PETR LEONIDOVICH KAPITSA

is Russia's grand old physicist, now 85 years old. From 1921 to 1934, he worked with Lord Rutherford, the grandfather of atomic structure theory, at Cambridge University, mainly on low temperature physics. In 1934, on a visit to his native Russia, Stalin did not let him return to England, but bought up all the low-temperature equipment he had developed in England, and in 1935 appointed him director of the Institute of Physical Problems in Moscow. In 1946, he disappeared into the twilight of unpersonhood, and was variously reported as exiled to Siberia and even dead; but in 1955, two years after Stalin's death, he reappeared at his old post, publishing works on high-power electronics, ball lightning, plasmas, and a variety of other subjects.

Apparently he got into it by accident during his institute's investigations of high-powered microwave sources and of the theory of ball lightning. (Microwaves are non-ionizing radio waves used for UHF telephony, TV, microwave ovens, radar, and also for bogeys with which charlatans scare the ignorant and gullible.) They found that inside a microwave resonator¾which supports microwave oscillations in much the same way as an organ pipe supports acoustic oscillations¾there were spots where the temperature of the gas in the resonator reached 1,000,000 degrees K; more important, within a small fraction of an inch, the temperature was down to normal room value again.

Now the difficulty with fusion is not just producing temperatures of millions of degrees, but having a "vessel" in which to contain the hot plasma. (The danger is not so much that the-walls of the vessel would be melted by the plasma, but that they would cool it¾not that the bullets would break down the walls, but that the walls would stop the bullets from flying.) That is the reason why the plasma has to be confined by tokamaks, theta pinches and all kinds of complicated magnetic fields which are prone to instabilities and other nuisances.