bar layers

Performance of the Barrel DIRC for bars with multiple layers (with different ref index).

  • 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

Performance as the function of number of layers and random deviation of the ref index in ppm:

Deviation of the photon direction relative to the initial vector as the function of number of reflections. Bars with 50 layers of gradiantly changed ref index (within 100 ppm). Example for 3 photons:

Accumulation for ~2k photons:

Simulation of the laser beam (390 nm) along the bar. The bar has 100 layers which create 10 ppm gradient of refraction index. Position shift X along the bar thickness (outer bands for 3 mrad angle between laser beam and bar axis; inner for 2 mrad; upper two bands for photons with angle increasing in the direction of higher refraction index, lower two - opposite direction) :

Angle shift. The angle increases in the direction of higher refraction index:

The angle increases in the direction of lower refraction index: