Search found 67 matches

by pcatom
Thu Feb 13, 2014 7:17 pm
Forum: Science
Topic: FCC
Replies: 18
Views: 19374

Re: FCC

That is what we plan to find out!

There is nothing fundamental which prevents it.
by pcatom
Wed Feb 12, 2014 8:59 pm
Forum: Science
Topic: FCC
Replies: 18
Views: 19374

FCC

Is anyone following us:

http://indico.cern.ch/event/282344/

You thought LHC was good! :clap: This will blow it out of the water.
by pcatom
Wed Dec 11, 2013 6:23 pm
Forum: The Accelerator
Topic: RF frequncy of LHC: 400.789 MHz
Replies: 5
Views: 4716

Re: RF frequncy of LHC: 400.789 MHz

The beam must always see the same RF each time it passes. What this means is that the RF frequency, the Circumference of the machine and the speed of the particles are related. The ratio of the RF wavelength to the circumference is called the harmonic number - in LHC this is 35,640 exactly. Once thi...
by pcatom
Sun Jul 15, 2012 7:56 am
Forum: The Accelerator
Topic: 2012 Events Discussion
Replies: 100
Views: 104590

Re: 2012 Events Discussion

... Mainly having more time to get ready!
by pcatom
Wed Jul 11, 2012 7:50 pm
Forum: The Accelerator
Topic: 2012 Events Discussion
Replies: 100
Views: 104590

Re: 2012 Events Discussion

The decision has been taken to extend the run to beyond Christmas with the likely scenario to continue p-p until Christmas and delay the p-Pb run until January (exact arrangement still under discussion). Last beams will be on 11th Feb 2013. The main reason for the extension is technical, and not Phy...
by pcatom
Wed Jul 11, 2012 7:44 pm
Forum: The Accelerator
Topic: Why So QUIET ??? Machine Development !!!!!
Replies: 4
Views: 4621

Re: Why So QUIET ??? Machine Development !!!!!

OK Lets give it a go .... 25 ns. . . . . new settings !! . . . . . . . (what does 25ns mean if you are injecting one bunch ? just a doubled RF ?) 25ns is the distance between 2 adjacent bunches which are delivered from the injectors. It only makes sense in multi-bunch injections. A maximum of 72 bun...
by pcatom
Wed May 23, 2012 7:22 pm
Forum: The Accelerator
Topic: 1fb/week?
Replies: 5
Views: 5236

Re: 1fb/week?

Will continue to adiabatically push up the bunch intensity - to around 1.6x10+11 ppb. We know we can do this without increasing the emittance from the injectors too much. but don't expect any jumps ... If 1.6 is reached you can expect 20% more lumi ... say 7x10+33. Unlikely to get much higher than t...
by pcatom
Tue May 22, 2012 7:30 pm
Forum: The Accelerator
Topic: 2012 Events Discussion
Replies: 100
Views: 104590

Re: 2012 Events Discussion

Can anybody explain to me what causes the short downward blips every 100 mins or so in the luminosity trace during stable beams? At first I thought they were glitches but they seem too regular to be unintentional. Fingers crossed but things seem to be running smoothly again. Impressive work. Every ...
by pcatom
Tue May 22, 2012 7:27 pm
Forum: The Accelerator
Topic: 1fb/week?
Replies: 5
Views: 5236

Re: 1fb/week?

Made 980pb-1 last week ... hopefully more this week
by pcatom
Thu Apr 19, 2012 6:50 pm
Forum: The Accelerator
Topic: Why is there a difference in the Cms and Atlas luminosities?
Replies: 9
Views: 5370

Re: Why is there a difference in the Cms and Atlas luminosit

Last year they reached 3.5/nb/s with beta* = 1.0 so with beta* = 0.6 they should expect 3.5/0.6 = 5.8/nb/s assuming intensity and emittance are the same. So the CMS figure looks better. the VdM scans still need analysis before feeding back new calibrations. The "correct" value will lie somewhere be...
by pcatom
Thu Dec 15, 2011 9:51 pm
Forum: New Users Start Here
Topic: just to say Hi. thinking about gyroscopes
Replies: 3
Views: 3104

Re: just to say Hi. thinking about gyroscopes

Just wondered. The speed being almost c, resulting in very high relativistic mass, and very high omega (10e5 to 10e6 or so), what is the gyrocopic effect of a one direction mass/energy flow through the LHC on the orientation of the rotational axis of the earth?? Anyone did the math? Now that there ...
by pcatom
Mon Oct 17, 2011 8:27 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 83570

Re: 2011 Events Discussion

For those who don't know already, 5 fb-1 represents around 350 trillion proton-proton collisions (3.5x10+14). In that lot we might reasonably expect to have recorded around 100 million W's and Z's, maybe a million top events and perhaps 20-30,000 higgs (if it exists!). Talk about looking for a piece...
by pcatom
Tue Oct 04, 2011 7:05 pm
Forum: The Accelerator
Topic: Hang gliding weasels ???
Replies: 3
Views: 3200

Re: Hang gliding weasels ???

...It goes back a lot further than that ...

the original quote was used in LEP and came from Steven Wright

"Eagles may soar, but weasels don't get sucked into jet engines."
by pcatom
Tue Sep 20, 2011 6:00 pm
Forum: The Accelerator
Topic: Presentation for the Grid for UK Particle Physics
Replies: 5
Views: 3715

Re: Presentation for the Grid for UK Particle Physics

Talking of LHC status reports, next week there is an LHCC open session which starts with an LHC status report by someone familiar http://indico.cern.ch/conferenceDisplay ... fId=153317
It won't tell you lot anything you don't already know ;)
by pcatom
Tue Aug 02, 2011 10:47 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 83570

Re: 2011 Events Discussion

looks like they did manage 2000/ubs good stuff!
Record Peak luminosity is now around 2050 ub-1s-1