GEM Detector Development for MAGIX 6 th Apr 2016 LEPP Mainz Pepe - - PowerPoint PPT Presentation

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GEM Detector Development for MAGIX

6th Apr 2016 LEPP Mainz Pepe Gülker

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Requirements & Challenges

• Spatial Resolution < 50 μm
• Many Channels ~10k
• High Rate Capability ~1MHz

(Luminosity: 1035 cm−2 s−1)

• Minimize Material Budget

(Energy: < 105 MeV)

• Track Reconstruction
• Large Area 30 x 120 cm2

for the detector-system

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GEM

Pitch p = 70 μm Diameter D = 140 μm Copper dCu = 5 μm Kapton dKa = 50 μm

Gas Electron Multiplier

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Requirements & Challenges

• Spatial Resolution < 50 μm

→ achieved by COMPASS

• Many Channels → APVs
• High Rate Capability ~1MHz

→ Benlloch et al.

• Minimize Material Budget

→ Simulation

• Track Reconstruction

→ Try GEM hodoscope first!

• Large Area 30 x 120 cm2

for the detector-system

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Stretching

Mechanical Stretching

• Tensiometer controlled
• Method for 30x30 GEMs
• Under development
• Works for mashes as

well Thermal Stretching

• ΔT ~ 80 K
• Used for 10x10 GEMs
• Not scalable

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Profile Measurement

• Take data of foil
• Take data of table
• Correct foil data
• Apply linear and quadratic

Fit → Sagging < 100 μm

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GEM Development

• GEMs trained and

stretched

• 10x10 Prototype working
• In house production of

readout PCBs

• 16 pad-readout to

measure gain uniformity is set up

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GEM Development

100 200 300 400 500 600 700 800 900 charge [pC] 0.000 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 counts Photo Peak (5,89 keV) µ = 388.59 σ = 25.97 Escape Peak (2,70 kev) µ = 169.28 σ = 25.85

fe55_gainMeas_365 entries: 159593

360 365 370 375 UGEM[V] 200 300 400 500 600 700 800 900 1000 Mean of Photo Peak [pC]

a + b * e^{x/c} a = 93.6 +/- 18.5 b = 2.0e-09 +/- 2.6e-09 c = 14.18 +/- 0.68

55Fe Gain Measurement

55Fe-Spectra taken with QDC

• Single channel readout PCB
• Built PreAmp for GEMs
• Self triggered via LE-

discriminator Vary UGEM

• Fit charge of photo and

escape peak for different voltages

• Plot and fit with exp-

function FWHM 16%

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Ongoing

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Material Budget

Foil Readout 100 μm Kapton 1 μ m C u G E M s Default triple GEM detector 0.96% X0

GEM Kapton

0.38% X0 0.22% X0

R e a d

• u

t C u Readout PCB GEM Cu GEM Cu GEM Cu GEM Kapton GEM Kapton Readout Cu R e a d

• u

t C u

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Laser Calibration

Side (1) WCu = 4,4 eV > WAl = 4,1 eV Illuminate Al-dots on Cu-cathode with UV light to extract electrons on fixed grid. (T2K- Method) Top (2) Use a movable UV-Laser to create electrons on the bottom side of a thin aluminized Mylar cathode.

Diploma Thesis: Mirco Christmann Set up detector prototype (10x10) with multi channel readout. Perform conventional calibration with MICROMEGAS-Hodoscope. Proof of concept for the laser calibration setup.

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GEM I GEM II Cathode Readout

UV-Laser

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Beam Times

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Summary

• GEM Tracker for focal plane
• Infrastructure for GEM

development set up

• First prototype operational

next steps:

• Going bigger
• Going thinner

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Thank you

magix.kph.uni-mainz.de

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Backup

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MESA - MAGIX

Mode: EB User: P2 Current: 150 μA Energy: 155 MeV Circulations: 6 Mode: ERL User: MAGIX Current: 10 mA Energy: 105 MeV Circulations: 4 MESA P2 MX

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Spectrometers

Luminosity: 1035 cm−2 s−1

• rel. Momentum Res:

< 10-4 Angular Res: < 0,9 mrad

Particle path Focale plane GEM Tracker

The particle paths are bended inside the magnet spectrometers in such a way that momenta and scattering angles are mapped to points in the focal plane, which are measured by GEM detectors.

Target

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Readout PCB

Design Readout PCB

• different pitches
• pads and stripes
• angle between coordinates
• hex pads?

Minimize Material Budget

• Use Kapton based readout

foil → FlexPCB

• Use Electroplating

→ Peter Bernhard

• Think about Connectors

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Multi Channel Readout

• INFN Readout System
• APV25
• 128 Channels per

FrontEndCard

• 40 MHz
• Full Wavaform of each

Channel

• Panasonic Connectors P5KS

are deprecated...