Researches On The Image Properties Of Extreme Ultraviolet Optical System Based On Square-Hole MCP

In order to continuously meet the requirements of future space exploration programs, a new optical element which has a large field of view, a high resolution, can collect large amounts of radiations and collimate or focus them is needed for the X-ray optical systems. Based on the theory of total reflection, the square-hole micro-channel plate (MCP) optical imaging system has a large field of view, high resolution, compact conformation, light in weight, low cost and other advantages. Therefore, the new X-ray optical element has been applied and developed in more and more areas.In this paper, starting from the X-ray total reflection theory, the imaging principles of the flat square-hole MCP and the curved square-hole MCP are discussed, and the influence of the surface scattering on the image quality is also discussed.Then the solid model of the flat square-hole MCP is setup with the software TRACEPRO, and imaging simulations are carried out for MCPs with different structural defects with Monte-Carlo ray tracing method. The Taper-type, Twist-type and Nonsquare-type structure defects are investigated. Using a bromine tungsten-arc lamp as light source, the imaging experiments are done for the four available flat square-hole MCPs in the visible band. The experimental results are compared with the simulation results the use of Monte-Carlo to compare the composition, and they are basically the same, further verifying the correctness of the simulation results. Then using the extreme ultraviolet monochrome system composed of a concave grating monochromator and a laser-produced plasma source, imaging experiments are done for the flat square-hole MCP at30.40nm. The experimental results show that the peak intensity of the central spot has a gain nearly four times and this verifies the focusing properties of the MCP optical system.Finally, the applications of curved square-hole MCP are investigated. According to the imaging properties of the curved square-hole MCP, a super wide angle X-ray telescope and an imaging spectrometer based on transmission gating and MCP are designed. Basic researches have been done for the applications of the curved square-hole MCP.