LHC Physicists Use 'Ping-Pong Ball' Test: Maintenance Continues on Collider

The Large Hadron Collider (LHC) has been only working for five years, but now it's shut tow for a two-year revamp to double its power in order to aid its potential for helping scientists make new discoveries. As a part of this work, physicists are using some unusual techniques to test the LHC.

The LHC itself is massive, stretching for miles at the Organization for Nuclear Research (CERN) in the French village of Cessy. In fact, technicians routinely use bicycles to get around the collider's 17-mile-round tunnel. Yet its size serves a purpose; it could potentially help identify the nature of strange dark matter around planets, stars and galaxies, or even help discover new particles.

The LHC's shutdown began on Feb. 13 as researchers scrambled to work on maintenance that occurred across CERN's whole particle accelerator chain in preparation for higher-energy running. This work will include the consolidation of the 10,170 high-current splices between the superconducting magnets as 1,695 interconnections between each of the cryostats of the main magnets are opened. Teams will work on about 500 at a time.

This maintenance is primarily due to a 2008 incident that crashed the facility and which CERN blamed on a faulty electrical connection between two magnets. The event led to extensive collateral damage. Although the lab was able to do a quick fix, the LHC has been unable to run at full power since then.

The new upgrades, though, should fix the LHC's power problem. As part of this maintenance, physicists have sent a sterilized, slight-smaller-than regulation ping-pong ball through a 2-mile section of the LHC. The scientists were searching for possible defects in the connections between magnets that can occur when temperature changes.

The ball, which is called a radio-frequency ball, was first developed in 2007. It carries a small transmitter that allows scientists to track its progress through the section of the LHC, according to Symmetry magazine. Since the machine's interconnections are installed at room temperature but must operate well below freezing, it's important to make sure that they all fit properly.

The beam pipes are fragile," says Vincent Baglin, the leader of the LHC beam vacuum section at CERN, in an interview with Symmetry magazine. "We always have to check and crosscheck to minimize any problems. This is a simple test that can prevent complicated issues."

While the LHC has passed the "ping-pong" test, it still has many more to undergo. The LHC is currently set to restart in 2015, continuing its search for the particles that make up our universe.