Chinese scientists have built a device that can sustain fusion reactions to generate a limitless source of energy. They have created a fusion reactor that can generate incredible amounts of heat and power. The doughnut-shaped reactor, which some call an “artificial sun”, hit a personal-best temperature of 100 million degrees Celsius (212 million degrees Fahrenheit). That is six times as hot as the sun's core. Fusion is considered the holy grail of energy and is what powers our sun. Unlike…