Wavefront preserving and high efficiency diamond grating beam splitter for x-ray free electron laser
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2020-02-28 |
| Journal | Optics Express |
| Authors | Kenan Li, Yanwei Liu, Matthew Seaberg, Matthieu Chollet, Thomas WeiĆ |
| Institutions | SLAC National Accelerator Laboratory, Linac Coherent Light Source |
| Citations | 24 |
Abstract
Section titled āAbstractāX-ray free electron lasers (XFELs) provide femtosecond high-power x-ray beams with high spatial coherence, resulting in numerous influential discoveries. Diffractive optics allow for the easy manipulation and measurement of an x-ray beamās wavefront and enable the realization of complex designed properties and specifications. For example, phase gratings can be used as x-ray beam splitters to enable beam sharing by multiple end stations or in-situ beam monitoring, including spectrum and wavefront measurements. Wavefront preservation and high efficiency and survivability under high power are requirements for such beam splitters. Diamond is the most suitable choice for phase grating fabrication, due to its high thermal conductivity that enables it to survive high average power XFEL beams. We have fabricated a large area (2Ć2 mm 2 ) high aspect ratio (13:1) diamond grating on a diamond plate. Testing was performed at 9.5 keV and resulted in a high splitting efficiency (30%). Tunable efficiency was obtained via tilting the grating with respect to the x-ray beam. Wavefront fidelity of the split beams were measured to less than Ī» /100 using a Talbot wavefront sensor.