Accession Number : AD0778096
Title : A Fully Tunable Lyot-Ohman Filter.
Descriptive Note : Interim rept.,
Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS
Personal Author(s) : Beckers,Jacques M.
Report Date : MAR 1973
Pagination or Media Count : 17
Abstract : Incorporation of achromatic wave plates into the Lyot-Ohman type of birefringent filter and the introduction of computer control has made it possible to manufacture filters of that type which are rapidly tunable over a wide spectral range. This so-called Universal Birefringent Filter is now in use at the Sacramento Peak Observatory. It can be tuned within 2 seconds to any wavelength in the 4100 - 7100 A wavelength range. The initial bandwidth, which varies from 0.28 A at 7100 to 0.08 A at 4100 A, can be decreased by the addition of an extra filter element to 0.14 at 7100 A and 0.04 A at 4100 A. Peak transmission varies from 8 percent in the 5000 - 7000 A range to 2 percent at 4200 A. This filter, as part of the Sacramento Peak Observatory vacuum telescope, will be used for observation of solar intensity, velocity and magnetic fields. (Author)
Descriptors : *Optical filters, *Telescopes, Tuning, Birefringence, Astronomical instruments
Subject Categories : Astrophysics
Distribution Statement : APPROVED FOR PUBLIC RELEASE