Micropattern Gaseous Detectors
Generic R&D at CERN
current CERN GDD group projects
February 2018

Leszek Ropelewski CERN EP DT GDD & RD51

Recent reviews of Micro Pattern Gas Detector (MPGD) and RD51 collaboration•

High Rate Capability•

High Gain•

High Space Resolution•

Good Time Resolution•

Good Energy Resolution•

Excellent Radiation Hardness•

Good Ageing Properties•

Ion Backflow Reduction•

Photon Feedback Reduction•

Large Size•

Low Cost

Micromegas

GEM

Micro bulk

InGrid50µm GEMTHGEM

GLASS GEMMHSPTHCOBRA

Bulk

µPIC
2

The main objective is to advance MPGD technological development and associatedelectronic-readout systems, for applications in basic and applied research”.
http://rd51-public.web.cern.ch/rd51-public

10
58

15

3

• Large Scale R&D program to advance MPGD Technologies• Access to the MPGD “know- how”
• Foster Industrial Production• More than 80 groups• More than 400 people• National and International Laboratories• National Institutes and Universities
3

RD51 (well consolidated) Working Groups
Technological Aspects andDevelopment of New Detector
Structures

Common Facilities : Test Beam and Laboratory

WG1:
Common Characterization
and Physics Issues

WG2:

WG7:

RD51
WG4:

Production, quality
control, industrialization

WG6:
WG5:
MPGD Related Electronics

Academia-Industry Matching
Events, Training, Education

WG3:
Simulations and Software Tools

4

MPGD 2015 and RD51 CM in Trieste
MPGD2015 and RD51 CM

New Developments in MPDGs
Production techniques
Material and Ageing Tests
MPGD Detector Physics
Simulation and Software
Electronics
Applications

140 participants
120 abstracts

MPGD contributions in recent and running experiments
Conference Summary

Charpak Young Scientist Award

5

6

RD51 present and future activities
o R&D support for the experiments and LHC upgrades WG1o Generic R&D (new structures, ideas, detector physics) – RD51 Common Projects WG2Development of new structures and consolidation of the existing structureso Applications ; academia-Industry matching events, training, education WG3o Development and Maintenance of Software & Simulation Tools; basic studies &software support for the RD51 community WG4o Development and Maintenance of the SRS Electronics; An extended support for the SRS
including new developments and implementations of additional features WG5o

MPGD Industrialization and QA Control - GEM, MicroMegas, Thick GEM; WG6o Maintenance and extension of the RD51 Lab and Test-Beam Infrastructure WG7
o MPGD Education and Training : organization of schools for students and newcomers &academic training

7

Examples of CERN/LHC Upgrades
ATLAS NSW (mm)Micromegas Detectors for the Muon Spectrometer Upgrade of the ATLAS Experiment; M. Bianco, Elba 2015

A continuous read-out TPC for the ALICE upgrade, C. Lippmann, Elba 2015

ALICE (GEM)

LHC Upgrades: Original R&D efforts emerged from RD51 activities.
Today: production phase under the project effort , access to RD51 facilities (laboratory, test beam,
8
workshops) and tools (simulation, electronics,…) to facilitate this particular phaseExamples of CERN/LHC Upgrades
COMPASS RICH-1 (THGEM+mm)
Status of the Development of Large Area Photon Detectors based on THGEMs and Hybrid MPGD architectures for
Cherenkov Imaging Applications , C.A.Santos, Elba 2015

Status Report of the Upgrade of the CMS muon system with triple-GEM detectors, G. De Lentdecker, Elba 2015

CMS (GEM)

LHC Upgrades: Original R&D efforts emerged from RD51 activities.
Today: production phase under the project effort , access to RD51 facilities (laboratory, test beam, 9workshops) and tools (simulation, electronics,…) to facilitate this particular phase

MPT & Large MPGD assembly

https://indico.cern.ch/event/342026/session/20/contribution/240/material/slides/0.pptx

