Johansson Crystals for X-Ray Diffractometry and Demanding Spectroscopy Applications

摘要

Johansson crystals have been known for many decades as x-ray optical elements with a high resolving power and small foci. However, in the past their use in applications requiring a small focus and a narrow band pass were limited by imperfections caused by the technologies applied to their manufacture. While high performance Johansson crystals might have been achieved in some research facilities, such crystals were not commercially available. R1T has developed a process for fabricating precision Johansson crystals. The fabrication maintains the crystal structure intact. The angular precision of the bending process of atomic planes and the reflecting crystal surface is better than four arc seconds. In this paper, we will present the basic aspects of the technology and the achievements with Silicon and Germanium crystals.