Search found 30 matches

by Lexa
Sat Dec 05, 2009 5:57 pm
Forum: The Accelerator
Topic: Weekend of 12-3-09 collision events !
Replies: 188
Views: 53151

Re: *** COLLISION ALERT ***

2 years ago I worked on integrating the validation process of atlas paper (and maybe used for other exp now) into the cern library. It's quite... complex, and long. Involving multiple boards, and reviewing possible from any guy in the collaboration +2000 persons for the biggest :P). Otherwise, for w...
by Lexa
Wed Dec 02, 2009 9:35 am
Forum: The Accelerator
Topic: What sort of noise does the worlds largest machine make?
Replies: 11
Views: 5340

Re: What sort of noise does the worlds largest machine make?

You cannot be near the accelerators while they are working because of radioactivity. But I bet they are not making any sound. Or maybe just the power supply units and/or the cryo and cooling and ventilation. I already ask it a long time ago. People told me "it does not make any sound, nor vibration"...
by Lexa
Wed Dec 02, 2009 9:31 am
Forum: The Accelerator
Topic: 12/2/09 power loss and many systems down
Replies: 25
Views: 15781

Re: *** MAJOR power loss and many systems down

I have seen the power converter of the PS (well, the old one, and the new one we are currently working on it). If already 50 years ago they were able to do such machine that resilient to power cut, I believe for the LHC it is really not something to bother about. Protection, redundancy and backup ci...
by Lexa
Wed Dec 02, 2009 3:59 am
Forum: The Accelerator
Topic: 12/2/09 power loss and many systems down
Replies: 25
Views: 15781

Re: *** MAJOR power loss and many systems down

Page 1 just get updated.
Likely no beam before 12am.
by Lexa
Wed Dec 02, 2009 2:55 am
Forum: The Accelerator
Topic: 12/2/09 power loss and many systems down
Replies: 25
Views: 15781

Re: *** Complete internet access failure

Not quite completely :D
I think just the monitoring service are back online.

And it looks like the magnet did not warm up, phew!
by Lexa
Wed Dec 02, 2009 2:34 am
Forum: The Accelerator
Topic: 12/2/09 power loss and many systems down
Replies: 25
Views: 15781

Re: *** Complete internet access failure

Refer to this:
viewtopic.php?f=4&t=108

We are actually not completely off the internet. I reckon that cern network is really great because while Meyrin is off, Prevessin has still access to the world ^^.

A few, very few web servers are responding (but useless ones :D)
by Lexa
Wed Dec 02, 2009 2:24 am
Forum: The Accelerator
Topic: OY! Power Fail In meyrin.
Replies: 2
Views: 3320

Re: OY! Power Fail In meyrin.

Thanks for the info! I am currently on the secondary site (Prevessin) and I was wondering why cern servers are not responding anymore... Well, this answer it. *Frack* This is happening when I need these servers, of course. (I have no doubt the machine is not damaged. It is well designed for this kin...
by Lexa
Mon Nov 30, 2009 3:21 pm
Forum: The Accelerator
Topic: problems 10/26/09 - 10/28/09
Replies: 28
Views: 10209

Re: problems 10/26/09 - 10/28/09

I had confirmation today that problems affecting the cryo last week with the PLC might happen again at any time... Hopefully the LHC is a very resilient and well designed machine so it should not damage it. Just a few hours delays each time. I will avoid giving details, but it should be fixed by the...
by Lexa
Mon Nov 30, 2009 10:26 am
Forum: The Accelerator
Topic: Breaking news 11/23-11/30 09
Replies: 17
Views: 8009

Re: *** Breaking news ****

In the end, the first news was about an energy set at 1.18 TeV but not reached. They latter achieved to reach this energy in a third attempt "in the early hours of the morning" according to what Rolf Heuer said us this morning. The LHC news page is now giving more details (but no timestamp expect "S...
by Lexa
Fri Nov 27, 2009 8:30 pm
Forum: The Accelerator
Topic: problems 10/26/09 - 10/28/09
Replies: 28
Views: 10209

Re: ** Current problem **

Speed is in millisecond for the QPS. I don't know for the dump thing. Its point is to protect a magnet by spreading a hot spot (created by a quench) to the whole magnet in order to avoid any local damage (that would impair the whole magnet x_x). So it has to detect a quench (in most of the configura...
by Lexa
Fri Nov 27, 2009 7:16 pm
Forum: The Accelerator
Topic: problems 10/26/09 - 10/28/09
Replies: 28
Views: 10209

Re: ** Current problem **

Quench Protection System

Speaking about commisionning very complicated devices, QPS is a good example :).
by Lexa
Fri Nov 27, 2009 4:37 pm
Forum: The Accelerator
Topic: problems 10/26/09 - 10/28/09
Replies: 28
Views: 10209

Re: ** Current problem **

It is likely to happen again ^^.
We could start betting on which sector will be affected next time!
by Lexa
Fri Nov 27, 2009 3:20 pm
Forum: The Accelerator
Topic: problems 10/26/09 - 10/28/09
Replies: 28
Views: 10209

Re: ** Current problem **

I don't want to spoil/leak anything, but... responsibility might not be on our custom stuffs in that case :].
by Lexa
Fri Nov 27, 2009 2:44 pm
Forum: The Accelerator
Topic: problems 10/26/09 - 10/28/09
Replies: 28
Views: 10209

Re: ** Current problem **

The "Automat" term refer to PLC.

The problem already shows up on wednesday in sector 12. And might happen again randomly if not solved.