穆森堡尔14.4keV波长绝对测量用复合X线迈克尔逊干涉仪的研制

元素Cu等的特征谱线因其波长相对稳定，不受温度、气压等环境条件的影响以及常被用于X线的衍射实验，被用来做X线区域的波长标准(CODATA)。但是由于这些谱线自身宽度的原因，测量精度达不到1x10-7。与此相反，完美单晶硅的晶格长度虽然受温度、气压等外界环境的影响，但其测量精度可以到好于2x10-8。为了解消这个拧巴的事情，在穆森堡尔效应被发现后，人们曾提出用14.4keV波长等做x线波长标准的建议，因为该波长的带宽只有几个neV。由于当时γ线源亮度很低，精密实验需要很长的时间，因此也很难获得较好的测量结果。利用同步辐射的核共振散射实验成功后，14.4keV波长的光源问题得以解决，测量该波长的时机亦日渐成熟。本申请提出了一个新X线迈氏干涉仪的设计方案，目标是能够通过平行移动调制X线干涉仪中的光路差，并且能观测到光路差变化时输出信号的强度调制，为将来绝对测量14.4keV波长奠定基础。

The wavelength standard in X-ray range is defined by CuKα1 and MoKα1 in CODATA. The characteristic X-ray lines of these elements are used in X-ray diffraction experiments, their wavelengths are stable, and are not affected by environmental conditions such as temperature and air pressure. However, the measurement accuracy of spectral lines is less than 1x10-7 due to the natural width of spectral lines. On the contrary, the lattice length of perfect silicon is affected by external environment such as temperature and air pressure, but its accuracy can be better than 2x10-8. .In order to solve this problem, after the Mössbauer effect was discovered, people proposed to use 14.4 keV line of 57Fe as the X-ray wavelength standard. However, due to the low brightness of the γ source at that time, the precision experiment required a long time, so it is difficult to achieve the high accuracy measurement in technology. After the success of synchrotron radiation nuclear resonance scattering experiment, the problem of a source of 14.4 keV photon has been solved. In this application, we proposed a new design scheme of a Michelson type X ray interferometer, where the difference of two optical paths can be generated by a parallel moving modulation. This X ray interferometer will be a starting platform for the absolute measurement of the 14.4 keV Mössbauer photon wavelength in the future.