1 Working Group 1 Summary Technological Aspects and Developments of New Detector structures

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Working Group 1 Summary

Technological Aspects and Developments of New Detector structures

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WG1: Technological Aspects and Developments of New Detector Structures

ObjectiveObjective: Detector design optimization, development of new multiplier geometries : Detector design optimization, development of new multiplier geometries and techniques.and techniques.

Task 1: Task 1: Development of large-area Micro-Pattern Gas Detectors (large-area modules, material budget Development of large-area Micro-Pattern Gas Detectors (large-area modules, material budget reduction).reduction).

Task 2: Task 2: Detector design optimization including fabrication methods and new geometries (Bulk Micromegas, Detector design optimization including fabrication methods and new geometries (Bulk Micromegas, Microbulk Micromegas, single-mask GEM, THGEM, RETGEM, MHSP, charge-dispersive readout, Ingrid).Microbulk Micromegas, single-mask GEM, THGEM, RETGEM, MHSP, charge-dispersive readout, Ingrid).

Task 3: Task 3: Development of radiation-hard and radio-purity detectors.Development of radiation-hard and radio-purity detectors.

Task 4: Task 4: Design of portable sealed detectors.Design of portable sealed detectors.

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How will we work?Obviously, the work has to start from the Applications.

There will be meetings on the various tasks to compare findings, exchange experience from the applications

The first step was to ask, end of May 2008:

- What is your preferred technology?(GEM, Micromegas, THGEM, RETGEM, MHSP, Cobra, PIMS, Microgroove, microwell, microdots…)

- What are your main applications? (calorimetry, TPC, photon detection, medical, imaging,…

- What is your timescale (small prototyping, scale 1 prototyping, delivery of detector, …)

38 institutes out of 54 expressed interest in tasks of Working Group 1 28 on Large Area Detectors (task 1)9 on Design optimization (task 2, strong overlap with WG2)

20 on Radiation hard and high radiopurity (task 3)3 on sealed detectors (task 4, recently added)

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Task 1: Task 1: Development of large-area Micro-Pattern Gas Detectors Development of large-area Micro-Pattern Gas Detectors (large-area modules, material budget reduction).(large-area modules, material budget reduction).

Bulk Micromegas

Read-out board

Laminated Photoimageable coverlay

Frame

Stretched meshon frame

Laminated Photoimageable coverlay

Exposure Development+ cure

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Raw material

Single-side copper patterning

Chemical polyimide etching

Chemical copper reduction

Single mask GEM

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Copper Thick GEM

Raw material

CNC drilling

Electrodes etching

Small rim if needed

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Development of large-area Micro-Pattern Gas Detectors

Bulk Micromegas Single mask GEM

RD51 effect: progress is much faster!

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300x300mm2 THGEM!

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0.8mm0.8mm 0.6mm

Read-out boardSpacer pillar

(coverlay)

Mesh

Mechanical milling 0.6 mm tool diameter

2.4mm dead region

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Practical limits (raw material roll width : 600 mm => GEM and mM need seams)

-Bulk Micromegas: oven size : 1000 x 2000. Laminator: 1200 x …

-GEM: 450mmx100m. No firm limitation provided seems are accepted

-THGEM: Time (10-20h for 1000x600 even with 4 drills x 2 PCBs

Rui de Oliveira

This is the point of view of the fabrication. There are also limits from the point of view of the detector operation and robustness: capacitance

Segmentation and possibly resistive components might be necessary for large size detectors. Currently R&D for SLHC muon chambers, calorimetry, etc…

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CERN

Rui de Oliveira TS-DEM

Large volume effect

Large volume effect

Volume

Price/area

GEM

Micromegas

THGEM

Depends on initial investments

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Joerg Wotschack

Arizona, Athens (U, NTU, Demokritos), Brookhaven, CERN,Harvard, Istanbul (Bogaziçi, Doğuş), Naples, Seattle, USTCHefei, South Carolina, St. Petersburg, Shandong, Thessaloniki,…

Very big collaboration to replace some of the ATLAS Muon chambers (230 m2)

Needs triggering capabilities as well as 100 position resolution and high-rate capability (5 kHz/cm2). Micromegas bulk technology considered as candidate.

