A NASA antimatter detector is scheduled to be boosted up to the International Space Station next year.
Researchers will be searching not only for antihydrogen, but also for larger antiatoms, such as antihelium, anticarbon, and antinitrogen.
Although antimatter sounds like science fiction, antielectrons are used every day in hospitals and clinics around the world. They are the key to the positron emission tomography, or PET, scans employed since 1950 to observe what's going on inside a human brain.
Positrons are found in cosmic rays and can be produced on Earth by bombarding ordinary atoms with protons, causing them to break up and emit various particles, including these useful bits of antimatter.
Other subatomic forms of antimatter, including antiquarks and antimesons—particles even smaller than protons—have been created in antimatter "factories" at Fermilab; at Stanford University in Stanford, California; near Osaka, Japan; and at the European Organization for Nuclear Research, known as CERN, in Geneva.
Moving Too Fast
A small number of antihydrogen atoms were produced in the mid-1990s at CERN and at Fermilab, but they were moving extremely fast and vanished before they could be analyzed.
This year's big new batch of antihydrogen was created at CERN by the ATHENA Experiment, a collaboration of physicists from 11 European universities.
Positrons and antiprotons were cooled to about 450 degrees below zero Fahrenheit to slow them down, and then combined in a magnetic trap. The magnetic force kept them briefly from colliding with the walls of the trap and obliterating themselves.
Their lives were short. Even at this temperature, antihydrogen lasts less than a hundredth of a second before it hits the wall, according to Jeffrey Hangst, physics coordinator of the ATHENA project, from the University of Aarhus at Denmark.
Before the antimatter vanished, it left a distinctive signature in a particle detector, demonstrating that it was antihydrogen, Hangst said.
Because it is so difficult and expensive to create and store antiatoms, scientists say it is impractical to use them as a power source.
All the antimatter produced at CERN in a year would light a 100-watt bulb for only 15 minutes, Hangst said.
Nevertheless, physicists expect the study of antimatter will help them understand the fundamental nature of matter and what happened during the first few seconds of the universe.
Copyright 2002 Miami Herald
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