Diapositive 1

Micromegas for a DHCALLAPP, AnnecyCatherine AdloffJan BlahaSbastien CapMaximilien ChefdevilleAlexandre DalmazCyril DrancourtAmbroise EspagilireRenaud GaglioneRaphael GalletNicolas GeffroyClaude GirardJean JacquemierYannis Karyotakis Fabrice PeltierJulie PrastJean TassanGuillaume Vouters1

14/01/2009Ambroise Espargilire1Outline2Micromegas R&D for DHCALX-ray and beam tests with Analog ReadoutMicromegas with Digital ReadoutSimulationFuture1 m prototypeConclusion

Micromegas detectors at LAPP3Description:Gas mix: Argon+IsobutaneDrift and Mesh HV < 500 VHigh rate capabilityRobust, cheap (industrial process)Thickness: 3.2 mmLow hit multiplicityHigh detection efficiencyDelicate functioning: sparks

Readout:Analog for characterisation GASSIPLEX + CENTAURE DAQDigital :HARDROC or DIRAC + Detector InterFace (DIF) board +EUDET DAQ2 or CrossDAQ

or padsDetector layout4Bulk Micromegas :Mesh laminated on the PCBIndustrial process Cheap and robust

Steel top :Part of the absorberHoles for X-ray testsHolds a 55 m thick cathodeGlued on a plastic frame 3 mm above mesh

Bulk technology from R. De Oliveira & O. Pizzirusso

55Fe X-ray test5Setup6 x 16 cm2 meshSource collimated above 1 padReadout mesh signals

Collection efficiencyPlateau for field ratios larger than 50

Gas gain (assume 230 primary e-)Gain doubles every 20 VDecreases with pressureMax around 2.104

Energy resolution at 5.9 keV17 % FWHM

Slope yields -2 fC/mbarADC CountsPressure (mbar)Beam test setup6Trigger: 3 scintillators3 Micromegas 6x16 pads1 Micromegas 12x32 padsSteel absorber option

GASSIPLEX readoutVME modules (ADC) + CENTAURE

Ccharacterisation of the prototypesefficiency and multiplicityresponse uniformityX-talk studiesbehaviour in hadronic shower

Aug & Nov 2008 at CERN PS and SPS400.103 Pions and Muons of 200 GeV250.103 Pions with 1 steel block + absorbers200.103 Pions of 7 GeV

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T9 line at PS-CERN (Nov. 2008)Signal distribution on each pad7Select event with one and only one hit in each chamberInsure all charge collected on one padHit if ADC > 27 countsLandau distribution MPV is at 45 fCShows variations of 10% RMS over all pads

platinum events

MPV ~ 45 fCentriesall triggersADC counts

Chamber 0Chamber 1Chamber 2Chamber 3Efficiency and multiplicity8Require one and only one safe hit in three chambersADC > 51 counts (5.3 fC)Hit position in fourth chamber extrapolatedCount hit (ADC > 27 counts) in 3x3 pad area

Efficiency between 92 and 99 %Multiplicity between 1.07 and 1.15

Efficiency map of one chamber

gold events

Hit multiplicity distributions of 2 chambersMicromegas with Digital readout9PCB with DIRAC1 64 channels ASIC (R. Gaglione, IPNL)Digital link to DAQ (possibility to chain detectors)3 thresholds and 2 gains (RPC and Micromegas modes)Synchronous architectureFirst operational Bulk Micromegas with embedded readout electronics !

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DIRACSparks protectionsmask for bulk laying8x8 pads with bulkBulk from R. De Oliveira & O. PizzirussoMicromegas with digital readout10Tested during August 2008 test beamMinimum threshold of 19 fCOnly one detector availableNo efficiency/multiplicity measurements yetPrepare more prototype for next beam test

Beam Profilewhen moving the X-Y tableMicromegas with digital readout11PCB with 4 HARDROC164 channels ASIC, detector active area 8x32 cm2

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sparks protectionsHARDROC1

bulkMicromegas with digital readout12Readout : DIF boardSeparated from the SLABFor large number of ASICsHARDROC, DIRAC and also SPIROC and SKYROCDIF task force interface : USB or EUDET DAQTested during the November 2008 TBExcellent work from Guillaume Vouters (DIF) and Christophe Combaret (CrossDaQ)

HV stability issues during testsData (almost) under study

PCBwith ASICs

Simulation13ToolsSLIC full simulation (Geant 4)Analysis using JAS3

2008 beam test setup

DHCAL with MicromegasComparison between analog, digital and semi-digitalThresholds & absorber studies

142008 beam test setup is being simulatedComparison with real dataBetter understanding of our detectorPreparation for next test beam

30 cm iron absorber in front

SimulationTest beamDHCAL with Micromegas15Full 1 m geometry implementedReadout: from 0.5 x 0.5 cm2 to 4x4 cm pads3 mm drift gapGas mix. Argon/Isob. 95/51.9 cm thick absorber between layersdifferent absorber materials40 or 80 layers (~4, 5 or ~9 )Thickness of active layer: 3.2 mm

Ideal Micromegas, digitization not yet fully implemented

DHCAL 40 planes

100 GeV Pions16Sum up hits and energy in all cellsApply a single threshold (1 MIP)Look at distributions RMS

E(GeV)Nb of Hits1 MIP thresholdPions

Nb of HitsNb of events

Nb of HitsNb of eventsAnalogresponseat 10 GeVDigitalresponseat 10 GeV1 MIP thresholdEnergy resolution17

Hit thresholdThreshold (MIP)E/E

Pion energyE (GeV)E/EThreshold range with constant energy resolutionWorse resolution at High energy Need more than 1 threshold ?A lot more is under study Future 1 m prototype: 6 Active Sensor Units18

9 216 channels - 96 x 96 cm active area - 3 DIF + interDIF boards1 m2 prototype status19DIF & DAQ almost ready

ASU :24 HARDROC2 Design and routing done Single ASU test box under conception

Mechanical prototype under constructionConclusion20Micromegas R&D for DHCAL very active!ASIC developmentsInnovative prototypes, first digital readout prototypesTests Beam: very promising results (still a lot to analyze)Beam tests planned in 2009, first in May

Next steps1 m2 prototype should be ready for test before 2010Calorimeter prototype of 1 m3

In parallel : work on simulation TB prototypes, future 1 m3 and leakage less 8 m3Different absorber material, active medium, pads size

Thanks for your attentionAcknowledgements

Catherine AdloffJan BlahaSbastien CapAlexandre DalmazCyril DrancourtAmbroise EspagilireRenaud GaglioneRaphael GalletNicolas GeffroyClaude GirardJean JacquemierYannis Karyotakis Fabrice PeltierJulie PrastJean TassanGuillaume Vouters