10Technology Development Highlights
THGEM Surface Treatment

Polyurethane Treatment

Non-treated THGEM suffers from: limited
max. gain, response non-uniformity andtime instabilities

Polishing and Cleaning

11

Examples of new ideas, applications….
Fast Timing

Calorimetry with MPGD

New Materials (Glass GEM)

≈50phe≈50pheThe Latest Results of Crystalized Glass GEM, Y.
Mitsuia, RD51 miniweek (GDD/RD51 lab)

Resistive Material

New Large Area Thin Detectors

Neutrons Detection
B10

Gd

A. OchiEuropean Spallation Source (ESS)12Physics, Garfield & Simulation Tools
Continuous implementation of the available tools
and simulation capabilities

Detector Modelling

Simulation & data for the better
understanding of the detectors physics

Improving computation time13

The RD51 Scalable Readout System (SRS)SRS & APV25 FE chipWorldwide use in the RD51 community (>2000 hybrids)

SRS: Different System
SRS for R&D on Detectors

SRS+SiPM (NEXT TPC)

SRS-FEC+TOTEM DAQ
SRS for experiments (ATCA)
SRS+Timepix (LC-TPC) – Bonn/Desy

2015

Very appealing for the future: VMM (NSW ATLAS FE chip)Baseline solution for
RD51 SRS community.

SRS for spatially distributed system (optical SRS)Interest and support
from ESS (European
Spallation Source) and
ALICE FOCAL

http://indico.cern.ch/event/356113/session/6/contribution/29/material/slides/1.pdf

14

Laboratory equipments for MPGD developed by
the RD51 community, few examples:(* SRS compliant)

QUAD MPGD signal
amplifier 2 GHz, 25dB(* SRS compliant)[CERN][CERN][CERN]
Floating Multichannel
Pico Ammeter

MoCoS: Monitoring and control
system[CERN](* SRS compliant) [CERN](Optical data transmission)[Zagreb Univ.](* SRS compliant)15

PH-DT-DD GDD Laboratory … Laboratory available for the RD51 collaboration

Permanent installations (Today): ALICE, ATLAS, ESS
CMS moved roughly two years ago to TIFF, access to the lab for specific measurements
More than 15/20 groups per year coming to perform measurements
Clean Rooms

Mechanical and Electronic Workshop

Technical support
MPGD Detectors
Gas system and services
Readout electronics (std and custom
RD51 SRS&APV)
Radioactive Sources
Interface with CERN services (RP, gas,
metrology, irradiation facilities,…)
16

Semi permanent test beam in the SPS extraction Line

Building 887 – EHN1
H4 (PPE134)

Three periods of two
weeks each per year
About fifteen-twenty
users per year

Goliath Magnet  Ship?

A warm and special thanks to the SPS,
the North Area Facility and to all thepeople that supports our installations
Examples of the test beam user teams

CMS (GEM)

WIS/A/C(WELL, THGEM)

ATLAS NSW (mm)

BESS III & SHIP (GEM)

LAPP/DEM/IRFU(mm) ALICE TPC (GEM and mm)

17

Technology: MPGD Production @ CERNInteresting Workshop Overview Capabilities

New Capabilities….

OK

Antonio TeixeiraOKOK

https://indico.cern.ch/event/352483/

OK

MPGD Projects….
OKOK

installation of the new infrastructure (to fabricate 2x1m2 Bulk MM& 2x0.5m2 GEM) COMPLETED

Construction of the newworkshop’s building:Start : beginning 2012
End: end 201718

Technology: Industrialization
Technology Industrialization  transfer “know-how” from CERN workshop to industrial partners
GEM Technology (contacts)••••

Mecharonix (Korea, Seoul)Tech-ETCH (USA, Boston)
Scienergy (Japan, Tokyo)
TECHTRA (Poland, Wroclaw

