GridPix/Gossip for

ATLAS SCT UpgradeILCCLIC.insulators in strong E- fields..the frustration of innovation..Harry van der GraafNikhef, Amsterdam

IEEE-NSS ConferenceMPGD-Si Detector WorkshopDresden, Oct 18, 2008

Micro Strip Gas Counters: hard to operate:

discharges, ruining electrodes ageing

! Very strong electric field in insulators volume & surface !

GEMs:

often cascade of 3 GEMs used to limit gain per GEM to ~40 rim (dia hole Cu/kapton) critical shape of hole wall critical charge up effects

Atsuhiko OCHIKobe University, JAPAN13 Oct. 2008 2nd RD51 workshop in Paris

GEM ProductionRemove copper by wet etchingIrradiate CO2 laserRemove remaining edge from the other sideRIKEN/SciEnergy GEM(thick-foil and fine-pitch) pitch 80um hole 40um thickness 100umRecent Status of Development

GEM test setup and parametersThick-foil and fine-pitch GEM (single layer)HV supplied through a resister chainEd=2.5kV/cm, Ei=4~5kV/cm, VGEM=300~600V Gas: Ar+CO2(30%) flowReadout by 1cm x 1cm pad Gain measurementGain vs applied voltageX-ray from Fe-55 (5.9keV)Gain Curve (RIKEN GEM)gain=3x104To keep good spatial resolution and keep discharge point at high gain.Our GEM is most suitable for Cosmic X-ray Polarimeters.Recent Status of Development

Gain instability (RIKEN GEM)No gain increase in short measurementsThis is not for a special batch of GEMs but for all GEMs we producedPossible reasons;Less charging-up due to cylindrical hole shapeLess polarization of Liquid Crystal PolymerNo increase and decrease just after HV on.Recent Status of Development

GemGrid 1GemGrid 2

Bulk high-resistivity materialshydregenated amorphous silicon

allowed gains up to 5 105staying proportional!Si-rich silicon nitride (Si3N4)

Measurements on Si-rich Silicon Nitride (Si3N4)Column resistance: D/OPotential surface measurable: gain drop factor 2 at dV = 17.5 VWith known current: bulk resistivity measurable: ~ 1 50 1013 Ohm cm

Surface time constant: Column resistance x (virtual colum capacitance) =

( D/O)*( O/D) = (independant of layer thickness D!)

Resistive Plate Chambers (RPCs)

essential: high-resistivity material- quenches sparks- sufficient charge compensation current

Traditional: insulator + dope (Sardinian oils?)New: high-resistivity bulk (ceramic) material: higher counting ratesCompare graphite covered mylar foil

Micromegas on pillarsEdge discharge protection foildischarges + vibrationsconductivity of kapton

Charge-up effects

After (rapid) ramping of HV:

polarisation: reduction of E-field in insulator (bulk) volumeIn homogeneous field with insulator // to field: nothingWith E component perp. on insulating surface: modificationof potential by hitting e- and/or ions until E // surface

GEM hole

region ofworse insulationequalizing with water

Stronger effects forgood insulator

Very preliminary:

Use as little as possible insulating surfaces // strong E fieldsApply high-resistivity materials instead of insulators

Even more preliminary:

As for gain: GEMs perform les than (corresponding) Micromegas

April 2004Micromegas + MediPix 2NIKHEF/Saclay/Univ. Twente:MediPix2 pixel sensorBrass spacer blockPrinted circuit boardAluminum base plateMicromegasCathode (drift) plane55FeBaseplateDrift space: 15 mmMIPsNo source, 1s55Fe, 1sHe/Isobutane80/20Modified MediPix-ray!14 mm

Integrate Micromegas and pixel sensor:

InGridwafer post processingby Univ. of Twente, MESA+

Full post-processing of a TimePixTimepix chip + SiProt + Ingrid:

UniformMESA+ IMT NeuchatelCharge mode14 mm

A long cosmic trackTimepix + 20 m thick Siprot + IngridStable operation in He iC4H1010 mmcathode @ - 1500 V14 mm

Si (vertex) track detector GOSSIP Si strip detectors Si pixel detectors MAPs

Gas: 1 mm as detection medium99 % chance to have at least 1 e-Gas amplification ~ 1000:

Single electron sensitive

All signals arrive within 16 ns

Gossip: replacement of Si tracker

Essential: thin gas layer (1.2 mm)1.2 mm

GOSSIP-Brico: PSI-46 (CMS Pixel FE chip)First prototype of GOSSIP on a PSI46 is working:

