Many news outlets widely—and inaccurately—reported new results from the huge National Ignition Facility (NIF) as achieving the long sought- after goal of breakeven for fusion. What NIF in fact reported was a fusion yield of 17 kJ, more than the energy actually absorbed by the fuel pellet. The total input energy to the machine was far larger—some 500 MJ, so that 1 J of fusion was produced for each 30,000 J of input. This was indeed a big step upwards for NIF researchers but far from break-even.
Meanwhile, science news reporters overlooked a major accomplishment in fusion a year ago by Russian researchers using a plasma focus device. These researchers performed their work at the Russian Federal Nuclear Center, All Russian Scientific Research Institute of Experimental Physics, in Sarov. They reported fusion yields of 30 J (1.3 x 10^13 neutrons) with the same deuterium-tritium fuel used by NIF. Since the total energy fed into the capacitors was 135 kJ, the Sarov team achieved a fusion yield of 1 J per 4,500 J of input, more than six times better than the NIF results. (The record for any DT fusion experiment is the JET tokamak in the UK, which in 1997 produced 1 J of energy per 450 J of input.)
While LPP’s FF-1 device is not intended for use with DT fuel, it is useful to compare our results with those of the Sarov machine when using pure deuterium, a far less reactive fuel. With pure deuterium (D), Sarov produced 1 J of output per 2.2 MJ of input. FF-1’s best results are 1 J of output per 400 kJ of input, about four times better. (The best results for any plasma focus using pure D are around 1 J for 100kJ of input, about the same as the best results ever obtained for tokamaks using the same fuel.)
