Analysis of a New Method for Determining Optical Constants in the Soft X-ray Region

In this paper, a new method for measuring optical constants using transmission gratings is presented and analysed. The method, based on utilizing the properties of ultra-thin transmission diffraction gratings, is independent of the absolute intensity of the radiation source, the most critical part of the experiment being the accurate measurement and control of the diffraction grating parameters. By way of example, this paper relates the use of the new method to gold in the soft X-ray regime. By extension, it is shown that the same technique may be used on other materials, as long as they may be shaped into similar grating structures, and as long as they fulfil certain other criteria, outlined in the main body of this paper.