Photoelectron shield for the first mirror of a soft X-ray beamline

2021 ◽  
Vol 28 (1) ◽  
pp. 86-90
Author(s):  
Daisuke Wakabayashi ◽  
Hirokazu Tanaka ◽  
Akio Toyoshima ◽  
Shohei Yamashita ◽  
Yasuo Takeichi
Keyword(s):  
Heat Generation ◽  
Heat Load ◽  
Vacuum Chamber ◽  
Light Emission ◽  
High Heat ◽  
Total Electron Yield ◽  
Total Electron ◽  
X Ray ◽  
Chamber Temperature ◽  
High Heat Load

At a soft X-ray beamline with an undulator source, significant heat generation at the first-mirror chamber and light emission at the viewport were found, which can be explained by photoelectrons from the mirror. The chamber temperature increases up to approximately 50°C over a period of several hours. A photoelectron shield consisting of thin copper plates not only prevents the heat generation and light emission but also improves the pressure of the vacuum chamber, if a voltage of a few tens of V is applied to the shield. The total electron yield of the shield reached as much as 58 mA under high heat-load conditions, indicating the emission of numerous photoelectrons from the first mirror. Heat-balance analyses suggest that approximately 30% or more of the heat load on the first mirror is transferred to the surroundings.

Diamond channel-cut crystals for high-heat-load beam-multiplexing narrow-band X-ray monochromators

2021 ◽  
Vol 28 (6) ◽  
Author(s):  
Yuri Shvyd'ko ◽  
Sergey Terentyev ◽  
Vladimir Blank ◽  
Tomasz Kolodziej
Keyword(s):  
Heat Load ◽  
Narrow Band ◽  
Bragg Reflection ◽  
High Heat ◽  
High Repetition Rate ◽  
X Rays ◽  
Ray Optics ◽  
X Ray ◽  
Load Beam ◽  
High Heat Load

Next-generation high-brilliance X-ray photon sources call for new X-ray optics. Here we demonstrate the possibility of using monolithic diamond channel-cut crystals as high-heat-load beam-multiplexing narrow-band mechanically stable X-ray monochromators with high-power X-ray beams at cutting-edge high-repetition-rate X-ray free-electron laser (XFEL) facilities. The diamond channel-cut crystals fabricated and characterized in these studies are designed as two-bounce Bragg reflection monochromators directing 14.4 or 12.4 keV X-rays within a 15 meV bandwidth to 57Fe or 45Sc nuclear resonant scattering experiments, respectively. The crystal design allows out-of-band X-rays transmitted with minimal losses to alternative simultaneous experiments. Only ≲2% of the incident ∼100 W X-ray beam is absorbed in the 50 µm-thick first diamond crystal reflector, ensuring that the monochromator crystal is highly stable. Other X-ray optics applications of diamond channel-cut crystals are anticipated.

scholarly journals Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving X-ray crystal optics

2016 ◽  
Vol 23 (5) ◽  
pp. 1118-1123 ◽  
Author(s):  
Stanislav Stoupin ◽  
Sergey Antipov ◽  
James E. Butler ◽  
Alexander V. Kolyadin ◽  
Andrey Katrusha
Keyword(s):  
Surface Area ◽  
Heat Load ◽  
Crystal Surface ◽  
High Heat ◽  
Peak Position ◽  
Large Surface Area ◽  
Crystal Optics ◽  
Rocking Curve ◽  
X Ray ◽  
High Heat Load

Fabrication and results of high-resolution X-ray topography characterization of diamond single-crystal plates with large surface area (10 mm × 10 mm) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics are reported. The plates were fabricated by laser-cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature methods. The intrinsic crystal quality of a selected 3 mm × 7 mm crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. Wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking-curve topography. The variations of the rocking-curve width and peak position measured with a spatial resolution of 13 µm × 13 µm over the selected region were found to be less than 1 µrad.

scholarly journals Contact-cooled U monochromators for high heat load x-ray beamlines

1996 ◽  
Author(s):  
Ali M. Khounsary ◽  
Wenbing Yun ◽  
Emil M. Trakhtenberg ◽  
Shenglan Xu ◽  
Lahsen Assoufid ◽  
...  
Keyword(s):  
Heat Load ◽  
High Heat ◽  
X Ray ◽  
High Heat Load
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