BTEV MIRROR REFLECTANCE

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BTEV MIRROR REFLECTANCE

• CERN VUV REFLECTOMETER

• Measurements made by Andre Braem, CERN
• Confined to UV (D2 lamp, same as our cutoff)
• Measured twice, and compared to standard mirror
  produced for LHCb RICH2 (consistent)
• Measured at small angle of incidence (5.deg), at
  the center of the mirror
• Baffle cuts out any stray light (suppressing the
  background, D953.mm)
• Previously spec gt85 by COMPAS, and assumed 90
  (measured for similar HERA-B mirrors)