More realistic plasmoid simulation confirms net energy production
An improved computer simulation of a plasmoid, the dense region where focus fusion energy generation takes place, has confirmed that net energy production is feasible, and in fact has shown higher energy production than previous, less realistic, simulations.
In the latest simulations, energy output from the plasmoid in the form of x-rays and an ion beam exceed energy input by as much as a factor of 2.0, significantly more than the factor of 1.6 generated in previous simulations. The fact that the more realistic simulations actually improve results is very encouraging for the success of the project.
The plasmoid simulations have been one of the main scientific efforts of LPP President Eric Lerner over the past nine months. There have been a number of major improvements on the previous simulations. First, the model now contains collective heating mechanisms. These collective heating modes occur when high energy particles move thorough a plasma, creating plasma waves, like the wake of a speed boat. The waves then heat the electrons in the plasma. This is addition to the normal particle-to-particle heating caused by collisions among individual ions and electrons.
A second and more important change in the simulation is in the treatment of the density of the plasmoid when compression ends. This density is determined by a balance with the magnetic field energy. In essence, as density and magnetic field both increase, at a certain point the electron frequency in spiraling in the magnetic field is faster than the electron frequency vibrating in the plasma. In technical terms, the synchrotron frequency exceeds the plasma frequency. This briefly allows radiation to escape, triggering a sharp local fall in magnetic energy, the generation of an enormous electric field, and the initiation of the ion and electron beams that start heating up the plasmoid.
The new simulation uses more sophisticated physical corrections in determining this balance, and thereby shows that higher plasma densities will be obtained for a given magnetic field. This in turn leads to a faster and more thorough fusion burn and thus higher energy yield.
In one simulation run, with the maximum magnetic field at 13 GG (billion gauss) x-ray energy emitted was 90% of input energy and beam energy was 94%, for a total energy multiplication factor of 1.84. In a second run, with a maximum magnetic field of 15 GG, x-ray energy was 122% of input energy and beam energy was 77% for a total energy multiplication factor of 1.99. With these energy multiplication factors, using reasonable energy conversion efficiencies, net power production will certainly be feasible.
These results are being prepared for publication.
Lerner is continuing work on the simulation, developing it into a multi-layer model that will begin to reflect variations of conditions within different parts of the plasmoid. Eventually, a full three-D simulation will be generated using the powerful drift kinetic fluid particle technique under development by LPP collaborator Robert Terry.