Combining rotation and translation in a variable line space high-resolution soft-X-ray monochromator: Design requirements and performance evaluation of a novel grating mount

1994 ◽  
Vol 347 (1-3) ◽  
pp. 264-268 ◽  
Author(s):  
Mike V. Fisher ◽  
Norbert Steinhauser ◽  
Dave Eisert ◽  
Bill Winter ◽  
Bill Mason ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
High Resolution ◽  
X Ray ◽  
Variable Line ◽  
Design Requirements ◽  
And Performance ◽  
Line Space

X-ray monochromator combining high resolution with high intensity

2002 ◽  
Vol 35 (1) ◽  
pp. 41-48 ◽  
Author(s):  
M. Servidori
Keyword(s):  
High Resolution ◽  
High Intensity ◽  
Asymmetry Factor ◽  
Photon Flux ◽  
Wavelength Band ◽  
Germanium Crystal ◽  
X Ray ◽  
Band Pass ◽  
And Performance ◽  
Exit Beam

A two-germanium-crystal four-220-reflection (+ - - \,+) monochromator, combining high intensity with high resolution, is proposed in this work. The main characteristic is that only the first reflection is asymmetric. The asymmetry factor was chosen so as to allow mixing of asymmetric and symmetric reflections in a monolithic channel-cut crystal without the need for rotation of the two monolith components to correct for the different refraction-induced angular shifts of the reflection pair. It is demonstrated that the exit-beam divergence in the diffraction plane and the fractional wavelength band-pass are smaller by 40% than those of the widely used germanium 220 Bartels monochromator, while the photon flux collected from the source is larger by a factor of five. The optical features and performance of the monochromator are discussed and compared with those of other (+ - - \,+) monochromators reported in the literature.

scholarly journals AP-XPS beamline, a platform for operando science at Pohang Accelerator Laboratory

2020 ◽  
Vol 27 (2) ◽  
pp. 507-514
Author(s):  
Geonhwa Kim ◽  
Youngseok Yu ◽  
Hojoon Lim ◽  
Beomgyun Jeong ◽  
Jouhahn Lee ◽  
...  
Keyword(s):  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Experimental System ◽  
Photon Flux ◽  
Acceptance Angle ◽  
X Ray ◽  
Pohang Accelerator Laboratory ◽  
And Performance ◽  
X Ray Absorption

Beamline 8A (BL 8A) is an undulator-based soft X-ray beamline at Pohang Accelerator Laboratory. This beamline is aimed at high-resolution ambient-pressure X-ray photoelectron spectroscopy (AP-XPS), soft X-ray absorption spectroscopy (soft-XAS) and scanning photoemission microscopy (SPEM) experiments. BL 8A has two branches, 8A1 SPEM and 8A2 AP-XPS, that share a plane undulator, the first mirror (M1) and the monochromator. The photon beam is switched between the two branches by changing the refocusing mirrors after the monochromator. The acceptance angle of M1 is kept glancing at 1.2°, and Pt is coated onto the mirrors to achieve high reflectance, which ensures a wide photon energy range (100–2000 eV) with high resolution at a photon flux of ∼1013 photons s−1. In this article, the main properties and performance of the beamline are reported, together with selected experiments performed on the new beamline and experimental system.

Performance Evaluation of an MR-Compatible Rotating Anode X-Ray Tube

2013 ◽  
Author(s):  
Mihye Shin ◽  
Prasheel Lillaney ◽  
Waldo Hinshaw ◽  
Rebecca Fahrig
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Moments ◽  
X Ray ◽  
Close Proximity ◽  
Motor Design ◽  
Design Requirements ◽  
And Performance ◽  
The Magnetic Field ◽  
Lorentz Force Law

The key technical innovation needed for close proximity hybrid x-ray/MR (XMR) imaging systems is a new rotating anode x-ray tube motor that can operate in the presence of strong magnetic fields. In order for the new motor design to be optimized between conflicting design requirements, we implemented a numerical model for evaluating the dynamics of the motor. The model predicts the amount of produced torque, rotation speed, and time to accelerate based on the Lorentz force law; the motor is accelerated by the interaction between the magnetic moments of the motor wire loops and an external magnetic field. It also includes an empirical model of bearing friction and electromagnetic force from the magnetic field. Our proposed computational model is validated by experiments using several different magnitudes of external magnetic fields, which averagely shows an agreement within 0.5 % error during acceleration. We are using this model to improve the efficiency and performance of future iterations of the x-ray tube motor.

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