From
http://www.britainus...ticles_show.htm
First Controlled Production Of Atomic Antimatter
UK Engineering and Physical Sciences Research Council, 18 September 2002
Physicists have just achieved the world's first controlled production of anti-hydrogen atoms, the crucial first step towards precision studies of its properties.
This achievement has opened up the potential to cool, trap and study anti-atoms.
A team from the University of Wales - Swansea, led by Professor Michael Charlton, played a key role in this major breakthrough as part of an international consortium, ATHENA. The Swindon based Engineering and Physical Sciences Research Council provided funding for the Swansea team of $1.9 million (£1.2 million) over the past 6 years.
"This is a milestone that has opened up new horizons, to enable scientists to study symmetry in nature and explore the fundamental laws of physics which govern the universe, said Professor Charlton. "We are also asking the related question 'where has all the antimatter gone?' Today our Universe appears to consist entirely of matter: but we know that equal amounts of matter and antimatter were created in the Big Bang."
The first step in producing anti-atoms is to confine positive and negative antiparticles in traps at very low temperature. Then they are slowly allowed to react in ultra-high vacuum, which is essential, as the antiparticles will annihilate when they meet normal matter. The result of the interaction is the first and simplest of anti-atoms, anti-hydrogen.
The breakthrough is timely as it coincides with the centenary of the birth of Paul Dirac, who first predicted in 1930, that every particle has an equivalent antiparticle. The British physicists at Swansea played a vital role in the project by making the trap for the positively charged antiparticles, known as positrons.
Professor Charlton acknowledges the support he has received for this research, "EPSRC took a chance in funding this highly speculative project in 1996. This acted as a catalyst, which persuaded other countries to contribute to the ATHENA consortium."
Notes:
For 70 years scientists have known that all matter from which the universe is made, has a mirror image. Matter is made up of atoms, which are composed of two types of charged particles, protons (positive) and electrons (negative). Anti-particles, which make up anti-matter, have the opposite electric charge. Anti-electrons (known as positrons) come from radioactive substances. The radiation from these positrons when they annihilate is used in medical imaging, a technique known as 'positron emission tomography'. Anti-protons on the other hand, can only be made at large facilities, for example, the unique Antiproton Decelerator, at CERN - the European Organization for Nuclear Research near Geneva. This decelerator is a ring-shaped tunnel that slows down anti-protons and reduces their energy, an important step in making antimatter atoms.
Paul Dirac, born in Bristol 100 years ago, realized that the theory of quantum mechanics used by physicists to describe atoms, was not consistent with Einstein's theory of special relativity. As a consequence of his mathematical results, Dirac realized that, unexpectedly, there must also exist, sub atomic particles with opposite charge to electrons and protons. He predicted the presence of positively charged anti-electrons and negatively charged anti-protons in 1930, when he was only 28. He won the Nobel Prize for Physics in 1933.
Scientists soon had evidence of the existence of these antiparticles. However, the creation of the world's first low energy anti-atoms has taken much longer. With sophisticated traps using electric and magnetic fields, and in a low temperature environment, the first few thousand low energy anti-atoms have now been made. The anti-particles are made to react to make an anti-hydrogen atom by bringing them together in a small volume of a few cubic centimeters. How do we know they are there? When the anti-atoms are formed they migrate out of the trap; they have no charge so can no longer be confined. On leaving, they collide with the trap wall and annihilate, giving off a characteristic signal of high-energy light (two gamma rays) and a splash of charged particles called pions, all caught by a special detector.
The ATHENA consortium is made up of around 40 scientists from 11 different institutions worldwide. There are 5 in the Swansea team; in addition to Professor Charlton - Research Fellows Dr Lars Jørgensen and Dr Dirk Peter van der Werf and postgraduate students Terri Watson and Matt Collier.
The Engineering and Physical Sciences Research Council (EPSRC) is the UK's main agency for funding research in engineering and the physical sciences. The EPSRC invests more than $619 million (£400 million) a year in research and postgraduate training to help the nation handle the next generation of technological change. The areas covered range from information technology to structural engineering, and mathematics to materials science. This research forms the basis for future economic development in the UK and improvements for everyone's health, lifestyle and culture. EPSRC also actively promotes public awareness of science and engineering. EPSRC works alongside other Research Councils with responsibility for other areas of research. The Research Councils work collectively on issues of common concern via Research Councils UK. Website address for more information on EPSRC: www.epsrc.ac.uk
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An aside:
Let's hope we don't find to many developments along the lines of the following website on a-m bombs, intellectually stimulating as they may be:
http://www.masterevi...files/frame.htm
On the good side, a-m space propulsion can be found at:
http://www.engr.psu....troduction.html
from Penn State University (very interesting)
Edited by Avatar Polymorph, 10 January 2003 - 08:17 AM.