1.2 mm drift gap Grid signal used as trigger 30 m layer of SiProt

Tracking sensor material: gas versus Si it is light

primary electrons can simply be multiplied: gas amplification: low power

no bias current: low power & simple FE circuits

gas can be exchanged: no radiation damage of sensor

gas has a low r: with small voxels the source capacity can be small (10 fF) allowing fast, low-noise, and low-power preamps

gas is usually cheap

low sensitive for neutron and X-ray background

-rays can be recognized

[high ion & electron mobility: fast signals, high count rates are possible]

discharges/sparks: readout system should be spark proof ageing: must be solved and must be understood / under control diffusion: limits max. drift length

CMOS Chip protection against - discharges- sparks- HV breakdowns- too large signalsEmperical method:Try RPC technologyAmorph Si (segmented)Silicon Protection: SiProt

Qmax ~ 1 2 fC

Chip may die if Qmax > 10 fC

Ageing

Radiation damage of CMOS pixel chip is relevant- common for all tracking detectors- believed to widthstand ATLAS Upgrade Dose in 90 nm technology

Radiation damage of sensor: not relevant for Gossip sensor since this is gas being exchanged

Typical for gaseous detectors: the deposit of an (insulating) polymeron the electrodes of a detector. Decrease of signal amplitude

Little ageing expected: little primary ionisation (~ 10 e-/track) low gas gain (500 1000) large anode surface (compare pixel anode plane with surface of thin wire) E-field at flat anode ~3 lower than E-field at anode wire

gas: standard Ar/Methane 90/10. Deposit containing C found on anode

Irradiation with 8 keV X-rays:

No rate effects up to anode current density of 0.2 A / mm2

very fast track counting possible!

After 0.3 Coulomb/mm2:

(eq. 3.7 x 1016 MIPs/cm2 !!)

deposit of carbon polymer on anode is clearly visible. Micromegas is clean (!?)Little deposit on cathode, andChamber still worked!

Ageing

Construction of many test chambersprototypesNext-1,2,3,4,5Next QuadNext-64 (ReNexed, ReLaXd)DICEAgeing Chambers

Next-64 / ReLaXd / ReNexd

CO2 cooling!

DICE

DICENuclear ReactorWater Bassin10 x 10 x 10 m3ReactorInstituteDelftRID

Upgraded SCT: Gossip could replace:

Pixel vertex detector: Gossip Si Strip detectors: replace by Gossip Strixel detectors TRT: use Gossip as tracker/TR X-ray detectorEssentials:

power dissipation: 60 mW/cm2 intrinsic mass: 0.1 % radiation length low cost: 10 $ / cm2

Barrel SCT unitEndCap SCT unit

Semiconductor (pixel, strip) detectorsDepleted Si, 300 m(pixel) chip withpreamps, shapers,discriminatorsVbias = 150 Velectron-holepairs

ATLAS pixel: basic element

- Ladder strings fixed to end cones Integration of beam pipe, end cones & pixel vertex detector 5 double layers seems feasible

Gossip in ATLAS (Goat-1) StaveTimePix-2 chipSiNProt layerInGrid (Si3N4)Gas CoverG(round)StringP(ositive)Stringcarrying 1.3 VRoad: C-fibre reinforced databus + aux servicesStiff, light Stave formed by G-stringP-stringRoadtriangleStainlessSteel tubefor CO2 coolingcasted aluminiumpower linegasmanifold

60mm BeampipeInner Layer: 7 double Goat stringsCO2 cooling channelsP-string conductor (+voltage)G-string conductor (+voltage)Gossip detector unitGossip readoutGOAT: GOssip in ATlas

Upgraded SCT: Gossip/GridPix could replace:

Pixel vertex detector: Gossip Si Strip detectors: replace by Gossip Strixel detectors TRT: use GridPix as tracker/TR X-ray detectorEssentials:

power dissipation: 1/16 x 60 mW/cm2 = 4 mW/cm2now:25 mW/cm2 intrinsic mass: 0.1 % radiation length low cost: 10 $ / cm2~ 20 mm

Upgraded Tracker: Gossip could replace:

Pixel vertex detector: Gossip Si Strip detectors: replace by Gossip Strixel detectors TRT: use Gossip with 17 mm Xe layer as tracker/TR X-ray detector

Essential: high position-resolution tracker throughout tracker low mass, low cost detector Efficient TRD possible

