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dimensions of particle physics

dimensions of particle physics

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Liveblogging: LHC first beam day begins!

September 10, 2008

Liveblogging: LHC first beam day begins!

The LHC control room is buzzing with activity as CERN scientists and technicians prepare to circulate the beam all the way around the 27km tunnel for the first time.

LHC Project leader Lyn Evans and CERN Director-General Robert Aymar have made brief addresses to staff and viewers, announcing the staged process they will use to try to circulate the beam for the first time.

Many people are having trouble getting a connection as there are only 2000 web connections available. However, the process seems to be progressing and everybody is nearly ready to go as I write. If the connection holds up, I'll try to update this as the attempt continues.

9:30 a.m. (All times are CERN local time): Many senior physicists are milling around including past Directors-General of CERN. Evans is explaining the process of injecting the beam and giving status updates of where the beam is.

9:33: Beam is in the LHC now. A small flash appeared on a monitor to indicate beam has been injected. The stopper is about to be removed. They are about to attempt circulation through the first 3 kms.

9:35: The beam dump has been removed and they are ready to inject again.

9:37: The beam is already making progress through the first sector, from point 2 to point 3. Time to remove another block and go further.

9:38: Applause breaks out as the beam makes it through the second sector to point 3.

9:40: Next injection will continue beyond point 3 to point 5.

9:44: No beam made it through on this cycle. Time to try again on the next cycle.

9:45: The beam has made it through the CMS detector at point 5. Each success is seen as a flash of light on a beam monitor. Between each test, they remove a beam block so they can send it the next step. So far, the beam is replicating progress it has made before in tests over the past few weekends. From here on in, it is all new. Interestingly, Lyn Evans insisted that they not do a secret trial run before hand but they will attempt this live under the scrutiny of the world.

9:54: The beam made it to point 6, new territory for the LHC beam! More applause breaks out. The whole beam might now be dumped and started again. Evans is insisting that the beam quality needs to be better before trying to send it further.

10:05: There are still some decisions being made about whether to send the beam all the way around. (That means through point 8 and back to point 2 where the injection begins.)

10:06: The beam is through to point 7! More applause breaks out. The beam needs some reshaping and steering so it is in good shape to send through to point 8.

10:09: The LHCb is at point 8 so that is the next place to send the beam. People are sitting in the control rooms for each experiment watching progress. As the beam passes through the detector, various signals appear although they are very different ones to when beams are colliding inside the detectors.

10:12: The reshaped beam has made it to point 8 now and the excitement is clearly building in the control center. Only one more experiment to pass through and then back to the starting point.

10:16: "Masters of the beam"--the commentators are pulling out all the hyperbole as it goes. However, it is fair to say this is going as smoothly as anybody could have hoped and progress is faster than most people expected.

10:17: The beam has made it to ATLAS! Through all the experiments and nearly a complete sequence. Lyn Evans commented that he is going to win his bet. It seems that he was betting they would get the beam all the way around in one hour. They have about 10 minutes left to achieve that!

10:20: All five living Directors-General of CERN are present for the event. The first four have all died. That gives a sense of the long times scales of laboratories like this.

10:23: The last block is being removed so the beam can travel the last sector. Only a minute or so to go.

10:25: They made it! The beam has made it all the way around the LHC! Everybody is ecstatic in the control room. Two spots of light appeared as a flash on a monitor to signal the beam was all the way around.

10:28: The whole process took less than hour, which is faster than expected. People are happy but they are still hard at work because they want to get the beam all the way from injection for a full circuit of the accelerator in one go, which will be the standard way the LHC operates.

10:30: The group is taking a break for a moment before they try to get more beam circulation or try sending the beam the other direction. The experiments are all checking out how their equipment is seeing the beam.

10:42: ATLAS saw a big burst of muons as the beam passed by. The scientists there are already collecting the data for analysis to get the detector ready for collisions in a few weeks. All the other experiments are engaged in similar activities.

10:50: The main control center is looking a lot calmer now. There is still a lot of energy but people aren't quite so anxious now. I hope Lyn Evans won something great in his bet, but I am sure that the satisfaction of seeing this machine through to this point is a big enough prize for the day.

10:56: You can see the beam status diagram online.

11:00: The press release about the successful circulation of the beam is out now.

11:02: The team is definitely going to try to get the beam circulating in the opposite direction today also.

11:09: So many people are trying to read the blog that I can't actually update it successfully any more so I'm calling it a night here, will get a few hours sleep, and then be up to check if the beam has made it other way through the machine. The team is hoping to start that process at noon, CERN time.

Enjoy watching the feed from CERN and bask in the excitement of this stage of the LHC startup!