Stray light analysis of a reflecting UV coronagraph/polarimeter with multilayer optics
Abstract
An analysis is presented of the stray light expected in a Coronagraph/Polarimeter operating at the H I Lyman (alpha) (Ly-(alpha) ) line ((lambda) 121.6 nm) and utilizing multilayer interference film optics and ultrasmooth substrates (i.e., rms-smoothness <EQ 0.1 nm). This instrument is designed to measure the linear polarization of the coronal Ly-(alpha) up to 2 solar radii (R.) from sun center. The interpretation through the Hanle effect of these measurements would yield information on the magnetic fields of the solar corona. Analytical methods and laboratory measurements of substrate rms-smoothness are used to carry out the stray light analysis. Our analysis shows that with the use of ultrasmooth multilayer optics, it is possible to design UV coronagraphs that, unlike visible light coronagraphs, can observe the inner corona (i.e., up to heliocentric distances of about 2 R.) without occulters.
- Publication:
-
X-Ray and Ultraviolet Polarimetry
- Pub Date:
- February 1994
- DOI:
- 10.1117/12.168591
- Bibcode:
- 1994SPIE.2010...78F