Preliminary design of the full-Stokes UV and visible spectropolarimeter for UVMag/Arago
Preliminary design of the full-Stokes UV and visible spectropolarimeter for UVMag/Arago
复制标题
UVMag/Arago全斯托克斯紫外可见分光偏振计的初步设计
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
G. van Harten
中科院分区：
文献类型：
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作者：
M. Pertenais;C. Neiner;L. Parès;P. Petit;F. Snik;G. van Harten
UVMag联合体在其M4电话会议上向欧空局提出了空间使命项目Arago。Arago致力于研究恒星和行星的动态3D环境。这一空间使命将配备一台工作波长为119至888纳米的高分辨率分光偏振计。整个仪器的初步光学设计已经准备好，并在这里提出。设计包括望远镜、仪器本身和聚焦光学系统。不仅考虑到科学要求，而且考虑到适合M级使命的成本和尺寸限制，该望远镜有一个直径为1.3米的主镜，是一个经典的卡塞格伦型望远镜，可以无偏振聚焦。旋光仪放在卡塞格伦焦点上。这是使命的关键要素，也是设计中最具挑战性的要素。主要的挑战在于仪器提供的巨大光谱范围;旋光仪必须以高精度提供从FUV（119 nm）到NIR（888 nm）的全斯托克斯矢量。旋光模块之后是一个高分辨率阶梯光谱仪，在可见光范围内达到35000的分辨率，在紫外线范围内达到25000。这两个通道在中阶梯光栅之后被分离，从而允许用于UV和可见光范围的特定交叉色散和聚焦光学器件。考虑到大视场和高数值孔径，紫外和可见光通道的聚焦光学系统是一个三反射镜天文（TMA）望远镜，需要将各种波长和许多阶次聚焦到探测器上。
Abstract The UVMag consortium proposed the space mission project Arago to ESA at its M4 call. Arago is dedicated to the study of the dynamic 3D environment of stars and planets. This space mission will be equipped with a high-resolution spectropolarimeter working from 119 to 888 nm. A preliminary optical design of the whole instrument has been prepared and is presented here. The design consists of the telescope, the instrument itself, and the focusing optics. Considering not only the scientific requirements, but also the cost and size constraints to fit an M-size mission, the telescope has a 1.3 m diameter primary mirror and is a classical Cassegrain-type telescope that allows a polarization-free focus. The polarimeter is placed at this Cassegrain focus. This is the key element of the mission and the most challenging one to be designed. The main challenge lies in the huge spectral range offered by the instrument; the polarimeter has to deliver the full Stokes vector with a high precision from the FUV (119 nm) to the NIR (888 nm). The polarimeter module is then followed by a high-resolution echelle-spectrometer achieving a resolution of 35000 in the visible range and 25000 in the UV. The two channels are separated after the echelle grating, allowing specific cross-dispersion and focusing optics for the UV and the visible ranges. Considering the large field of view and the high numerical aperture, the focusing optics for both the UV and the visible channels is a Three-Mirror-Anastigmatic (TMA) telescope, needed to focus the various wavelengths and many orders onto the detectors.