This is the first time I blog and I expect it to be a very enjoyable experience, for me and – hopefully – for the reader! While thinking of the first post, I recalled a “colloquium” held at CERN a couple of weeks ago. (For Quantum Diaries new comers, CERN is the world’s largest particle physics laboratory. Located at the border of Switzerland and France, it hosts particle accelerators and was the site of several milestone discoveries in our field.) The invited speaker was the Intel CEO. Regardless his familiarity with high tech., he did not hide deep fascination when exposed to the technological challenge we are facing to design, build, commission, operate, and maintain our instruments.
The idea of the Large Hadron Collider (LHC), began in the early 1980s while Spring 1992 marked the real beginning. The machine was finally turned on September 10th 2009, but activities had to be interrupted soon after due to an electrical failure. Operations will resume in late 2009. But, what is the LHC ?
The LHC accelerator
It is a circular particle accelerator sitting 100 m underground with a circumference of 27 km. At full power, trillions of protons will race around the LHC accelerator ring 11245 times a second, traveling at 99.99% the speed of light. Two beams of protons will each travel at a maximum energy of 7 TeV (tera-electronvolt), corresponding to head-to-head collisions of 14 TeV. Altogether some 600 million collisions will take place every second. The LHC is the emptiest space in the Solar System. To avoid colliding with gas molecules inside the accelerator, the beams of particles travel in an ultra-high vacuum pipe with a pressure ten times less than the pressure on the Moon. The LHC is a machine of extreme hot and cold. When two beams of protons collide, they will generate temperatures more than 100 000 times hotter than the heart of the Sun, concentrated within a minuscule space. By contrast the LHC is kept a the temperature of -271.3C (1.9 K), even colder than outer space. The number talks by themselves: the LHC is one of the greatest endeavour in science!
Come and visit CERN, if you can. You will have a unique opportunity before the door is shut for the years to come. Otherwise, you can learn more at http://cdsmedia.cern.ch/img/CERN-Brochure-2008-001-Eng.pdf. This gigantic adventure is however just the beginning. When the protons collide, they fragment into constituents which subsequently can combine to form new particles. This “event” is recorded by detectors sitting along the ring. Detectors to come in the next posts.
