LAMOST多目标光纤光谱仪的研制及试运行

LAMOST望远镜（郭守敬望远镜）配置了16台低分辨率多目标光纤光谱仪,一次曝光可同时获得4000个天体的光谱信息.LAMOST低分辨率光谱仪采用新型体位相全息光栅,双通道大视场施密特光学系统,准直光束口径200mm.每台光谱仪分红、蓝区两个通道,红蓝区各配置按工作波段优化的4K×4K科学级CCD芯片,CCD采用液氮制冷.光谱仪波长覆盖范围370～900nm,光谱分辨率R=1000～10000.研制完成后的16台光谱仪安装于国家天文台兴隆观测站LAMOST焦面楼光谱房内,这些光谱仪已经用于科学试观测并取得了一批科研成果.

Construction and commissioning of LAMOST low resolution spectrographs

There are 16 low resolution multi-objects fiber-fed spectrographs （LRS） for the LAMOST project.The spectrographs are of double-beam full Schmidt design by using volume phase holographic gratings.Each spectrograph will be accommodating 250 fibers of 320 micron in diameter which corresponds 3.3 arcsec.The 200 mm diameter collimated beam is split into two separate channels by a clichroic filter.The blue channel is optimized for 370–590 nm,and the red channel for 570–900 nm.Spectra are focused onto 4 K×4 K CCD using fast camera with focal ratio of 1.25.The spectrum resolution is 1000 for low resolution mode.Resolution of 5000 is available by automatic switching to different gratings and by changing camera working angles.The resolution could be doubled by restricting the width of a slit to half the size of fiber diameter.These spectrographs are installed under focal plane of LAMOST at Xinglong observatory.Some of the results obtained during commissioning period are reported.