Page 3 of 4

Re: 2010 Briefings, Schedules and Problems

Posted: Mon Mar 22, 2010 5:26 pm
by Xymox
Something is wacky...

Global moderators are missing options to "Change topic to announce, sticky"

Im working on it...

I moved this topic...

Re: 2010 Briefings, Schedules and Problems

Posted: Mon Mar 22, 2010 6:07 pm
by March_Hare
Has the forum been commissioned already?

(sorry for this awful joke. couldn't resist)

Re: 2010 Briefings, Schedules and Problems

Posted: Tue Mar 23, 2010 3:21 pm
by Danny252
Tues
15:00 - 20:00 : Collimator setup 3.5 TeV.
20:00 - 04:00 : LBDS 450 + 3.5 TeV.
04:00 - 08:00 : SF

Weds
08:00 - 12:00 : Measurements at 3.5 TeV.
12:00 - 20:00 : Collimator setup 3.5 TeV.
20:00 - 04:00 : LBDS 450 + 3.5 TeV.
04:00 - 08:00 : Beam dump at 2 TeV.

More playing with collimators and optics, but all at 3.5 TeV, so a few ramps!
Then some Beam Dumping at 2 TeV - no idea why at 2 TeV (maybe so it's quicker to reramp), and not sure what they're testing there.

Re: 2010 Briefings, Schedules and Problems

Posted: Thu Mar 25, 2010 6:41 am
by Xymox
Commissioned !?!? we dont need no stinkin commissionin, we just fly by the seat of our pants..

Yea well this is a production release of PHPBB3 so you WOULD THINK it would WORK..

Hmmm.... of course *might* be operator error.. Naaaaaaaaaa... Just cuz ive never done this before doesn't mean I am not a expert. :rolleyes:

Re: 2010 Briefings, Schedules and Problems

Posted: Thu Mar 25, 2010 11:44 am
by Danny252
* 08:00 - 12:00 : Orbit & optics at 3.5 TeV.
* 12:00 - 20:00 : Collimator setup 3.5 TeV.
* 20:00 - 04:00 : LBDS 450 + 3.5 TeV.
* 04:00 - 08:00 : Collimation check 450 GeV.

They had great fun with dead cryo last night (seems it came back around 0200). Collimator setup is, however, on time and ongoing as I write this, so they did a good job of getting back on schedule. LBDS is Beam Dump Studies iirc, and the 450 GeV collimator study seems likely to be to double check they've not knackered things up for low energy beams whilst configuring for 3.5TeV!

Re: 2010 Briefings, Schedules and Problems

Posted: Thu Mar 25, 2010 12:32 pm
by BenM
Seems there was an emergency beam dump at 12:20-12:40ish CET ... after quite a while with beams running at 3.5TeV. Hope it isn't anything serious - but as it is commented on as successful I guess it was a useful test of the nQPS :D

B.

Re: 2010 Briefings, Schedules and Problems

Posted: Thu Mar 25, 2010 2:41 pm
by DCWhitworth
BenM wrote:Seems there was an emergency beam dump at 12:20-12:40ish CET ... after quite a while with beams running at 3.5TeV. Hope it isn't anything serious - but as it is commented on as successful I guess it was a useful test of the nQPS :D

B.
More cryo problems in sector 23 caused by the ALICE dipole tripping things out. Won't get beam back before 2am CERN time.

Re: 2010 Briefings, Schedules and Problems

Posted: Thu Mar 25, 2010 2:59 pm
by Wallmott
Does anyone know if the beams have interacted with each other at anytime yet?

It would be embaresing if they did it the first time on the 30th and it did not work.

Oh sorry press, we got cryo problems, come back in 8 hours.

Re: 2010 Briefings, Schedules and Problems

Posted: Thu Mar 25, 2010 3:30 pm
by Kasuha
They are actually saying it might happen.
"The LHC is not a turnkey machine," said CERN director general Rolf-Dieter Heuer. "The machine is working well, but we're still very much in a commissioning phase and we have to recognize that the first attempt to collide is precisely that. It may take hours or even days to get collisions."

Re: 2010 Briefings, Schedules and Problems

Posted: Thu Mar 25, 2010 3:33 pm
by Wallmott
Kasuha wrote:They are actually saying it might happen.
"The LHC is not a turnkey machine," said CERN director general Rolf-Dieter Heuer. "The machine is working well, but we're still very much in a commissioning phase and we have to recognize that the first attempt to collide is precisely that. It may take hours or even days to get collisions."