L=30 mm0.05 mmfV0V1Anatoli Romaniouk, Serguei Morozov, Serguei KonovalovMartin Fransen, Fred Hartjes, Max Chefdeville, Victor Blanco CarballoTransition RadiatorTestbeam Nov 5 12, 2007PS/T9: electrons and pions, 1 15 GeV/c

Samples pions (left) and electrons (right)Particle Identification 6 GeV/c

5 (double) layer Gossip Pixel4 layer Gossip Strixel3 layers Gossip TRTradiator

Gas instead of SiPro: no radiation damage in sensor: gas is exchanged modest pixel (analog) input circuitry: low power, little space no bias current: simple input circuit CMOS pixel chip main task: data storage & communication (rad hard) low detector material budget: 0.06 % radiation length/layertypical: Si foil. New mechanical concepts low power dissipation : little FE power (2 W/pixel); no bias dissipation operates at room temperature (but other temperatures are OK) less sensitive for neutron and X-ray background 3D track info per layer if drift time is measured

Con: Gaseous chamber: discharges (sparks): destroy CMOS chip gas-filled proportional chamber: chamber ageing Needs gas flow Parallax error: 1 ns drift time measurement may be required

New mechanics + cooling concepts for Gossip

As little as possible material detector consists of foil! less power required ( less cooling) w.r.t. Sistring: power, chip support, coolingin 2030.balloonlaundry line

Minimum Material Budget(% rad length)Z = 0 mmZ = +/-600 mmGossip detector (50 m Si)0.060.06

Cooling (stainless steel tube)0.0010.001

Power (max 0.28 mm aluminium)0.00.3

Data transfer (max 1.7 mm kapton)0.00.6

total0.061

angle correctionx 20.09x 2 x 23

- Ladder strings fixed to end cones Integration of beam pipe, end cones & pixel vertex detector 5 double layers seems feasibleVirtual goal: ATLAS pixel vertex

Gossip in ATLAS (Goat-1) StaveTimePix-2 chipSiNProt layerInGrid (Si3N4)Gas CoverG(round)StringP(ositive)Stringcarrying 1.3 VRoad: C-fibre reinforced databus + aux servicesStiff, light Stave formed by G-stringP-stringRoadtriangleStainlessSteel tubefor CO2 coolingcasted aluminiumpower linegasmanifold

60mm BeampipeInner Layer: 7 double Goat stringsCO2 cooling channelsP-string conductor (+voltage)G-string conductor (+voltage)Gossip detector unitGossip readoutGOAT: GOssip in ATlas

The future:

Electron Emission Foil

MEMS made MicroChannelPlates: 200 ps time resolution: CLICelectron emission foilCMOS pixel chipelectron avalanche in gasEE-Foil replaces InGridParallel Plate Chamberelectron emission foilCMOS pixel chipreplace gas by vacuumMicro Channel Platesub-ns time resolutionNote CLIC experiments

July 2005: ATLAS Upgrade Worlshop GenuaContribution Gossip was refused:..pixel B-layer replacement too soon for new R&D projects..

Sept 2006: ATLAS Upgrade Workshop Liverpool:Contribution Gossip was granted (after repeated requests)

Dec 2007: ATLAS Upgrade Workshop Valencia:Invited to present Gossip R&D project

Sept 2008: PSD8, Glasgow:keynote: Norbert Wermes: Pixel detectors for charges particlesmentions 3D, Diamond, MAPs, but NOT Gossip

Si tracking detectors

the ultimate detector in HEP associated with Moores Law, chip technology

Proposal:

(imaginary) separation of

Interaction Matterand

readout electronics

Integration (MAPs) maybe profitable later

Si (vertex) track detector GOSSIP Si strip detectors Si pixel detectors MAPs

Gas: 1 mm as detection medium99 % chance to have at least 1 e-Gas amplification ~ 1000:

Single electron sensitive

All signals arrive within 16 ns

NIKHEFHarry van der Graaf, Max Chefdeville, Fred Hartjes, Jan Timmermans, Jan Visschers, Marten Bosma, Martin Fransen, Yevgen Bilevych,Wim Gotink, Joop Rovekamp

University of TwenteCora Salm, Joost Melai, Jurriaan Schmitz, Sander Smits,Victor Blanco Carballo

University of Nijmegen Michael Rogers, Thei Wijnen, Adriaan Konig, Jan Dijkema,Nicolo de Groot

CEA/DAPNIA SaclayD. Atti, P. Colas, I. Giomataris

CERNM. Campbell, X. Llopart

University of Neuchatel/MTINicolas Wyrsch

Czech Tech. Univ. Prague, PrahaPixelman: T. Holy et al.

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