As forecast in the last report, we were able to get steadily better breakdowns, with less voltage oscillation. When we got the oscillations below the threshold of about 28 kV, we got our first pinch on shot 1 of March 7. A “pinch” is when the current twists itself up into a plasmoid, generating increased density and high temperatures. This is a big step forward, even though no fusion reaction were observed. It shows that with a mix that is still mostly boron by mass we can get an adequate breakdown for a substantial pinch.
The HVP and MRC data indicate why no fusion happened. Three distinct pinches are observed, with the first and third being considerably larger than the second. The first pinch was at 1.49 microsecond and the third at 1.92 microseconds. In each pinch, the voltage rises and the current falls, indicating energy being drawn into the plasmoid.
The likely hypothesis is that the first sheath was almost entirely hydrogen and the third almost entirely boron ions. Because of what is known as the “Alfven critical velocity” phenomenon, the boron ions have a “speed limit” in the rundown of about 7 cm/microsecond. Beyond that velocity the tightly bound inner electrons of each boron ion start getting stripped off and the energy loss prevents the boron ions from accelerating beyond that velocity. This is a similar phenomenon to boiling water—it can’t reach temperatures above 100 C (at standard pressure). The third sheath in this shot was traveling at very close to that velocity.
Figure 1 The voltage graph from shot 1, March 7, shows the first pinch with a hydrogen-boron mix. The voltage spike at 3300 ns show the initial pinch—the formation of a dense, hot plasmoid. However, the subsequent spikes show that more than one current sheath was formed. We think the hydrogen was in the first sheath and the boron in the third one, preventing fusion of the two elements.
However, given the observed fill pressures of boron and hydrogen, there is magnetic field energy left over once the boron ions reach the critical velocity. This is available to accelerate the protons in a separate sheath since the protons, being fully stripped of electrons, can accelerate to as fast a velocity as there is energy for. So a separation is possible and would of course eliminate any fusion reactions.
The evident cure is to add enough more boron so that there is no extra energy left over to accelerate the protons in a separate sheath.