STE Highlights, August 2023

Marcelo Jaime (MPA-MAGLAB) has been appointed to the editorial board of Physical Review B. His three-year term began in May. As a board member, Jaime joins a diverse, international team of active, distinguished scientists selected by the journal editors to provide advice during the peer-review process.

Physical Review B is the world’s largest dedicated physics journal, publishing roughly 100 new papers each week, with authors and referees from over 130 countries. The most highly cited journal in condensed matter physics, Physical Review B is part of the Physical Review family of journals published by the American Physical Society (APS).

As a scientist at the National High Magnetic Field Laboratory-Pulsed Field Facility, Jaime has developed techniques to better understand emergent behavior of quantum materials by measuring their thermal and lattice properties in very high magnetic fields, both pulsed and continuous, at low temperatures. He joined the Lab in 1997 as a postdoctoral researcher, performing the first-ever specific heat measurement in pulsed magnetic fields up to 60 Tesla. Prior to joining the Lab, Jaime earned a doctoral degree in physics from Instituto Balseiro, in Bariloche, Argentina with a doctoral fellowship from CONICET — the national scientific and technical research council of Argentina — and completed a postdoctoral appointment at the University of Illinois Urbana-Champaign.

Jaime is a fellow of the APS and the American Association for the Advancement of Science. He is the recipient of the Tooru Atake Lectureship Award from Japan Society of Calorimetry and Thermal Analysis, the “Science above 100T” Team Distinguished Performance Award from Los Alamos National Laboratory and the James J. Christensen Memorial Award from Brigham Young University. He currently serves as past chair in the four-year chair line for the APS Topical Group on Magnetism and its Applications.

The Center for Integrated Nanotechnologies (CINT) Gateway facility at Los Alamos recently earned “My Green Lab” platinum-level certification. This endorsement is the second highest category achievable in the world-wide program recognized by the United Nations Race to Zero climate campaign as a key measure of progress toward a zero-carbon future. Considered the gold standard for lab sustainability best practices, the nonprofit certification program involves scientists in minimizing their environmental impacts and identifies waste-reduction opportunities so more is invested in science.

The CINT Gateway, a combination research and office building complex, features 11,000 square feet of lab space for materials synthesis, characterization, fabrication and advanced computation. CINT is a DOE Office of Science Nanoscale Science Research Center. Its researchers focus on providing the scientific basis for integrating nanoscale materials and enhancing materials performance.

CINT’s platinum-level efforts expands on sustainability practices underway when the facility earned My Green LANL certification in 2022. The program’s 2023 assessment noted that, in particular, CINT stood out for sustainable practices across a number of areas:

• Large equipment: The facility is dedicated to using shared printers; checking and maintaining high pressure lines or vacuum lines for leaks; turning off vacuum pumps when not in use; and powering down rooms or environmental spaces not in use.
• Waste management: The CINT Gateway takes advantage of the Lab’s recycling programs, and, when feasible, reuses disposable plastic and glass and minimizes single-use items.
• Resource management: The facility maintains an inventory of reagents, chemicals, laboratory supplies and equipment and shares equipment with colleagues rather than purchasing duplicates.
• Community: The facility communicates and engages with others about CINT’s sustainability goals and efforts; trains staff using common equipment or space on relevant sustainability best practices; and trains new hires and visiting researchers on lab sustainability best practices.

An experimental platform at the National Ignition Facility (NIF) uses colliding planar shocks to create warm dense matter with uniform conditions and enables high-precision equation of state measurements. The development of the platform furthers efforts to leverage programmatic work at the NIF, allowing universities and other researchers to access a large national resource to do cutting-edge science. The colliding planar shocks platform was described in Physics of Plasmas, work selected as an Editor’s Pick by that journal.

Accurate equation of state models are essential to understanding a material’s properties and for performing high-fidelity simulations. In the warm dense matter regime, equation of state models — models that account for the relationship between density, temperature and ionization in the regime — are required to predict the interior structure and evolution of astrophysical bodies and are critical in the design of inertial confinement fusion implosions. Yet such data is difficult to model in this regime due to its complexity. While high-quality experimental benchmarks are essential to guide models, little experimental data exists.

The result of a years-long effort, the colliding planar shock experimental platform was designed using a combination of several previously successful platforms at the NIF. The design of the X-ray Thomson scattering shielding was developed for X-ray scattering measurements on the National Ignition Facility’s gigabar platform. The physics package, laser drive and radiography setup use the fundamental design of the shock/shear platform developed at Los Alamos National Laboratory, with the core physics package and drive platform developed nearly a decade ago to study hydrodynamic instabilities in the high energy density regime relevant to inertial confinement fusion physics.

The colliding planar shocks/equations of state experiment is the latest to use a derivative of the shock/shear platform. In the experiment, the nominal beryllium tube was shortened and filled with a solid polystyrene cylinder to create quasi-steady-state and uniform condition of interest in the shocked solid polystyrene long enough to make the measurement. Los Alamos brings a unique capability to the project as the only Department of Energy laboratory that can supply machined beryllium parts. Beryllium is the only material strong enough to serve as a shock tube, yet transparent enough to allow scattered X-rays to be collected via Thomson scattering.

Comparing hydrodynamic simulations to X-ray radiography data from initial experiments studying hydrocarbons, the researchers demonstrated plasmas with uniform densities within plus or minus 25% of the average probed condition.

The work leverages Los Alamos expertise in high energy density science, inertial confinement fusion, target fabrication, and large-scale modeling of the platform using Laboratory supercomputers.

Funding and mission

The Los Alamos portion of the work was funded by the U.S. Department of Energy National Nuclear Security Administration’s Office of Experimental Science and the NIF Discovery Science Program. The research supports the Laboratory’s Global Security mission and its Nuclear and Particle Futures capability pillar.

Reference

“The colliding planar shocks platform to study warm dense matter at the National Ignition Facility,” Physics of Plasmas 30, 062701 (2023); DOI: 10.1063/5.0146624. Authors: M. J. MacDonald, T. Döppner, D. Kalantar, S. J. Ali, P. M. Celliers, R. Heredia, J. A. Gaffney, A. M. Saunders and R. Zacharias (Lawrence Livermore National Laboratory); C. A. Di Stefano, K. A. Flippo, E. C. Merritt, D. W. Schmidt and C. T. Wilson (Los Alamos National Laboratory); L. B. Fletcher and S. H. Glenzer (SLAC National Accelerator Laboratory); S. Vonhof (General Atomics); G. W. Collins (University of Rochester); D. O. Gericke (University of Warwick); D. Kraus (University of Rostock); R. W. Falcone (University of California, Berkeley).

Technical contact: Kirk Flippo (P-2)