scholarly journals Vibration measurements of high-heat-load monochromators for DESY PETRA III extension

2015 ◽  
Vol 22 (4) ◽  
pp. 879-885 ◽  
Author(s):  
Paw Kristiansen ◽  
Jan Horbach ◽  
Ralph Döhrmann ◽  
Joachim Heuer
Keyword(s):  
Measurement Techniques ◽  
High Heat ◽  
Direct Drive ◽  
Double Crystal ◽  
Relative Pitch ◽  
Double Crystal Monochromator ◽  
Synchrotron Beam ◽  
High Heat Load ◽  
Low Emittance

The requirement for vibrational stability of beamline optics continues to evolve rapidly to comply with the demands created by the improved brilliance of the third-generation low-emittance storage rings around the world. The challenge is to quantify the performance of the instrument before it is installed at the beamline. In this article, measurement techniques are presented that directly and accurately measure (i) the relative vibration between the two crystals of a double-crystal monochromator (DCM) and (ii) the absolute vibration of the second-crystal cage of a DCM. Excluding a synchrotron beam, the measurements are conducted underin situconditions, connected to a liquid-nitrogen cryocooler. The investigated DCM utilizes a direct-drive (no gearing) goniometer for the Bragg rotation. The main causes of the DCM vibration are found to be the servoing of the direct-drive goniometer and the flexibility in the crystal cage motion stages. It is found that the investigated DCM can offer relative pitch vibration down to 48 nrad RMS (capacitive sensors, 0–5 kHz bandwidth) and absolute pitch vibration down to 82 nrad RMS (laser interferometer, 0–50 kHz bandwidth), with the Bragg axis brake engaged.

In situ surface monitoring system for synchrotron mirrors under high heat load

1997 ◽  
Vol 36 (22) ◽  
pp. 5546 ◽  
Author(s):  
Peter H. Mui ◽  
George Srajer ◽  
Dennis M. Mills
Keyword(s):  
Monitoring System ◽  
Heat Load ◽  
High Heat ◽  
High Heat Load ◽  
Surface Monitoring

Augmentation of the step-by-step Energy-Scanning EXAFS beamline BL-09 to continuous-scan EXAFS mode at INDUS-2 SRS

2016 ◽  
Vol 23 (6) ◽  
pp. 1518-1525 ◽  
Author(s):  
Ashwini Kumar Poswal ◽  
Ankur Agrawal ◽  
Himanshu Kumar Poswal ◽  
Dibyendu Bhattacharyya ◽  
Shambhu Nath Jha ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Energy Calibration ◽  
Acquisition Time ◽  
High Signal ◽  
Signal To Noise ◽  
Double Crystal ◽  
Time Resolved ◽  
Synchrotron Source ◽  
Double Crystal Monochromator

An innovative scheme to carry out continuous-scan X-ray absorption spectroscopy (XAS) measurements similar to quick-EXAFS mode at the Energy-Scanning EXAFS beamline BL-09 at INDUS-2 synchrotron source (Indore, India), which is generally operated in step-by-step scanning mode, is presented. The continuous XAS mode has been implemented by adopting a continuous-scan scheme of the double-crystal monochromator and on-the-fly measurement of incident and transmitted intensities. This enabled a high signal-to-noise ratio to be maintained and the acquisition time was reduced to a few seconds from tens of minutes or hours. The quality of the spectra (signal-to-noise level, resolution and energy calibration) was checked by measuring and analysing XAS spectra of standard metal foils. To demonstrate the energy range covered in a single scan, a continuous-mode XAS spectrum of copper nickel alloy covering both Cu and NiK-edges was recorded. The implementation of continuous-scan XAS mode at BL-09 would expand the use of this beamline inin situtime-resolved XAS studies of various important systems of current technological importance. The feasibility of employing this mode of measurement for time-resolved probing of reaction kinetics has been demonstrated byin situXAS measurement on the growth of Ag nanoparticles from a solution phase.

Advantages of in-situ LTP distortion profile test on high heat load mirrors and applications

1996 ◽  
Author(s):  
Shinan Qian ◽  
Werner H. Jark ◽  
Giovanni Sostero ◽  
Alessandro Gambitta ◽  
Fabio Mazzolini ◽  
...  
Keyword(s):  
Heat Load ◽  
High Heat ◽  
High Heat Load

Fabrication and Evaluation of B4C/Cu FGM as Plasma Facing Materials

2005 ◽  
Vol 475-479 ◽  
pp. 1475-1478 ◽  
Author(s):  
Zhang Jian Zhou ◽  
Chang Chun Ge
Keyword(s):  
Load Resistance ◽  
High Heat ◽  
Plasma Irradiation ◽  
Physical Sputtering ◽  
Heat Loading ◽  
Graded Material ◽  
High Heat Load ◽  
Plasma Facing Materials ◽  
Distribution Water

B4C is a promising candidate for using as plasma-facing material in fusion devices. In this paper, both B4C/Cu coating FGM (Funetionally graded material) and B4C/Cu bulk FGM containing a spectrum of 0-100% compositional distributions of B4C were fabricated by atmosphere plasma spray and ultra-high pressure consolidation respectively. The microstructure of B4C/Cu FGM showed good graded composition distribution. Water quenching and high heat loading experiments using an electron beam were carried out to evaluate the high heat load resistance of B4C/Cu FGMs. The in situ plasma irradiation in a Tokamak facility showed that the B4C/Cu bulk FGM has higher physical sputtering performance than that of B4C/Cu coating FGM.

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