LHC Has First Collisions After Years of Waiting

An anonymous reader writes "Only four days after the first attempt to send a particle beam around the LHC, we have arrived at the point when all four experiments got their first real collisions from the machine. This was met by celebrations and champagne, as people have been waiting years and years for this moment. It is a testament to the engineering of the machine that collisions were reached already, so few days after restarting. The LHC had already demonstrated ca 10h stable beams, and now also stable beams in both directions at the same time. In the coming weeks, we need only wait for increased intensity and the first attempts at acceleration."

Comments

Data from first collision through CMS detector

[TooMuchToDo]

http://cmsdoc.cern.ch/cms/performance/FirstBeam/pictures221109/CollisionEvent.png

The beams aren't squeezed right now, just centered. You have a higher probability of collisions when they're squeezed (which will be coming up shortly). It was very cool to be in the control room when the first collision took place =)

Re:Data from first collision through CMS detector

[42forty-two42]

And here are the real webcams.

Crossing the Streams

[sexconker]

Despite all the hoopla, all they've really done is cross the streams.

Today the LHC circulated two beams simultaneously for the first time, allowing the operators to test the synchronization of the beams and giving the experiments their first chance to look for proton-proton collisions. With just one bunch of particles circulating in each direction, the beams can be made to cross in up to two places in the ring. From early in the afternoon, the beams were made to cross at points 1 and 5, home to the ATLAS and CMS detectors, both of which were on the look out for collisions. Later, beams crossed at points 2 and 8, ALICE and LHCb.

An important step, sure. But low-speed collisions and beam tuning are not what the LHC is designed to do. It's akin to a pitcher throwing a few warmup pitches - he won't be bringing the heat til he's out on the mound, he's just trying to make sure he shoulder is fucking healed after he blew it out in his first opening game.

By the end of the year we should have some real info about the first useful collisions.

GNOME

[Ivan Stepaniuk]

Some screenshots at the CERN site show GNOME's 'Clearlooks' window manager theme. At least BSOD will not be a source for further delays.

Re:Banging rocks together...

[Gryle]

Scientific research often usually comes down to "what happens when I mix these two things together?" and "poke it with a stick and see what happens." The biggest variation is the type of stick we use.