Coronograph, Refractive, Basic
Sunday, September 03, 2006
The basic design of the Coronagraph incorporates an occulting disk in the primary image plane of the telescope. This occulting disk blocks the image of the Sun. The primary objective (a lens or polished mirror) is specified to minimizing scattered light. The light diffracted by the objective edge is minimized. An aperture (Lyot Stop, invented by B. Lyot) is located at the image of the objective formed by a field lens, with an aperture slightly smaller than the objective image. A relay lens behind the Lyot stop forms the Sun corona image at the final image plane.
The Refractive Coronagraph objective lens is made of high quality glass and is polished to high specifications. The rest of the optical system is a basic telescope. A polished conical disk eclipses the disk of the Sun. The light diffracted by the edge of the objective is gathered by a field lens. This is focused on to an undersized diaphragm and the final lens images the Sun corona on the focal plane of the telescope.
Source: Various Publications
Reference: Raymond N. Scott
Industrial Products
posted by JD52 @ 12:34 AM,
