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Posts Tagged ‘first beam’

Very early this morning we got the first lead-lead collisions at the LHC!  I am all a twitter.  This is a very exciting time.  I just arrived at CERN today and I am very, very jet-lagged, so I’ll keep this short.

Pictures.  What you all want to see is pictures.

Here are some event displays with the first Pb+Pb collisions seen by ALICE.  This is an example:

These event displays only show information with the Inner Tracking System (ITS).  Our main tracking detector, the Time Projection Chamber (TPC), was off for these collisions.  The reason is that the beams were not perfectly stable for the first collisions and we did not want to damage our TPC.

And check out this video of an event display (the original video is here):

And now that we have lead-lead data, we have a lot of work to do.  Expect the first lead-lead paper soon.  It will be a multiplicity paper like ALICE’s first few proton-proton papers.  We will just measure the number of charged particles in an event.  This information alone will tell us a lot about heavy ion collisions – the first estimates for how many particles we should see in an event varied by a factor of 4, from 2000-8000 tracks.


LHC Collisions Playlist

Thursday, November 12th, 2009

The first LHC collisions won’t be for at least a few weeks, but there’s a critical question I’m sure you’re already asking: what music should I listen to for the big event? Here are some suggestions:

Collide – Howie Day
Key lyrics: “Out of the back you fall in time / I somehow find you and I collide”

Surfin Bird (Bird is the Word) – The Trashmen
Key lyrics: “A-well-a everybody’s heard about the bird / B-b-b-bird, bird, bird, b-bird’s the word.”

If You Don’t Cry – The Magnetic Fields
Key lyrics: “Another five years off your life / If you don’t cry, it isn’t love.”

Collider – Les Horribles Cernettes
Key lyrics: “You never spend your nights with me / You don’t go out with other girls either / You only love your collider”

Still Alive – GLaDoS and Jonathan Coulton
Key lyircs: “This was a triumph / I’m making a note here: huge success”

Have more song ideas? You know what to do: comment here, on Facebook, or on Twitter — with enough good suggestions, there might be another post!


More on LHC beam in CMS

Sunday, November 8th, 2009

As noted here, CMS started observing LHC beam splash events for the first time in 2009 on Saturday evening (Geneva time).  What is happening here is that a beam is sent into a collimator upstream of the CMS detector, resulting in a spray of particles that then go through the detector, lighting up a number of components.  Such splashes are happening again this evening.  (Accelerators usually do their best stuff on the weekend, when there are fewer people tinkering with things.)

Darin Acosta, one of the detector operations leaders, has been posting interesting news from the detector as it comes in — follow him here.  Of course there is much further to go yet, but there is a lot of excitement in CMS as we end our fourteen months of patience and preparation and start detecting beam particles once more.


from the media center…

Wednesday, September 10th, 2008

I was just handed an ATLAS postcard with a graphical display of one of the first debris events on it.

All I could think was: Wow, those guys are fast!


first CMS beam event

Wednesday, September 10th, 2008

This morning, at about 9:55 CERN time, the LHC beam was dumped on a
collimator just upstream of CMS. This is when we first saw for the
first time the beam activity in the detector, a picture is attached.

What you see is the debris of the beam particles hitting the collimators. The resulting shower then produced a lot of activity in our hadron calorimeter (blue) and some hits in our muon system (small green rectangles). And all of those dirty messy particle showers from three different angles, which is why we have three different figures for the same events. The inner detector was turned off due to the beam still being very unstable and it can actually be damaged easily by randomly flying particles.

I am so excited! I am currently in the CERN media center where things are buzzing with journalists from all over the world! Before I forget to brag about the fact that the google home page is LHC themed today!

First CMS beam event


For the Rest of Us at CERN

Wednesday, September 10th, 2008

auditorium at cern, 0915 on 10 septThose of us here at CERN who don’t have something to do in one of the control rooms are in the auditoriums, watching the same webcast that anyone can watch:

See the webcast here

They’re putting the machine on right now. There was just a big burst of applause for the first milestone… I’d better stop blogging and go watch!

Update, 10:20: They’re telling us here that the beam has now made it around to ATLAS, seven eighths of the way around the LHC. See anything yet, Adam?

Update, 10:24: The LHC has gone around the entire ring! We just saw two spots at point 2, which means we were seeing the injected beam and the same beam on the second loop. Less than an hour, and already we’ve achieved the main goal of the day: the beam goes around and everything works. The room here broke into thunderous applause when we saw the two dots!


Why I will sleep tonight

Tuesday, September 9th, 2008

Well, somebody should play the contrarian around here, and today it will be me.

On the first day ever of classes at the University of Chicago in 1892, President William Rainey Harper declared that there should be no particular celebration of the event, saying that the first day should go on as if the university had existed for a thousand years already.  And so I feel about the LHC.  Tomorrow will of course be a milestone in the history of the project, but let us keep in mind that this is not all about one day.  Two decades of effort by thousands of people have preceded it, and the first circulation of beam can be viewed as just one more evolutionary step in that context.  And like Churchill said, this is not the end, or even the beginning of the end — it’s only the end of the beginning.  What comes next, after our friends in the press have left and the Champagne bottles have been drained, is what we all really signed on for: the scientific discoveries that, over the next decade, are going to change our understanding of how the universe works.  At the University of Chicago’s decennial celebration in 1901, Harper said, “In these modern times ten years count for as much as one hundred years did formerly.”  I think we’ll be saying the same thing in 2018.

Now, this is all easy for me to say, as I’m not on the CERN site to share the excitement, and in fact the festivities start at 2 AM my time.  Not quite so festive for a day person like myself!  So, best of luck to all of my colleagues and fellow bloggers in Geneva; I’ll check in on you around 4 PM your time to see how things are going.  I’m sure there will be good news, and thus I will sleep soundly.

Oh, and for all of you who are wondering whether the LHC has destroyed the Earth, you can check on the status here.  Like I said, I’m going to sleep soundly.


Are we there yet ?

Friday, August 8th, 2008

It is like a fish market in the main control room now. Today, Aug 8, 2008 at 16:40 all the safety interlocks tests in the LHC were completed and the machine was fully closed for the first beam tests. However, it hasn’t without some small hickups, a fire alarm in the pre-injector (PS) and along with some other cabling problems, small panics before the big thing…

It is about 6pm now and they have managed to put the beam through the injector chain and all the way through the transfer line just 15 m before the LHC tunnel where it is stopped. The stopper in the transfer line will be removed shortly (6-8pm). The plan is to then adjust the timing of the injection magnets to put the beam into the LHC and thread the beam thereafter the sector 2-3 before midnight. Slightly optimistic but when you wake up tomorrow could the “first beam in the LHC” already be an old story ?