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Weekend of 12-3-09 collision events !

Posted: Fri Dec 04, 2009 7:00 pm
by Xymox
450 GEV COLLISIONS PLANNED SATURDAY/SUNDAY

Schedule at http://lhc-commissioning.web.cern.ch/lh ... C-news.htm. Collisions at 450GeV are planned at:

Saturday 1600 - 450 GeV Beam Collisions, Intensity of 4e9
Sunday 0000 - As Above
Sunday 1400 - 450 GeV Beam Collisions, Intensity of 2e10

I believe the latter one will be the highest intensity collisions in the LHC so far.

Of course, schedules don't always hold!

Re: *** COLLISION ALERT ***

Posted: Fri Dec 04, 2009 7:47 pm
by Danny252
The Saturday collision has been retimed to 1700. All other details hold.

Re: *** COLLISION ALERT ***

Posted: Fri Dec 04, 2009 9:48 pm
by Danny252
Also, of note is that the collisions this weekend will be the first multi-bunch collisions. The Saturday + Midnight ones are planned to be 4x4 - 4 bunches in each beam. The Sunday one will be 2x2, but at higher intensity.

A "bunch" is a group of particles orbiting in the LHC - previously, only one bunch per beam has been used. The first multi-bunch beams were put in earlier tonight (see Schedule+Hiccups for a bit more info).

Re: *** COLLISION ALERT ***

Posted: Fri Dec 04, 2009 10:12 pm
by Xymox
Wow.... This is great !.. Danny is faster then me on this stuff !..

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 12:30 am
by DCWhitworth
Interesting to note that on the same schedule between the 1700h and 0000h collisions they are doing 'Trial ramp plus pre-cycle'

Maybe there's a chance that they might make the 0000h collisions higher than 450GeV if things go well ?

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 1:33 am
by Stephen
Any idea on when they are going to do collisions higher than 1 TeV?

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 2:50 am
by Xymox
1TeV collisions might happen sooner rather then later. The -original- plan was mid December if memory serves me... However they are ahead of schedule. They don't have anything really limiting them for doing it almost anytime. I think they are more focused on colliding more bunches then higher energy. But who knows, maybe they will do both. Maybe this weekend. Maybe not.

They have been sneaky fun before and hid major events.

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 3:03 am
by Texanguy
I recently read that they've promised collisions of an energy no greater than 450 GeV until next year.. can't remember exactly where though ._.

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 7:39 am
by Xymox
That was a older schedule. I think... The much larger collisions are clearly next year...

Danny252 is really the expert.. He has done amazing amounts of research...

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 4:19 pm
by mikeymac0811
A picture of page 1 (With words) is worth 1000 Words.... Once again they've surprised us (though only by about 3 hours):
5 DEC, 13:10, COLLISIONS!

**From the CMS Latest Updates Page at 13:04pm**
LHC is currently colliding. Beam intensities are about 3.5E9 protons/bunch. The minbias trigger rate is of the order 0.3 Hz at CMS. This a tuning period, preparing for a relatively long time of running overnight with collisions.

Well naysaysers.... Time to take the tin foil off and go Christmas Shopping...

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 4:20 pm
by Texanguy
awesome man :D

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 4:24 pm
by DCWhitworth
:( How did I miss that ? I've had page 1 up for most of the day.

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 4:25 pm
by Texanguy
I totally missed it as well.. I had been asleep. ._. shame on me.

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 4:28 pm
by mikeymac0811
Go to CMS Experiment and the "Latest Updates" and it's on there.... it looks like they did it for a short time..... It's not on Twitter (but then again, I'm guessing the Public Relations office, who probably runs the Tweets/press releases, runs on a reduced staff on weekends) like I thought it would also be.

Re: *** COLLISION ALERT ***

Posted: Sat Dec 05, 2009 4:35 pm
by Texanguy
Hmm, awesome :}