MIT teams attempt fusion experiment
By Gaurav Rewari
Ever since Stanley Pons and Martin Fleischmann announced in Utah, just over a week ago, that they had invented a device that could achieve the hitherto unheard-of phenomenon of nuclear fusion at room temperatures, a wave of excitement and skepticism has rocked the international scientific community.
Scientists around the world have scurried to their labs in an effort to duplicate the sensational experiment. These include researchers in England, Los Alamos National Laboratory in New Mexico, General Electric, Lawrence Livermore National Laboratory in California, and scores of universities across the United States. At MIT alone there are several groups working on the experiment. None of these groups, however, have yet seen anything unexpected.
"Based on pre-prints of the paper and media information, we feel we are reproducing all the conditions of the Utah experiment," said Stanley C. Luckhardt, principal research scientist at the MIT Plasma Fusion Center and member of a multi-disciplinary group trying to recreate the original experiment. However, there are still some unknowns regarding the preparation of the palladium rods in the Pons/Fleischmann experiment. The information on this in the literature and in various talks so far has been conflicting, according to Luckhardt.
"We had started our experiments more than a week ago, and as of yet we haven't seen any increase in the neutron counts or any evidence of a fusion reaction," Luckhardt said. Most researchers caution, however, that it may take a few months before any conclusions can be drawn about the experiment.
Fusion is the process in which the nuclei of light atoms, such as hydrogen, fuse together, resulting in the production of energy in the form of heat. The Utah experiment used deuterium, an isotope of hydrogen containing a proton and a neutron in its nucleus that is abundant in sea water.
In the "normal" fusion process when deuterium fuses, half the reaction results in the production of an energetic neutron. The fact that no neutron radiation was observed in the Pons/Fleischmann experiment has led scientists to speculate on the possibility of a different path to fusion. Such a path would result in the formation of two protons and two neutrons -- an alpha particle -- from each reaction.
Steven Jones, a scientist at Brigham Young University, claimed to have performed a similar experiment last year. Luckhardt, however, said that while the Jones and the Pons/Fleischmann experiments were both cold fusion experiments, the former was essentially different in that the fusion rates were on the order of a few neutrons per hour. The power output for the Jones experiment was in the neighborhood of 10[el-4]13 watts.
In the experiment carried out by Jones, there did appear to be some fusion reactions at a low level -- a few standard deviations above the the background level, Luckhardt said.
But the Pons/Fleischmann experiments have much more extravagant claims. The researchers claim to have produced a device that produces an energy output greater than the energy input. They have also said that they can produce fusion reactions at room temperature on solids such as palladium instead of in very hot gases. These claims, if proved to be true, could have far-reaching consequences in the future. Pons and Fleischmann have asserted that if commercialized, the technique could produce enough heat and electricity to cause the virtual elimination of oil, coal and nuclear power.
And though this may send more imaginative minds into speculations about the effect of such an inexpensive energy source, researchers at MIT and laboratories across the nation are playing it very cautiously.
"Pons and Fleischmann are highly respected in their fields, which is electro-chemistry, and so we owe it to them to give them the benefit of the doubt," said Ian H. Hutchinson, associate professor of nuclear engineering at MIT. "But while we are taking their claims seriously, we are not taking them for granted," he added. Hutchinson felt that the claims called for a lot of investigation and that one would have to wait months before concluding one way or another.
"To achieve the power output that they report, i.e. `1 watt in, 4 watts out', without lethal doses of neutron radiation appears to be one of the mysteries that surrounds the Utah experiment," Luckhardt said. According to him, theoretically one would expect a tremendous level of neutron radiation. But no one died out of radiation exposure in Utah, and that's a good neutron detector, he added.
Hutchinson also felt that it was "doubly puzzling how on earth such a fusion reaction could take place at room temperature in the first place, and how on earth it could do so without giving rise to neutron or other radiations."
According to Luckhardt, even if the new fusion method were to be used to build a power reactor of 1000 megawatts, for example, tremendous quantities of palladium would be required. "Therefore it is by no means clear how it can be used for commercial power generation," he said.
So the scientific community will have to spend the next few weeks maintaining both its excitement and its skepticism. As Institute Professor Emeritus Phillip Morrisson said in an interview last week, "I think there's a chance it's the most important development for a century, and there's a chance it's nothing at all."