Accession Number : AD0778107

Title :   The Universal Birefringent Filter at Sacramento Peak.

Descriptive Note : Interim rept.,

Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS

Personal Author(s) : Beckers,J. M.

Report Date : 02 NOV 1973

Pagination or Media Count : 10

Abstract : Recent developments in the construction of achromatic wave-plates here made it possible to make Lyot filters which are tunable over a wide spectral range. Zeiss (Oberkochen) and Spectra-Optics (La Crescenta, CA) have constructed such a Universal Birefringent Filter which is tunable from 4200 A to 7000 A with a bandpass ranging from 40 mA at 4200 A to 130 mA at 7000 A. The wavelength tuning of this filter is done by means of computer control. The optical system, of which the filter is a part, will also include polarizing beamsplitters which will enable velocity and magnetic field observations. All variable elements are under computer control so that one can obtain in each 30 second interval six observations consisting of any combination of filtergrams, tachograms and magnetograms in any lines in the filter wavelength regions. Preliminary results of the Universal Filter observations are presented. (Author)

Descriptors :   *Optical filters, *Telescopes, Tuning, Birefringence, Astronomical instruments

Subject Categories : Astrophysics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE