基于同步辐射软X射线能区的Al和Fe薄膜光吸收截面的初步研究

利用北京同步辐射装置(BSRF)?3W1B光束线产生的单色软X射线分别测定了Al和Fe薄膜在L2?,3吸收边附近的光吸收截面.测量值与理论值比较在远离吸收边时偏差较小,并逐渐趋于一致,在吸收边附近有较大偏差,这主要归因于理论计算所采用的独立电子近似方法在吸收边附近是无效的.测量结果与若干文献中的实验结果也进行了对比.虽然由于光束线分辨率和高次谐波的影响,实验结果和理论结果在实验能区有一定的偏差,但测量结果说明用薄膜透过率测定金属薄膜光吸收截面的方法是可行的.

Determination of the Photoabsorption Cross-Sections of Al and Fe Films in the Soft X-Ray Region Using Synchrotron Radiation

Photoabsorption cross sections at the Al and Fe L 2,3 edges on thin films have been measured at the Beijing Synchrotron Radiation Facility (BSRF) using monochromatic soft X-ray radiation. The measured Fe and Al cross sections are in good agreement with theoretical predictions for energy below the edge, while a poor agreement is observed near the edge region probably because the independent atom approximation is not suitable for photon energy near the absorption edge. Experimental data have been also compared with previous data available in the literature. This work demonstrates that cross section determinations of thin films of low Z atoms in the transmission mode are difficult but are feasible and can be substantially improved using synchrotron radiation.