The European Organization for Nuclear Research (CERN) announced on Friday that it had circulated beams of sub-atomic protons in its Large Hadron Collider at 3.5 trillion volts in both directions around the 27-kilometer (17-mile) tunnel which straddles the Swiss-French border.

"This is the highest energy yet achieved in a particle accelerator, and an important step on the way to the start of the LHC research program," a statement issued by CERN said.

The Large Hadron Collider is designed to probe the origins of the universe by recreating the conditions that followed the Big Bang and to learn more about the sub-atomic structure of matter.

"We have crossed an important milestone that showed that we can reach an energy of 3.5 TeV (tera electron volts)," said CERN spokesman James Gillies.

CERN scientists hope to unlock the secrets of the universe

The next step is expected to be announced in several days when CERN starts colliding beams in a new round of research at 7 TeV, or twice Friday's level.

Before the LHC experiment, no particle accelerator had exceeded 0.98 TeV. One TeV is the energy equivalent expended by a flying mosquito.

German fails to prove atom smasher will end world

Meanwhile, a German woman who fears the Earth could be sucked into a black hole by the activity of the Large Hadron Collider has lost her court appeal to halt experiments at the CERN accelerator.

The woman, who has not been named, had gone through the German judicial system to seek an injunction but lost her final appeal last week at the Federal Constitutional Court in Karlsruhe.

Germany's highest court threw out the case after determining that the woman was unable to give a coherent explanation to substantiate her claims.

Other opponents have also sought to stop the collider, fearing either a black hole, or a theoretical particle, known as a strangelet, which would turn the planet into goo.

gb/dpa/ap/AFP

Editor:Susan Houlton