then the Princeton Large Torus (PLT) to test whether the theory that larger machines would be more stable was true. Starting in 1975, PLT verified these "scaling laws" and then went on to add neutral beam injection from Oak Ridge that resulted in a series of record-setting plasma temperatures, eventually topping out at 78 million Kelvin, well beyond what was needed for a practical fusion power system. Its success was major news. With this string of successes, PPPL had little trouble winning the bid to build an even larger machine, one specifically designed to reach "breakeven" while running on an actual fusion fuel, rather than a test gas. This produced the Tokamak Fusion Test Reactor, or TFTR, which was completed in 1982. After a lengthy breaking-in period, TFTR began slowly increasing the temperature and density of the fuel, while introducing deuterium gas as the fuel. In April 1986, it demonstrated a combination of density and confinement, the so-called fusion triple product, well beyond what was needed for a practical reactor. In July, it reached a temperature of 200 million degrees, far beyond what was needed. However, when the system was operated with both of these conditions at the same time, a high enough triple product and temperature, the system became unstable. Three years of effort failed to address these issues, and TFTR never reached its goal. The system continued performing basic studies on these problems until being shut down in 1997. Beginning in 1993, TFTR was the first in the world to use 50/50 mixtures of deuterium-tritium. In 1994 it yielded an unprecedented 10.7 megawatts of fusion power. Later designs In 1999, the National Spherical Torus Experiment (NSTX), based on the spherical tokamak concept, came online at the PPPL. Laboratory scientists are collaborating with researchers on fusion science and technology at other facilities, both domestic and foreign. Staff are applying knowledge gained in fusion research to a number of theoretical and experimental areas including materials science, solar physics, chemistry, and manufacturing. Odd-parity heating was demonstrated in the 4 cm radius PFRC-1 experiment in 2006. PFRC-2 has a plasma radius of 8 cm. Studies of electron heating in PFRC-2 reached 500 eV with pulse lengths of 300 ms. In 2015, PPPL completed an upgrade to NSTX to produce NSTX-U that made it the most powerful experimental fusion facility, or tokamak, of its type in the world. In 2017, the group received