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 youll need a minimum of a half-billion dollars to get your gear up and running.

[quote]

Antiparticles dont 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. Youll need a miles- (kilometers-) long accelerator to get your proton beam up to (light) speed. You use protons since theyre 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, its time to sit back and wait for all those antiprotons youre anticipating.

You wait a while. Then youll wait a while longer. Then theres 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, thats true at nuclear physics facility Fermilab, outside Chicago in Batavia, Illinois. Says Dave McGinnis, an antiproton expert and department head of Fermilabs Antiproton Source, "Most of what comes off is heat, radiation and a zoo -- a whole bunch of particles you dont 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 were 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.