Tuesday 16 September 2008

Update - no beam before Thursday

Just as I was completing the last entry, news came in that another 18kV transformer has blown in point 8, and needs to be replaced. As a result, there will be no beam through ATLAS until Thursday evening. The machine may continue with single-turn tests.

All Quiet on the ATLAS front

After a fantastic start-up and following days, the LHC hit a teething problem when a power transformer blew at point 8. As a result, beam could not do full circuits and ATLAS has seen no beam since 12th September, but before that they had the beams circulating for lengthy periods, and had hoped for collisions this Thursday.
The power transformer has now been repaired using a spare from the CMS. The last sector is due back on Wednesday morning, at which point LHC comes out of the commissioning mode. I would guess that we will not see collisions before the weekend, but we have had such good progress in the last 10 days, who knows?!

Thursday 11 September 2008

Flash moves on an 'open' web page

For those struggling to access the flash movies I gave a link for yesterday, I have uploaded them to a page in Lancaster. Be warned, they are large (about 50MB).
http://www.hep.lancs.ac.uk/~rjones/startup_pictures/gallery.html
Forgive the other pictures on the page, they are for the local press in the Lancaster area for articles earlier this week.

Back to earth

After the excitement of yesterday, things are a little quieter today. The accelerator is intending to run with single beams from this afternoon and overnight. ATLAS identified some collisions between protons in the beam and gas in the beampipe overnight, a different sort of beam related event to the beam halo we saw yesterday. We are still trying to time-in the detectors, at which point we can go beyond the full reconstruction of the events (which can produce segements of tracks for example, even if the segments are out of time) and produce something more 'joined up' - at which point we can produce the analysis format.
The UK has received all its datasets, but we are currently struggling with a problem in the disk storage at RAL, which is actually caused by the complex software used to manage the files over the Grid. On the positive side, at least we saw the probelm before the real collision data starts!

Wednesday 10 September 2008

Test go on, but I don't

The tests are continuing, with work currently concentrating on beam 2. There is also a very dense mass formed below this control room - but it is made up of ATLAS members all trying to see the 3-d video and have a little champagne. I am going over to do one more talk with the media, then celebrate today away from the control room. I will bring this blog up to date tomorrow morning with further news.

Beams around both rings

My updates are getting later, but at 17:35 local time the LHC got beams around both rings. This is I think further than people had reasonably hoped to get in the first day. However, I would be very surprised if they tried to bring anything into collision; the beams are only doing a few turns, and you need the rf system to keep them stable for longer.
Still, this is amazing progress, and the detector, software and offline computing all worked pretty well for ATLAS.

LHC goes for another beam injection; new pictures

The LHC are about to attempt to inject a beam once again. In the meantime, there are more images and a very nice FLASH graphic showing how well be have reconstructed the data so far in ATLAS at
http://atlas.web.cern.ch/Atlas/GROUPS/OPERATIONS/prodSys/atlasoracleadmin/10Sep2008/beam/index.php
If this is protected for general readers, I can copy the flash images elsewhere. (I am sure someone will let me know!)

Beam 2 circulates a full turn and is seen by ATLAS

At about 15:08 local time, beam 2 made a full turn and was seen by ATLAS. This is really quite remarkably fast progress!
My apology for the slightly late news, I was being interviewed by 24 TV from Turkey. (It's that kind of a day - I'm pleased to say, all of ATLAS can claim celebrity for the moment.)

Beam now reaches point 3 - 3/4 around

Beam 2 is now 2/3 of the way around the ring; this machine is really starting like a dream. 14:33 CERN time.

Beam 2 injected into sector 78

Beam has been injected into sector 78, but the cryogenics were lost. We now have beam through to point 6, two sectors.

First attempt at injection of beam 2

They are just starting to inject beam 2. It does not seem to have made it yet into the first sector (sector 78 in this case).

And while we wait


And while we wait for the second beam, we note that we have achieved the ultimate recognition. Not a visit from Andrew Marr. Not a Torchwood special on Radio 4. No, a customized logo of the day for Google. Admittedly, the logo looks like it is getting sucked into the collision, but you cannot have everything!

And now to beam 2

After managing to get beam one to complete three circuits of the machine, they are now setting-up to try to inject beam two into the machine.

First and second beam-related events, displayed using the ATLAS eScience event display, ATLANTIS


And the beam goes all the way round at 10:27


First beam circulated at 10:27. Above is the data export log. We saw activity in the calorimeters.....

beam reaches point 1 (ATLAS).

Beam reaches ATLAS at 10:15 - one sector to go. People are frantic in ATLAS, looking for muons from the beam dump into the collimator upstream of us.
The ATLAS run number is 87764.

Beam now from ALICE (point 1) to LHCb (point 8)

Almost there - beam is now going through all but 2 sectors. ATLAS will be the last to seem beam, although we may see muons from the beam dump when they do the next sector.

Beam now going from ALICE (point 1) to point 7

10:05 and we have beam going another sector. There are two sectors to go.

Beam now reaches the beam dump area, half way around

They have now got beam as far as the beam dump, in the old OPAL pit. This means that one of the beams have gone half way around. This is further than the 'synchronisation tests' had managed. Things are really progressing rather well, the schedule of one beam circulating by 11am still seems quite possible.

LHC first official beam in the machine

The LHC ring finally had all sectors cooled to working temperature at about 09:20 CERN time, 08:20 UK time. The first official beam into a sector was at 09:38, which went into one sector. This was after a first attempt that was blocked by beam dump. 
The current estimate for real circulating beam is 11am CERN time.

More news as we have it. ATLAS is ready!