NAPAC2019 - List of Authors (Zhou, G.)

Paper	Title	Page
TUPLH09	Thermal Effects on Bragg Diffraction of XFEL Optics	506
SUPLH05	use link to see paper's listing under its alternate paper code
	Z. Qu, J. Wu, G. Zhou SLAC, Menlo Park, California, USA Y. Ma, Z. Qu UC Merced, Merced, California, USA B. Yang Western Digital, Milpitas, California, USA
	Funding: The US Department of Energy (DOE) (DE-AC02-76SF00515); The US DOE Office of Science Early Career Research Program grant (FWP-2013-SLAC-100164). Crystal optical devices are widely used in X-ray free electron laser (XFEL) systems, monochromators, beam splitters, high-reflectance backscattering mirrors, lenses, phase plates, diffraction gratings, and spectrometers. The absorption of X-ray in these optical devices can cause increase of temperature and consequent thermal deformation, which can dynamic change in optic output. In self-seeding XFEL, the thermal deformation and strain in monochromator could cause significant seed quality degradation: central energy shift, band broadening and reduction in seed power. To quantitatively estimate the impact of thermomechanical effects on seed quality, we conduct thermomechanical simulations combined with diffraction to evaluate the seed quality with residual temperature field in a pump-probe manner. With our results, we show that a critical repetition rate could be determined, once the criteria for deviation of the seed quality are selected. This tool shows great potential for the design of XFEL optics for stable operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH09
About •	paper received ※ 28 August 2019 paper accepted ※ 13 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPLE13	Analytical Thermal Analysis of Thin Diamond in High-Intensity High-Repetition-Rate Application	587
SUPLO09	use link to see paper's listing under its alternate paper code
	Y. Hong, B. Yang University of Texas at Arlington, Arlington, USA J. Wu, G. Zhou SLAC, Menlo Park, California, USA
	Thin diamond plates are used in monochromator for X-ray Free-Electron Laser self-seeding scheme. To function properly, they must endure high-intensity and high-repetition-rate laser pulses without crossing thresholds set by various adverse effects, such as thermal strain-induced diffraction distortion and graphitization. In this work, a theoretical model is developed, and an analytical solution is derived to elucidate potential thermal runaway under edge cooling condition. It is shown that the crystal edge cooling can effectively mitigate the issue to a certain extent. The analytical solution can be used as an efficient tool for XFEL operation parameter setup.
	Poster TUPLE13 [0.939 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLE13
About •	paper received ※ 27 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

TUPLH09

Thermal Effects on Bragg Diffraction of XFEL Optics

506

SUPLH05

use link to see paper's listing under its alternate paper code

Z. Qu, J. Wu, G. Zhou
SLAC, Menlo Park, California, USA
Y. Ma, Z. Qu
UC Merced, Merced, California, USA
B. Yang
Western Digital, Milpitas, California, USA

Funding: The US Department of Energy (DOE) (DE-AC02-76SF00515); The US DOE Office of Science Early Career Research Program grant (FWP-2013-SLAC-100164).
Crystal optical devices are widely used in X-ray free electron laser (XFEL) systems, monochromators, beam splitters, high-reflectance backscattering mirrors, lenses, phase plates, diffraction gratings, and spectrometers. The absorption of X-ray in these optical devices can cause increase of temperature and consequent thermal deformation, which can dynamic change in optic output. In self-seeding XFEL, the thermal deformation and strain in monochromator could cause significant seed quality degradation: central energy shift, band broadening and reduction in seed power. To quantitatively estimate the impact of thermomechanical effects on seed quality, we conduct thermomechanical simulations combined with diffraction to evaluate the seed quality with residual temperature field in a pump-probe manner. With our results, we show that a critical repetition rate could be determined, once the criteria for deviation of the seed quality are selected. This tool shows great potential for the design of XFEL optics for stable operation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH09

About •

paper received ※ 28 August 2019 paper accepted ※ 13 September 2019 issue date ※ 08 October 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPLE13

Analytical Thermal Analysis of Thin Diamond in High-Intensity High-Repetition-Rate Application

587

SUPLO09

use link to see paper's listing under its alternate paper code

Y. Hong, B. Yang
University of Texas at Arlington, Arlington, USA
J. Wu, G. Zhou
SLAC, Menlo Park, California, USA

Thin diamond plates are used in monochromator for X-ray Free-Electron Laser self-seeding scheme. To function properly, they must endure high-intensity and high-repetition-rate laser pulses without crossing thresholds set by various adverse effects, such as thermal strain-induced diffraction distortion and graphitization. In this work, a theoretical model is developed, and an analytical solution is derived to elucidate potential thermal runaway under edge cooling condition. It is shown that the crystal edge cooling can effectively mitigate the issue to a certain extent. The analytical solution can be used as an efficient tool for XFEL operation parameter setup.

Poster TUPLE13 [0.939 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLE13

About •

paper received ※ 27 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)