionresolution

The resolution of a MPGD is limited by ionisation statistics, gain fluctuations and finite pad size effects

Given the lack of charge sharing between neighbouring pads, the resolution is, at best, 10% of the pad width

1/√12

1/√(12.Neff)

1010

Extrapolation to ILC TPCExtrapolation to ILC TPC

Conclusion: even with 1mm pads, a standard pad Micromegas would not reach the 130 m resolution goal.

However with a resistive foil and 2.3 mm pads, this goal is fulfilled (red curve).

1111

Resistive foilResistive foilA resistive foil glued on the anode A resistive foil glued on the anode turns it into a Resistance and turns it into a Resistance and Capacity network which spreads the Capacity network which spreads the charge charge

Proc. of LCWS 2005

A A 50 microns50 microns resolution is obtained resolution is obtained at small driftat small drift

(and at all drifts for B large enough)(and at all drifts for B large enough)

Test beam at KEK B=1T

Micromegas with res.foil

Q

ns

Cosmiques en champ magnétique

To appear in NIM A

See talk by A. Bellerive

1212

Resistive bulkResistive bulk The ‘Bulk’ technology The ‘Bulk’ technology NIM A 560 (2006) 405NIM A 560 (2006) 405

yields high robustness with no dead area yields high robustness with no dead area (no frame) (no frame) (See R. De Oliveira, I. Giomataris and (See R. De Oliveira, I. Giomataris and A. Delbart’s talks)A. Delbart’s talks)

Next step: combine it with the resistive foil Next step: combine it with the resistive foil technologytechnology

Lab tests : resistive bulk manufacturing, Lab tests : resistive bulk manufacturing, resistivity, measurements, uniformity, etc…resistivity, measurements, uniformity, etc…

Beam or cosmic tests at CERN and/or Beam or cosmic tests at CERN and/or TRIUMF or FermilabTRIUMF or Fermilab

1313

200 m

MESHESMESHES

ElectroformedChemically

etched Wowen

PILLARSPILLARS

Deposited by vaporization

Laser etching, Plasma etching…

Many different technologies have been developped for making meshes (Back-buymers, CERN, 3M-Purdue, Gantois, Twente…)

Exist in many metals: nickel, copper, stainless steel, Al,… also gold, titanium, nanocristalline copper are possible.

Can be on the mesh (chemical etching) or on the anode (PCB technique with a photoimageable coverlay. Diameter 40 to 400 microns

1414

SiTPCSiTPC Alternative to the resistive foil solution for the problem of Alternative to the resistive foil solution for the problem of

the finite pad size: detect ionization electrons one by one the finite pad size: detect ionization electrons one by one on 55 micron pixelson 55 micron pixels

Demonstrated in 2004 with Medipix Demonstrated in 2004 with Medipix NIM A 540 (2005) 295NIM A 540 (2005) 295 Continuation with TimePix (time or TOT recording on each Continuation with TimePix (time or TOT recording on each

pixel) (see J. Timmermans’s talk)pixel) (see J. Timmermans’s talk)

He 20% iC4H10 Ar 20% iC4H10

1515

Medipix2/TimePix at CERNMedipix2/TimePix at CERN

14.8 mm

11 22 44

55

66

55μm

55μm

65000 pixels on 2cm2

14 bits counter

10 to 100 MHz clock

See M. Campbell’s talk

1616

TimePix detector being assembled for- gain fluctuations studies, Fano factor measurement

- Study of X-ray polarization

Also work in progress at NIKHEF

(see Jan Timmermans’s talk)

1717

NIKHEFTwente Univ.

InGrid : Integrated GridInGrid : Integrated Grid

(post-processing on silicon)

Avoids dead areas, allows manufacturing of perfect grids

Useful tool to study Micromegas: easy to produce various gaps, hole sizes and gaps,… Allows study of energy resolution, gain fluctuations, ion feedback… (See D. Attié’s talk)

NIM A 556 (2006)

Energy Resolution (55Fe) 5.0% r.m.s.

1818

The “Large The “Large Prototype”Prototype”

World-wide collaboration coordinated World-wide collaboration coordinated by LC-TPC by LC-TPC (see K. Dehmelt’s talk)(see K. Dehmelt’s talk)

Goal : almost full scale test of various Goal : almost full scale test of various technologies technologies

Field cage : DESYField cage : DESY Electronics : Lund+CERN, (+Saclay Electronics : Lund+CERN, (+Saclay

for Micromégas) for Micromégas) (See L. Musa and P. Baron’s (See L. Musa and P. Baron’s talks)talks)

1919

The “Large Prototype” The “Large Prototype” endplateendplate

Schedule

1st Micromegas panel with 1700 channels ready end of 2007

First cosmic tests in 2008

2020

The ideal TPC endplate…The ideal TPC endplate…

Detector side

Electronics side

Resistive bulk

1000 l.p.i. Nanocrystalline copper mesh, or gold mesh

Credit-card-like integrated electronics

Low-mass cooling

Each yellow item is a R&D topic

Res. foil grounding on the side

Optical link

Mechanical flatness

2121

CollaborationsCollaborations

All these R&Ds progressed in the past few years All these R&Ds progressed in the past few years thanks to collaborationsthanks to collaborations Berkeley-Orsay-Saclay : addressed space resolution Berkeley-Orsay-Saclay : addressed space resolution

issuesissues Ottawa-Orsay-Saclay : resistive foil effectivenessOttawa-Orsay-Saclay : resistive foil effectiveness NIKHEF-Twente-CERN-Saclay : CMOS pixel readout NIKHEF-Twente-CERN-Saclay : CMOS pixel readout

demonstrationdemonstration Japan-France-Germany-Canada collaboration: beam test Japan-France-Germany-Canada collaboration: beam test

and deep understanding of the resolutionand deep understanding of the resolution CERN-Saclay : Bulk technique(s)CERN-Saclay : Bulk technique(s)

Also T2K-TPC ND280 is a goal-oriented Also T2K-TPC ND280 is a goal-oriented collaboration which allowed progress, mainly on collaboration which allowed progress, mainly on large volume production and reliability issueslarge volume production and reliability issues

2222

InfrastructureInfrastructuress

may 2007

Class-1000 clean room

UNIGE Laminar flux

Many infrastructures are setting Many infrastructures are setting up:up:

-Class 10000/100000 Clean Class 10000/100000 Clean rooms at Saclayrooms at Saclay

-2 new R&D labs being equipped 2 new R&D labs being equipped for T2K and ILCfor T2K and ILC

-1 room equipped with X-ray gun 1 room equipped with X-ray gun and laserand laser

-Lab for gas analysis in Saclay Lab for gas analysis in Saclay (mass spectrometry, gas (mass spectrometry, gas chromatography, infrared chromatography, infrared absorption)absorption)

-Wafer probing facilities at CERN Wafer probing facilities at CERN and NIKHEFand NIKHEF

-Joint IFAE/Saclay/UNIGE Joint IFAE/Saclay/UNIGE assembly and testing facility at assembly and testing facility at CERNCERN

-……

Wafer probing at CERN

2323

ConclusionsConclusions

Many R&D collaborations and Many R&D collaborations and infrastructures exist for Micromegas infrastructures exist for Micromegas TPC TPC

Recognition by CERN is always Recognition by CERN is always welcomewelcome

Beam tests at CERN will be needed Beam tests at CERN will be needed