bar imperfections 2

Performance of the Barrel DIRC for bars with rounded sides.

  • PandaRoot simulations without field
  • configuration with narrow bars, 3 layer spherical lens, and 8 MCPs layout with ~17 mm gap
  • default radii of the lenses ([95,50])
  • pions and kaons @ p = 3.5 GeV/c @ theta = 22 deg @ phi = 10.825 deg
  • time-imaging reconstruction with full-simulated pdfs
  • 30k tracks for pdf generation (per each particle species); 5k for determining separation
  • ~2 mrad tracking resolution
  • realistic time precision
  • QE=18(24)% ( black curve). CE=95%
  • spatial QE = 1

Bar with rounded sides:

Geant4 (pandaroot) simulation with 1000 mkm sagitta:

Geometrical reconstruction (without per-pmt Cherenkov angle correction):

Difference between 10 mkm (red) and 100 mkm (blue):

Different shapes of the edges:

Geometrical reconstruction (with per-pmt Cherenkov angle correction):

Time imaging with PDFs from imperfect bar (with corresponding shape):

Time imaging with PDFs from ideal bar:

Deviation of the photon direction relative to the initial vector as the function of number of reflections (10 mkm). Example for 3 photons using "shape d":

Accumulation for ~2k photons:

100 mkm:

Shape f with 100 mkm:

Cancellation in shape f: