Click for more photos

This photo, taken on July 22, shows the retooled Beijing Electron-Positron Collider II .

A Beijing-based electron-positron accelerator -- China's biggest scientific experimental device -- has been retooled successfully for trial operation, the Chinese Academy of Sciences (CAS) said on Tuesday.

The upgraded device, called the Beijing Electron-Positron Collider II (BEPCII), was retooled at the Institute of High Energy Physics under the CAS. The project started in January 2004 and cost 640 million yuan (93.8million U.S. dollars).

The Beijing Electron-Positron Collider (BEPC), the BEPCII's predecessor, was originally built in 1988. It was previously the world's eighth largest high-energy accelerator experiment center.

Institute director Chen Hesheng revealed the upgrade would help the BEPC attain its forward status as one of the most advanced ideal colliding experiment facilities of its kind; it would maintain the leading forward role of China in the field of global high-energy physics.

To add a new storage ring to the existing ring of the collider to spur the electron and positron beams' movement and collision in the colliding zone, the retooled collider BEPCII had 93 pairs of electron beams against the original's one pair. Its luminosity, a leading parameter, was 100 times stronger than that of the original BEPC.

The electron-positron collider is now applied to a range of research topics covering material, pharmaceutical, semi-conductor and micro-electronic researches.