1 / 34

TPC R&D in Canada

TPC R&D in Canada. Dean Karlen / University of Victoria & TRIUMF Canadian LC-TPC Group: Carleton University: Robert Carnegie, Madhu Dixit, Hans Mes, Kirsten Sachs University of Montreal: Jean-Pierre Martin

skah
Download Presentation

TPC R&D in Canada

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. TPC R&D in Canada Dean Karlen / University of Victoria & TRIUMF Canadian LC-TPC Group: Carleton University: Robert Carnegie, Madhu Dixit, Hans Mes, Kirsten Sachs University of Montreal: Jean-Pierre Martin University of Victoria: D.K., Paul Poffenberger, Gabe Rosenbaum

  2. Outline • Focus of the Canadian LC-TPC R&D program • Updates: • On the eastern front: TPC1 • finalizing analysis of P10 and ArCO2 cosmic data from 2002 • investigation of resistive foil for induction signals • On the western front: TPC2 • first results from cosmic data in magnetic field (June 2003) • comparison with Monte Carlo simulation • Plans... TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  3. Focus of Canadian TPC R&D • Investigate the design of the end plate for the TPC to achieve its objectives: • micropattern gas avalanche detector • modest size pads: ~2 mm  ~6 mm pads • ~100 micron resolution per pad row in the transverse direction • good two particle separation power TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  4. Endplate design • Significant effort to study the performance of GEM devices with rectangular readout pads • cosmics used to measure resolution properties TPC 1A Fall 2001 TPC 1B Summer 2002 TPC 2 Summer 2003 TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  5. Cosmic ray tracking • The traditional approach: • examine data from eachrow separately: define a point along the track TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  6. Cosmic ray tracking • The traditional approach: • examine data from eachrow separately: define a point along the track • find best track that goesthrough points TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  7. Cosmic ray tracking • The traditional approach: • examine data from eachrow separately: define a point along the track • find best track that goesthrough points • measure resolution by thescatter of the dots from thetrack TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  8. Cosmic ray tracking • Problem with the traditional approach: • information in one rowis not sufficient to definea point along the track: • charge sharing depends on • x coordinate • azimuthal angle • width of charge cloud • dependence is non-linear • linear centroid findingdegrades resolution TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  9. Cosmic ray tracking • Our whole track approach: • combine information fromall rows to determine thetrack parameters: • x coordinate • azimuthal angle • width of charge cloud • the concept of a point on the track is non-existent • x resolution for a singlerow is measured byperforming two track fits TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  10. Cosmic ray tracking • The sharing of charge byneighbouring pads is a simple enough concept to develop a first principles model formaximum likelihood • Benefits of the whole trackapproach: • no empirical parameters • less calibration • reasonable estimates forerror matrix • better resolution TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  11. News from the Eastern Front • Finalizing analysis of data from TPC-1b • F analysis code developed TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  12. Transverse resolution • 100 mm resolutionachieved with 2 mmpads… furtherimprovements expected TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  13. Resistive anode studies • To spread signals over larger area, a resistive film can be used: • Especially importantfor Micromegas… TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  14. Resistive anode studies • Early results look promising TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  15. News from the Western Front • Progress since Arlington: • New TPC (TPC2) commissioned in Victoria • Cross compiler for STAR electronics developed to build more efficient DAQ system • Cosmic tracking indicated field distortions • TPC redesign fixed the distortions • TPC brought to TRIUMF for magnetic field tests • Track fitter extended for curved tracks • Begin using JAS3 for automated analysis • Analysis of the magnetic field runs • code is publicly available via anonymous CVS access TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  16. Victoria group • Graduate student: • Gabe Rosenbaum • RA (part-time): • Paul Poffenberger • Summer students: • Camille Belanger-Champagne • Brie Hoffman • Technical support: (many) • D.K. TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  17. TPC2 commissioned • Constructed at Carleton University, operated at the University of Victoria with cosmic telescope TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  18. Data acquisition • Cross compiler built (Paul) • can compile applications for STAR electronics on Linux, and load onto VxWorks platform • see www.linearcollider.ca for information • New data acquisition program (Paul/Gabe) • data runs written to single file • contains header information for run/event • only channels connected to FEE cards written • ~10% deadtime loss for cosmics TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  19. Tracking with 6 STAR FEE cards TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  20. Tracking distortions found • Residual from track depends on track location: mean residual for centre row (mm) x coordinate (mm) TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  21. TPC modification • End of drift volume had a wire mesh to terminate cylindrical volume just in front of square GEMs: source of field distortions? drift volume wire mesh TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  22. TPC modification • New endpiece constructed: • 70 mm wire strung with 2.5 mm spacing TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  23. Tracking distortions fixed • With new end piece, problem is solved mean residual for centre row (mm) x coordinate (mm) TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  24. Analysis code • Track fitting now with curvature data taken with no mesh: large field distortions! TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  25. Setup at TRIUMF TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  26. Example events at ~25 cm drift Gas: P10 0 Tesla 0.45 Tesla 0.9 Tesla s = 2.3 mm s = 1.2 mm s = 0.8 mm TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  27. Diffusion measurements • Transverse diffusion significantly reduced at high B fields B = 0 B = 0.45 T B = 0.9 T 3cm 30 cm TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  28. Track resolution • Fit track to all but one row • fix f0, 1/r, and s,fit to one rowalone • compare x0from the two fits • fit to Gaussian B = 0 B = 0.45 T TDR spec. goal B = 0.9 T 3cm 30 cm TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  29. Resolution dependencies • No large dependencies on threshold or gain • Track angle effect visible ~ 2 primary ~ 1 primary 0.05 < f < 0.1 ~ 5000 0 < f < 0.05 ~ 2500 TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  30. Comparison with MC simulation • Goodagreement • MC truth info confirms thatprocedure tomeasure resolutionis sensible TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  31. Induction signals visible • Pads next to those collecting electrons see induced pulses (also seen in our x-ray test cell) TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  32. Magnetic field distortions • Field not completely uniform within drift volume: • cause ionization tracks to rotate in azimuth TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  33. Magnetic field distortions • To check, use cosmic telescope to define a standard beamof cosmics • mean f anglechanges inthe directionexpected TPC R&D in Canada / D. Karlen / UVic & TRIUMF

  34. Plans for TPC2 • With the successful TRIUMF magnet tests, we will take the TPC to DESY for tests in their superconducting magnet (up to 5 Tesla) • starts next week! TPC R&D in Canada / D. Karlen / UVic & TRIUMF

More Related