Z machine transitions to fusion tests with deuterium–tritium mix

Science : Located at Sandia National Laboratories in Albuquerque, New Mexico, the Z machine is an experimental fusion reactor that eschews the toroidal containment walls of tokamak reactors. The system compresses a pencil eraser–sized fuel container with a blast of electricity to initiate the fusion reaction. Until August, tests with the Z machine had used pure deuterium as the fuel. But since then researchers have been adding tritium to the mix, and over the next five years they will ramp up the proportions to reach a 50–50 blend. That balance produces 60 to 90 times as many neutrons as the deuterium-only fuel and more than four times as much energy. The hope is that the machine can exceed the fusion power record of 16 MW set by the Joint European Torus tokamak in 1997. Using tritium is difficult because it is expensive, mildly radioactive, and combines with water to become significantly more hazardous. But the researchers at Sandia believe that moving forward with the substance is necessary to achieve viable fusion systems.