Some of the world's top physicists made a hard yet crucial decision over the technological route of the construction of the largest-ever particle accelerator in history -- a step that may help us solve many more secrets of the universe.

The International Committee for Future Accelerators (ICFA), meeting during an international physics conference in Beijing last week, endorsed the recommendation of a panel of physicists on the technology choice for a proposed future international particle accelerator.

The 12-member International Technology Recommendation Panel (ITRP), chaired by Barry Barish of the California Institute of Technology of the United States, recommended the superconducting technology be adopted for the proposed International Linear Collider.

The superconducting technology has been developed by an international collaboration centered on the DESY lab in Germany.

The rival technology, which operates accelerating structures at room temperature, has mainly been developed in the United States and Japan.

According to the recommended proposal, the collider would occupy a tunnel of up to 40 kilometers long with experimental areas located at the midpoint, where the electrons and positrons collide.

"A decade ago such a high-energy linear collider was just a dream -- a vision for a revolutionary tool to answer some of the most fascinating and compelling questions about the nature of our universe," said Cornell University's Maury Tigner, chair of the International Linear Collider Steering Committee, which appointed the panel.

Particle research

During their research, physicists discovered the universe, from stars, earth and trees to everything we see around us, is made up from a small number of basic building blocks, which are termed by scientists as elementary particles.

Some are stable and form the normal matter but others may live for just fractions of a second and then decay to the stable ones. All of them coexisted for an instant after the Big Bang.

In order to look back in time and to get a glimpse or even study how the universe, the stars, the earth or even ourselves are formed, scientists have attempted to recreate an environment somehow similar to the Big Bang.

What do they do? They have found that the environment similar to the Big Bang, or an enormous concentration of energy, can be reached somehow in an accelerator.

Today, it is estimated there are around 10,000 particle accelerators in the world. Over half of them are used in medicine and only a few in fundamental research.

In medicine, accelerators are used to obtain better imaging for more accurate diagnosis and to engage in therapy, fixing only to definite tissues or organs.

Accelerators are also indispensable assistants to researchers who have unraveled the structure of viruses like HIV, the age of artifacts like ancient cave paintings and the events that happen in the epicenter of stars.

Accelerators are used in industry as well. Engineers have turned to accelerators to improve the quality of manufactured goods, to sterilize medical equipment and food, to make semiconductors for the computer industry, to refine aircraft engines and artificial hips, to investigate how car engines wear out, to look for contraband in harbors and airports, and to help survey for underground tunneling.

New international accelerator

However, scientists need to go further in their studies of the compelling questions about dark matter, the existence of extra dimensions and the fundamental nature of matter, energy, space and time, and eventually about ourselves.

The proposed international linear collider may help.

Thus, the ITRP's decision is viewed as opening the way for the world particle physics community to unite behind one technology and concentrate their resources on the design of a superconducting-technology linear collider.

Chinese contribution

Chinese scientists, represented by the Institute of High Energy Physics (IHEP) under the Chinese Academy of Sciences, also participated in the international particle research, according to Chen Hesheng, director of the institute.

In fact, one spin-off of the international cooperation has enabled the IHEP to introduce the Internet to China.

Chen said at a press conference that Chinese physicists will get more involved in the future.

The institute also hosts an electron positron collider that has been running for 15 years.

"With the experience gained from our previous work with the collider, we are willing to make more contributions to this exciting project of building the international linear collider," said Chen.

(China Daily August 25, 2004)