VIRTUAL

 

Thursday, August 19th    2021

3:45 – 4:45 p.m.

WEBEX

  

Speaker:  Hermann Geppert-Kleinrath

 

 

P-4: THERMONUCLEAR PLASMA PHYSICS

 

 

“Diagnosing Thermonuclear Burn in Fusion Implosions using ultra-fast Gas Cherenkov Detectors”

 

 

 

Abstract: 

In Inertial Confinement Fusion (ICF) gas filled targets are compressed and heated by a powerful laser drive to reach thermonuclear conditions. Different hydrogen species, most commonly Deuterium and Tritium, fuse together creating a miniature sun for just a brief moment. Experiments at ICF facilities such as OMEGA in Rochester, NY or the National Ignition Facility (NIF) in Livermore, CA allow for the investigation of fusion burn, astrophysics, as well as materials under extreme conditions, making ICF facilities a vital tool for fundamental science and the US stockpile stewardship program.
The extreme conditions in these experiments, and the harsh background environments put tough requirements on diagnostic instruments. Gas Cherenkov Detectors (GCD) are exceptionally fast with temporal resolutions of ~100 ps and allow coarse spectroscopy with their energy threshold capability, thereby enabling direct measurements of the fusion rate. The GCDs provide crucial performance data for experiments, delivering critical values like bang time and burn width, while also benchmarking radiation-hydrodynamic plasma simulations. The novel Pulse Dilation – Photomultiplier Tube (PD-PMT) allows for unprecedented temporal resolution of ~10 ps and is opening up new domains of physics to be investigated by GCDs. Pusher velocity at bang time, ablator mix, and ion temperature history are only some of the physics applications explored by LANL’s P-division.

This work has been supported by the C-10 Inertial Confinement Program and the P-4 Group.