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SLAC Publication: SLAC-PUB-17285
SLAC Release Date: August 6, 2018
THE DESIGN OF LCLS-II PHOTON BEAM CONTAINMENT SYSTEM
Wang, Hengzi.
LCLS-II will produce very powerful and collimated FEL photon beams. Unlike conventional synchrotrons, the LCLS-II beam containment components withstand not only the high average beam power and/or power density, but also the instantaneous thermal shocks from the pulsed beam structure, which can potentially reach 9mJ/pulse. With a beam repetition rate up to 1MHz, regular metal based beam collimators and absorbers used in synchrotrons will no longer work, because of the likelihood of fatigue fail... Show Full Abstract
LCLS-II will produce very powerful and collimated FEL photon beams. Unlike conventional synchrotrons, the LCLS-II beam containment components withstand not only the high average beam power and/or power density, but also the instantaneous thermal shocks from the pulsed beam structure, which can potentially reach 9mJ/pulse. With a beam repetition rate up to 1MHz, regular metal based beam collimators and absorbers used in synchrotrons 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 LCSLII. 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 gas burn-through monitors have been also introduce d in the photon beam containment system design. Show Partial Abstract
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  • Interest Categories: Engineering, X-Ray Free Electron Laser