THGEM Technology (contacts):••

ELTOS S.p.A. (Italy),
PRINT ELECTRONICS

GEM Licenses signed by:• Mecharonics, 21/05/2013• TECH-Etch, 06/03/2013• China IAE, 10/01/2012• SciEnergy, 06/04/2009• Techtra, 09/02/2009• CDT, 25/08/2008• PGE, 09/07/2007

GEM Industrialization Status (today):ELVIATECHTRAELTOS• Production Line Operational• Stable process for 10cm x 10cm
• Single Mask process completely understood – 10cm x 10cm produced•30cm x30cm Single Mask Produced

•
•
•
•

ELTOS S.p.A. (Italy)
TRIANGLE LABS(USA, Nevada)
SOMACIS (Italy, Castelfidarco)
ELVIA (France, CHOLET)

Micromegas Industrialization Status (today):

TECH-ETCH• Single Mask process fully understood. Many 10cm x 10cm produced andcharacterized.
• 40cm x 40cm GEM successfully produced• CMS GE1/1 size of 1m x 0.5m started

MicroMegas Technology(contacts):• Bulk Micromegas detectors are routinely produced with sizes up to 50cm
x 50 cm.
• Contract for ATLAS NSW module-0 signed•Tendering process for full production ongoing• Many small size bulk Micromegas detectors have been produced.
• Contract for ATLAS NSW module-0 signed•Tendering process for full production ongoing

MECHARONICS• 10cm x 10cm double mask produced and tested• 30cm x 30cm double mask under evaluation @ CERN•CMS GE1/1 size of 1m x 0.5m started

19

Academia-Industry Matching Events (understanding requirements, applications, approaching new communities and technologies)
Neutron Detection 1st

https://indico.cern.ch/event/265187/

Summary(arXiv 1410.1070)

Neutron Detection 2nd

https://indico.cern.ch/event/365840/

Photon Detection

https://indico.cern.ch/event/392833/

Press release

20

21

RD51 & International School
RD51 schools
MPGD assembly

RD51 MPGD Lectures:
MPGD students lectures (1 week)at the International Workshop on
Advance Detectors & RD51 CM in
Kolkata

MPGD Simulation

MPGD Electronics

XII ICFA School (Bogota, Colombia)

Danube School on Instrumentation in Elementary Particle & Nuclear Physics (Novi Sad Serbia)

22

RD51 Achievements and Highlights
o Consolidation of the Collaboration and MPGD community integration ( 86 Institutes, ~500 members);o Major progress in the MPGD technologies development in particular large area GEM (single mask),
MicroMegas (resistive), THGEM; some picked up by experiments (including LHC upgrades);ALICE, TPC read-out, 130 m2 to be instrumented
ATLAS, small wheels, 1200 m2 to be instrumented
CMS, forward detectors, 1000 m2 of GEM foils
COMPASS RICH, 4.5 m2 to be instrumented, single photon detectiono Secured future of the MPGD technologies development through the EP DT MPT workshop upgradeand FP7 AIDA & AIDA2020 contribution;o Contacts with industry for large volume production, MPGD industrializationo Major improvement of the MPGD simulation software framework for small structures allowing first
applications;o Development of common, scalable readout electronics (SRS) (many developers and > 50 user groups);
Production (PRISMA company and availability through CERN store); Industrialization (re-design of SRS
in ATCA in EISYS);o Infrastructure for common RD51 test beam and lab facilities (>20 user groups)
23http://cerncourier.com/cws/article/cern/62507

24

Future of the Detector R&D at CERN

25

Gaseous Detectors Development
team, resources, infrastructure and activities

Leszek Ropelewski
Eraldo Oliveri
Miranda van StenisVeronique Wedlake

staff; Coordination
staff; Technical Coordination; R&D support
staff; (DT-EF); 50% Technical Support
staff; (AGS-SE); 10% Administrative Support

