writes with good news for the National Spherical Torus Experiment. Tucked away from major roadways and nestled amid more than 80 acres of forest sits a massive warehouse-like building where inside, a device that can produce temperatures hotter than the sun has sat cold and quiet for more than two years. But the wait is almost over for the nuclear fusion reactor to get back up and running at the Princeton Plasma Physics Laboratory. "We're very excited and we're all anxious to turn that machine back on," said Adam Cohen, deputy director for operations at PPPL. The National Spherical Torus Experiment (NSTX) has been shut down since 2012 as it underwent a $94 million upgrade that will make it what officials say will be the most powerful fusion facility of its kind in the world. It is expected to be ready for operations in late winter or early spring, Cohen said.