REMINISCE: refurbishment of mirrors to increase sustainability at light sources

Contamination or damage to X-ray optics is becoming increasingly problematic for beamlines at 3rd and 4th generation storage-rings and FEL sources. Carbon contamination, induced by ultra-intense photon-beams, can cause a major loss in flux, focusing power, and specific absorptions which are detrimental to spectroscopy. For new light sources, with higher coherence, intensity, and repetition rates, contamination and accumulated damage will occur more rapidly. Replacing damaged optics is a time-consuming, risky, and expensive task. Production times are typically >6 months, and sometimes exceed 1 year. Costs per optic are typically tens of thousands of Euro, and can exceed 100k Euro. If several optics need to be replaced on a beamline, the overall cost can be hundreds of thousands of Euros. It is not sustainable or cost effective to replace optics on a yearly basis. Most facilities have independently investigated optical contamination over many years, but coordinated action is now required before the problem gets out of control. These issues motivate two-fold action: find practical methods to slow down the rate of contamination and damage; and develop protocols to safely remove contamination and return the optic to a pristine condition. High-quality metrology and surface science techniques are required to quantify the topography and chemical nature of the contamination, and assess the effectiveness of methods to reduce or remove it. To achieve these challenging goals requires a community effort. We propose an extensive collaboration, including experts from a range of scientific disciplines at various synchrotron and XFEL labs. X-ray optic community projects have recently delivered improvements in the quality X-ray mirrors via enhanced optical metrology. It is hoped that a concerted group effort will deliver similar major advancements, thereby helping to provide beamlines with cleaner, better-performing, X-ray optics.