2020 DPP symposium schedule

November 8 2020


6:00    Dr. Njema Frazier (video)

NNSA perspective on HEDP

6:20    Dr. Jim Van Dam (pdf and video)

OFES perspective on HEDP

6:40    Owen Mannion (pdf and video)

Applications of Neutron Spectroscopy in High-Energy-Density Science

Laboratory for Laser Energetics, U. of Rochester

In recent decades, many advancements in understanding the extreme high-energy-density (HED) plasma conditions [i.e., pressure >1 Mbar] created in the laboratory on the picosecond to nanosecond time scale were due to experimental insights realized with advanced diagnostics and experimental techniques. Innovations in x-ray, nuclear, particle, and gamma-ray diagnostic development are crucial for understanding HED plasmas. Neutron diagnostics are complementary to photon and charged-particle based diagnostics since neutrons can penetrate deep into HED plasma. In this talk, the neutron detectors and spectroscopic techniques that are currently being used at the Omega Laser Facility to study HED plasma science will be discussed. In particular, it will be shown how the fusion neutron energy spectrum emitted from a hot (>1-keV), dense (>10-g/cm3) plasma can be used to determine the velocity and ion temperature of the plasma, which are key parameters for the inertial confinement fusion (ICF) research field. Additionally, the spectral shape of neutron backscatter edges will be discussed and shown to provide insights into HED plasmas having temperatures above 100 eV, density above 100 g/cm3, and flow velocity above 105 cm/s. Extending the neutron spectroscopic techniques developed for the ICF research field to the broader field of HED physics research will be highlighted. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0003856.

 7:05    Dr. Arianna Gleason (pdf and video)

New Light on the Frontier Matter in Extreme Conditions

SLAC/Stanford University

The study of matter under extreme conditions is a highly interdisciplinary subject with broad applications to materials science, plasma physics, geophysics and astrophysics. Understanding the processes which dictate physical properties in warm dense plasmas and condensed matter, requires studies at the relevant length-scales (e.g., interatomic spacing) and time-scales (e.g., phonon period). Experiments performed at XFEL lightsources across the world, combined with dynamic compression, provide ever-improving spatial- and temporal-fidelity to push the frontier. This talk will cover a very broad range of conditions, intended to present an overview of important recent developments in how we generate extreme environments and then how we characterize and probe matter at extremes conditions– providing an atom-eye view of transformations and the fundamental physics dictating materials properties. Examples of case-studies closely related to Earth and planetary science relevant materials will be discussed.

 7:30 Prof. Alexey Arefiev (pdf and video)

Unlocking new physics regimes with high-power high-intensity lasers

UC San Diego

Astrophysical environments are known for extreme and exotic physics regimes -- whether it is the creation of matter and antimatter from light alone in a pulsar's magnetosphere, or the generation of extreme magnetic fields on a surface of a neutron star that exceed anything achievable with magnets by many orders of magnitude. High-power high-intensity multi-beam laser systems that are becoming operational around the world will provide us with unique experimental tools to probe some of these regimes. This talk will review several phenomena that can be studied with experimentally achievable laser intensities at multi-PW laser facilities. Some of these include generation of MT magnetic fields, emission of dense gamma-ray beams, and electron-positron pair creation from light alone.

 7:55 Dr. Stephanie Hansen (pdf and video)

Spectroscopy: from Atoms to Astrophysics

Sandia National Laboratories

Spectroscopy is a measurement technique that separates photons according to their energy, which can reveal the electronic structure of atoms and ions. Historically, spectroscopy played a key role in the development of quantum mechanics. Today, we use established atomic theory to help interpret signals from plasma sources that are far away (e.g. stars and accretion disks) or small and short-lived (e.g. inertial confinement fusion experiments), where spectroscopy can tell us about their composition, conditions, and relative motion. This talk will touch on several such applications, as well as new frontiers for atomic theory that are enabled by high-energy density experiments. Sandia National Laboratories is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. This work was supported by the Sandia LDRD program and the U.S. Department of Energy, Office of Science Early Career Research Program, Office of Fusion Energy Sciences under Grant No. FWP-14-017426

 8:20 Dr. Luis Chacón (pdf and video)

Recent progress and future directions in kinetic modeling of ICF implosions

 Los Alamos National Laboratory

The difficulty of rad-hydro simulations in capturing many experimental observables, including integrated metrics such as yield and bang time in many paradigmatic ICF capsule implosions has prompted the community to look into broader, higher fidelity physical models for such systems (e.g., the Vlasov-Fokker-Planck equation) [1]. However, these improved models are not incremental in sophistication, but disruptive, becoming higher dimensional (due to the need to describe phase space), strongly nonlinear, nonlocally coupled, and demanding entirely new numerical strategies to solving them on a computer. This numerical barrier has made their development and deployment for system-scale simulations of ICF implosions and other HED experiments very challenging, with only a few such tools currently available in the community. In this presentation, I will describe our progress in developing practical, efficient, and accurate kinetic simulation tools [2] and their application to multispecies plasma shocks [3] and ICF implosions [4]. I will also discuss recently started efforts at LANL to develop a kinetic simulation capability for hohlraum environments in multiple dimensions.

1. Rinderknecht et al., PPCF, 60 (6) 2018
2. Taitano et al., CPC 258 (2021); JCP 365 (2018); JCP 318 (2016); JCP 297 (2015)
3. Keenan et al., PoP 25 032103 (2018); Keenan et al., PRE 96 (2017)
4. Keenan et al., PoP 27 (2020); Taitano et al, PoP 25 056310 (2018)

 8:45    Adjourn