Antimatter Makers Chase Ultimate Energy Source
Source: Space.com
January 11, 2001
With antimatter in the tank, taking the family rocket
out for a spin to the nearest M-class planet would be a relative
breeze. Miniaturized antimatter fuel might consist of a thumb-sized
canister with an energy source no bigger than an aspirin and no need
of replenishment for hundreds of light-years -- or, locally, tens of
millions of intra-solar-system miles.
Turning a Positive Into a Negative
Producing antimatter is a difficult expensive process.
Ever since the 1930s, scientists have known of the
existence of a twin to ordinary matter. Antimatter has the same mass
but opposite spin and charge. Put matter and antimatter together and
it's like Einstein said, E=mc2 -- 100-percent energy conversion.
Luckily for normal-matter humanity, there doesn't seem to be too much
antimatter left over from the Big Bang to cause random
ultra-explosions.
Cosmic paucity, however, hasn't stopped human
manufacture. More antimatter is now being produced artificially than
at any previous time in human history. So where are the
next-generation, Star Trek-like antimatter rocket engines? Only in the
imaginations of futurists, and definitely not on the drawing boards,
retort researchers.
"The power we use now to make antimatter is close to a
billion times more than we can produce [with antimatter]," said Dave
McGinnis, an antiproton expert and department head of the Antiproton
Source at Fermi National Accelerator Laboratory (Fermilab) in Batavia,
Illinois. Fermilab is one of the world's leading makers of antimatter
for scientific study. "It's remarkably inefficient and just not
economical. That's the bottom line and the reason we don't yet have an
antimatter rocket."
Changing the equation
Hoping to change the antimatter cost equation is
Chicago-area startup Technology Antimatter Production LLC, helmed by
former Fermilab accelerator physicist Gerry Jackson, now the company's
president. Jackson says new techniques that he and his seven
collaborators are devising could lead to more efficient techniques.
Within the decade, Technology Antimatter --- using the Fermilab
particle accelerator under a cooperative business agreement with the
laboratory --- could produce 1,000 times more antiprotons than are
currently manufactured annually at Fermilab, and at less expense.
"Right now antiprotons are being generated for
high-energy physics experiments," Jackson said. "The requirements are
very restrictive. It 's possible to modify the equipment to vastly
increase antiproton numbers."
Should the company be able to solve the twin problems of
storage and use --- two major problems, Jackson admits --- the market
in medical applications, such as diagnostic scanners, could be
substantial. But antimatter propulsion is also a possibility.
Technology Antimatter will partner with NASA's Marshall Space Flight
Center to capture and
store antiprotons in a Marshall apparatus known as a High Performance
Antimatter Trap, or HiPAT. Propulsion experts will use the trap to
study ways of making antimatter engines a reality. If they're
successful, given the enormous amounts of thrust potentially
available, trips to the Moon could take minutes and Mars would be a
day or so away.
"Marshall is looking at spaceflight 30 to 40 years out,"
Jackson said. "Now is the time to do the 'R and D' for those missions.
We'll be providing them the fuel they need for those engine tests."
Radical breakthroughs?
Gerald Gabrielse, one of the world's foremost experts on
the manufacture of antihydrogen and chair of the Harvard University
physics department, remains skeptical. He leads an international
collaboration to produce and store antihydrogen in special facilities
at CERN, a physics research complex located in Geneva, Switzerland.
Assuming you were able to collect all the antiprotons ever made,
Gabrielse points out, heating something as small as a cup of coffee
would prove impossible. Antimatter's most likely future is as a
subject for scientific investigation, not as fuel for futuristic space
vehicles.
"Making antimatter fuel for one rocket is theoretically
possible. But I don't see it happening anytime soon," Gabrielse said.
"There are significant problems I don't know how to solve. A fuel that
requires more energy to make than it releases is not much of a fuel
source. It' s pretty clear no one is going to make a rocket engine
fueled by antimatter in the next 10 years."
Skepticism doesn't faze Gerry Jackson. He concedes that
antimatter-driven spaceflight may be decades away. Nevertheless, given
the rate of technological innovation and unanticipated ingenuity, he
thinks radical breakthroughs in antimatter technology and near-term
applications may be closer at hand than even advocates dare hope.
"You would never have thought of [desktop personal]
computers when the transistor was invented. That's probably where we
are now," he said. "It's easy to say an idea is crazy, but you really
need to sit down with present technology and extrapolate it forward.
Right now, of course, no one can build an antimatter engine. But 10
years down the road, and I think we're going to start to get
close."
by James Schultz
http://www.space.com/news/antimatter_fuel_0010111.html