LPP’s Newly Assembled DPF Achieves First Shots and Pinch
The baby is born! After seven years of theoretical work and raising money, five months of design, five months of construction and assembly, and a week of testing, LPP now has a functioning dense plasma focus, Focus-Fusion-1. The first shot, using helium as the fill gas, was achieved at 5:29 PM today, Oct.15, and the first pinch was achieved at 6:04 PM on the second shot. The fact that a pinch was achieved so soon was evidence of the soundness of the design.
The following is taken from LPP’s announcement:
First Shots Fired
[Refresher: What was the goal of the first shots?]
The shots were produced with a charging potential of 20 kV, a bit less than half the full bank charge of 45 kV. We will not know the exact current achieved until we reduce some instrumental noise in the next day or so. It is probably around 0.9 MA and within 10% of our predictions.
The pinch is clearly evident in the voltage probe curve, below, of the sixth shot. The first peak is when the machine turns on, while the second, higher, peak in voltage is from the energy transfer into the pinch region and the plasmoid.
LPP’s team completed assembly of the Focus-Fusion -1 Dense Plasma Focus at 12:30 AM Oct.10. We were racing the clock to complete assembly while John Thompson, who led this phase, was still in NJ. Dr. Thompson had to return to San Diego on Oct.10. We began initial testing of the device up until 5:30 AM on the 11th when we ran out of time (and energy!). We succeeded in evacuating the vacuum system to 1.5 millitorr, (two millionths of atmospheric pressure) and in charging the capacitor bank repeatedly to 25 kV. However, we were unable to get the trigger system, which triggers the 12 switches on the capacitors, to function, so we did not yet have our first shot. We worked to resolve the issue this week and are very pleased by this day’s results.
The first shots represent the first in a series of shots that will be taken along the road to demonstrate the scientific feasibility of Focus Fusion as a net source of clean, abundant, cheap energy. The machine is still in the initial phase of fine tuning and “conditioning”. In addition, we need to locate a leak in the vacuum system in order to pump down to our goal of a few microtorrs before re-filling with deuterium. Finally, we still need to put in place all our instruments, several of which must also be assembled. We hope to complete all this shortly and be ready to start data collection.
LPP is especially indebted to Dr. Thompson for the outstanding work he has done in the detailed design of FF-1 and in his unflappable leadership and very long hours of hard work in constructing the device over the past six weeks. LPP President Eric Lerner and Senior Research Scientists Murali Subramanian and Abdelmoula Haboub also actively participated in this work. We were assisted by Joe Gorman of Frank Construction. Rezwan Razani, Executive Director of the Focus Fusion Society, also pitched in when needed, as well as recording our effort in stills and video (see the Focus Fusion website). Thanks to all!
More information about LPP’s a two-year-long experimental project to test the scientific feasibility of Focus Fusion.
And here is a great animation by Torulf showing what theoretically could happen with a DPF. The lightbulb is an artistic touch - the machine is not set up that way at this phase. The lightbulb test will be a part of the engineering feasibility phase that comes later.