'Antimatter
factory' starts work
BBC
SCI/TECH NEWS
Thursday, 10 August, 2000, 12:29 GMT 13:29 UK
Scientists
at Europe's biggest high-energy physics laboratory have
built an "antimatter factory" to study why the
world is made of matter, not its mirror image.
The experiment at Cern, in Geneva,
aims to produce antiatoms, and to slow them down long
enough to conduct experiments on them.
It is hoped the results will explain
why the world is made of matter rather than antimatter -
which only occurs naturally in cosmic ray collisions.
Scientists have been puzzling for
years over the disappearance of antimatter, as the Big
Bang should have created the same amount of matter and
antimatter, and in principle the two should have wiped
each other out.
Search for a difference
The experiment will be looking closely
for any difference between antimatter and matter to
explain the asymmtery.
Rolf Landua: what would an
antimatter Universe be like?
|
A spokesman for one of three antimatter
projects at Cern, Rolf Landua, said: "We are
looking at how the Universe would look if it was made
out of antimatter. Would there be the slightest
difference between our Universe and the Universe of
antiatoms?"
Even a minute difference could explain
why the world is made of matter, and why antimatter
disappeared.
The antimatter factory cost $11.5
million to build, and consists of a circular concrete
box containing a ring of high-tech magnets.
It slows antiprotons, the antimatter
equivalent of the proton, down to what Cern describes as
a "leisurely pace" - one tenth of the speed of
light.
After trapping the antiprotons, the
scientists mix them with positrons, the antimatter
equivalent of the electron, to produce antihydrogen.
Precision technology
Cern succeeded in creating nine
antihydrogen atoms in 1996, but they disappeared almost
instantly.
"These antiprotons are an unruly
bunch," said Cern spokesman Neil Calder. "They
disappear the moment they touch matter.
This is the first time we'll be able
to study in great precision the behaviour of
antihydrogen and poke around with it because now we have
the technology to hold the antihydrogen in place to
study it. That's the breakthrough."
Cern hopes to have the first
antihydrogen atoms by the end of 2000, and to have
analysed some of the results by the end of 2002.
Two other projects on antimatter, at
Stanford in California, and at a Japanese national
laboratory, presented initial results last week.
Those projects do not aim to build
antiatoms, but to compare the decay of antiparticles
with the decay of normal particles.