Yeah i also read that.

But have the beams interacted at any point yet?


I remember last year that it did and they got some colissions before they expected because the beams were interacting with each other it and then it leaked out to the public.

Re: 2010 Briefings, Schedules and Problems

Posted: Thu Mar 25, 2010 4:05 pm
by Kasuha
Wallmott wrote:But have the beams interacted at any point yet?


I remember last year that it did and they got some colissions before they expected because the beams were interacting with each other it and then it leaked out to the public.
No, they're loading proton bunches in a way which does not allow them to meet at any of the experiments. Last year they were intentionally loading bunches to have chance to collide at experiments to give them calibration data and even dedicated some reasonable time just to colliding. Now they are avoiding any collisions - I believe at least partially it is because they want to do it on 30th the first time. But the fact is, they are still pretty busy setting things up so there wouldn't be too many collisions anyway.

Another thing is, collisions introduce beam losses. And if they want to find the optimum beam trajectory with minimum losses collisions (and subsequent losses) would make it much more difficult.

Re: 2010 Briefings, Schedules and Problems

Posted: Thu Mar 25, 2010 4:19 pm
by Harbles
The transformer for the Alice Dipole power converter just shorted, it will take a few days to replace. They should be able to continue with beam commissioning but Alice will not be able to gather data with the dipole on till it's fixed.
I imagine a some of the items that were reused from LEP will be problematic as things progress.

Re: 2010 Briefings, Schedules and Problems

Posted: Fri Mar 26, 2010 3:33 pm
by Danny252
26 FRI 1900-2300 LBDS 450 + 3.5 TeV
26 FRI 2300-0300 LBDS 450 + 3.5 TeV
26 FRI 0300-0700 Protection and collimator check - 3.5TeV
27 SAT 0700-1500 Protection and collimator check - 3.5TeV
27 SAT 1500-2300 'Higher' intensity 450 GeV - preparation for stable beams
27 SAT 2300-0700 Two beam operation 3.5 TeV - non-colliding STABLE 2-3h
28 SUN 0700-1500 Collimation 450 GeV - if needed
28 SUN 1500-2300 Contingency
28 SUN 2300-0700 450 GeV Collision STABLE BEAMS
29 MON 0700-1500 Contingency
29 MON 1500-2300 Contingency
29 MON 2300-0700 Preparation MD

Things of Interest:

High Intensity 450GeV on Saturday - may imply multiple bunches.
Two stable 3.5TeV beams afterwards - possibly higher intensity as well?
Collisions - 450GeV stable beams with collisions on Sunday.
Lots of Contingency time - they want those 3.5TeV collisions on time!

Re: 2010 Briefings, Schedules and Problems

Posted: Sun Mar 28, 2010 1:44 pm
by Danny252
A different day, a different schedule format...

Ramp to 3.5 TeV
Setup of collimators at 3.5 TeV
Setup of TCDQ at 3.5 TeV
5 end of fill tests to verify collimator hierarchy (ca. 4h per fill preparation):
one fill for horizontal resonance blow up of Beam1 and Beam2
one fill for vertical horizontal resonance blow up of Beam1 and Beam2
one fill for momentum (RF) change Beam1
one fill for momentum (RF) change Beam2
one fill with de-bunched beams to simulate asynchronous dump

I believe all these refer to multi-bunch beams (wouldn't make much sense without!). As I type, the ELogbook states that collimator setup is done and that TCDQ setup is commencing (the TCDQs are collimators for the dumps, and so are setup by the dump team separately).

Re: 2010 Briefings, Schedules and Problems

Posted: Mon Mar 29, 2010 8:51 pm
by Danny252
22:00-01:00: Beam left at 3.5 TeV–IR steering
01:00: Beam dumped
01:00–02:00: Ramping down
02:00-03:00: Back at 450 GeV–Colliding bunch pattern Single_2b_1_1_1 with B1 (1, 17851), B2 (1, 8911) - Checking beams
03:00–04:00: Ramping to 3.5 TeV
04:00 …. Preparation for stable beams
09:00: Yayfuntimes!

Ok, Yayfuntimes! may not be a direct quote from CERN. But it's about right :)

So mostly beam prep tonight. Schedule for tomorrow, and the webcast, is at:
http://press.web.cern.ch/press/lhc-firs ... s/webcast/