The best of both worlds: automated CMP polishing of channel-cut monochromators

Conference · Thu Sep 03 04:00:00 EDT 2015

DOI:https://doi.org/10.1117/12.2196034· OSTI ID:1295769

Kasman, Elina; Erdmann, Mark; Stoupin, Stanislav

The use of a channel-cut monochromator is the most straightforward method to ensure that the two reflection surfaces maintain alignment between crystallographic planes without the need for complicated alignment mechanisms. Three basic characteristics that affect monochromator performance are: subsurface damage which contaminates spectral purity; surface roughness which reduces efficiency due to scattering; and surface figure error which imparts intensity structure and coherence distortion in the beam. Standard chemical-mechanical polishing processes and equipment are used when the diffracting surface is easily accessible, such as for single-bounce monochromators. Due to the inaccessibly of the surfaces inside a channel-cut monochromator for polishing, these optics are generally wet-etched for their final processing. This results in minimal subsurface damage, but very poor roughness and figure error. A new CMP channel polishing instrument design is presented which allows the internal diffracting surface quality of channel-cut crystals to approach that of conventional single-bounce monochromators

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: USDOE Office of Science - Office of Basic Energy Sciences
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1295769
• Country of Publication: United States
• Language: English

Related Subjects

CMP
channel-cut
coherence
polishing
rocking curve
subsurface damage
x-ray monochromator