Patrik Thuiner
Michael Lupberger
Florian Brunbauer

fellow; (BrightnESS); ESS detector; generic R&D
fellow; (BrightnESS); electronics
PHD student; (A program); generic R&D

Fabio Sauli
Sebastian White
Hans Muller
Rob Veenhof
Hans Taureg

free lance; generic R&D
partially supported by EP project; generic R&D
free lance; electronics for MPGD
RD51 supported free lance; detector physics and software tools
free lance; RD51 finance and administration

Financial Resources:

CERN EP Project & Exploitation Budgets; EU BrightnESS & AIDA2020 projects, RD51 Common F
undInfrastructure:

GDD lab in Bld. 154 and RD51 semi-permanent test beam facility in SPS H4

Mandate and Activities:• R&D Support to Experiments and Projects• RD51 Coordination (Collaboration Management, Administration, Infrastructure Maintenance)
26• Generic R&D and Applications

GEM – Gas Electron Multiplier
I+

Ions

e40 %

Induction gap

60 %

5 µm

e-

Electrons

Fabio Sauli

50 µm
55 µm
70 µm

Thin, metal coated polyimide foil perforated
with high density holes.
Electrons are collected on patterned readout board.
A fast signal can be detected on the lower GEM electrodefor triggering or energy discrimination.
All readout electrodes are at ground potential.
Positive ions partially collected on the GEM electrodes.

27

GEM – Gas Electron Multiplier
Full decoupling of the charge amplification
structure from the charge collection andreadout structure.
Both structures can be optimized
independently !

A. Bressan et al, Nucl. Instr. and Meth. A425(1999)254

CartesianCompass, LHCb

Small angle

Hexaboard, pads
MICE

Compass

Totem

Most of the detectors use three GEM foils in cascade for amplification
to reduce discharge probability by reducing field strength.

Mixed
Totem
28

Gaseous Detectors Development
over years

1983 wires

1996 strips

2009 begining of RD51

2005 holes

292015 RD51; optical readout and Picosec
30

GDD Mandate and Activities:• R&D Support to Experiments and Projects• RD51 Coordination (Collaboration Management, Administrati
on, Infrastructure Maintenance)• Generic R&D and Applications

Effect of extreme operating conditions
on the GEM detector components

32Effect of extreme operating conditions
on the GEM detector components

33

Ion density effects in
multiGEM

Ion charges instantaneously modify the electric fields
Measurement

Transfer field modification:
increase of the effective gain
Ion distribution at the hole entrance:
reduction of the amplification field

10kHz/mm2

100kHz/mm2 1000kHz/mm2

Computation

34

Gating GEM
Motivation

High transparency for electrons
when certain potential is applied
between electrodes – gate open
Low (no) transparency for ionswhen reversed potential is applied
between electrodes – gate closed
Difference between those twopotentials should be as small as
possibleelectrons
ions
ΔVopenΔVclosed

Electrons reach anode
Gate is triggered

GEM voltage flipped until
all ions are collected

35

Gating GEM (Fujikura Ltd)
Setup

Hole size
Hole pitch
Optical transparency
Cu thickness (front)
Cu thickness (back)Insulator thickness
Rim width (front side)
Rim width (back side)
Active area

303.4 μm
335.0 μm
82%
7.2 μm
1.2 μm(?) 12 μm
27.7 μm
31.6 μm
10 cm x 10 cm

Top (detail)Bottom (detail)Top

Cross-section (detail)36

Gating GEM

Ion back-flow at equal fields
Ion back-flow reaches maximum
at approx. same voltage as forelectron transparency
Higher voltages than for electrons
to fully close gate
Very preliminary data with large
error bars (not shown)!
IBF normalized to ΔVGEM = 20 V

Ar/CO2 70/30 pre-mixed, 5 L/h37Collaboration with UCLGraphene

Membrane opaque to ions and transparent to electrons:~99% (suspended)- solution of the ion back-flow in gaseous detectors
graphene tri-layer coverage- protective layer on photocathodes- enhancement of electron emission

