MEDSI2018 - List of Authors (Wang, H.)

Paper	Title	Page
TUPH39	The Design of LCLS-II Photon Beam Containment System	133
	H. Wang, Y. Feng, S. Forcat Oller, J. Krzywiński, E. Ortiz, M. Rowen SLAC, Menlo Park, California, USA
	LCLS-II will produce very powerful photon beams. Unlike conventional synchrotrons, the LCLS-II beam containment components withstand not only the high average beam power and power density, but also the instantaneous thermal shocks from pulsed FEL beam, which can reach ~9mJ/pulse. With beam repetition rate up to 1MHz, regular metal based beam collimators and absorbers will no longer work, because of the likelihood of fatigue failure. And because of the poor thermal conductivity, the old LCLS B4C based absorber would need very shallow glancing angle and take valuable beamline space. Hence, a low-Z and high thermal conductivity CVD diamond based photon beam collimator and absorber systems have been developed in LCSL-II. The initial damage tests using LCLS FEL beam provided positive results that graphite coated CVD diamond can endure per pulse dose level to ~0.5eV/atom. For the beamline and personnel safety, in addition to the passive CVD diamond collimators and absorbers, newly developed photon diode beam mis-steer detection systems and conventional SLAC pressurized burnt-through monitors have been also introduced in the photon beamline system design.
	Poster TUPH39 [1.251 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-TUPH39
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPH11	LCLS-II FEL Photon Collimators Design	358
	S. Forcat Oller, Y. Feng, J. Krzywiński, E. Ortiz, M. Rowen, H. Wang SLAC, Menlo Park, California, USA
	The unique capabilities of LCLS, the world's first hard X-ray FEL, have had significant impact on advancing our understanding across a broad range of science. LCLS-II, a major upgrade of LCLS, is being developed as a high-repetition rate X-ray laser with two simultaneously operating FELs. It features a 4 GeV continuous wave superconducting Linac capable of producing ultrafast X-ray laser pulses at a repetition rate up to 1 MHz and energy range from 0.25 to 5 keV. The LCLS-II upgrade is an enormous engineering challenge not only on the accelerator side but also for safety, machine protection devices and diagnostic units. A major part of the beam containment is covered by the FEL beam collimators. The current collimator design is no longer suitable for the high power densities of the upcoming LCLS-II beam. Therefore, a complete new design has been conceived to satisfy this new constrains. Moreover, a special FEL miss-steering detection system based on a photo diodes array has been designed as an integral part of the photon collimator as additional safety feature. This poster describes the new LCLS-II FEL Collimators, their mechanical design and challenges encountered.
	Poster THPH11 [1.164 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-THPH11
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

The Design of LCLS-II Photon Beam Containment System

133

H. Wang, Y. Feng, S. Forcat Oller, J. Krzywiński, E. Ortiz, M. Rowen
SLAC, Menlo Park, California, USA

LCLS-II will produce very powerful photon beams. Unlike conventional synchrotrons, the LCLS-II beam containment components withstand not only the high average beam power and power density, but also the instantaneous thermal shocks from pulsed FEL beam, which can reach ~9mJ/pulse. With beam repetition rate up to 1MHz, regular metal based beam collimators and absorbers will no longer work, because of the likelihood of fatigue failure. And because of the poor thermal conductivity, the old LCLS B4C based absorber would need very shallow glancing angle and take valuable beamline space. Hence, a low-Z and high thermal conductivity CVD diamond based photon beam collimator and absorber systems have been developed in LCSL-II. The initial damage tests using LCLS FEL beam provided positive results that graphite coated CVD diamond can endure per pulse dose level to ~0.5eV/atom. For the beamline and personnel safety, in addition to the passive CVD diamond collimators and absorbers, newly developed photon diode beam mis-steer detection systems and conventional SLAC pressurized burnt-through monitors have been also introduced in the photon beamline system design.

Poster TUPH39 [1.251 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-TUPH39

Export •

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

THPH11

LCLS-II FEL Photon Collimators Design

358

S. Forcat Oller, Y. Feng, J. Krzywiński, E. Ortiz, M. Rowen, H. Wang
SLAC, Menlo Park, California, USA

The unique capabilities of LCLS, the world's first hard X-ray FEL, have had significant impact on advancing our understanding across a broad range of science. LCLS-II, a major upgrade of LCLS, is being developed as a high-repetition rate X-ray laser with two simultaneously operating FELs. It features a 4 GeV continuous wave superconducting Linac capable of producing ultrafast X-ray laser pulses at a repetition rate up to 1 MHz and energy range from 0.25 to 5 keV. The LCLS-II upgrade is an enormous engineering challenge not only on the accelerator side but also for safety, machine protection devices and diagnostic units. A major part of the beam containment is covered by the FEL beam collimators. The current collimator design is no longer suitable for the high power densities of the upcoming LCLS-II beam. Therefore, a complete new design has been conceived to satisfy this new constrains. Moreover, a special FEL miss-steering detection system based on a photo diodes array has been designed as an integral part of the photon collimator as additional safety feature. This poster describes the new LCLS-II FEL Collimators, their mechanical design and challenges encountered.

Poster THPH11 [1.164 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-THPH11

Export •

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