In-situ measurements of whole-dish reflectivity for VERITAS
نویسندگان
چکیده
The VERITAS array is a set of four imaging atmospheric Cherenkov telescopes (IACTs) sensitive to gamma rays with energies above 80 GeV. Each telescope based on tessellated mirror, 12 metres in diameter, which reflects light from gamma-ray-induced air shower form an image pixellated ‘camera’ comprising 499 photomultiplier tubes. brightness the primary measure ray’s energy so knowledge mirror reflectivity important. We describe here method, pioneered by members MAGIC collaboration, whole-dish reflectivity, quickly and regularly, that effects aging can be monitored. A CCD camera attached near centre dish simultaneously acquires both star its reflection target made Spectralon, highly-reflective material, placed at focus telescope. ratio their brightnesses, as recorded CCD, along geometric factors, provides estimate few systematic errors. filter wheel deployed camera, allowing one function wavelength. present results obtained since 2014.
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ژورنال
عنوان ژورنال: Astroparticle Physics
سال: 2021
ISSN: ['0927-6505', '1873-2852']
DOI: https://doi.org/10.1016/j.astropartphys.2020.102556