Displacement Cascade Dynamics: LCLS-II Materials Science

1. Displacement Cascade Dynamics: LCLS-II Materials Science Ben Larson, ORNL, USA; Tom Cowan, HZDR, Germany • Displacement Cascade Dynamics and Evolution – sub-picoseconds to microseconds • Dynamics of cascades on 100-femtosecond to few-picosecond time-scale • X-ray scattering measurement of cascade defect generation/recombination • Electronic/ionic energy partition (electron-phonon coupling) • Classical and first-principles molecular dynamics simulations • Cascade defect evolution and clustering on ~5-ps to µs • Residual defect cluster density, type, and size evolution • Advanced Monte Carlo simulation of defect evolution/clustering • Laser Generated Proton and Heavy-Ion Pulses – picoseconds to nanoseconds • 1- to 5-picosecond ion pulse-width, MeV-energy, “low-density” proton or high-Z ion pulses • Picosecond to microsecond range proton or high-Z ion pulse-widths to control dose rate • Pump-probe synchronization of laser-driven ion pulses with individual LCLS pulses • X-ray pulse parameters for cascade dynamics and evolution investigations • Pulse-width ~100-femtoseconds; Pulse power >1012ph./pulse; X-ray energy ~8-20 keV • Monochromatic (seeded) x-ray pulses; focusing from ~100-nanometers to ~ 300 microns • LCLS-II Infrastructure • PW-Class, 10s-to-100 Joule laser pulses to generate MeV range proton or High-Z ion pulses • Diffractometer, scattering chamber, sample translation/orientation, area detector