National Synchrotron Light Source Seminar

There are several next-generation synchrotron and free-electron laser (FEL) x-ray facilities currently under construction around the world. The unprecedented brightness, coherence, and resolution properties of these sources will enable tremendous advances in the fields of biology, physics, and materials sciences. This presentation will discuss the development of reflective optics for the x-ray offset mirror systems of the Linac Coherent Light Source (LCLS), a 0.15−1.5 nm FEL currently being installed at the Stanford Linear Accelerator Center by a multi-institution consortium. The unique properties of the LCLS FEL beam translate to strict limits in terms of thermal stability and materials choice, thus leading to an x-ray mirror design consisting of a reflective coating deposited on a silicon substrate. Furthermore, the physics requirements for these mirrors result in stringent surface figure and finish specifications that challenge the state-of-the-art in x-ray optics manufacturing and metrology capabilities. Keeping in mind all aforementioned requirements, candidate silicon substrates have been evaluated using full-aperture interferometry, phase-measuring microscopy and atomic force microscopy. The experimental optimization of the reflective coating and the expected performance of the LCLS x-ray mirror system will also be discussed.