Search found 160 matches

by jmc2000
Thu May 26, 2011 8:12 pm
Forum: The Accelerator
Topic: The cost of days without runs
Replies: 5
Views: 9289

Re: The cost of days without runs

Hard to guess... It is direct cost due to the repairs or indirect cost due to the inactivity? Inactivity mainly, but also having to spend money on people's time bringing the system back to where it was. During inactivity, people can manage their work to compensate, whereas the cost of people's time...
by jmc2000
Wed May 25, 2011 11:35 pm
Forum: The Accelerator
Topic: The cost of days without runs
Replies: 5
Views: 9289

The cost of days without runs

Today, there's a communication problem with the cryogenics whcih means there's no beam for 1 1/2 days. I don't think this would have happened if they had doubled up with a backup, but only if it was economically feasible to do this on the least reliable and least espensive parts. So does anyone know...
by jmc2000
Mon May 23, 2011 12:02 pm
Forum: The Accelerator
Topic: Questions on the LHC display dashboard
Replies: 2
Views: 7898

Questions on the LHC display dashboard

Where can I get an explanation of what the various displays on the LHC dashboard mean?
http://lhcdashboard.web.cern.ch/lhcdashboard

On fill 1803, the beam size becomes erratic every half an hour. What's going on?
by jmc2000
Thu May 19, 2011 11:40 am
Forum: The Accelerator
Topic: 108b injection scheme
Replies: 2
Views: 5502

108b injection scheme

Will the 108b injection scheme be used for all further luminosity increases from now on, or are there other schemes which need to be used?
by jmc2000
Tue May 17, 2011 3:22 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 257046

Re: 2011 Events Discussion

Physics runs are back after the technical stop. They are now running with 228 bunches and will step up through 480 and 768 bunches to get back to previous luminosities. After two more good fills with 768 bunches they can move up to 912 bunches, but that will require a new injection setup for 108 bu...
by jmc2000
Sun May 15, 2011 7:54 pm
Forum: The Accelerator
Topic: The cryogenics at the LHC
Replies: 2
Views: 6793

Re: The cryogenics at the LHC

Over the past few weeks I've noticed that they might lose between 1/2-1 days on the cyrogenics failing. How good are the cryogenics at the LHC compared to the Tevatron? What are the problems with cryogenics upto now and how difficult have they been to fix? Which part of the tunnel is the least acce...
by jmc2000
Sat May 14, 2011 10:31 am
Forum: The Accelerator
Topic: The cryogenics at the LHC
Replies: 2
Views: 6793

The cryogenics at the LHC

Over the past few weeks I've noticed that they might lose between 1/2-1 days on the cyrogenics failing. How good are the cryogenics at the LHC compared to the Tevatron? What are the problems with cryogenics upto now and how difficult have they been to fix? Which part of the tunnel is the least acces...
by jmc2000
Thu May 12, 2011 11:50 pm
Forum: The Accelerator
Topic: Improved performance after MD and TS?
Replies: 11
Views: 15346

Re: Improved performance after MD and TS?

If the question is about performance perhaps it should have been about any premature end to a fill, not just quenches. Yes, I'm interested in the causes for a fill to be abandoned and the beam having to be dumped/quenched. Quenched and dumpled are the same thing, correct? If you look at slide 15 in...
by jmc2000
Wed May 11, 2011 12:27 am
Forum: The Accelerator
Topic: Improved performance after MD and TS?
Replies: 11
Views: 15346

Re: Improved performance after MD and TS?

Is that enough detail?? Hey, thanks for the useful info. At the Tevatron, they've managed to limit 1 quench to around 20 fills. Do you know what the figure is for the LHC and if they have a realistic chance of reducing it? They were also managing to get remarkable fill times of 70% so I'm curious t...
by jmc2000
Sun May 08, 2011 3:12 pm
Forum: The Accelerator
Topic: Improved performance after MD and TS?
Replies: 11
Views: 15346

Improved performance after MD and TS?

This coming Sat, the LHC will be back in fills for physics, so afer the technical stop and machine development phase should be expect any improvement in the performance of the machine? I've also noticed that the plan was to get to 900 bunches with 75ns, whereas they were using 50ns so will they stop...