Das N C, Madden R P, Seyoum H M
Spectroscopy Division, Bhabha Atomic Research Center, Bombay2400 085, India.
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
J Res Natl Inst Stand Technol. 1998 Sep-Oct;103(5):483-495. doi: 10.6028/jres.103.029. Epub 1998 Oct 1.
A high resolution VUV spectroscopic facility has been in use for several years at SURF II, the Synchrotron Ultraviolet Radiation Facility at the National Institute of Standards and Technology in Gaithersburg, Maryland. At this facility, a combination of three cylindrical mirrors is utilized to focus the light originating in the storage ring onto the horizontal entrance slit of the spectrometer. The spectrometer uses a 6.65 m concave grating having a groove density of 4800 lines/mm in the off-plane Eagle mounting. In preparation for the installation of an array detector in the exit image plane, a ray tracing program has been formulated and spot diagrams have been constructed by plotting the coordinates of the points of intersection of the diffracted rays with the image plane, which is tangent to the Rowland circle. In creating the spot diagrams, we have considered both parallel and tilted configurations of the entrance slit with respect to the grating grooves. It is shown that the line widths of the spectral images can be reduced when the entrance slit is properly tilted. Finally, we have estimated the spectral widths of the images when they are recorded on an array detector placed tangent to the Rowland circle. We conclude that an image spectral width of 0.41 pm to 0.88 pm in first order can be achieved over the wavelength region of 40 nm to 120 nm.
位于马里兰州盖瑟斯堡的国家标准与技术研究所的同步加速器紫外辐射设施SURF II，一个高分辨率真空紫外光谱设备已经使用了数年。在该设施中，使用三个柱面镜的组合将源自存储环的光聚焦到光谱仪的水平入口狭缝上。光谱仪使用一个6.65米的凹面光栅，在离平面鹰式安装中，其刻线密度为4800线/毫米。为了在出射图像平面安装阵列探测器做准备，已经制定了一个光线追踪程序，并通过绘制衍射光线与与罗兰圆相切的图像平面的交点坐标来构建光斑图。在创建光斑图时，我们考虑了入口狭缝相对于光栅刻槽的平行和倾斜配置。结果表明，当入口狭缝适当倾斜时，光谱图像的线宽可以减小。最后，我们估计了将图像记录在与罗兰圆相切放置的阵列探测器上时的光谱宽度。我们得出结论，在40纳米至120纳米的波长范围内，一阶图像光谱宽度可以达到0.41皮米至0.88皮米。
