2022 Operation

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M.
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Re: 2022 Operation

Post by M. » Fri Aug 12, 2022 9:00 am

The "outliers" are recent quenches in S56 :-)

But clicking on these plots will replace the image by a fully interactive version where you can zoom in, inspect, etc.

On the cryo plot you won't see much of the head load though, as the temperature is actively regulated - the extra heating just puts more load on the cryo system, which can cope with it up to some point (about 200-250 W/half-cell). At that point the intensity will be limited until the e-cloud situation improves.

tomey36
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Re: 2022 Operation

Post by tomey36 » Fri Aug 12, 2022 6:57 pm

On the topic of the e-cloud. Can the current high bunch fills do much do reduce it, or do more dedicated scrubbing runs need to be done?

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Tau
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Re: 2022 Operation

Post by Tau » Sat Aug 13, 2022 8:06 pm

trobbins wrote:
Fri Aug 12, 2022 12:23 am
The Dashboard Heat Load plot
That page sounds interesting. I don't recall seeing a public URL for the heat load (or the "regular" LHC dashboard).
Could you post these URLs, please, if they are publicly accessible?
- Tau

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trobbins
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Re: 2022 Operation

Post by trobbins » Sun Aug 14, 2022 12:27 am

See post by M. » Sun Aug 07, 2022 11:49 am

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Tau
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Re: 2022 Operation

Post by Tau » Sun Aug 14, 2022 6:43 pm

trobbins wrote:
Sun Aug 14, 2022 12:27 am
See post by M. » Sun Aug 07, 2022 11:49 am
I found the post (which wasn't trivial because of time zones :D ), but that link only shows luminosity plots.
I was looking for things like real-time tune, chromaticity, and so on. Basically, what the dashboard did before it froze permanently in 2019 :-(
- Tau

jmc2000
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Re: 2022 Operation

Post by jmc2000 » Mon Aug 15, 2022 10:30 pm

Tau wrote:
Sun Aug 14, 2022 6:43 pm
trobbins wrote:
Sun Aug 14, 2022 12:27 am
See post by M. » Sun Aug 07, 2022 11:49 am
I found the post (which wasn't trivial because of time zones :D ), but that link only shows luminosity plots.
I was looking for things like real-time tune, chromaticity, and so on. Basically, what the dashboard did before it froze permanently in 2019 :-(
I think it's been permanently disabled, possibly because the public have increasingly lost interest in having access to it, since the remaining runs appear to be geared towards confirming the Standard Model rather than discovering new physics as was hoped for:
https://op-webtools.web.cern.ch/vistar/ ... CDASHBOARD

JMc

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Tau
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Re: 2022 Operation

Post by Tau » Tue Aug 16, 2022 6:09 am

And now the dashboard page changed to OFFLINE UNDER REVIEW.
Somebody out there must be watching us!
- Tau

M.
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Re: 2022 Operation

Post by M. » Tue Aug 16, 2022 9:31 am

jmc2000 wrote:
Mon Aug 15, 2022 10:30 pm
I think it's been permanently disabled, possibly because the public have increasingly lost interest in having access to it,
It's somewhat simpler, unlike many of the other Vistars the "Dashboard" is not really used in daily operation, and it is built on a different technology that never followed the control system changes during Long Shutdown 2. Hence it was frozen on some pre-LS2 state.

Yet unclear if and in what form it will return, there are more urgent issues for now...

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Re: 2022 Operation

Post by dukwon » Tue Aug 16, 2022 9:44 am

jmc2000 wrote:
Mon Aug 15, 2022 10:30 pm
the remaining runs appear to be geared towards confirming the Standard Model rather than discovering new physics as was hoped for
You make it sound like we've stopped looking for new physics, which is absolutely not the case. Even "confirming the Standard Model" is itself a way of looking for new physics.

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Tau
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Re: 2022 Operation

Post by Tau » Fri Aug 19, 2022 9:14 am

Tau wrote:
Tue Aug 16, 2022 6:09 am
And now the dashboard page changed to OFFLINE UNDER REVIEW.
Somebody out there must be watching us!
While they are watching us, how about the "abort gap" vistar? Apparently nobody (except for me, of course 8-) ) looks at it, since is has been defunct since the last LS.
I had a quick look there every once in a while to check the beam quality. It was especially interesting during commissioning of the dump system, of course, when they purposely let protons leak out of their buckets to check what would happen.
- Tau

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trobbins
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Re: 2022 Operation

Post by trobbins » Sun Aug 21, 2022 11:57 am

It's good to see the "Schedule, Predicted and Achieved Luminosity" datapoints starting to creep up again. Can't wait to see a nice summary/assessment of downtime causes and remedial actions.

RocketManKSC
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Re: 2022 Operation

Post by RocketManKSC » Sun Aug 21, 2022 6:18 pm

Yes the last two day have seen some consistent run times. Still some work on general lost over time. Seems to be staying up should start seeing some early results. :clap: :dance:

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trobbins
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Re: 2022 Operation

Post by trobbins » Mon Aug 22, 2022 8:50 am

They have just gone from 240bpi-12inj to 180bpi-16inj. Any ideas what that changes and why ?

M.
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Re: 2022 Operation

Post by M. » Mon Aug 22, 2022 8:40 pm

The 180bpi is trains of 5*36 bunches while the 240bpi is 5*48 bunches. The shorter train length helps to reduce electron cloud buildup, which in turn allows increasing the intensity per bunch.

Compared to the fill before the heat load is ~10% lower for the same total intensity.
Screenshot from 2022-08-22 22-37-45.png

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trobbins
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Re: 2022 Operation

Post by trobbins » Mon Aug 22, 2022 11:52 pm

Ta muchly. I can now appreciate that 5*36*16 = 5*48*12, so re-arranging the deckchairs has tweaked the heat load down a titch.

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