Time resolved X-ray diffraction using the FIDDLE diagnostic at NIF: Preliminary assessment of diffraction precision

Conference · Thu May 16 04:00:00 EDT 2024

OSTI ID:2584638

Vennari, C. E. ^[1]; Palmer, N. E. ^[1]; Nyholm, P. R. ^[1]; Bhandakar, N. S. ^[1]; Nagel, S. R. ^[1]; Petre, R. B. ^[1]; Stan, C. V. ^[1]; Eggert, J. H. ^[1]; Bradley, D. K. ^[1]; Ping, Y. ^[1]; Thomas, A. ^[1]; Swift, D. C. ^[1]; Carpenter, A. C. ^[1]; MacKinnon, A. J. ^[1]; Benedetti, L. R. ^[1]

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1. Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

The Flexible Imaging Diffraction Diagnostic for Laser Experiments (FIDDLE) is a new diagnostic at the National Ignition Facility (NIF) designed to observe in situ solid-solid phase changes at high pressures using time resolved X-ray diffraction. FIDDLE currently incorporates five Icarus Ultrafast X-ray Imager sensors that take 2 ns snapshots and can be tuned to collect X-rays for tens of ns. The platform utilizes the laser power at NIF for both the laser drive and the generation of 10 keV X-rays for ~10 ns using a Ge backlighter foil. We aim to use FIDDLE to observe diffraction at different times during compression to probe the kinetics of phase changes. Pb undergoes two solid-solid phase transitions during ramp compression: from FCC to HCP and HCP to BCC. Results will be reported on some of the first shots using the FIDDLE diagnostic at NIF on ramp compressed Pb to a peak pressure of ~110 GPa and a single undriven CeO2 calibration shot. A discussion of the uncertainties in the observed diffraction is included.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-07NA27344
• OSTI ID: 2584638
• Report Number(s): LLNL-CONF-864496; IM #: 1098211
• Country of Publication: United States
• Language: English