Speaker - Dr Rodney Mason

Laser Fusion was first proposed in the early 70’s as a means for the extraction of energy from the burn of thermonuclear hydrogen fuels in the laboratory. Long-pulse (nanosecond) time-shaped laser beams would be used for the adiabatic compression of micrograms deuterium-tritium microspheres, and for the subsequent shock-heating of the central fuel in these targets to kilovolt temperatures. The earliest predicted required laser energies were in the kilojoule range, from which 10-fold breakeven fusion yields were expected. In the four decades intervening, experimental experience has shifted the required input laser energy to the megajoule range, culminating most recently in the completion of the NIF facility in Livermore, CA, which will soon test this approach to fusion energy.

In the mid-90’s the new availability of picosecond lasers suggested that, as a second possibility, the final heating of compressed target fuel might be accomplished with independent short-pulses at extreme intensities. The energy from such lasers makes copious relativistic “hot” electrons, which stream for the absorbing surface to the compressed core of a target. The timing and spectrum of these “hots” must be adjusted to optimize the heating in time and space for maximum thermonuclear yield production. Also alternatively, the short-pulses might be used to first generate focused fast ions to initiate the thermonuclear “burn.”

Aspects of such Fast Ignition (FI) by hot electron and/or fast ions are now receiving vigorous world wide study. This approach may prove crucial to success in Inertial Confinement Fusion. Modelling of the underlying hot electron and ion transport for FI presents particular challenges, which will be emphasized in this talk. Sample applications from our code ePLAS (which has Los Alamos roots) will be discussed. The focus will be on the novel code features, such as the implicit treatment of active self-consistent electromagnetic fields and hybrid particle and fluid treatments for the background plasma. We will show that useful intuition can be gained through calculations on a simple portable PC, and aided by copious graphical output.

The special implicit/hybrid features of ePLAS permit diverse application to other pressing plasma physics issues, such as plasma jet formation for Magnetically Insulated Fusion, and lightning studies. The talk will outline these capabilities, as well.

About the speaker

Dr Rodney Mason is president of the Research Applications Corporation (RAC), a small business in Northern New Mexico. He received his BA in Physics with Honours and his PhD in Aerospace Engineering. both from Cornell University. Thereafter, he was a Fulbright Scholar at the Institute for Plasma Physics, Garching, Germany, and spent two years as a Ford Fellow and Asst. Prof. at MIT.

Rod is a leading researcher in plasma physics, with more than 100 refereed papers and 250 professional presentations, achieving Fellowship in the American Physical Society for contributions to Laser Fusion and Plasma Simulation Code Development. He co-authored the first PRL on Laser Fusion and the first POP article on Fast Ignition. He holds a patent for multi-gap Plasma Opening Switches.

He worked at the Los Alamos National Laboratory for many years in Laser Fusion and Pulsed Power after a period of ionospheric shock research at the Bell Laboratories. He has served as a Visiting Professor at Imperial College, London, and at Cornell University, and recently at the ILE, Osaka, Japan. He has received Distinguished Performance Awards for plasma code development and short pulse laser fusion studies from both the Los Alamos and Livermore Laboratories, and in 2009 the ILE Research Prize from Osaka. At Los Alamos he served as a Deputy Group Leader, and as a member of the Laboratory Post-Doc committee. Currently, at RAC he provides overall administrative direction to a small professional staff, developing and applying codes for the modelling of electron transport in ICF Fast Ignition, plasma dynamics for jet production in MIF, and laser-induced lightning.

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