2018 Truman Fellow
Daniel Ruiz received his PhD in plasma physics from Princeton University in August 2017. Additionally, he has a MS degree in nuclear reactor physics from the Institut National des Sciences et Techniques Nucléaires in France and a BA degree in physics engineering from the Instituto Tecnológico de Monterrey in Mexico. During his PhD studies, Daniel’s research was mainly focused on developing a new systematic approach based on variational principles to describe wave dynamics. In particular, he extended and reformulated geometrical optics as a first-principle Lagrangian theory that correctly describes polarization effects, such as mode conversion and the polarization-driven bending of ray trajectories. During the same period, he received two fellowships: the National Defense Science and Engineering Graduate Fellowship and the Presidential Fellowship from Princeton. He is an author of 13 peer-reviewed publications and gave an invited talk at the 2016 APS Division of Plasma Physics Conference.
Daniel’s Truman Fellowship research will focus on developing a new theoretical model to better understand the basic physics of laser-plasma instabilities (LPI) processes relevant to the magnetized liner inertial fusion (MagLIF) experiment at Sandia. In recent years, the MagLIF platform has become one of nation’s leading experiments in inertial confinement fusion. In MagLIF, a pre-magnetized deuterium fuel is heated by a 2.5 KJ, 1 TW laser and is then magnetically imploded by a 19 MA, 100 ns rise-time current. This unique experimental platform has achieved extreme fusion-relevant plasma conditions hard to reproduce elsewhere. More excitingly, MagLIF still has room for improvement. Much work remains to be done to optimize the MagLIF laser-heating stage. Current experiments suggest that only a fraction of the laser energy is transferred to the fuel in MagLIF, while the rest of the energy is lost. The low-energy coupling is mainly due to the presence of LPI processes, for example laser scattering. The development of a general understanding of LPI processes and the eventual leveraging of that understanding to optimize the MagLIF preheat is of central importance to the entire MagLIF campaign.
In his Truman work, Daniel’s research will mainly focus on developing an advanced Lagrangian theory to better describe laser scattering processes, such as stimulated Raman scattering and stimulated Brillouin scattering. He plans to construct a model that incorporates fluid nonlinearities, trapped-particle effects, and wave-wave coupling. Working with Sandia experts, he hopes to implement his models in Sandia’s high energy density physics codes that are presently used to design experiments on Z. This simulation capability would be the first of its kind. Daniel is conducting his research with the “Radiation and ICF Target Design” group (1684). His mentor is Michael Glinsky, and his manager is Kyle Peterson. Daniel began his fellowship in October 2017.