کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1829180 | 1027452 | 2008 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Refractive index of silica aerogel: Uniformity and dispersion law Refractive index of silica aerogel: Uniformity and dispersion law](/preview/png/1829180.png)
Two methods for the measurement of the uniformity of the refractive index nn within a single block of silica aerogel are described. One is based on the deflection of a laser beam induced by transverse index gradients. The second exploits the Cherenkov effect, measuring the emission angle of photons radiated by 500 MeV electrons traversing the aerogel. The beam can scan the full aerogel surface providing information on point to point variations of nn.The measurement of the dispersion law n(λ)n(λ) is also reported. An Xe lamp coupled to a diffraction grating provides the monochromatic source. The index for each λλ is measured by the prism method at a corner of an aerogel sample. A Sellmeier functional form for n(λ)n(λ) is assumed, and the parameters best fitting the experimental data are given.
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment - Volume 595, Issue 1, 21 September 2008, Pages 183–186