Recent test beams being analysed. 55 position resolution demonstrated with strip pitch 250 at 90°. Cosmic test will follow, 50% prototype being built.

Need to keep resolution at angles down to 45°.

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Serge Duarte Pinto

Modules in 2 parts because limitation to 457 mm width from raw material.

‘Splicing’ needed

Single mask GEM used to avoid alignment difficulties between top and bottom copper foil.

Large GEMs for a forward tracker.

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Serge Duarte PintoLarge GEMs for a forward tracker.

3mm seam behaves as expected

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Task 2: Task 2: Detector design optimization including fabrication Detector design optimization including fabrication methods and new geometries (Bulk Micromegas, Microbulk methods and new geometries (Bulk Micromegas, Microbulk

Micromegas, single-mask GEM, THGEM, RETGEM, MHSP, charge-Micromegas, single-mask GEM, THGEM, RETGEM, MHSP, charge-dispersive readout, Ingrid).dispersive readout, Ingrid).

KLOE and CLAS12 cylindrical trackers also need large GEMs or Micromegas.

Why not cylindrical? Low material budget, challenges Silicon

Half-cylinder vs full cylinder – integrated and sealed drift cathode.

Beam tests at CERN and Brookhaven

75° Lorentz angle in 5T for CLAS12 at Edrift =1kV/cm, reduced to 14° with Edrift=10kV/cm, lower drift velocity (tan = vB/E)

Cylindrical and flexible GEM and Micromegas (Giani Bencivenni, Frascati and Stephan Aune, Saclay)

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- - CLEAN ROOM :CLEAN ROOM : we had too many shorts in the detector: ≥ 11 shorts (5% area) in 1.2 m2 of GEM foils (to

be compared with) 0 shorts in 4.5 m2 of GEM foils for LHCb

CGEM for KLOE tracker

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Micromegas Bulk for CLAS12

vertex tracker

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•PCB: 100 µm FR4 with 5 µm thick Cu strip•100 µm amplification gap•Woven Mesh Gantois non stretched bulk with an array of 400 µm pillar every 2 mm•Dimension: 180 mm x 60 mm

First curved bulk (09-2006)

Picture: bulk curved, 100 mm radius

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SUMMARY on THGEM (Amos Breskin)● In Ar+5%CH4 the maximum achievable gains measured with UV-light (~106) are ~100-fold higher than with 55Fe (~104)● Probable explanation is the Raether limit● In Ne and Ne-CH4 (5-23%) mixtures, under gas flushing, the maximum gains with UV and 55Fe are closer (105 - 106)● Possible explanation: 55Fe photoelectron-tracks are longer in Ne and its mixtures lower density of ionization per hole lower max. gain-difference caused by charge-density effects.● In pure Ne scintillation prevents high gains & “masks” p.e. extraction quencher● For RICH: optimal would be Ne–based mixtures● Quencher additives to be optimized – for high gain and efficient p.e. extraction.● Preliminary results indicate upon ~70% extraction efficiency in Ne/23%CH4

similar to Ar/5%CH4.● Charge-up: geometry (rim), gain and rate dependent. ● It seems that rimless holes are advantageous, but need to establish detectors’ parameters (eff QE, e-transfer photon detection efficiency) with the right conditions and gas● Need to compare stability of LARGE-AREA rim/rimless THGEMs with UV photons● Tests in RICH mode? Who? When? – Trieste ordered 60x60 cm THGEMs.● 30x30cm THGEM tests: tested end 2008 at WIS● Expected results in Cryo-THGEMs Gas Photomultipliers/LXe: early 2009.

