New model ultra-soft X-ray spectrometer for microanalysis

Abstract

The authors developed a new general-purpose analytical apparatus that includes a high-resolution ultra-soft X-ray spectrometer, which notably can be used to efficiently measure the ultra-soft X-ray spectrum over the 30–150 eV range. Over this energy range, the analysis of ultra-light elements, such as Li, can be performed, as well as the direct analysis of the chemical bonding state of any element. The motivation for the development of the apparatus was that there is currently no general-purpose apparatus for direct measurement over the ultra-soft X-ray energies of less than 100 eV. The recent developed system is made up of a commercial-base scanning Auger analyzer and the new spectrometer of ultra-soft X-rays. This spectrometer uses two types of flat field spherical varied line spacing gratings, the same focal curve for both grating, a poly-capillary at the input to aid in transmission and to decrease the limitations of the mounting geometry, and a backside-illumination type CCD camera for high sensitivity and high efficiency. This means that the system has no moving parts that can reduce the accuracy of the measurements; an important features. This system was used to measure Li Kα for the first time as a general-purpose apparatus. It was confirmed that the resolution of the measurement exceeded the predefined limits (100; E/ΔE). However, it was difficult to remove higher order interference lines.