Research On Ultraviolet Integral Field Spectrograph Of Space Telescope

For neighboring galaxies,ultraviolet is special for studying the large-mass stars,broad absorption lines,and so on.The UV 3D spectrographic observations have great scientific value for both the neighboring galaxies and for the red-shifted galaxies with z 1-2.Spatially-resolved spectroscopy is often obtained by Integral Field Unit(IFU),which is assembled on Integral Field Spectrograph(IFS),combining spectral and imaging functions.The UV IFU/IFS provide us parameters that are important for galaxy evolution.At present,exist IFUs are mainly concentrated in optics and infrared,while the ultraviolet IFU is relatively scarce.This paper studied the UV IFU technology and the high-resolution UV imaging spectroscopy technology.A set of UV IFS is designed and developed.The main research of this article and the results obtained are as follows:(1)Fully researched the development trend of IFU at home and abroad,and conducted research on key technologies such as IFU and high-resolution imaging spectrum.According to the scientific demand and the IFS principle,system index was determined.Designed the high-resolution UV IFS system and the subsystems of the high-resolution UV IFS.(2)Designed a set of 8×8 IFU.Compared with the three methods of IFU,considering optical efficiency,processing difficulty,manufacturing cycle,and cost,using the simplified method of bare fiber bundles.The fibers are stacked into a matrix to segment the target image on the focal plane of the telescope,and the fibers at the IFU output end are arranged in a row.The sampled beams are sent to the spectrometer.(3)The design of high-resolution UV imaging spectroscopy system was carried out in this paper.Grating is used for spectral splitting by comparing the prism and grating.The two imaging spectral structures: Dyson and Offner concentric structures were analyzed and compared.The improved structure based on the Offner imaging spectral system of convex gratings not only possesses the advantages of Offner structure with high image quality,low smile and keystones,and easy alignment,but also realizes high resolution and system miniaturization.(4)According to the Offner concentric structure and the diffraction properties of the convex grating,a method for high-precision calibration of the Offner concentric three-inverse structure and the Offner-optimized structure with a meniscus correction lens using an interferometer is designed.Complete the installation of the spectroscopic system.(5)Use mercury lamp as calibration light source to complete system spectral calibration.Used UV-enhanced xenon arc lamp as light source,use several targets to perform spectral imaging experiments.Used monochromator as the light source to complete the system spectral resolution test.The results show that the spectral resolution in the 322-400 nm band is 0.5 nm.The main innovations in this article are:(1)Based on fiber bundle,a kind of UV IFS system design was proposed.The UV IFS system was pioneered in exploratory design and test validation.A set of high-resolution UV IFS system was developed.At present,there are few reports on UV IFS in China.The system's working wavelength is 250-400 nm,the spectral resolution is 0.6 nm,the spatial angle resolution is 21.6”×21.6”,and the FOV is 172.8”×172.8”.(2)Completed the key technology of high-resolution UV Offner imaging spectroscopy subsystem and designed a set of UV imaging spectroscopy.The system not only has high image quality,low smile and keystones,easy to adjust,but also achieve high-resolution and miniaturization.The NA of the spectral system is 0.14 and the spectral resolution is 0.6 nm.(3)Completed the key technology of UV IFU design,analyzed the characteristics of different types of IFU and the influence of UV on the IFU optical efficiency.Designed a set of UV IFU.The UV IFU was verified the size of 8×8 and the fill factor is 74.6%.