The place to discuss the LHC. Commissioning, operation, issues, events ....
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Bornerdogge
- Posts: 100
- Joined: Wed Apr 14, 2010 10:03 am
- Location: Belgium
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by Bornerdogge » Sat Jun 18, 2011 9:47 am
Looks like they're going for the next step - 1236b - this afternoon, at last!
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tomey36
- Posts: 108
- Joined: Wed Apr 14, 2010 11:39 pm
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by tomey36 » Tue Jun 21, 2011 4:24 am
or not
i was excited aswell, i guess they wanted to do one more run to check for any problems after the cryo loss. hoping for tomorrow
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oldboson
- Posts: 3
- Joined: Sun May 30, 2010 6:03 pm
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by oldboson » Tue Jun 21, 2011 4:10 pm
New production record on a single fill here... #1883 ATLAS yield >47 pb-1 and counting...
Kinda they postponed dumping (15pm, then 18pm, now 18.30pm...) to get a new record, well done guys, the machine is running smoothly!
Oldboson.
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conrad
- Posts: 7
- Joined: Thu Aug 19, 2010 4:41 pm
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by conrad » Tue Jun 21, 2011 5:55 pm
What are -RF problems? What does RF stand for? Why, after 18 hours to prepare, can't the SPS have a beam? a newbie.
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Kasuha
- Posts: 570
- Joined: Tue Dec 15, 2009 1:22 pm
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by Kasuha » Tue Jun 21, 2011 6:49 pm
conrad wrote:What are -RF problems? What does RF stand for? Why, after 18 hours to prepare, can't the SPS have a beam? a newbie.
RF stands for "Radio Frequency" I believe and it means the high frequency cavities (klystrons) which are accelerating the beam and keeping it organized in bunches.
Postponing beam dump in case there is technical problem on SPS is normal - without SPS they cannot refill.
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pjotertje
- Posts: 14
- Joined: Fri Jun 03, 2011 5:18 pm
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by pjotertje » Wed Jun 22, 2011 9:49 am
Now.
Protestation movement
no beam, no access
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DCWhitworth
- LHCPortal Guru
- Posts: 599
- Joined: Mon Nov 30, 2009 8:13 am
- Location: Norwich, UK
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by DCWhitworth » Wed Jun 22, 2011 12:13 pm
pjotertje wrote:Now.
Protestation movement
no beam, no access
Ummm, what ? Page 1 says access ongoing.
DC
The LHC - One ring to rule them all !
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pjotertje
- Posts: 14
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by pjotertje » Wed Jun 22, 2011 12:42 pm
DCWhitworth wrote:pjotertje wrote:Now.
Protestation movement
no beam, no access
Ummm, what ? Page 1 says access ongoing.
That was this morning on CPS page!!
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StevieB
- Posts: 4
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- Location: Dublin, Ireland
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by StevieB » Wed Jun 22, 2011 1:18 pm
pjotertje wrote:DCWhitworth wrote:pjotertje wrote:Now.
Protestation movement
no beam, no access
Ummm, what ? Page 1 says access ongoing.
That was this morning on CPS page!!
Something to do with this maybe?
http://cdsweb.cern.ch/journal/CERNBulle ... 7595?ln=en
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adam_jeff
- Posts: 49
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by adam_jeff » Wed Jun 22, 2011 3:14 pm
pjotertje wrote:DCWhitworth wrote:pjotertje wrote:Now.
Protestation movement
no beam, no access
Ummm, what ? Page 1 says access ongoing.
That was this morning on CPS page!!
There was a 4 hour work stoppage by CERN staff this morning in protest at proposed changes to their pension scheme. I don't know how many people took part or what effect it had on the operation of the various machines though.
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DCWhitworth
- LHCPortal Guru
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by DCWhitworth » Fri Jun 24, 2011 8:07 am
Now filling with 1236 bunches - at last !
DC
The LHC - One ring to rule them all !
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jmc2000
- Posts: 160
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by jmc2000 » Fri Jun 24, 2011 6:03 pm
DCWhitworth wrote:Now filling with 1236 bunches - at last !
Watch for the spikes in the beam size when filling. It's usually a good indication of things being amiss.
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conrad
- Posts: 7
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by conrad » Sun Jun 26, 2011 4:37 pm
In the last 24 hours there were 5 successful fills for physics. The average run was about 2 hours. Things kept going wrong. Is this just bad luck?
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jmc2000
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by jmc2000 » Sun Jun 26, 2011 6:18 pm
conrad wrote:In the last 24 hours there were 5 successful fills for physics. The average run was about 2 hours. Things kept going wrong. Is this just bad luck?
They had problems with vacuum in B2 IR4 dumping the beam three times before changing the threshold. I don't think it's anything to do with bad luck as such, but what happens when a large machine is being commissioned in unknown territory.