SEM

38

Neutron detectors

39

40

41

42

43

44

Precise timing with MM

Aim at < 50ps resolution
R&D on:- Cherenkov radiator - photocathode protection- Photocathode- photocathode alternatives- 200um drift- secondary emitter materials- MicroMeGas

Pre-amplification:role in the signal formation

45

46

Precise timing with MM•

Trigger: coincidence of two 5x5 mm2 scintillators and a veto downstream (avoid
showers)•

Tracker: three GEMs to measure where the triggered particle passed (reject showers
too)•Time reference: two Hamamatsu MCP-PMTs (160 ps rise time)•

Tracking acquisition: APV25 + SRS•Timing acquisition: CIVIDEC C2 preamp + 2x 2.5 GHz LeCroy scopes (synchronisedwith the tracker) and SAMPIC

47

48

49

50

51

52

Optical readout of GEMs

6MP CCD camera

10x10cm2 GEM-based detector intransparent gas volume filled with
Ar/CF4 gas mixture at 1 bar

25mm lens53Camera options
6 MP CCD

QImaging Retiga R6
4.54x4.54µm2 pixels
5.7e- read noise
20Hz frame rate

4MP CMOS

Hamamatsu ORCAFlash4.0
6.5x6.5µm2 pixels
1.6e- read noise
100Hz frame rate

0.25MP EM-CCD

Hamamatsu ImagEM X2
16x16µm2 pixels
EM gain up to 1200x
1e- read noise (max.)
70Hz frame rate54

Optical readout of GEM-based
detectors

Applications

55

X-ray radiography

Imaging

1 cm
GEM holes:⌀ 70µm, pitch
140µm

56

Small mammal(bat) X-ray imaging

X-ray fluoroscopy

10cm
57

10 Hz movie of remote controlled
flying drone under X-ray
irradiation

X-ray tomography

Crushed plastic cupwith two pens(changing pixel value
threshold)

DIP chip3D reconstruction of turning objects in front of detector
Images → Sinograms → Filtered back projection ⇒ 3D image
F. Resnati, EP Detector Seminar - CERN - Friday 29th of April

58

Energy resolved imaging
5.9keV

Optical readout
with CCD
Events

GEM charge
readout

Events

5.9keV

Energy (a.u.)

5.8keV
3.1keV
5.8keV
5.9keV
5.7keV 6.0keV

Energy (a.u.)

55Fe spectrum

Energy resolution preserved in opticalreadout
Individual 55Fe x-ray photons
59X-ray fluorescence
40keV X-rays
Characteristic X-rays
from different
materials
Color coding by
X-ray energy

Cu (green), Fe (pink), Zn (blue)60

Parallax error
X-ray tube
CrystalDiffraction
pattern

Parallel drift field results inparallax-induced
broadening

Radially focused drift fieldpreserves spatial
resolution
61Prototype62

Minimised parallax
errorStandard (straight) drift
field

Radial drift field

Disk with hole pattern (representing diffraction pattern)
irradiated with x-rays from point-like source
Radial drift field minimises parallax error
63

X-ray fluorescence
Flat drift field with parallax
error

Radial drift field

X-ray fluorescence of Cu grid with corrected parallax error
64

Alpha tracks

Alpha track from 220Rn decay
with GEM holes visible in inset

220Rn

65

𝛼

55s

216Po

𝛼

0.14s

212Pb

Alpha track from 220Rn withsubsequent 𝛼-decay of 216Po

Particle tracks

Muon tracks

Muon tracks with δ-ray

Hadronic shower

recorded in SPS H4 beam line with muon or Pion beams during RD51 test
beams
66

Optically read out
TPC
Stack of 3 GEMs
gain ≈ 5x104

Field shaper
PMT
timing signal

Camera2D readout

ITO anode
20 cm

67

•
•
•
•
•

Optically transparent
Electrically conductive
Simple deposited of thin films by
evaporation
Can be etched in HCl
Routinely used in LCD displays,
touchscreen, solar cells, EMI shielding,…

