An Interview With Dr. Sam Cohen

An Interview With Dr. Sam Cohen

Guest Bio - Dr. Sam Cohen

For 44 years, Dr. Sam Cohen has worked as a physicist at Princeton University. He currently serves as director of the Plasma Science and Technology program at the Princeton Plasma Physics Laboratory. Since 1998, Sam has been performing research on plasma devices known as Field-Reversed Configurations (FRCs), studying their potential as power plants and rocket engines. In November of 2013, his small group announced that they had held an FRC stable for 300 milliseconds - a world record, by a large margin. Our interview covers a transition period in his career, from his time spent as a manager on the US ITER effort to his personal experiences rubbing shoulders with physics luminaries to the beautiful physics and practical aspects of field-reversed configurations. Dr. Cohen offers advice on how the US government could accelerate progress in fusion by re-invigorating research into small, clean fusion reactors, an activity now proceeding almost exclusively with venture capital support.

Seven Ways To Model Plasma

Seven Ways To Model Plasma

This post covers seven ways to model plasma: charged ideal gases, charged single fluid, two charged fluids, gyrokinetic, kinetic, everything and quantum.  The post was inspired by a recent paper trying to model plasma using Quantum Field Theory.  It opens with short histories of the charged ideal gas model and magnetohydrodynamics.  An example from magnetic mirrors is used to show flaws in the MHD model.  Next, the two-fluid model is explained based on differences between the ion and the electron.  After this, particle-in-cell is covered and how it fits with gyrokinetics and kinetics.  Gyrokinetics is shown to simplify ions’ corkscrewing motion.  Kinetics is shown as (BIC) blob-in-cell modeling.  Quantum and klimontovich (everything) models are covered at the end.

The VLAB Fusion Panel (11–7–2017)

The VLAB Fusion Panel (11–7–2017)

On Tuesday November 7th 2017 a fusion panel discussion was held on Stanford’s campus. The panel was organized by Virtual Labs, a non-for-profit organization in Silicon Valley. The goal of VLAB is connect entrepreneurs to technologists. Former members of the VLAB group have included managers at some of the valleys’ premier technology companies. The event was organized by Michelle Tsing, a lawyer and an entrepreneur. The panel was moderated by Dr. Rachel Slaybaugh a member of nuclear engineering department at Berkeley. The panel also included Dr. Michele Lebarge from General Fusion, Dr. Thomas McGuire from Lockheed Martin and Ray Rothrock, a former member of Venrock capital. It also included Dr. Matt Thompson from TA Technologies (Tri alpha rebranded, more on this later). I reached out to Michelle and she was gracious enough to share a 90 minute recording of the panel. You can watch the event through facebook - here. After watching this talk, I wrote this quick summary of the event. Enjoy.