Multicomponent drift gas mixtures for the SHiP Muon Magnetic - - PowerPoint PPT Presentation

Multicomponent drift gas mixtures for the SHiP Muon Magnetic Spectrometer

DPG Frühjahrstagung Münster 2017 Stefan Bieschke

Universität Hamburg

27 March 2017

Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 1 / 12

Content

1

The SHiP experiment

2

Experimental setup

3

FADC data

4

Drift time spectra

5

rt-relations

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The SHiP experiment Detector overview

SHiP experiment

Figure: SHiP detector layout [1]

Proposed beam dump experiment (SPS beam) Search for Hidden Particles

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Experimental setup Lab setup

Test setup

Figure: Photo of the experimental setup

shortened tube from OPERA mass production

L = 30 cm r ≈ 1.8 cm

gas at atmospheric pressure FADC readout goal Find a drift gas mixture that is fast and has a more linear rt-relation

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FADC data Overview

Raw FADC data

Event #5 Entries 423 Mean 2824 − Std Dev 4365 time [ns] 500 1000 1500 2000 2500 3000 voltage [V] 0.8 − 0.6 − 0.4 − 0.2 − Event #5 Entries 423 Mean 2824 − Std Dev 4365

FADC data

Figure: Voltage pulse for Ar:CO2 80:20

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FADC data Overview

Raw FADC data

pulse end time threshold voltage trigger position drift time voltage offset due to amplifier

Figure: Voltage pulse for Ar:CO2 80:20

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Drift time spectra Ar:CO2 80:20

OPERA gas mixture

Drifttime spectrum Entries 17069 Underflow 1064 drift time [ns] 200 400 600 800 1000 1200 1400 1600 1800 2000 # counts 100 200 300 400 500 Drifttime spectrum Entries 17069 Underflow 1064

Drift time spectrum Ar:CO2 80:20 (2300V)

Figure: Drift time spectrum for Ar:CO2 80:20

Reproduction of known results from OPERA with FADC readout Maximum drift time around 1.5 µs Edge effects present for all gases, remain comparable

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Drift time spectra Comparison

Drift time spectra overlay

drift time [ns] 200 400 600 800 1000 1200 1400 1600 # counts (normalized to 1) 0.005 0.01 0.015 0.02 0.025 0.03

Mixtures Ar:CO2 80:20 Ar:CO2:N2 96:3:1

Drift time spectra

Figure: Normalized drift time spectra

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rt-relations Differences

rt-relations for Ar:CO2 80:20 and Ar:CO2:N2 96:3:1

drift time [ns] 200 400 600 800 1000 1200 1400 1600 drift radius [mm] 2 4 6 8 10 12 14 16 18

Mixtures Ar:CO2 80:20 Ar:CO2:N2 96:3:1 rt relations

Figure: overlay of the rt-relations

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rt-relations Differences

Ar:CO2:N2 96:3:1 pulse shape

Event #6 Entries 800 Mean

• 7259

RMS 8453 time [ns] 500 1000 1500 2000 2500 3000 voltage [V]

• 1.4
• 1.2
• 1
• 0.8
• 0.6
• 0.4
• 0.2

0.2 Event #6 Entries 800 Mean

• 7259

RMS 8453

FADC data

Figure: Voltage pulse for Ar:CO2:N2 96:3:1

signals of individual pulses overlap ⇒ possible to determine time of pulse end

correlated with time of particle transition

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rt-relations Differences

Summary and outlook

Summary reduction of maximum drift time of about 40% significantly more linear rt-relation Outlook spatial resolution dependence on high voltage

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rt-relations Differences

Thanks

Thank you for attending

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rt-relations Differences

Bibliography

SHiP Collaboration. A facility to Search for Hidden Particles (SHiP) at the CERN SPS. Technical proposal, CERN, April 2015. arXiv:1504.04956v1.

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Backup

Pulse integrals

time [ns] 500 1000 1500 2000 2500 3000 a.u. 40 − 30 − 20 − 10 − Event #20 (integrated) Entries 800 Mean 1418 Std Dev 717.2

Integrated FADC data

Figure: Pulse integral for Ar:CO2 80:20

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Backup

Integral minimum distribution

integral minimum position

Entries 56365 Mean 600.5 RMS 52.48 integral minimum time [ns] 200 400 600 800 1000 1200 # counts 500 1000 1500 2000 2500

integral minimum position

Entries 56365 Mean 600.5 RMS 52.48

integral minimum position distribution

Figure: Integral minimum distribution

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