PEBS Positron Electron Balloon Spectrometer Detector Concept CERN

PEBS - Positron Electron Balloon Spectrometer Detector Concept CERN, January 2009 Stefan Schael I. Physikalisches Institut B RWTH Aachen 1

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PEBS Experiment 1, 6 m improve the momentum resolution by a factor of 10 ! 4

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SRD RICH 8

Physic-Programm: • Positron – Spectrum 1 Ge. V - 700 Ge. V • Electron – Spectrum 1 Ge. V – 1000 Ge. V B-Field: 0. 7 Tesla Superconducting magnet, 850 kg PEBS-ECAL 2. 0 m Acceptance: 3000 cm 2 sr 6 Si-Inner-Tracker Planes (red), single Point resolution 0. 010 mm 4 Sc. Fi-Outer Tracker Planes (pink) single Point resolution 0. 050 mm 1. 2 m 0. 86 m momentum resolution: 20% @ 1000 Ge. V 2 TRD‘s, each with 12 layers, Proton Rejection 104 @ 100 Ge. V Electron Efficiency 80% 11 X 0 ECAL, Weight 650 kg Weight: 1700 kg 1. 0 m TRD 1 TRD 2

80 cm long ladders ! 10

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Upper Sci. Fi Tracker Inner Si Tracker Upper Sci. Fi Tracker Circle-Fit Inner Si Tracker: B=0. 7 Tesla, L=1 m, n. Layer=6, σx=0. 010 mm 13

Upper Sci. Fi Tracker Inner Si Tracker Upper Sci. Fi Tracker Angle-Point - Measurement Inner Si Tracker: B=0. 7 Tesla, Lin =1. 0 m, n. Layer=4, σin=0. 010 mm Upper Sci. Fi-Tracker: Lup=1. 2 m, n. Layer=4, σup=0. 050 mm 14

Upper Sci. Fi Tracker Inner Si Tracker Upper Sci. Fi Tracker Angle-Angle - Measurement Inner Si Tracker: B=0. 7 Tesla, Lin =1. 0 m, n. Layer=4, σin =0. 010 mm Upper Sci. Fi-Tracker: Lup =1. 2 m, n. Layer=4, σ out=0. 050 mm Lower Sci. Fi-Tracker: Ldown=1. 2 m, n. Layer=4, σout=0. 050 mm 15

Track-Fit Performance at P=100 Ge. V 16

No correlation visible for Circle-Fit and Angle-Point measurement => take the weighted mean 17

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Magnet Top View, center of the coils 19

Magnet Side View, center of the coils Coil 20

Z=2. 2 m L=1 m z 3 z 2 z 1 z [m] 21

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Electron-Efficiency 70% 29

Proton Rejection: Ecal 103, E/P=10 + TRD 30

PEBS - RICH Physic-Programm: • Positron/Electron – Spectrum up to 200 Ge. V • He 3/He 4 for 1 Ge. V/n <= E/n <= 100 Ge. V/n • Be 10/Be 9 for 1 Ge. V/n <= E/n <= 100 Ge. V/n Weight Budget for RICH 600 kg Gas RICH TRD 1 TRD 2 Aerogel RICH

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PEBS - SRD Physic-Programm: • Positron – Spectrum 1 Ge. V - 1500 Ge. V • Electron – Spectrum 1 Ge. V – 3000 Ge. V U-TRD: 12 Layer upper TRD Proton Rejection 36 Layer TRD 5 104 @ 500 Ge. V Electron Efficiency 70% Weight 50 kg Weight Budget for SRD (green) 400 kg SRD Acceptance 100, 000 cm 2 sr SRD U-TRD 1 TRD 2

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