Weekend of 12-3-09 collision events !

The place to discuss the LHC. Commissioning, operation, issues, events ....
User avatar
Xymox
Site Admin
Posts: 1022
Joined: Wed Nov 11, 2009 12:55 pm
Location: Phoenix, Az USA
Contact:

Re: Weekend collision events !

Post by Xymox » Mon Dec 07, 2009 10:11 pm

I found out about the Rubber Ducks in the ATLAS control room seen via the live video stream.

http://lhcportal.com/Forum/viewtopic.ph ... 49&start=0

User avatar
Xymox
Site Admin
Posts: 1022
Joined: Wed Nov 11, 2009 12:55 pm
Location: Phoenix, Az USA
Contact:

Re: Weekend collision events !

Post by Xymox » Mon Dec 07, 2009 11:06 pm

Im going to need to retire this thread soon... Its been a good one.

I will put up a new one for reporting, commenting on the current events..

It will go into the Collider forum with a date on it..

User avatar
DCWhitworth
LHCPortal Guru
Posts: 581
Joined: Mon Nov 30, 2009 8:13 am
Location: Norwich, UK

Re: Weekend of 12-3-09 collision events !

Post by DCWhitworth » Mon Dec 07, 2009 11:12 pm

Nice work finding out about the ducks ! :D

Did you ever find out if they did higher power collisions ?

I guess right now there's little point in that other than to set a record as the scientific value would be limited until they've confirmed all the experiments are calibrated well.
DC

The LHC - One ring to rule them all !

User avatar
Xymox
Site Admin
Posts: 1022
Joined: Wed Nov 11, 2009 12:55 pm
Location: Phoenix, Az USA
Contact:

Re: Weekend of 12-3-09 collision events !

Post by Xymox » Mon Dec 07, 2009 11:18 pm

I think they are pondering this...

I would imagine a press conference is coming on all these events..

I have not kept up with press event schedules..

User avatar
March_Hare
Posts: 135
Joined: Tue Dec 01, 2009 6:09 pm
Location: The Netherlands

Re: Weekend of 12-3-09 collision events !

Post by March_Hare » Mon Dec 07, 2009 11:23 pm

Reposting here; this was actually my response to the same discussion in "Several biggest errors of particle physicists"

AFAIK LHC have circulated beams at 1.18 TeV but done no collisions at that energy yet. Last weekend's collisions were at 450 GeV according to what I saw in logs etc. Of course I missed the event so I may be wrong here...

But... It makes no sense to me to do a lot of calibration and beam stability studies at 450 GeV (which seems to have been what happened last week) and then go for collisions at an energy level higher than what was tested before. If I were to commission a machine like this I'd get confident at 450 first and do collisions at that level so as to give the experiments (ATLAS, CMS, etc.) a chance to test their equipment. Then, I'd repeat the process at a higher energy level (possibly with some shortcuts -- if appropriate).

There are more parameters that are important than the energy, by the way, one of them is Luminosity, another Intensity. Could it be that there is some confusion about that?

Also...
1 GeV = 1 x 10^9 eV (or in shorthand 1e9)
1 TeV = 1 x 10^12 eV (or 1e12)
1.48e10 = 1.48x10^10 = 14.8 x 10^9 ... don't believe for a second those are eV because it would mean collisions at an underwhelming 14.8 GeV
Nothing travels faster than the speed of light with the possible exception of bad news, which obeys its own special laws.
~Douglas Adams

User avatar
DCWhitworth
LHCPortal Guru
Posts: 581
Joined: Mon Nov 30, 2009 8:13 am
Location: Norwich, UK

Re: Weekend of 12-3-09 collision events !

Post by DCWhitworth » Mon Dec 07, 2009 11:35 pm

I completely agree there's no scientific reason to go for higher power collisions just yet, but there might be a temptation to do it in order to 'tick the box' and get it over and done with.
DC

The LHC - One ring to rule them all !

Stephen
Posts: 496
Joined: Sun Nov 22, 2009 11:09 pm

Re: Weekend of 12-3-09 collision events !

Post by Stephen » Tue Dec 08, 2009 1:00 am

I prefer them to take it slowly, but there's some advantages to do it without early warnings. I know I would have probably been nervous if they announced the first collisions, so it was a nice surprise when I found out collisions were already made and nothing bad happened.

User avatar
Xymox
Site Admin
Posts: 1022
Joined: Wed Nov 11, 2009 12:55 pm
Location: Phoenix, Az USA
Contact:

Re: Weekend of 12-3-09 collision events !

Post by Xymox » Tue Dec 08, 2009 5:34 am

yes completly operator error on my part...

However..

Higher energy tuning starts shortly according to the commissioning schedule.

My guess is next weekend might be interesting..

User avatar
March_Hare
Posts: 135
Joined: Tue Dec 01, 2009 6:09 pm
Location: The Netherlands

Re: Weekend of 12-3-09 collision events !

Post by March_Hare » Tue Dec 08, 2009 5:46 pm

... and I'm looking forward to it. Go, LHC go!
;)
Nothing travels faster than the speed of light with the possible exception of bad news, which obeys its own special laws.
~Douglas Adams

Post Reply