LAMOST高分辨率光谱仪研制

为了充分利用LAMOST望远镜,实现对银河系不同星族的分布与整体性研究,以及极端贫金属星元素丰度测定等科学目标,研制了LAMOST高分辨率光谱仪,光谱分辨率R≥30 000,光谱覆盖范围380～740 nm。在充分考虑台址因素与现有条件后,采用中继倍率0. 7倍的准白瞳设计方案,使用大芯径光纤、拼接大光栅、棱栅组合式横向色散器、缝前像切分器等措施来满足性能要求。进行了效率估算与杂散光分析,光谱仪本体效率峰值大于30%,杂散光照度占CCD总照度的2. 55%,信噪比为16. 01 d B。试运行阶段实测了太阳光谱,温度稳定性达到±0. 03℃,光谱仪效率峰值约为33. 5%,满足稳定、高效的运行要求。

Construction of a LAMOST high resolution spectrograph

In order to make full use of the LAMOST telescope, as well as to achieve scientific goals such as the distribution and integrity of different stellar populations in the galaxy or the measurement of elemental abundance in extremely metal-poor stars, a LAMOST high-resolution spectrometer was developed with a spectral resolution of R ≥ 30 000 and spectral coverage range of 380-740 nm. After fully considering the factors of the site and its existing conditions, a quasi-white pupil design scheme with a repeater magnification of 0.7×was applied, using a large-core fiber, a large-diameter tiled-grating, a prism-grating disperser, and an image slicer to meet the perfermence requirment. Efficiency estimation and stray light analysis were performed. The peak efficiency of the spectrograph was more than 30%, the stray light illumination accounted for 2.55% of the total CCD illumination and the signal-to-noise ratio was 16.01dB. The solar spectrum was measured during the trial run with a temperature stability of±0.03℃ and a peak efficiency of approximately 33.5%, thus meeting requirements for stable and efficient operation.