Word: zeta
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
Controlled nuclear fusion may be farther away than had been hoped. Last week Dr. B.FJ. Schonland, director of Britain's Atomic Energy Research Establishment, announced that the neutrons emitted from the famous ZETA fusion apparatus (TIME, Feb. 3) did not come from fusion of heavy hydrogen atoms at uniform high temperature. As the U.S.'s Atomic Energy Commission had indicated, they were apparently a result of collisions of high-velocity atoms with low-velocity ones. Experts in fusion techniques do not class this action as real thermonuclear fusion...
...Harwell scientists, led by Peter Clive Thonemann, have made ZETA's pinch behave by passing a second current through coils around the torus. This current creates a second magnetic field which keeps the pinch away from the walls for as long as five one-thousandths of a second. The deuterium in it is heated to 5,000,000° C. (one-third of the temperature at the center of the sun), and free neutrons shoot out of the torus...
...most impressive U.S. thermonuclear work was done at Los Alamos Scientific Laboratory with a machine called Perhapsatron S-3. Its doughnut is made of glass surrounded by copper, and is about as big as a scooter tire, with its minor diameter (through the dough) about 2 in. compared to ZETA's 39 in. The temperature of its pinch is higher than ZETA's (about 6,000,000° C.), but the pinch lasts only a few millionths of a second, about one-thousandth as long as ZETA's. Other thermonuclear machines at Los Alamos use short, straight...
...question is whether these neutrons really come from the fusion of deuterium into helium 3. Powerful electrical discharges can give "false neutrons." formed in other and less important ways, but Scientist Cockcroft is "90% certain" that at least some of ZETA's neutrons come from a thermonuclear reaction. Dr. Thonemann of Harwell does not want to commit himself definitely. U.S. scientists are not sure either. Dr. James Tuck, head of the Los Alamos group, wants to learn more before he makes positive statements...
...British thermonuclear scientists do not say flatly that they are ahead of their U.S. colleagues, but Dr. Thonemann, master of ZETA, points out that with a small thermonuclear doughnut it is hard to keep the pinch away from the walls for long. "You have to go fairly big," he says, "if you want to put up temperature and put up containment time too." The U.S. Atomic Energy Commission apparently agrees with this reasoning; it is building at Princeton, N.J. a very large thermonuclear device, a "Stellarator," which is scheduled to start operation...