JT-60

rdf:langString JT-60

rdf:langString JT-60

rdf:langString Japan Torus-60

rdf:langString JT-60SA

rdf:langString yes

rdf:langString JT-60 (short for Japan Torus-60) is a large research tokamak, the flagship of Japan's magnetic fusion program, previously run by the Japan Atomic Energy Research Institute (JAERI) and currently run by the Japan Atomic Energy Agency's (JAEA) Naka Fusion Institute in Ibaraki Prefecture. It is properly an advanced tokamak, including a D-shaped plasma cross-section and active feedback control. First designed in the 1970s as the "Breakeven Plasma Test Facility" (BPTF), the goal of the system was to reach , a goal set for the US's TFTR, the UK's JET and the Soviet T-15. JT-60 began operations in 1985, and like the TFTR and JET that began operations only shortly before it, JT-60 demonstrated performance far below predictions. Over the next two decades, JET and JT-60 led the effort to regain the performance originally expected of these machines. JT-60 underwent two major modifications during this time, producing JT-60A, and then JT-60U (for "upgrade"). These changes resulted in significant improvements in plasma performance. As of 2018, JT-60 currently holds the record for the highest value of the fusion triple product achieved: 1.77×1028 K·s·m−3 = 1.53×1021 keV·s·m−3. To date, JT-60 has the world record for the hottest ion temperature ever achieved (522 million °C); this record defeated the TFTR machine at Princeton in 1996. In March 2021, the JT60SA successfully reached its full design toroidal field.