介绍了一种用于测量软X线的掠入射平场谱仪,依据变栅距刻线光栅的光路函数,计算了曲率半径为5649mm的光栅各点的间距,并推导和计算了入射光源为点光源时在聚焦平面上形成的聚焦点的分布,验证了先前文献中给出的结论.进一步计算了当改变入射距离为155mim时所形成的像散,理论上验证了缩短入射距离后谱仪的可用性.
A grazing incidence flat field spectrometer for the use of measurement of the soft X-rays was introduced. Based on the aberration-corrected concave gratings light path function,the space of the aberration-corrected concave gratings with the curvature radius of 5 649 mm was calculated. The focal point of distribution on the flat field when the incident light source was the point light source was deduced and calculated. The previous literature's conclusion was validated. The astigmatism when the incidence distance change to 155mm was calculated. It is proved that the 155 mm grazing incidence flat field spectrometer is available.