TY - JOUR
T1 - Optical characterization of n = 1.03 silica aerogel used as radiator in the RICH of HERMES
AU - Aschenauer, E.
AU - Bianchi, N.
AU - Capitani, G. P.
AU - Carter, P.
AU - Casalino, C.
AU - Cisbani, E.
AU - Coluzza, C.
AU - De Leo, R.
AU - De Sanctis, E.
AU - De Schepper, D.
AU - Djordjadze, V.
AU - Filippone, B.
AU - Frullani, S.
AU - Garibaldi, F.
AU - Hansen, J. O.
AU - Hommez, B.
AU - Iodice, M.
AU - Jackson, H. E.
AU - Kaiser, R.
AU - Kanesaka, J.
AU - Lagamba, L.
AU - Muccifora, V.
AU - Nappi, E.
AU - Nowak, W. D.
AU - O'Neill, T. G.
AU - Potterveld, D.
AU - Ryckbosch, D.
AU - Sakemi, Y.
AU - Sato, F.
AU - Schwind, A.
AU - Suetsugu, K.
AU - Shibata, T. A.
AU - Thomas, E.
AU - Tytgat, M.
AU - Urciuoli, G. M.
AU - Van De Kerckhove, K.
AU - Van De Vyver, R.
AU - Yoneyama, S.
AU - Zhang, L. F.
N1 - Funding Information:
The support from Monbusho, JSPS, and Toray Science Foundation (JAPAN) is kindly acknowledged.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2000/2/1
Y1 - 2000/2/1
N2 - The optical properties of silica aerogel tiles with a refractive index of 1.03 and dimensions 11 × 11 × 1 cm3, produced by the Matushita Electric Works (Japan), have been measured in the wavelength range from 200 to 900 nm. The tiles are used as one of the two radiators of the ring imaging Cherenkov counter of the HERMES experiment at DESY-HERA. The transmittance of light has been measured on 200 tiles by means of a double beam spectrophotometer. The light transflectance and reflectance have been measured on one tile by means of a single-beam spectrophotometer and an integrating reflecting sphere. Typical values of the measured transmittances at a wavelength λ = 400 nm are around 0.67. The measured transflectance increases almost linearly from 0.4 to 0.96 in the interval 200-300 nm, and remains nearly constant at the value 0.95 in the complementary λ-range. The measured reflectance, mostly confined below 400 nm, is completely interpretable as backscattering from inside the aerogel, revealing an absence of light reflection at the aerogel surfaces. The transmittance data have been fitted with the Hunt formula, whose parameters have been used to evaluate the number of unscattered and scattered Cherenkov photons produced by aerogel. For stacks of 5 tiles and quantum efficiencies of phototubes with bialkali photocathodes, rings with up to 19 photoelectrons/event can be expected for β = 1 particles.
AB - The optical properties of silica aerogel tiles with a refractive index of 1.03 and dimensions 11 × 11 × 1 cm3, produced by the Matushita Electric Works (Japan), have been measured in the wavelength range from 200 to 900 nm. The tiles are used as one of the two radiators of the ring imaging Cherenkov counter of the HERMES experiment at DESY-HERA. The transmittance of light has been measured on 200 tiles by means of a double beam spectrophotometer. The light transflectance and reflectance have been measured on one tile by means of a single-beam spectrophotometer and an integrating reflecting sphere. Typical values of the measured transmittances at a wavelength λ = 400 nm are around 0.67. The measured transflectance increases almost linearly from 0.4 to 0.96 in the interval 200-300 nm, and remains nearly constant at the value 0.95 in the complementary λ-range. The measured reflectance, mostly confined below 400 nm, is completely interpretable as backscattering from inside the aerogel, revealing an absence of light reflection at the aerogel surfaces. The transmittance data have been fitted with the Hunt formula, whose parameters have been used to evaluate the number of unscattered and scattered Cherenkov photons produced by aerogel. For stacks of 5 tiles and quantum efficiencies of phototubes with bialkali photocathodes, rings with up to 19 photoelectrons/event can be expected for β = 1 particles.
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U2 - 10.1016/S0168-9002(99)00923-7
DO - 10.1016/S0168-9002(99)00923-7
M3 - Article
AN - SCOPUS:0034140593
VL - 440
SP - 338
EP - 347
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
SN - 0168-9002
IS - 2
ER -