Thermal diaphragm suitable for annular solar telescope

Abstract

The invention provides a thermal diaphragm suitable for an annular solar telescope. One end of the thermal diaphragm suitable for the annular solar telescope toward the direction of light incidence isa reflective surface, and the other end is a bottom surface; the reflective surface of the thermal diaphragm suitable for the annular solar telescope is an inverted cone shape, and the bottom surfaceis a positive cone shape; the reflective surface with the inverted cone shape and the bottom surface with the positive cone shape are tangent at the vertexes of the two cones to form a light passinghole; and the cone angle of the inverted cone of the reflective surface is 88 to 93 degrees. The thermal diaphragm structure design provided by the invention strengthens the thermal control ability near the light passing hole, optimizes the temperature field near the light passing hole, reduces stray light to the greatest extent, and suppresses a ghost image; and the thermal diaphragm suitable forthe annular solar telescope has good temperature control effect, no ghost image and good stray light suppression effect, which ensures the imaging quality of the telescope.

Description

technical field [0001] The invention relates to the technical field of precision optical instruments, in particular to a thermal aperture suitable for an annular solar telescope. Background technique [0002] The design of solar telescope thermal aperture faces the problem of thermal control of the aperture and the processing of light outside the field of view. Regarding thermal control, the local seeing at the thermal aperture has an important impact on the final imaging effect of the telescope. The turbulence generated by the heat of the thermal aperture will cause image plane jitter, image plane defocus, and image quality degradation. In order to suppress The thermal diaphragm is affected by the thermal turbulence of the light surface on the image quality, so it needs to be thermally controlled to ensure that the thermal diaphragm is not damaged by heat. Regarding the processing of light outside the field of view, it can be divided into two parts: ghost image and stray l...

AI Technical Summary

Problems solved by technology

The other type of aperture is a flat plate type, and the uniformity of the temperature field is not well controlled. The reflective surface is a plane mirror with an inclined angle, and the light outside the field of view is directed to a predetermined direction. If the direction avoids the surrounding truss, it can be ideally processed. out-of-field light

[0004] However, the shape structure of the conical and flat thermal diaphragms leads to sharp corners near the light hole (the conical type is especially obvious), because the sharp corner shape structure will cause the problem of long heat conduction path and small heat conduction cross-sectional area, which is not conducive to Heat conduction at this position affects the heat dissipation effect, resulting in a higher temperature near the light hole

[0005] In addition, the current open large-aperture solar telescopes use two cooling methods for the diaphragm body, jet impact and flow diversion. However, due to the influence of the shape and structure of the flat plate and conical thermal diaphragms, there are sharp edges in the cooling cavity near the aperture. horn

For the jet impingement cooling method, the sharp corner makes it difficult for the jet nozzle to approach the light hole area, and the coolant in the sharp corner area is not easy to flow, and it is easy to form stagnant water areas; for the diversion method, in order to ensure the thermal diaphragm Heat dissipation efficiency, the deflector also acts as a heat dissipation fin, and should be connected with the upper cover structurally, but the space here is small, and it is extremely difficult to process the deflector in the inner cavity of the upper cover

[0006] Therefore, the disadvantages of the current solar telescope thermal diaphragms in terms of temperature control are that the temperature of the existing flat and conical thermal diaphragms is high at the position of the aperture, and the existing cooling methods cannot effectively control this position. temperature, resulting in thermally induced turbulence generated in the vicinity of the aperture has a more serious adverse effect on imaging

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