| The lobster eye lens is a structural biomimetic focusing element,which is different from conventional optical lens.A spherical symmetric structure composed of rectangular microchannels can achieve a total external reflection condition of radiation flux,which has a high collection efficiency for high energy radiation flux.X-ray lenses capable of large-field imaging are key elements in the study of astrophysics and cosmology.X-ray lenses capable of large-field imaging are key elements in the study of astrophysics and cosmology.Therefore,the lobster eye lens of the X-ray spectrum segment has extremely high potential application value.This thesis focuses on the mission requirements of future space exploration,and fundamental research on the focusing mechanism and application of lobster eye lens in extreme X-ray radiative soft X-ray spectra is launched.The main work of this thesis includes: Based on the principle of prism expansion,a ray tracing mathematical model of the lobster eye lens is established.According to the mathematical model,the total reflection imaging mechanism of the lobster eye lens is completely described.According to the characteristics of no-axis aberration and no color difference of the lobster eye lens,the formula for calculating the vertical axis aberration was given.The soft X-ray energy model of the lobster eye lens was established by combining the ray tracing model of the lobster eye lens with the material X-ray reflectance function,taking into account both the total external reflection limit angle and the internal reflection critical angle problem.According to the model,the relationship between the imaging beam form and the structure of the lobster eye lens is discussed.The light collection efficiency and the form of aberrations are analyzed in two cases respectively;The effects of key parameters such as channel length,cone apex angle and lens radius on image quality are discussed in detail.The odd-order reflection energy ratio,maximum vertical axis aberration,spot diameter and average light intensity in the meridional direction of lobster eye lens are described.It is concluded that in the effective optical aperture,the ratio of width to length determines the light collection efficiency of the whole structure.After selecting the appropriate aspect ratio,odd reflection efficiency is up to 58.5%.After using this aspect ratio for verification in a two-dimensional lobster eye lens,the overall structure of the light collection efficiency reaches 34%.A method of shaping the inner wall of microchannel reflection using variable period blazed grating is proposed in this thesis,which to improve the efficiency of collecting light and reduce the diameter of dispersion spot.The diffraction interference factor and diffraction field of the blazed grating with variable period are analyzed theoretically.Besides,the axial field of view and the 0.1 degree off-axis field of the one dimensional lobster eye structure after micro shaping are simulated,and the spot diameter and the concentration of light under different effective aperture are analyzed. |
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