Older Events and discussion 3/22/10

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DCWhitworth
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Re: ** Current Events and discussion **

Post by DCWhitworth » Mon Mar 08, 2010 12:42 pm

Pre-cycling now, looking good :)
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Re: ** Current Events and discussion **

Post by Danny252 » Mon Mar 08, 2010 7:36 pm

Both beams back at 2032.

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BillyPilgrim
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Re: ** Current Events and discussion **

Post by BillyPilgrim » Tue Mar 09, 2010 12:28 am

It looked like a disaster when first we heard of a fire, alarms etc. But I take solice in the facts that the machine has been running fantastic. We see a nQPS system that is sometimes too sensitive, beams circulating and systems performing as designed. So it appears that an emergency stop system, or circuit, or device triggered the latest scary event. Instead of worry, I rejoice that an emergency stop system worked. Power was cut, beams of (n)energy and intensity were effectively dumped safely, without damage to machine, man, or planet. Inject and dump studies suggest that all this can function, but there is nothing like an unplanned push of the button to truly test the system. It appears that it works. Congrats CERN. A marvelous machine indeed. Onward to greater energies and discoveries!!

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Re: ** Current Events and discussion **

Post by Shadowdraxx » Tue Mar 09, 2010 7:20 pm

Image

On the 19th, can anyone tell me (or point me to in case i missed this) what "SF" means?

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Re: ** Current Events and discussion **

Post by Danny252 » Tue Mar 09, 2010 9:00 pm

I wonder if it's "Scheduled F..."? Going by how all the SFs are a fair way in the future and are a whole shift, it might be scheduled slack time of some sort.

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Re: ** Current Events and discussion **

Post by Harbles » Tue Mar 09, 2010 11:00 pm

Darn Vistars are stuck. 21:42:09.

Reset the Display Crate!

Seems like a lot of rebooting crate going on. A lot of crates I suppose. Any one know about how the multi processor network is managed? Heartbeat?

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Re: ** Current Events and discussion **

Post by Danny252 » Tue Mar 09, 2010 11:02 pm

Funny thing is that the ALICE site is still showing the Page 1 status notes - maybe these are sent through a different system than the VISTARs?

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Re: ** Current Events and discussion **

Post by Harbles » Tue Mar 09, 2010 11:22 pm

Shadowdraxx wrote:Image

On the 19th, can anyone tell me (or point me to in case i missed this) what "SF" means?

I'm guessing but what I found was this; "RESQP execution steps (SF: Safe failures, DF: Dangerous failures, MF: Main failures)." from document ( https://lhc-commissioning.web.cern.ch/l ... ober09.pdf ~5MB

So I guess it's testing the various systems under various conditions to ensure Safe Failure.

As I say only a guess as there are several days in the schedule http://lhc-commissioning.web.cern.ch/lh ... hedule.pdf allocated to "SF".

Any more guesses or even confirmed fact? lol

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Re: ** Current Events and discussion **

Post by LarryS » Tue Mar 09, 2010 11:24 pm

The reporting via LHCPortal and MELTRONX are both frozen at the exact same times. Viewing the LHC OP logs shows this is the exact point when the "ramp-up" reached 1.18 TeV. This was followed by some cryo problems and some "trips" during the following "ramp-down."

From what I can interpret it is a series of small problems and with nothing major.

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Re: ** Current Events and discussion **

Post by Harbles » Tue Mar 09, 2010 11:44 pm

LarryS wrote:The reporting via LHCPortal and MELTRONX are both frozen at the exact same times. Viewing the LHC OP logs shows this is the exact point when the "ramp-up" reached 1.18 TeV. This was followed by some cryo problems and some "trips" during the following "ramp-down."

From what I can interpret it is a series of small problems and with nothing major.

It's the op-vistar sub system that's pooched.
If one checks CMS daq screen http://cmsonline.cern.ch/daqStatusSCX/a ... tusGre.jpg notice the upper left quadrant screen an image of LHC1 alternates with L1 scalers. If you CTRL+ a few times ( I have old eyes) you can see the time stuck there too but the cms clock time (just above LHC1 area) has current time.
:shock:

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Re: ** Current Events and discussion **

Post by Shadowdraxx » Wed Mar 10, 2010 4:39 am

Ok thanks for that,

So am I right in thinking there wont be any "new record" energy collisions before the end of march?

All i can see is ramps and testing with some 900 gev Collisions which im assuming is to fine tune the experiments?.

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Re: ** Current Events and discussion **

Post by Harbles » Thu Mar 11, 2010 1:09 am

Knowing how CERN likes pleasant surprises and the way the dates line up I wouldn't put it past them to try a few collisions on Fri 25 Mar. But who knows? Tuesday 30 th would be fine if they actually meet the timeline.

Uh Oh from the schedule it looks no beam till Friday " No beam from Thursday 04:00 onwards (nQPS work and cleaning of cryo filters) for 32 h!" from http://lhc-commissioning.web.cern.ch/lh ... -news.html.

Just a few more weeks.

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Re: ** Current Events and discussion **

Post by Wallmott » Fri Mar 12, 2010 1:52 pm

Does anyone know when they will do the higher energy colissions?

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DCWhitworth
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Re: ** Current Events and discussion **

Post by DCWhitworth » Fri Mar 12, 2010 2:10 pm

Wallmott wrote:Does anyone know when they will do the higher energy colissions?
Best you can says is "When they're ready" to be honest. Fairly soon I would think
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Re: ** Current Events and discussion **

Post by Wallmott » Fri Mar 12, 2010 2:18 pm

DCWhitworth wrote:
Wallmott wrote:Does anyone know when they will do the higher energy colissions?
Best you can says is "When they're ready" to be honest. Fairly soon I would think

Have they done any collisions at all this year?

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