Showing posts with label European Organisation for Nuclear Research. Show all posts
Showing posts with label European Organisation for Nuclear Research. Show all posts

Tuesday, September 30, 2008

LSAG physicist CERN stated not involved with LHC, was involved

CERN stated for months theoretical physicists, like John Ellis, who was part of the LHC Safety Assessment Group (LSAG), was not involved with Large Hadron Collider's (LHC) experiments prior to their report:
"CERN has mandated a group of particle physicists, also not involved in the LHC experiments, to monitor the latest speculations about LHC collisions." Link (Fixed)

Mandated LHC Safety Assessment Group (LSAG):
John Ellis, Gian Giudice, Michelangelo Mangano and Urs Wiedemann, of CERN, and Igor Tkachev, of the Institute for Nuclear Research in Moscow. Link

The machine was still under construction, so experimental involvement with the LHC was impossible, to include all CERN physicists since it wasn't operational, so CERN wasn't lying... but... John Ellis has given experimental presentations at Workshops, seminars at universities around the world about Large Hadron Colliders as far back as 1987, but that doesn't count, right? RIGHT?
NEW PHYSICS IN HIGH-ENERGY e+ e- AND HADRON HADRON COLLISIONS.
John R. Ellis (CERN) . CERN-TH-4888/87, Oct 1987. 28pp.
Invited talk given at ICFA Seminar on Future Perspectives in High Energy Physics, Upton, N.Y., Oct 5-10, 1987. Link

You know what bugs me, John Ellis promoting the LHC in a video back in 2006 stating "We don't know exactly what we're going to find, but we know whatever it is it's going to be something new." He must have been joking, because why would CERN ask him to help with a new LHC safety report?
He gave them a good laugh?
http://www.itnsource.com/shotlist/ITN/2006/12/19/T19120645

Ellis was really lucky to be given that honor of evaluating the safety of collisions at the LHC, because it must have sucked being Cern's chief theorist Professor promoting the LHC, since CERN probably denied his involvement for over 20 years like he was some kind of stepchild. Poor guy...

Update, December 3, 2008: The first Link above has been fixed. CERN made some changes to their page recently, Safety at the LHC, so we're linking to an archive version of it through Archive.com's Wayback Machine to show you their statement as stated above.

Funny, the third link down still works, but when you click it, the link (QCD183:I2:1987) on that page to the lecture John Ellis gave which was published in a book shows an error:
"No such subfile: BOOKS * Error attempting to select BOOKS * message = Unable to select BOOKS, error code 162 * Cleaning up and trying again -No such subfile: BOOKS Unable to select BOOKS, error code 162."

Why link to it when it no longer exist on their site?

Friday, September 26, 2008

LHC accidental quench of 100 magnets raises questions

By Walter L. Wagner

The accident of September 19, 2008 poses a number of serious questions. It is unheard of to have 100 consecutive magnets quench, totaling some 1.5 kilometers in length.

If the connector between two magnets lost superconductivity, engaged in ohmic resistance heating, and melted, as suggested in initial reports, it raises several questions regarding how that happened.

It occurred while they were testing that sector by raising the current/field-strength from what it takes to curve a 0.45 TeV beam [injection speed/energy] to a field-strength that would curve a 5 TeV beam [stated goal to engage in collisions at 10 TeV in October, 2008]. Each magnet had reportedly been tested independently before installation, but the whole length of magnets had not been tested, thus the testing requirement for each sector as a whole, before beam injection.

So, the question is, at what field strength did the connector fail? At 1 TeV, 2 TeV, 5 TeV?. And the second question, was this the last of the sectors to be tested, or the first?

In any event, it calls into question the engineering design of the connectors. It will likely be determined that they can/will/do fail with their current design. If so, they will all have to be replaced/retrofitted in all magnets along the full 27 kilometer length. That won't happen this Winter, I'm fairly certain.

Another question pertains to potential damage to the magnets during the quench process. It appears the temperature gauges were damaged - they all stopped reporting save one, which stopped reporting five days after the accident. This implies physical damage to the gauges, and ergo, another design defect that would have to be retrofitted/corrected on all magnets.

And then, it still remains to be determined whether heating from 2K to 100K in a fraction of a second caused any damaged. It's not supposed to happen, according to the design. But then, 100 magnets are not supposed to quench simultaneously either, according to the design. So those magnets will need to be tested to see if they suffered any physical damage. If any of them did, that would imply a design defect that would need to be retrofitted on all magnets.

This accident is far more serious than initially being reported - and this is likely known by those engineers in the know, but possibly not yet being reported to management [Engelen/Aymar].

And, they're also having difficulties with maintaining their cool [pun intended]. Both ends of sector 3-4 are slowly warming. And even sector 2-3 is showing some difficulty. Perhaps they need more Helium, and it's not available?

In any event, they also have to worry about keeping everyone busy during the down-time, creating 'make-work' projects. It would be nice if they started working on the ideas we've proposed to look for the proofs of safety, if they exist. That's all good science too.

http://www.lhcdefense.org