TIME: Almanac 1993/TIME Almanac 1993.iso/time/041789/04178900.063

Text File | 1992-09-23 | 5.8 KB | 115 lines

                :                                                              SCIENCE, Page 72

Trying to Tame H-Bomb Power


Researchers rush to check out a possible breakthrough in fusion


    The claim was so spectacular that it was difficult to
believe. News reports suggested that scientists might have
achieved the world's first controlled, energy-yielding
nuclear-fusion reaction -- a Holy Grail of physics for nearly 40
years. Moreover, the event had not occurred in one of the great
national laboratories; it was the work of a pair of chemists
operating on a shoestring budget and using little more than a
test tube, a pencil-thin strip of metal and a car battery. Even
more incredible was the assertion that this humble apparatus,
fueled with a form of hydrogen found in ordinary seawater, had
generated four times as much energy as it consumed. Could this
be a new and virtually limitless source of cheap, clean power?

    Thus late last month began a saga that continues to engage
the attention of the scientific world as rarely before. The
announcement by the two chemists, B. Stanley Pons of the
University of Utah and Martin Fleischmann of the University of
Southampton in England, while greeted with skepticism, also
triggered a kind of free-for-all as researchers rushed to
re-create the controversial experiment.

    There were grounds for skepticism. While well respected in
their fields, Pons and Fleischmann were far from the mainstream
of fusion research. In addition, they had released their
results in a manner that tended to cast suspicion on their
claims, staging a press conference in Utah complete with
television cameras. For several days researchers around the
world were dependent on TV and newspapers for scraps of
information about what could conceivably be the biggest science
story of the year -- if not the decade.

    Then the details of the experiment began to emerge. By an
informal process known as "publication by fax," copies of a
paper Pons and Fleischmann had prepared began to circulate from
lab to lab. Next, one of the best-known figures in the field,
physicist Steven Jones of Brigham Young University, announced
that he too had achieved fusion in a jar, although,
significantly, with far lower energy output. Even a pair of
Hungarian scientists claimed to have carried out
room-temperature fusion.

    Last week, in an unusual move, a Dutch scientific journal
pushed forward its schedule and published the report by Pons and
Fleischmann. But at week's end the more prestigious British
journal Nature had not yet decided whether to print their
findings. The scientific community, while not at all convinced
by the claim that the power of the H-bomb had finally been
harnessed, was at least taking it seriously.

    Nuclear fusion, the process that fires the sun, usually
occurs when two atoms are squeezed together at very high
temperatures to make one new atom. For example, two atoms of
deuterium -- an isotope of hydrogen -- can be fused to form a
helium atom and a neutron, releasing a sizable burst of energy.
But before that can occur, deuterium nuclei generally need to be
compressed with sufficient force to overcome their mutually
repellent electrical charges. In H-bombs, that force is
supplied by the detonation of an A-bomb. Conventional fusion
techniques require giant magnets, powerful laser beams and
particle accelerators. But none of these approaches have
succeeded in generating more energy than they use.

    The researchers at B.Y.U. and Utah took a different tack.
Each constructed an apparatus similar to that used by
ninth-grade science students to split water into hydrogen and
oxygen. Instead of ordinary H2O, however, they used
deuterium-rich heavy water (D2O). The scientists tried an array
of exotic elements for their electrodes, including palladium, a
semiprecious metal known to absorb large numbers of hydrogen --
and deuterium -- atoms. Plunged into a bath of heavy water and
charged by a twelve-volt battery, a palladium rod will draw
swarms of deuterium ions out of the liquid and into its
latticelike crystal structure. There the ions lodge and gather
in such concentrations that they supposedly overcome their
natural repulsion and fuse. Just how that happens, even
B.Y.U.'s Jones cannot say. "We have an experiment but not a
theory," he confesses. "We have Cinderella, but we don't have
her shoe."

    Where the B.Y.U. and Utah teams part company is over how
much energy such a device can produce. The startling claim by
Pons and Fleischmann was that for every watt they pumped into
their crude fuel cell, more than four watts came out. Jones, on
the other hand, measured less than a trillionth of a watt. That
is quite a gap. As he puts it, "It's the difference between a
dollar bill and the national debt."

    Why the huge discrepancy? One hypothesis, put forward by a
group at England's Birmingham University, is that Pons and
Fleischmann achieved fusion in an unconventional fashion. They
had added lithium to their heavy water to make it a better
conductor of electricity, and the lithium may have fused with
the deuterium. This might account for the exceptionally high
energy output.

    Researchers are working feverishly to make sense of the
fusion mystery. A British lab was swamped with requests from
the public for advice on how to re-create the reaction,
including one from a housewife who said she had already
stockpiled a supply of heavy water. But even if the experiment
is successfully duplicated, there is no guarantee that it will
lead to a large-scale power plant. It could be decades before
the commercial potential of the process, if any, is determined.
For now, no one knows whether Pons and Fleischmann have simply
made an embarrassing blunder, or if they are destined to become
two of the most famous scientists who ever lived.