X ray wide spectrum three-layer film reflector structure design method

Abstract

The invention relates to an X ray wide spectrum three-layer film reflector structure design method. The three-layer film reflector structure comprises a substrate, a high density layer, a middle density layer and a low density layer orderly arranged from bottom to top, and the design method comprises the following steps: a material selection step: according to application environment of a reflector and an incident spectrum energy range with a weight factor, determining materials of the high density layer, the middle density layer and the low density layer; a thickness setting step: according to a grazing incidence angle of the X ray, building an evaluation function through taking that integrated reflectivity is highest in a target energy spectrum range as an optimization goal, and obtaining thickness of the high density layer, the middle thickness layer and the low density layer. Compared with the prior art, the reflector structure designed by the method provided by the invention is simple and easy to prepare, can realize relatively higher integrated reflectivity area and can effectively increase effective light gathering acreage of a telescope.

Description

Technical field [0001] The invention relates to the technical field of optical thin films, to a reflector structure of an X-ray astronomical telescope, in particular to a structure design method of an X-ray broad spectrum three-layer film reflector. Background technique [0002] In the field of X-ray astronomy, X-ray imaging telescopes have very important applications in astronomical observations. The two most important factors for evaluating the performance of a telescope are angular resolution and effective light collection area. The effective light collection area is expressed as [0003] [0004] Where r N Is the half aperture of the Nth layer of the telescope, L P Length of main mirror, θ N Is the grazing incidence angle of the Nth layer, and R is the reflectivity of the mirror. It can be seen from formula (1) that the effective light collection area can be increased by increasing the number of nesting layers of the telescope and increasing the reflectivity of the lens. In ...

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Problems solved by technology

However, with the increase of the critical angle of total reflection, the absorption of heavy metal materials for the relatively low energy range (1-6keV) becomes larger, which reduces the integrated reflectivity of this energy range, and finally causes serious damage to the effective light-collecting area of ​​the telescope. Impact

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