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Identification of Charged Particles in Straw Tube Detectors Sedigheh Jowzaee Jagiellonian University MESON2012 Conference, Krakow, Poland, 31May-5June.

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Presentation on theme: "Identification of Charged Particles in Straw Tube Detectors Sedigheh Jowzaee Jagiellonian University MESON2012 Conference, Krakow, Poland, 31May-5June."— Presentation transcript:

1 Identification of Charged Particles in Straw Tube Detectors Sedigheh Jowzaee Jagiellonian University MESON2012 Conference, Krakow, Poland, 31May-5June 2012 INTERNATIONAL PHD PROJECTS IN APPLIED NUCLEAR PHYSICS AND INNOVATIVE TECHNOLOGIES This project is supported by the Foundation for Polish Science – MPD program, co-financed by the European Union within the European Regional Development Fund 1

2 Outline PANDA experiment Straw Tube Tracker Straw tube simulation Straw front-end electronic PID Methods Separation π-K-p Summary 2

3 1. PANDA Experiment Interaction of antiproton with momentum range ( GeV/c) Hydrogen Target Charmonium spectroscopy Exotic hadrons (hybrids, glueballs, multi-quark states) Strange and charmed baryons Structure of the nucleon Nuclear Target Hadron properties in the nuclear medium γ -ray spectroscopy of hypernuclei PANDA Program Two-body thresholds Molecules, Multiquarks Hybrids Glueballs qq ̄ Mesons 3

4 1. PANDA Experiment Full angular acceptance and angular resolution Particle Identification (p,π,K, e, μ) in the range up to ~ 8 GeV/c High momentum resolution PANDA (antiProton Annihilation at Darmstdat) Detector Target spectrometerForward spectrometer 4

5 2. Straw Tube Tracker STT layout 4636 straw in 2 semi-barrels around beam/target pipe planar layers in 6 hexagonal sectors Length: 1500 mm+150 mm (read- out) Angular acceptance: near 4 π FST layout straw tubes 6 tracking station: 2 before, 2 inside and 2 after the dipole magnet 4 double layers per tracking station Angular acceptance: ±5 ̊ vertically, ±10 ̊ horizontally 5

6 2. Straw Tube Tracker Straw tube structure Al-mylar tube, 29 μm thick, Ø=10 mm Gold-plated anode, Ø=20 μ m End plug (ABS thermo-plastic) Crimp pin (Cu, gold-plated) Gas tube (PVC med, 150 μ m wall) 2.5 g weight per tube Advantages of straws Modules (easy to exchange, high flexibility) Low mass (self supporting by gas overpressure ) High rates (1 MHz/wire) Low ageing Fast readout (pulse shaping and digitalization) 6

7 3. Straw Tube Simulation Garfield 9: program for the detailed simulation of gas detectors Simulation of transport properties of electrons and ions with new version Magboltz Gas mixture: 90% Ar, 10% CO 2 (the best gas mixture for high-rate, no polymeric reactions ) Temperature 300 K, absolute pressure 2 atm Pure Argon Argon+ 30% CO 2 10% 2% 1% 20% 10% 20% Pure Ar 50% Ar+75% CO 2 Drift velocityTownsend 7

8 3. Straw Tube Simulation The gain curve with 0%, 20%, 30%, 40%, 60% and 100% Penning rate No penning transfer Full penning transfer Gas gain simulation Comparison the measured gain with Diethorns formula Agreement with 34% penning rate 8

9 The first prototype new front-end chip fabricated in AMS 0.35 µm technology Preamplifier with variable gain CR-RC 2 with variable T peak Tail-cancelation with 2 variable time constants Baseline stabilizer Leading edge discriminator for timing Buffered analog output 4. Straw Front-end Electronic 9

10 Each ASIC includes 4 channels Digital LVDS & Buffered analog outputs Flash program memory ATMega controller for ASIC parameters (gain, shaping) Baseline and threshold set with external voltage source Optimum configuration The ASIC test-board v. 2 10

11 Transfer function produced by injection of delta like pulse to front-end 4. Straw Front-end Electronic The transfer function The 55 Fe pulse convoluted by transfer function 11

12 4. Straw Front-end Electronic Minimum ionizing proton beam of the intensity 1.2 MHz/straw signals were recorded by means of fast sampling ADC in long window of 5μs Baseline keeps always stable Energy resolution of the straws would not be affected in high counting rates The high-rate test 12

13 5. PID Methods Energy loss: below 1 GeV PID based on dE/dx: TOT ? Q Straw Tube Tracker (STT) 13

14 5. PID Methods Response of 24 single straws to 400 tracks Set the threshold as low as possible for high position resolution Correction to distance dependence Truncated average for 24 straw layers TOT simulation Straw Tracks 14

15 5. PID Methods Single straws response for 0.7 GeV/c particles before distance correction After distance correction After truncated average by removing 30% of the highest numbers Reasonable for PID 15

16 5. PID Methods TOT spectra measured with 55 Fe source shows good agreement with simulation for HV 1750 V and threshold based on 20 primary electrons 16

17 5. PID Methods TOT vs. input charge plot shows good agreement between simulation and test with 55 Fe source For high input charges, the measured TOT deviates from simulations due to saturation of pulses in the shaper 17

18 6. Separation p-K- π Separation power for p-π, p-K and π-K pairs based on TOT () and charge () measurement. The threshold level was set based on 20 primary electrons 18

19 6. Separation p-K- π The separation power for K-π and p-K pairs calculated using TOT and Q are different due to saturation of TOT as a function of Q for high energy deposits in the straws Saturation leads to smaller relative smearing and lower difference of the corresponding mean values of TOT than Q 0.3 GeV/c proton kaon pion 0.7 GeV/c proton kaon pion 19

20 6. Separation p-K- π The Separation power for π-K pair based on TOT with threshold levels based on 20 and 10 primary electrons and comparison with Q 20

21 7. Summary Modular straw tube trackers are good tools for tracking and identification of particles in large scale experiments New front-end chip works very well for straw read-out Distance correction improves the results of TOT and Q for PID The separation power based on the TOT and Q measurements are comparable in the investigated momentum range GeV/c TOT works very well for PID in straw tube trackers 21

22 THANK YOU FOR YOUR ATTENTION MESON2012 Conference, Krakow, Poland, 31May-5June

23 5. PID Methods Tot vs. drift time for Muon 1GeV/c passing with 30 degree to wire Drift time spectra for Muon 1GeV/c TOT & Drift time simulation for cosmic rays 23

24 6. Position Resolution threshold based on 20 primary electrons proton 1 GeV/c threshold based on 10 primary electrons 24

25 1. PANDA Experiment Full angular acceptance and angular resolution High momentum resolution Particle Identification (p, π,K, e, μ ) in the range up to ~ 8 GeV/c PANDA (antiProton Annihilation at Darmstdat) Detector 25

26 3. Straw Tube Simulation Adding CO 2 to Ar is efficient way to reduce the diffusion coefficient 15% 20% 50% Ar+10% CO 2 Longitudinal diffusion Transverse diffusion 15% 20% 50% Ar+10% CO 2 26

27 3. Straw Tube Simulation CO 2 as a quencher for the good drift properties and low ageing Ar is a main component that dominantly ionized 10% 20% 50% Ar+ 75% CO 2 attachment Ionization rate 27

28 4. Straw Front-end Electronic Different settings of time constants in tail-cancelation and shaping part Optimum configuration based on fast shaping and higher amplitude and lower undershoot 28


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