Technical Seminar with Debbie Callahan

Abstract: Using a laser to produce energy from fusion has been a grand challenge since shortly after the laser was invented. Historic advances in inertial fusion have been made in the past few years on the National Ignition Facility (NIF) laser. First was a "burning plasma" - where the plasma heating by fusion alpha particle deposition became the dominant source of heating. Shortly after, the first experiment to achieve ignition, defined by the Lawson criterion, occurred. This experiment demonstrated the first plasma where alpha heating dominated over all loss mechanisms, producing strong heating of the plasma, and fusion "gain" (energy out divided by laser energy in) of 0.72. Lastly, fusion gain greater than 1 was achieved - fusion energy out more than 1.5x the laser energy put into the target. 

The next grand challenge is to take the results from NIF to build a fusion power plant. For a power plant, target gain of ~ 100 is needed and the design needs to be robust and reliable.
In addition, targets need to be produced and fielded at high repetition rate ~10 z) but with low cost and the laser needs to be efficient. Finally, a reactor chamber needs to be able to capture the fusion neutrons to produce electricity as well as breeding tritium fuel for future targets. In this talk, we will discuss path to ignition on NIF, lesson's learned from NIF, and how we will use those to design and build a fusion pilot plant.

Bio: Debra (Debbie) Callahan is Chief Strategy Officer at Focused Energy Inc., which she joined after 35 years at Lawrence Livermore National Laboratory as a physicist and associate division leader for HED-ICF target design. She was part of the scientific leadership of the team that recently achieved ignition on the National Ignition Facility (NIF) Laser. Dr Callahan is a Fellow of the American Physical Society and a co-recipient of the Dawson Award for Excellence in Plasma Physics in 2012 and 2022. She was recognized in 2022 by Fusion Power Associates for "her decades of leadership and outstanding contributions to the design of hohlraum targets for implosion experiments on NIF." She was awarded the Ronald Davidson Prize by the American Institute of Physics (2023) and the E. Gail de Planque Medal (2023) by the American Nuclear Society for her contributions to fusion and nuclear science.