利用平晶谱仪测量谱线波长的新方法

为了满足激光等离子体X射线波长测量的需要,在辅助光阑法的基础上,从理论上提出了一种用平面晶体谱仪确定波长的新方法.发展了改进的辅助光阑法来确定晶体面与记录面的交线到第一条辅助光阑的距离,并且利用某一条谱线的曲率得到记录面与晶体表面的夹角.这两个参量在一般的辅助光阑法中需借用参考谱线得到,而采用新的方法可在不使用任何参考谱线的情况下得到所有光谱线的波长.实际使用中通过增大光阑间的间距,根据不同的波长范围调节晶体与记录面的相对位置,可使波长的测量精度达1×10-3nm.

Novel Method of the Wavelength Determination of Spectral Lines with Planar Crystal Spectrometer

For the need of X-ray wavelength determination of laser plasma, based on the auxiliary diaphragm method, a novel method was presented for the wavelength determination of the X-ray spectral lines measured with planar crystal spectrometer in theory. We develop an improved method to determine the distance from the crossing line of crystal and recording plane to the first auxiliary diaphragm, and curvature of spectral line is used to determine the angle between crystal and recording plane. In normal auxiliary diaphragm method, reference line is used to determine the two parameters. However, we can obtain wavelengths for all recording spectral lines without any reference lines by using this method. In practical use, the precision of wavelength determination can achieve 1×10-3 nm by increasing the distance between two diaphragms and adjusting the relative position between crystal and recording plane.