Last week whilst traveling to work, I noticed huge plumes of steam rising over the Geneva jura – just one sign of things beginning to start up again here at CERN.
The source of the steam are the huge cooling towers required by the Large Hadron Collider (LHC). A complex cryogenic system sits in the tunnel of the LHC in order to cool the tunnel and equipment to 1.9 kelvin. This is no mean feat, as 1.9 kelvin equates to -271C or -456F which is much colder than outer space (around 2.7 kelvin). However, the temperature needs to be so low so that the magnets can become ‘super-conducting’ – conducting electricity with zero resistance.
Not only is it very difficult to achieve this low temperature, but the equipment within the tunnel has had to be carefully designed to withstand such low temperatures. As we all know from our early science lessons at school, if you cool a liquid down the molecules have less kinetic energy, and become a solid. When a solid is cooled the same occurs, and basically leads to the solid contracting.
This was one of the reasons for the problem when the LHC started up last year – the ‘quench’ described by the physicists at CERN was essentially caused by a faulty magnet. Part of the magnet designed to be able to withstand the contraction fractured, leading to a leak of liquid helium, which then caused problems to the surrounding areas of the LHC tunnel.
CERN physicists have therefore spent the last 13 months carefully checking and replacing magnets, and installing a new quench protection system.
The announcement that 1.7 kelvin has been reached is indeed exciting news, as it means that the physicists at CERN can begin to feed particles into the ring, and test the new quench protection system.
The next developments to watch out for will be the circulation of a beam around the whole LHC ring, expected by the end of November. At the moment, the first collisions are likely (realistically) in January.
On another note, talk in Restaurant 1 at CERN have turned to news of Adiene Hicheur, a French-Algerian physicist suspected of links with Al-Qaeda.
The story broke first on the French news sites, before hitting the English news stands later in the day. Quite interestingly Hicheur works for the same experiment as me – LHCb, so I heard about the news before most at CERN.
Some of the news stories surrounding this have been quite funny. I guess this is because most don’t really understand what CERN does, and then there’s the fact the organisation’s title is ‘Organisation Européenne pour la Recherche Nucléaire’ and we all know what happens to people when they hear the word nuclear don’t we….
But, contrary to some of the more far fetched stories there’s not that much to worry about. Although it is a bit strange to think that someone associated with Al-Qaeda might have been sat just down the corridor from me, he actually had very little security clearance, and didn’t have access to the LHC tunnel or ‘the pit’ where the LHCb experiment is housed. Plus, even if he did, i’m not sure what he’d be able to do with it!!
Oh and to all those with ideas of antimatter in their heads and cities being destroyed (thanks Angels and Demons)… it’s not like you’d be able to walk out of the door with a tank of it hidden under your coat! And even if antimatter were easily portable, CERN has only produced enough to light an electric light bulb for a few minutes in all the years they’ve been studying antimatter….!