The quest for usable energy from fusion involves the use of interlocked magnetic fi elds to contain very hot (180 million degrees Fahrenheit) and highly compressed (to a density 20 times that of lead) electrically charged plasma (a kind of gas) within a vacuum chamber. The plasma must never touch the solid walls of its container, for if it does it instantly loses its heat and can never be coaxed into undergoing fusion. One scientifi c report put the problem this way:
Everything depends on keeping the plasma’s magnetic bottle tightly stoppered . . . [but] confining a dollop of super-hot compressed plasma has proved to be harder than compressing and shaping a blob of jelly using only rubber bands. Each clever idea of the plasma physicists for solving this problem has been matched by a new challenge.
—Malcolm W. Browne, “Reviving the Quest to Tame the Energy
of the Stars,” The New York Times , 8 June 1999