Search found 153 matches

by jmc2000
Wed Jun 01, 2016 11:14 pm
Forum: The Accelerator
Topic: How stringent is the ~100fb for 2016-2018?
Replies: 7
Views: 4308

Re: How stringent is the ~100fb for 2016-2018?

Currently at 2048b, the LHC is accumulating ~1.5fb/week for 30% stable beams which is great news, considering the lost two weeks over bad luck. If they can get to 2800 bunches, that should mean ~2fb/week bringing 25fb/year on target!

Cheers,

jmc
by jmc2000
Mon May 30, 2016 12:57 pm
Forum: The Accelerator
Topic: How stringent is the ~100fb for 2016-2018?
Replies: 7
Views: 4308

How stringent is the ~100fb for 2016-2018?

For 2016, they're hoping to accumulate ~25fb. But suppose instead they only manage ~15fb and ~80fb for 2016-2018. Will they extend the run for another year, say, or just accept what data has been accumulated?

Regards,

Jmc
by jmc2000
Tue May 24, 2016 5:29 pm
Forum: The Accelerator
Topic: Other examples of bad luck?
Replies: 2
Views: 2597

Other examples of bad luck?

The LHC has suffered very bad luck over the past three weeks with regard to the failure of the PS and a fried weasel. Can anyone think of other incidents similar to these that have brought the LHC to a halt for a few weeks in the past?

Regards,

jmc2000
by jmc2000
Mon Apr 25, 2016 3:40 pm
Forum: The Accelerator
Topic: Is there machine development during beam commissioning?
Replies: 6
Views: 4322

Re: Is there machine development during beam commissioning?

Update: We had the first stable beams over the weekend, a bit earlier than planned. First 3, then 12 bunches, so the luminosity was tiny (0.05% to 0.35% of the design value), but it also means scrubbing starts today, 3 days earlier than planned. Do you know if the first stable beams were squeezed t...
by jmc2000
Sat Apr 16, 2016 11:39 pm
Forum: The Accelerator
Topic: Is there machine development during beam commissioning?
Replies: 6
Views: 4322

Re: Is there machine development during beam commissioning?

2015 was very useful, of course - the luminosty with stable beams should increase much faster this year, so we could reach that performance within a month or two. Pushing the limits will then be done with stable beams and in dedicated machine development blocks. Do you work on the LHC by any chance...
by jmc2000
Sun Apr 10, 2016 9:51 pm
Forum: The Accelerator
Topic: Is there machine development during beam commissioning?
Replies: 6
Views: 4322

Is there machine development during beam commissioning?

Is the purpose of the beam commissioning to bring beams back to the way they were in 2015, or are machine development investigations also being carried out to see what's possible for 2016?

Cheers,

JMc
by jmc2000
Tue Oct 27, 2015 9:58 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 35020

Re: What are the current records for LHC fills?

@mfb it's a record, despite the instantaneous luminosity being only 4.5nb/s compared to over 7nb/s in 2012, but the longer beam life time makes up for this: >30 hours compared to 10 hours in 2012.
by jmc2000
Wed Oct 07, 2015 5:44 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 35020

Re: What are the current records for LHC fills?

try this https://cern.ch/LHC-Statistics or from portal LHC-> Coordination -> LHC Statistics ( near top center of the page) Can I get the record for integrated luminosity in one fill from this? Fill #4467 has been going for 22 hours with an integrated luminosity of 230pb for Atlas, which I suspect i...
by jmc2000
Fri Oct 02, 2015 9:38 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 35020

What are the current records for LHC fills?

Is there a page that records current records for LHC fills?

In particular, I'm looking for records of: 1. max instantaneous luminosity, 2. Max integrated luminosity over (a)one fill (b)one day, (c) one week 3. Max time for one fill

Cheers,

jmc2000
by jmc2000
Fri Sep 11, 2015 8:58 pm
Forum: The Accelerator
Topic: 2014 machine commissioning and 2015 start up
Replies: 59
Views: 81684

Re: 2014 machine commissioning and 2015 start up

Fill #4349 with 745 25ns bunches is currently still looking beautifully stable with low losses after 4 hours: impressive! Should mean at least around 0.5 fb/week from now on, possibly matching 1 fb/week in 2012 by the end of the year! Does anyone know the number of bunches and Beta* they're going to...
by jmc2000
Mon Jul 27, 2015 11:59 pm
Forum: The Accelerator
Topic: 2014 machine commissioning and 2015 start up
Replies: 59
Views: 81684

Re: 2014 machine commissioning and 2015 start up

Does 25ns scrubbing also involve machine development at the same time that will ultimately aid the intensity ramp up?

Regards

jmc
by jmc2000
Tue Jul 14, 2015 10:27 pm
Forum: The Accelerator
Topic: Luminosity targets for 2015
Replies: 1
Views: 2204

Re: Luminosity targets for 2015

The luminosity target was 10fb, but at the last LHCC meeting was seen as "challenging" and changed to 5-10fb.

https://indico.cern.ch/event/389857/ses ... June15.pdf

Regards,

JMc
by jmc2000
Mon Jun 01, 2015 9:22 pm
Forum: The Accelerator
Topic: 2014 machine commissioning and 2015 start up
Replies: 59
Views: 81684

Re: 2014 machine commissioning and 2015 start up

And yesterday we had collisions with a beta of 80 cm. The beta is a measurement for the focus of the beam. If they say "we are at 80 cm", they mean "the beta is 80 cm at the collision points". The lower it is, the more focusued the beams are. Previous run the lowest possible value was 80 cm, but si...
by jmc2000
Thu Apr 16, 2015 11:40 pm
Forum: The Accelerator
Topic: 2014 machine commissioning and 2015 start up
Replies: 59
Views: 81684

Re: 2014 machine commissioning and 2015 start up

Does anyone know what sort of intensity relative to 2012 50ns operation the LHC gurus are aiming for this year? I believe it might be a further x2 which would give a possible integrated 2fb/week if I'm not mistaken According to the previous link given by Tau, the schedule is to initially try 50ns a...
by jmc2000
Mon Apr 13, 2015 2:18 pm
Forum: The Accelerator
Topic: 2014 machine commissioning and 2015 start up
Replies: 59
Views: 81684

Re: 2014 machine commissioning and 2015 start up

Does anyone know what sort of intensity relative to 2012 50ns operation the LHC gurus are aiming for this year? I believe it might be a further x2 which would give a possible integrated 2fb/week if I'm not mistaken. Good luck to the guys involved with commissioning and operating the LHC! Cheers, Jmc