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What is Focus Fusion? • Dense Plasma Focus ("DPF") • LPPX - LPP Experiment •

Z-pinch experiments demonstrate magnetic field effect

Posted by Admin on Nov 08, 2007 at 09:05 AM
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A new analysis by Lerner of experimental results from several z-pinch experiments show that the electron temperatures can only be explained by the magnetic field effect. The results therefore constitute the first laboratory confirmation of Lerner’s predictions about the effect and add credibility to our expectations that the effect will allow net energy production with pB11 fuel. The effect reduces the x-ray emission from the hot plasmoid and makes it possible for it to rapidly heat up to ideal fusion temperatures.

The z-pinch is a fusion device somewhat similar to the dense plasma focus (DPF). Like the DPF, it uses the pinch effect to generate high densities. However, it produces this effect by running a large current betweens two electrodes in a line, rather than co-axially. The current is often carried by an array of wires which vaporize to form the plasma. Hot spots - plasmoids - are often formed. The compressional energy is transferred to the ions first, which in turn heat up the electrons, in contrast to the DPF, where the electron beam first heats the electrons, which then heat the ions. The largest z-pinch device, Los Alamos’ z-machine, achieved the highest ions temperatures of any fusion device - 280 keV, over 3 billion degrees - with an iron plasma.

While the z-pinches have not achieved the gigagauss fields needed for B11 breakeven, the magnetic fields are high enough for the effect to be relevant. The effect increases in importance with lower ion temperatures and higher ion atomic masses and in the experiments studied one or both of these conditions are valid.

An LPP analysis of seven experiments by five different groups of researchers showed that in each case a calculation that ignored the magnetic field effect predicted electron temperatures that were much higher than those actually observed. This fact was noted in several papers on the experiments, but not explained. When the magnetic field effect was taken into account, the predicted electron temperatures were much closer to the observed ones, as shown in the figure below. In fact the average of the observed temperatures were within 20% of the average of the predicted temperatures.

These results are being prepared for publication.