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The Large Hadron Collider (LHC), the world's largest and highest-energy particle
The Large Hadron Collider (LHC), the world's largest and highest-energy particle accelerator complex, was started on September 10, when the first proton beam was circulated around the 27-km (17-mile) length of the accelerator's circular chain, first clockwise and then in the opposite direction, a prelude to colliding the two beams.

The system of magnets, which should have accelerated the beams to about 99.999999% of the speed of light, was not shut down. The beams were not forced to a collision point.

The first collision experiment was scheduled for September 21.

However, on the third day after the first beam was injected into the collider an accelerator-cooling transformer malfunctioned, sending the temperature to 4.4 Kelvin (-269 Celsius). Normal operation resumed several hours later.

Glitches that can temporarily stop operations, for shorter or longer periods, are considered normal, especially during early attempts and with such a unique system as the LHC.

Malfunctions were first registered in the collider during its construction, when composite fixtures of a superconducting magnet crumbled under asymmetric loads due to a miscalculation at the design stage.

These magnets are used to focus the beam before injecting it on a collision course with the opposite beam. The magnet was not properly tested before installation.

A much more serious accident occurred on September 19, when one of more than 9,000 superconducting magnets entered a resistive state. The problem was thought to have been caused by a quench in the connection between two magnets that may have melted a connection in a stretch of cabling called the bus bar.

Quench occurs when part of a superconducting magnet heats up and causes superconducting properties to be lost.

Such malfunctions were forecast at the design stage, but subsequent events were completely unpredictable. The magnet's temperature continued to grow and temperature in the affected part of the tunnel rose to about 100 Kelvin (-173 Celsius). As a result, approximately one ton of liquid helium used to cool the magnets was vented into the tunnel. Vacuum conditions in the beam pipe were lost.

The accident was not dangerous to personnel, but repairs may last longer than anticipated. To begin with, the faulty section must be heated to normal temperatures and then, after repairs, re-cooled to absolute zero (-273 Kelvin) to ensure the magnets' superconductivity.

Repairs will take two months; nevertheless, it has been decided to restart the collider only in the spring of 2009 or even later.

The European Organization for Nuclear Research (CERN) normally shuts down for winter, partly to save money on electricity during this period of peak demand.

In the spring, restart operations at the collider will proceed in several stages with a gradual increase in energy before beams are injected into the LHC. It is humanly impossible to rule out malfunctions at this stage, because the collider is a very complicated mechanism that needs more testing and refinement.

One of its tasks is to explore the validity and limitations of the Standard Model, the current theoretical picture for particle physics. It is theorized that the collider will confirm the existence of the Higgs boson - or the "God particle" - thought to be responsible for giving all other particles their mass. This would supply a crucial missing link in the Standard Model and explain how other elementary particles acquire properties such as mass.

Scientists believe that the collider will help them reproduce the so-called Big Bang - at a very low level, of course - which resulted in the creation of the Universe 13.5 billion years ago.

The essential idea is that the universe has expanded from a primordial hot and dense initial condition at some finite time in the past and continues to expand to this day.

The trouble is that nobody knows what consequences this experiment may have. Some physicists fear the collider may run amok, provoking an Earth-shattering catastrophe.

So far, the collider's official inauguration is still expected on October 21, 2008. Trouble or not, there must be festivities. This is probably a global practice. I remember how metro stations were inaugurated in Moscow in time for a date or holiday, and were then closed for months to clean up glitches.

***

The Large Hadron Collider (LHC) is the world's largest and highest-energy particle accelerator complex designed to collide opposing beams of protons (one of several types of hadrons) with very high kinetic energy. Scientists hope it will shed light on fundamental questions in physics.

Yury Zaitsev is an academic adviser at the Russian Academy of Engineering Sciences.

The opinions expressed in this article are the author's and do not necessarily represent those of RIA Novosti.


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