Soft Reflectometer

The reflectometer, enclosed within a 1.3 m³ vacuum vessel, is equipped with two interchangeable x-ray sources, one with an Al target and the other with a Cu target. The operational vacuum 1e-5 mbar is reached with a pump-down time of 4 hours; the ultimate pressure is 5e-8 mbar.

The versatile KB system delivers a high direct beam intensity with Zeiss optics, which provides a parallel beam 2.5 mm high and 0.5 mm wide for both sources. The KB optics system is optimized for Cu Kα Bragg reflection and Al Kα total external reflection, so the Al source requires the use of a flat multilayer monochromator. The source and collimating mirrors can be sealed off from the main vessel vacuum, such that the sources may be interchanged with practically no additional pump time.

A multi-sample holder situated on an x-y-z linear stage makes it straight forward to characterize many samples without breaking the vacuum.

The encoded theta and 2-theta goniometers provide the user with a wide range of scattering angles with a high resolution. For Al Kα, the range of scattering angles 2Θ extends from 0 to 35˚, whereas for the Cu Kα radiation, the 2Θ range extends from 0 to 20˚.

The 2D detector is optimized for the detection of low energy photons, providing the capability of 6 orders of magnitude detection for both sources within 10 s integration time. The detector’s active area is 26.6 mm wide and 6.7 mm high.

The vessel is equipped with four large viewports, which provide an excellent overview of the system during operation. The custom Al target source and collimating KB mirror setup are developed together with AXO DRESDEN GmbH.

Publications about and with this instrument.

Henriksen, P. L. et al. LEXR: A low-energy X-ray reflectometer for characterization of ATHENA mirror coatings. in Optics for EUV, X-Ray, and Gamma-Ray Astronomy IX vol. 11119 111191F (International Society for Optics and Photonics, 2019). https://doi.org/10.1117/12.2528144

Henriksen, P. L. et al. Qualification and performance of the Low-Energy X-ray Reflectometer (LEXR). in Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray vol. 11444 114444J (International Society for Optics and Photonics, 2020). https://doi.org/10.1117/12.2562242

Svendsen, S. et al. Performance and time stability of Ir/SiC X-ray mirror coatings for ATHENA. in Optics for EUV, X-Ray, and Gamma-Ray Astronomy IX vol. 11119 111190G (International Society for Optics and Photonics, 2019). https://doi.org/10.1117/12.2528664

Jafari, A. et al. X-ray reflectometry of a platinum coating as reference sample for the ATHENA coating development. in Optics for EUV, X-Ray, and Gamma-Ray Astronomy IX vol. 11119 111191K (International Society for Optics and Photonics, 2019). https://doi.org/10.1117/12.2527557