Making Antimatter - Complicated, Expensive
Source: Space.com
January 11, 2001
If you want to make antimatter, you'd better plan to
have a particle accelerator on hand and everything that goes with it:
radiation shielding, a massive power supply, steering magnets,
state-of-the-art particle detectors and powerful computers, along with
an army of scientists, engineers, technicians and administrators to
design, organize and run experiments. Unless you are somehow able to
recreate the Big Bang in your backyard, to get your antimatter factory
off the ground you'll need a minimum of a half-billion dollars to get
your gear up and running.
Antiparticles don't just pop out of thin air. To
generate them, you have to slam something (a beam of ordinary matter
particles, say) into a small gas or liquid target material. You'll
need a miles- (kilometers-) long accelerator to get your proton beam
up to (light) speed. You use protons since they're about 2,000 times
more massive than lightweight electrons and thus produce more
subatomic debris, including antiprotons. Once you have your target
squared away, your beam going and all your equipment in perfect
working order, it's time to sit back and wait for all those
antiprotons you're anticipating.
You wait a while. Then you'll wait a while longer. Then
there's some more waiting. Come to think of it, you could be waiting
for a couple of weeks.
For every 1 million protons sent careening into the
target, a mere 20 antiprotons are produced. At least, that's true at
nuclear physics facility Fermilab, outside Chicago in Batavia,
Illinois. Says Dave McGinnis, an antiproton expert and department head
of Fermilab's Antiproton Source, "Most of what comes off is heat,
radiation and a zoo -- a whole bunch of particles you don't want."
Once you have antiparticles you have to store them
safely. Otherwise, they will annihilate in interactions with ordinary
matter, including air molecules. Scientists now are perfecting cold
traps, devices cooled to near absolute zero, that should store much
larger numbers of antiprotons.
Not that we're talking huge amounts. So far the total
amount of antimatter produced worldwide is a fraction of the size of
the period at the end of this sentence.
By James Schultz
http://www.space.com/news/antimatter_side_0010111.html