Current Events Discussion

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Kasuha
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Re: Current Events Discussion

Post by Kasuha » Thu Nov 25, 2010 8:13 am

Looking at today's beam dump, it looks like the B2 "thick line" continues with a thin line for another loop... I wonder what is it?
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DCWhitworth
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Re: Current Events Discussion

Post by DCWhitworth » Thu Nov 25, 2010 8:46 am

How accurate is the display ? It looks like an inverted image of the main line. Is it real or some sort of an effect of the monitoring ? The beam 1 display has a bright area to the left, is this part of the beam ? I'd think it unlikely.

Edit - Just noticed the Page 1 PM Comment. It ends with "some debunc" but is cut off. So I guess there were some issues with beam debunching that might explain the shadowing, but I don't know how the effect would manifest itself on the dump. Don't know where else this information could be viewed, it's not in the Op Log Book.
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Kasuha
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Re: Current Events Discussion

Post by Kasuha » Thu Nov 25, 2010 11:45 am

I have slightly enlarged and enhanced the two displays.
1 - debunched beam in a gap
2 and 3 - probably dimmed image of the beam trace, displaced by a glass pane or another optics element
4 - no idea, the beam should not go through there
5 - trail of debunched beam in abort gap
6 - no idea, abort gap is IMO way shorter
7 - gap in B1
8 - no idea but this light has always been there. Background light or IR emission?
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DCWhitworth
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Re: Current Events Discussion

Post by DCWhitworth » Thu Nov 25, 2010 12:00 pm

Interesting. I'd want to see more dumps to work out what is actual beam effects and what is an effect of the display.

A thought - are the two displays rotationally the same ? If they're not (i.e one display goes clockwise and one anti-clockwise then 1 corresponds roughly with 7)

Could 2 and 3 be a debunching effect ?
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Kasuha
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Re: Current Events Discussion

Post by Kasuha » Thu Nov 25, 2010 12:14 pm

DCWhitworth wrote:Could 2 and 3 be a debunching effect ?
Definitely not, debunching is a longitudinal effect. Any beam that diverges too much from beam path is captured by collimators.

tomey36
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Re: Current Events Discussion

Post by tomey36 » Fri Dec 03, 2010 8:15 am

any one find any information about the seminar held on dec 2?

adam_jeff
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Re: Current Events Discussion

Post by adam_jeff » Fri Dec 03, 2010 1:15 pm

Kasuha wrote:...
5 - trail of debunched beam in abort gap
...
The abort gap is there to give the dump kicker time to switch. Any beam which is in the abort gap receives a partial kick and is lost on the collimators somewhere - it can't go down the dump line.

Kasuha
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Re: Current Events Discussion

Post by Kasuha » Fri Dec 03, 2010 3:12 pm

adam_jeff wrote:The abort gap is there to give the dump kicker time to switch. Any beam which is in the abort gap receives a partial kick and is lost on the collimators somewhere - it can't go down the dump line.
Contents of abort gap is not lost on collimators... at least not mostly. Even though the abort gap is cleaned, there is always some small population of particles cycling in its buckets (and note that in this case the beam was partially debunched). When the dumper kicker ramps up (it does so in order of microseconds but for the beam it's a looooong time), it sweeps abort gap population all the way from original beam route to the final beam route, i.e. from beam pipe all the way to the dump pipe. The horizontal line is artifact caused by that sweep.
In fact many beam dump displays have such line, more or less pronounced.

tomey36
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Re: Current Events Discussion

Post by tomey36 » Mon Dec 06, 2010 8:41 am

today is the last day of the phyics runs this year. it has been very exciting and alot has been acomplished. congragulations to the LHC team, for such a wonderfull job, and i look forward to next year!

BenM
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Re: Current Events Discussion

Post by BenM » Mon Dec 06, 2010 4:35 pm

tomey36 wrote:today is the last day of the phyics runs this year.
Is it? the schedule shows physics up to Friday...

B.

rasalhauge
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Re: Current Events Discussion

Post by rasalhauge » Mon Dec 06, 2010 6:25 pm

BenM wrote:
tomey36 wrote:today is the last day of the phyics runs this year.
Is it? the schedule shows physics up to Friday...

B.
Perhaps, but page 1 says: "No beam", followed by "end of ion run 2010". I would trust the latter=)

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CharmQuark
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Re: Current Events Discussion

Post by CharmQuark » Mon Dec 06, 2010 6:28 pm

Congrats guys :thumbup:
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tomey36
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Re: Current Events Discussion

Post by tomey36 » Tue Dec 07, 2010 5:49 am

Any one know where i can find any information on what they are doing durring the shutdown? thanks :)

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photino
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Re: Current Events Discussion

Post by photino » Fri Dec 17, 2010 8:46 pm

LHC End-of-year jamboree (talks summarizing the latest results etc)

http://indico.cern.ch/conferenceDisplay ... fId=113139

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Tim Bergel
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Re: Current Events Discussion

Post by Tim Bergel » Sun Jan 02, 2011 11:36 am

Anybody know what the schedule is for restarting operations in 2011? Will it be more ions work or will proton experiments be back?

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