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Task 2: Task 2: Detector design optimization including fabrication Detector design optimization including fabrication methods and new geometries (Bulk Micromegas, Microbulk methods and new geometries (Bulk Micromegas, Microbulk

Micromegas, single-mask GEM, THGEM, RETGEM, MHSP, charge-Micromegas, single-mask GEM, THGEM, RETGEM, MHSP, charge-dispersive readout, Ingrid).dispersive readout, Ingrid).

MHSP (Micro Hole and Strip Plate) (Joao Veloso) and PIC+Micromegas (Atsuhiko Ochi)

Micro-mesh Micro-pixel chamber : M3PIC

400m

100m

70m230m

165m

AnodeCathode

Support wire

Micro Mesh

1cmDrift/detection area(Filled by gas)

Drift plane

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MicroHole & Strip Plate (MHSP)• Operation Principle

JFCA Veloso et al., RSI 71(2000)2371

Gas

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MicroHole & Strip Plate (MHSP)

• Present Performance:

High gains – ~ 104-105

Fast charge collection – 10 ns

Excellent energy resolution – 13.5% @ 5.9keV x-rays - Xe

High rate capability – > 0.5 MHz/mm2

High pressure operation capability

High ion blocking capability

2-D intrinsic capability – σ~125μm (with resistive line)

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First demonstration of a GPM operation in visible range

A. Lyashenko et al., NIMA (2008), http://arxiv.org/abs/0808.1556v2

102 103 104 10510-5

10-4

10-3

10-2

Edrift

=0.5kV/cm

F-R-MHSP/GEM/MHSP

Edrift

=0.2kV/cm

Ar/CH4 (95/5), 760 Torr

IBF

Total gain

0.03%

No visible feedback

Paris, 13 – 15 of October 2008

W RD51 25

2D-Imaging – using resistive lines

FP

GA

4 -

AD

Cs

to computer through USBF

PG

A 4

-A

DC

s

to computer through USB

COMPUTER -Set time window

)( BA

BA

A

BA

A

yylEnergy

yy

yky

xx

xkx

Image reconstruction

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Carbon dissociated from ethane deposits on polyimide surface

5 sparks 50 sparks 150 sparks

200 sparks300 sparks

14th Octber 20082nd RD51 Paris

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Correlation between number of discharges and voltage drop after the test

14th Octber 20082nd RD51 Paris

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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.

Also fishing lines were used (Saclay, Lanzhou)

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drilling + chemical rim etching without maskMask etching + drilling; rim = 0.1mm

Detector design optimization, fabrication methods and new geometries

6 keV X-ray

104

pitch = 1 mm; diameter = 0.5 mm; rim=40; 60; 80; 100; 120 mm

THGEM Example

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Development of resistive anodes and grids

RTGEM: resistive electrode THGEM

3÷10 G/ copper oxide layer

resistive foilresistive foilgluegluepadspads

PCBPCB

meshmesh

Resistive anode:Charge dispersion readout

1 M/ plastic foil

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• A few people interested, will follow up

Task 3: Task 3: Development of radiation-hard and high radio-purity detectors.Development of radiation-hard and high radio-purity detectors.

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• New task (discussion this morning)• Make gas-tight low-outgasing detectors

with locally made high-voltage, and portable (USB?) electronics

• Possible applications: radiotherapy (positioning), teaching,…

• Interested people: Amos Breskin, Paul Colas, Rui de Oliveira, Per Baecklund, Fabrizzio Murtas, Joaquim Dos Santos,…

• ==> phone meeting early November.

Task 4: Task 4: Design of portable sealed detectorsDesign of portable sealed detectors

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Interactions of WG1WG2

WG1

WG6Production

WG5 Electronics

WG7Test beams

Characterization, basic studies on performance, aging

WG4

Simulations

New materials, new geometries

Protecti

on

Documents

1 Working Group 1 Summary Technological Aspects and Developments of New Detector structures