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 The SHiP experiment 1 Experimental setup 2 FADC data 3 Drift time spectra 4 rt -relations 5 Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 2 / 12

The SHiP experiment Detector overview SHiP experiment Figure: SHiP detector layout [1] Proposed beam dump experiment (SPS beam) Search for Hidden Particles Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 3 / 12

Experimental setup Lab setup Test setup shortened tube from OPERA mass production L = 30 cm r ≈ 1 . 8 cm gas at atmospheric pressure FADC readout Figure: Photo of the experimental setup goal Find a drift gas mixture that is fast and has a more linear rt -relation Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 4 / 12

FADC data Overview Raw FADC data FADC data voltage [V] Event #5 Event #5 Entries Entries 423 423 − − 2824 2824 Mean Mean 4365 4365 0 Std Dev Std Dev − 0.2 − 0.4 − 0.6 − 0.8 0 500 1000 1500 2000 2500 3000 time [ns] Figure: Voltage pulse for Ar:CO 2 80:20 Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 5 / 12

FADC data Overview Raw FADC data voltage o ff set due to ampli fi er drift time threshold voltage pulse end time trigger position Figure: Voltage pulse for Ar:CO 2 80:20 Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 5 / 12

Drift time spectra Ar:CO 2 80:20 OPERA gas mixture Drift time spectrum Ar:CO2 80:20 (2300V) Drifttime spectrum Drifttime spectrum # counts 500 17069 17069 Entries Entries Underflow Underflow 1064 1064 400 300 200 100 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 drift time [ns] Figure: Drift time spectrum for Ar:CO 2 80:20 Reproduction of known results from OPERA with FADC readout Maximum drift time around 1 . 5 µ s Edge effects present for all gases, remain comparable Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 6 / 12

Drift time spectra Comparison Drift time spectra overlay Drift time spectra # counts (normalized to 1) 0.03 Mixtures Ar:CO2 80:20 0.025 Ar:CO2:N2 96:3:1 0.02 0.015 0.01 0.005 0 0 200 400 600 800 1000 1200 1400 1600 drift time [ns] Figure: Normalized drift time spectra Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 7 / 12

rt -relations Differences rt -relations for Ar:CO 2 80:20 and Ar:CO 2 :N 2 96:3:1 rt relations drift radius [mm] 18 16 14 12 10 8 6 Mixtures 4 Ar:CO2 80:20 2 Ar:CO2:N2 96:3:1 0 0 200 400 600 800 1000 1200 1400 1600 drift time [ns] Figure: overlay of the rt -relations Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 8 / 12

rt -relations Differences Ar:CO 2 :N 2 96:3:1 pulse shape FADC data Event #6 Event #6 voltage [V] Entries Entries 800 800 0.2 Mean Mean -7259 -7259 RMS RMS 8453 8453 0 -0.2 -0.4 -0.6 -0.8 -1 -1.2 -1.4 0 500 1000 1500 2000 2500 3000 time [ns] Figure: Voltage pulse for Ar:CO 2 :N 2 96:3:1 signals of individual pulses overlap ⇒ possible to determine time of pulse end correlated with time of particle transition Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 9 / 12

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 Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 10 / 12

rt -relations Differences Thanks Thank you for attending Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 11 / 12

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

Backup Pulse integrals Integrated FADC data Event #20 (integrated) a.u. 800 Entries 0 1418 Mean Std Dev 717.2 − 10 − 20 − 30 − 40 0 500 1000 1500 2000 2500 3000 time [ns] Figure: Pulse integral for Ar:CO 2 80:20 Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 1 / 2

Backup Integral minimum distribution integral minimum position distribution integral minimum position integral minimum position # counts Entries Entries 56365 56365 2500 Mean Mean 600.5 600.5 RMS RMS 52.48 52.48 2000 1500 1000 500 0 200 400 600 800 1000 1200 integral minimum time [ns] Figure: Integral minimum distribution Stefan Bieschke (UHH) Multicomponent drift gases 03/27/2017 2 / 2