View inside Japan's JT-60 Tokamak which currently holds the record for highest temperature attained by a plasma at 520 million K (half a billion degrees). It also appears to hold the record for the highest performance attained by a plasma (producing a power gain of 1.25) source- http://www.mext.go.jp/english/news/1998/06/980611.htm More info- http://www-jt60.naka.jaea.go.jp/HOME.html http://en.wikipedia.org/wiki/JT-60
