After all these years, they havefinally developed a protocol that collects and stores anti matter in the formof anti hydrogen and did so in enough quantity to envision the possibility ofdoing direct experiments.
Obviously we can go beyond thisand plausibly see our way to producing working quantities of this stuff,although serious production will need to be conducted in space. One really can not get serious otherwise abouta product that will really ruin your day every time there is an accident.
In the meantime, this allows realwork to begin in the labs.
Antimatter atoms trapped for 16 minutes
By Emily Chung, CBCNews
Posted: Jun 6, 2011 11:40 AM ET
Some of the researchers involved in the discovery are from Canada,including, from left to right, Michael Hayden and Mohammad Ashkezari from SimonFraser University; Tim Friesen from the University of Calgary; Makoto Fujiwarafrom TRIUMF; and Andrea Gutierrez and Walter Hardy from the University ofBritish Columbia. They are shown with their experimental setup at the CERNLaboratory near Geneva
Antimatter atoms have been held captive and kept in existence for awhopping 16 minutes by a Canadian-led team — far longer than the researchersthought possible.
"It was quite a surprise," said Makoto Fujiwara, lead authorof a study published Sunday in Nature Physics. It reported trapping antiatomsof antihydrogen — the antimatter counterpart of a hydrogen atom — for 1,000seconds.
Antimatter is made up of "antiparticles" that have the samemass as corresponding particles of matter, but an opposite charge. For example,the antimatter counterpart of a negatively charged electron is a positivelycharged positron.
Antimatter is very difficult to keep in existence because the moment ittouches matter, which makes up most of our universe, both the matter andantimatter are annihilated, producing pure energy.
The scientists' recent achievement has extended the experimentallifetime of antihydrogen atoms 5,000-fold since the ALPHA experiment — aninternational collaboration Fujiwara is part of — first figured out how to trapthem at all.
The team, based at the laboratory of CERN, the European organizationfor nuclear research, near Geneva
Holding antiatoms captive for several minutes opens up a new range ofpossible experiments to probe the nature of antimatter, said Fujiwara, aresearch scientist at Vancouver-based TRIUMF and an adjunct professor at the University of Calgary
'Game changer'
Scientists will more easily be able to do experiments to compareantihydrogen to hydrogen and could even potentially test how antimatter atomsare affected by gravity, he added. "I call it a game changer."
An antihydrogen atom is released from the trap after 1,000 seconds, inan artist's conception. The squiggly line represents the atom's path in thetrap while it is trapped, and the curved tracks emerging represent the energyproduced when the released anti-atom hits the inner wall of the trap.CERN/ALPHA
Antihydrogen is made by mixing antiparticles called antiprotons (theantimatter counterparts of protons) and positrons (the antimatter counterpartsof electrons). In recent months, Fujiwara said, the ALPHA team has figured outhow to create very cold antiparticles and mix them more gently to produce andtrap antiatoms more efficiently, successfully trapping an average of oneantiatom per trial.
They also decided to test how long they could keep the antiatomstrapped. Fujiwara thought holding on to them for several seconds might bepossible and was stunned that they could survive for many minutes.
That will make it much easier to do experiments to compare antihydrogento hydrogen, he added.
For example, researchers can point lasers and microwaves at theantiatoms and figure out how the colours of light they shine back compare tothose shone back by hydrogen atoms under the same circumstances, Fujiwara said.
Aiming the lasers and microwaves precisely at the antiatoms using theright settings is very difficult right after the antiatoms are formed becausethey are in what's called an excited state — the positrons are orbiting thenucleus of the antiatom, but they're very far away, and they're constantlychanging their orbit.
Over time, they reach a stable orbit close to the nucleus known as the"ground state." That allows the lasers and microwaves to be aimedwith high precision. Theoretical calculations show that after several minutes,the antiatoms should all be in the ground state.
Studying the effect of gravity on antimatter is particularlychallenging because gravity acts so weakly compared to other forces onparticles with such a tiny mass, so a lot of time is needed.
"The possibility of studying gravitational effects really becomefeasible now," Fujiwara said. "That’s something I’m personallyinterested in pursuing."
About one-third of the 40 physicists who make up the ALPHAcollaboration are Canadian. The rest are from Brazil, Denmark, Israel, Japan,Sweden, the U.K. and the U.S.
Canadian funding for the project comes from NSERC (National Science andEngineering Research Council, TRIUMF, AIF (Alberta
The trouble with antimatter
Antimatter is produced in equal quantities with matter when energy isconverted into mass — this happens in particle colliders and is believed tohave happened during the Big Bang at the beginning of the universe. That's whyphysicists are puzzled about why there is no longer a significant amount ofantimatter in the universe.
But it's very difficult to study antimatter in order to answer suchquestions because antimatter and matter are both annihilated the moment theyencounter each other, producing pure energy.
The problem is our world is made almost entirely of matter, includingthe walls of any container that might be used to hold antimatter.
Charged antiparticles can be kept away from the walls of a matter-basedcontainer using electric fields, but neutral antiatoms are much harder to trap,and are typically annihilated as soon as they are created.
Last November, the ALPHA team reported that it managed to trapantiatoms by taking advantage of a very tiny, weak magnet inside each atom.They created the antiatoms by mixing positrons and antiprotons very carefullyinside a "magnetic trap" — a magnetic field generated by a powerfulsuperconducting magnet. If the newly formed antiatoms were extremely cold andmoving very slowly, the extremely weak magnetic force was enough to keep themfrom hitting the walls of the container.
After the experiment, they let the atoms out of the trap
No comments:
Post a Comment