Forward TOF Prototyping

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Forward TOF Prototyping. Ryan Mitchell GlueX Collaboration Meeting November 2005. Purpose of the Forward TOF. Forward TOF. Particle ID: π /K separation up to 1.8 GeV/c. Level-1 Trigger: Fast forward charged track count. Calorimetry: Tag hadronic showers in the forward calorimeter. - PowerPoint PPT Presentation

Transcript of Forward TOF Prototyping

  • Forward TOF PrototypingRyan MitchellGlueX Collaboration MeetingNovember 2005

  • Purpose of the Forward TOFParticle ID:/K separation up to 1.8 GeV/c.

    Level-1 Trigger:Fast forward charged track count.

    Calorimetry:Tag hadronic showers in the forward calorimeter.

    Forward TOFParticle ID:

    70 ps time resolution

    1% momentum and length resolutions

  • Current Design(and possible improvements)(Not to Scale)42 barsScintillators: 252 6 1.25cm Eljen-200 or BicronBeam Hole: 12 12 cm HolePhotomultiplier Tubes: XP2020Electronics: Alberta CFD JLab F1TDC fADCWould thicker bebetter?Is this the best we can do for...timing?fringe field? Need more experiencewith this (esp. range)...

  • Outline of Prototyping I:Finished/OngoingIHEP Test Beams 2001 to present-- < 80ps resolution is achievable with 200 6 1.25cm bars-- December 2005 tests will look at 250cm bars

    IU Cosmic Ray Tests Spring 2004-- First measurements were made with a 250 6 1.25cm bar-- Find 88ps resolution in the center region (2 bars)

    TRIUMF Beam Test Summer/Fall 2005-- Low energy //e beam used on two layers of scintillators-- Probing time resolution for a variety of dE/dx and all positions-- Discriminator performances

  • Outline of Prototyping II:3 Year PlanIU Cosmic Ray Tests 2006 to Spring 2007-- Another round of tests with the IU cosmic ray stand.-- 88ps is not sufficient; look at bar thickness.-- Try a variety of phototubes.-- Use Alberta CFD and commercial CFD and LED.

    Hall-B Electron/Photon Tests (with LGD) Fall 2007 Run-- Take the final design to the Hall-B alcove test-- Scan 2 walls of 10 bars each (one full length; one half length).-- Correlate with the LGD and tagger.

    Magnetic Field Tests (with LGD) 2008-- Make sure everything works in the fringe field.

  • 2004 IU Cosmic Rays SummaryPMT: XP2020TDC:LeCroy 2228A (50ps least count)ADC:LeCroy 2249A and IU fADCCFD:Ortec and University of AlbertaScint:250 6 1.25cmThree movable cosmic ray telescopes in a logical OR.Scintillator is enclosed in a light-tight box (the coffin).

  • 2004 IU Cosmic Rays SummaryAttenuation Length = 160.5 4.2 cmVelocity = 14.77 0.09 cm/nsTime Resolution = 88 ps

  • 2005 TRIUMF Test Beam SummaryFirst two weeks of June 2005.120 and 250 MeV/c //e beams.Full size and half size scintillators.

  • 2005 TRIUMF Test Beam SummarySame electronics as cosmic ray tests:PMT: XP2020TDC: LeCroy 2228A (50ps least count)ADC: LeCroy 2249A and IU fADCCFD: Ortec and University of AlbertaScint: 250 6 1.25cm

  • 2005 TRIUMF Test Beam SummarySample ADC and TDC from one bar end. -- 120 MeV/c //e beam -- 3 Moyal distribution fit to ADC -- 3 Gaussian distribution fit to TDCe+e+++++

  • 2005 TRIUMF Test Beam SummaryFour scans along a front bar.

    Mean ADC from the two bar ends are superimposed.Attenuation Length = 136.7 3.4 cmpionmuonelectron

  • 2005 TRIUMF Test Beam SummaryAnomalies in ADC vs TDCGoode+++Severetime-walkfor electrone+e+e+++++++Double-peakelectronDouble-peakmuon-- Similar behavior for both Alberta and Ortec CFD.-- Needs further analysis.-- Need more tests with different discriminators.

  • 2005 TRIUMF Test Beam Summary/e separation/e separation/ separationFour scans along a front bar.

    TDC differences from the two ends are superimposed.

    Very consistent run to run results.

    Nonlinearities are likely due toADC vs TDC anomalies.

    Very Important. Needs to beinvestigated further.

  • Three Outstanding Design IssuesThe 88ps resolution for the 252 6 1.25cm bars is not acceptable. Try doubling the bar thickness.

    Understand the discriminator issues. Try out a few commercial models (CFD and LED).

    Explore different phototube options. Can we find something better than the XP2020 for timing and performance in a magnetic field?

  • Phase I Prototype (2006): CosmicsPLAN:Use the existing IU cosmic ray test stand to explore: -- bar thickness -- discriminators -- phototubesBUDGET:Phototubes: 12k (e.g. Hamamatsu R9779, Hamamatsu R2083, Hamamatsu R1828, Electron D744, Photek PMT340)Discriminators: 12k (e.g. Ortec 935, Phillips 7106, 708, 710, 715, 730)2006 Request = 24k

  • Phase II Prototype (2007): Test BeamPLAN:Test 2 walls of 10 scintillators each (one long horizontal wall and one short vertical wall) in November 2007 along with the LGD. -- use electrons and photons from Hall-B -- scan bars for time and position resolutions. -- correlate the timing with the LGD and the tagger.BUDGET:Phototubes: 18k (instrument 20 bars with XP2020)Scintillators: 5kHigh Voltage: 25kCables: 5kSupplies: 6k

    2007 Request = 59k

  • Phase III Prototype (2008): MagnetPLAN:Test the prototype in the magnet fringe field.BUDGET:No new money anticiptated.2006-2008 Request = 83k