Transmission (%)

Indium tin oxide (ITO)
100
80
60
40
450 nm layer
25 nm layer

20
0
200

350

500

650

800

Wavelength (nm)Used as transparent anode in optically read out
detectors to collect energy spectra from charge
signals
T. Fujiwara et al 2016 Jpn. J. Appl. Phys. 55 106401

68

Alpha tracks
ITO strip
signals

Depth
informationCameraimage

3D track
visualisation

Projections

220Rn flushed into gas, 300 V/cm drift field, GEMs operated at 380V, 1.8 kV/cm induction field,

100x signal attenuation, recorded event rate ≈1.5 Hz, recorded with EMCCD camera with EM gainof 1000x
69Cosmic events
ITO strip
signals

Depth
informationCameraimage

3D track
visualisation

Projections

300 V/cm drift field, GEMs operated at 400V, 0.65 kV/cm induction field, no signal attenuation,
recorded event rate ≈1 Hz, recorded with EMCCD camera with EM gain of 1200x and 5x signal
amplification
70Cosmic events
ITO strip
signals

Depth
informationCameraimage

3D track
visualisation

Projections

300 V/cm drift field, GEMs operated at 400V, 0.65 kV/cm induction field, no signal attenuation,
recorded event rate ≈1 Hz, recorded with EMCCD camera with EM gain of 1200x and 5x signal
amplification
71

Proton beam monitoringin clinical hadron beam therapy facility

72

Concept

CameraThin beam
windowThin beam
window
Mirror

Incident beam

Ar/CF4 gas
1-4 GEMs
Cathode10cm

SPS H4 Pion beam

10cm
500ms exposures,
real time

Integrated beam profile
image (50x 10s exposure)74

Water equivalent thickness(WET)
Total thickness (µm)

WET (µm)

Mylar

92

120

Kapton50

70

Aluminium

20

40

Copper

10

60

Argon

308000390

Helium instead of
Argon

308000115

680µm
Total water equivalent thickness

Can be minimised by using Helium and decreasing detector thickness to well
below 500µm WET
75

Design

Incident beam

10cm

Incident
protonbeam

77

Beam spot images

Image of single spot beam passing through detector as recorded by
CCD camera
Clear beam spot images and high signal to noise ratios could beachieved with moderate GEM gains
78

Beam profile
5x5cm280 MeV

100 MeV

150 MeV

Beam spot width decreases withincreasing beam energy inagreement with nominal machineparameters
σ=7mm at 60MeV
σ=2.9mm at 226MeV
79

200 MeV

226 MeVResponse linearity
Integrated intensity from CCD(a.u.)

200

150

100
60MeV - GEM at 300V
226MeV - GEM at 300V
50

線形 (60MeV - GEM at 300V)
線形 (226MeV - GEM at 300V)

0
0

10

20

30

40

Deposited MU

Response is linear and good correlation between integrated intensityfrom optical images recorded with camera and deposited MU(reported by reference ionisation chamber) for full energy range from60 to 226 MeV is achieved80

Depth dose curve

Depth dose curve measured by adding
solid water blocks in front of detector
81Dose imaging

10cm

Optically recorded image of dose distribution fromscanning pencil beam, integrated exposure82Patient treatment plan

325 MUin 29 layers

83

Patient treatment plan

Schematic visualisation of deposited charge, total 325 MU
29 layers displayed at fixed arbitrary Z-spacing without taking into
account different beam energies and
84 dose depth curve for each energy

Imaging for medical
applications

Collaboration with a Swedish company
amma imaging and dosimetry based on GEMs

Collaboration with Swedish company~6MeV
gammas- Converter- Collimator- GEM- Readout8687