Independent simulations support LPP predictions at Singapore conference
Ion beam generation is critical for the functioning of a plasma focus device and will be the main source of energy in a future fusion generator. LPP predicts that with a maximum design current of 2.8 MA, the FF-1 plasma focus device will produce a 66 kJ beam, exclusive of any additional energy from fusion reactions. Now leading simulation expert Dr. Sor Hoeh Saw of the Malaysia Institute for Plasma Focus Studies has presented simulation results that match LPP’s experiments and predictions.
The new results were presented Dec. 4 at the International Conference On Plasma Science and Applications in Singapore. Dr. Saw used a somewhat different theoretical model for the plasma focus than that developed by LPP. This model is derived from the overall simulation tool developed by Dr. Saw’s collaborator, Dr. Sing Lee, and is the most widely used simulation tool for the plasma focus devices. For a 1 MA (million amp) peak current, the Saw simulation predicts an ion beam energy of 3.3 kJ, somewhat better than, but relatively close to, the observed 2 kJ beam measured at LPP’s FF-1 device, when it had a 1 MA current. At a peak current of 2.8 MA, the Saw simulation predicts an ion beam of 90 kJ, again close to, but somewhat larger than, the LPP prediction of 66 kJ. For comparison, the FF-1 device has a maximum energy input of 100 kJ, so both models predict the conversion of most of the input energy into beam energy.
This is an important result, because if so much of the input energy is converted to beam energy, which can then be readily re-captured as electricity, an additional fusion yield of about 30-40 kJ will result in more energy out than in, not even counting the additional energy output in x-rays.
At the same conference, LPP’s Lerner presented the teams’ latest results on the influence of impurities in the plasma and the proposed solution with a monolithic tungsten cathode. Several researchers commented favorably on the analysis and LPP’s innovative proposal for a cathode connected to the electric circuit outside the vacuum chamber, to avoid arcing.