After seven years of theoretical work and raising money, five months of design, five months of construction and assembly, and a week of testing, Eric Lerner and his team now have a functioning dense plasma focus machine, Focus-Fusion-1. Their first shot, using helium as the fill gas, was achieved at 5:29 PM EDST, 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.
Congratulations of the highest order are richly deserved.
The first shots are all about seeing if the machine works properly as designed. When the machine is turned on, the team wants to make sure nothing goes “bang” or emits acrid blue smoke. Electricity shouldn’t short through anywhere. It’s the ‘check the assembly for errors’ kind of thing.
At the web site a ‘shot’ is explained. A shot takes around 10 to 15 minutes and basically involves:
- Pumping the chamber to a vacuum state. There must be no gases in the chamber other than the gases to be tested.
- Pumping in a measured amount of gas (the first series of shots will be taken with Deuterium to calibrate the machine. The tests with boron and hydrogen come later.)
- Charge the capacitors – e.g., press a button, it will take ~1 minute to charge the capacitors up to 25kV (first shots at 25kV. The machine will be worked up to 45 kV later). When it reaches 25kV . . .
- “Fire” – this is where ‘Igor’ pulls the switch. Actually, Eric or Murali will press the red button.
- Look at readouts from the oscilloscopes and a few other diagnostic instruments attached to the machine.
- Pump down to a vacuum (and repeat for next shot).
The team is looking for:
- No shorting through the mylar. This could happen if dust or other impurities are on the high voltage plate. Such elements can redirect the electricity to penetrate the mylar insulation sheet.
- No breakage of the pyrex hat insulators. (Called “hat insulators” because of the hat shape). These insulators are made of pyrex and fitted to the anode. The fit must not be too tight or too loose as the anode expands and contracts with each charge, otherwise the pyrex could break
- The amount of current close to what is predicted.
- Possibly . . . evidence of a “pinch” – although this shouldn’t happen until after ~ 20 shots.
- Ideal outcome: The peak current will be somewhere around 1.2 to 1.3 MA (million amperes).
The desired effect is to get the energy out of the capacitors and into the machine as fast as possible. The capacitors store a fixed amount of energy. When the researchers “fire” (close the switch), the energy from the capacitor is released around the circuit. The faster that energy is released, the better. This is measured by time it takes for the current to reach its peak, called the ‘Rise time.’ Rise time will be measured immediately by the oscilloscopes. The researchers are hoping for the most rapid rise time (quicker is better).
After ~20 shots, the research team may start to see the formation of a plasmoid. This will be detected by a rapid change in current.
The actual test shots were produced with a charging potential of 20 kV, a bit less than half the full bank charge of 45 kV. The Lerner team will not know the exact current achieved until they reduce some instrumental noise in the next day or so. It is probably around 0.9 MA and within 10% of their 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.
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, the Lerner team needs to locate a leak in the vacuum system in order to pump down to the goal of a few microtorrs before re-filling with deuterium. Finally, the team still needs to put in place all their instruments, several of which must also be assembled. The Lerner team hopes to complete all this shortly and be ready to start data collection.
Lerner and his team are one of the leading edge researchers seeking a viable means to use fusion for producing energy. This writer hopes and wishes them success with more and better news at each test. Someone is going to crack a new path to net power first. Maybe this is the ‘one.’