Anti-matter experiment soon

Press, 2 April 1980, Page 8

Anti-matter experiment soon

NZPA-Reuter Geneva The world’s first largescale experiment with antimatter will start in the European Nuclear Research Centre outside Geneva next year, sources of the 12nation group have said. Essentially, the ex» periment consists in making protons collide with antiprotons at high energy, in the hope the effects of the collision will provide new insight into the forces holding matter together. Anti-matter is not nonmatter, but particles with an electric charge opposite to the one of their apparently “normal” state, like the positive protons at the nucleus of the atom and the negative electron circling around it. Thus, an anti-proton has a negative charge and an antielectron called positron is positive. The research centre is also preparing a project

for a. new installation for electron-positron collisions from the mid-1980s. Created in particle collisions, the anti-proton was believed to have an extremely short lifespan of small fractions of a second until two years ago when physicists at the research centre made a new experiment with a speciallybuilt machine. They created anti-protons by directing a beam of protons on to a small tungsten wire. The protons came from the laboratory’s small proton synchroton-accelerator — each creating three other protons and onh anti-proton on impact. The scientists managed to guide several hundred antiprotons into a small magnetic ring where they were kept circling for 85 hours, meaning that a method had been found for storing these particles.

Encouraged by this development, hailed as a breakthrough in fundamental particle research, the research centre decided to use its huge and powerful super-proton-synchcroton for future collisions between protons and anti-protons. “Such collisions,” the research centre says, “will allow researchers to explore r.ew fields of particle physic*: that would otherwise require accelerators some ten times more powerful than the biggest in the world.” The more a particle is accelerated, the more its mass increases and the easier the effects of collisions can be detected and observed. The super-proton-synchroton theoretically can bring protons near the speed of light. In the envisaged experiment protons and antiprotons would be brought to a kinetic energy of 270 gev

(billion electron-volt). Travelling in opposite ways they would collide head-on with a combined 540 gev on impact. To guide the particles and to observe them on collision a network of tunnels and new special chambers had to be added to the existing accelerators, all of which are underground, straddling the Swiss-French border. Called “cathedrals” because of their size, the two chambers, one in France, the other on the Swiss side of the border, look like tunnels 45m long and . 21m wide, 63m underground. The concrete-coated chambers will house the bulky, electronic observation equipment with which the researchers will work. Con« struction proceeded onl schedule and the new! installation will be fully equipped and operational t® mid-1981.-