Comments on: LHC – Take 2

By: LHC 2009 Restart | Cosmic Variance | Discover Magazine

LHC 2009 Restart | Cosmic Variance | Discover Magazine — Mon, 09 Feb 2009 22:39:36 +0000

[...] the devastating quench incident on September 19 of last year, resulting in the rupture of the cryogenic vessels within the LHC [...]

By: Photos Show What 10 Megajoules Worth of Damage To the LHC Looks Like [Large Hadron Collider] | The-Informer

Sat, 20 Dec 2008 17:35:33 +0000

[...] CERN also reiterated their hopes to get the Large Hadron Collider back to colliding by June of next year. Two of the 53 replacement magnets have already been installed. [CERN Press Release via Cosmic Variance] [...]

By: Markk

Markk — Sun, 14 Dec 2008 19:45:35 +0000

“If helium is released into space above escape volocity should there not be a plume of helium spiraling away from the earth at about CERNs latitude and declination?”

No helium was released into space at any velocity. What the comments about helium being above escape velocity are implying is this – the distribution of speeds of a helium atoms (molecules – they are the same) in Earth’s atmosphere has a significant portion of the distribution curve at speeds above escape velocity. So when the helium from LHC diffuses through the whole atmosphere, and some of the atoms get to the top parts of the atmosphere a hundred kilometers up, they will escape at a higher rate than all the other gasses in the atmosphere, which are also escaping, but at a lower rate since they are heavier molecules and thus going slower.

This takes a long time – decades, centuries, millenia plus.

By: Gregg Weber

Gregg Weber — Sun, 14 Dec 2008 16:20:00 +0000

If helium is released into space above escape volocity should there not be a plume of helium spiraling away from the earth at about CERNs latitude and declination? If that were so could it be detected shortly after the release event by people doing spectroscope work on stars so that those reading would produce absorption bands. This would prove the existance of such escaping helium and also corupt measurments of the helium in the stars atmosphere.

By: Vídeo e imágenes de las reparaciones en el LHC. |

Vídeo e imágenes de las reparaciones en el LHC. | — Sat, 13 Dec 2008 11:13:57 +0000

[...] y ampliación de información: – Blogs.discovermagazine: LHC – Take 2. – Cdsweb.cern: Repair of dipole magnets from sector 3-4 of the LHC. – Gizmodo: Photos Show What 10 [...]

By: Peter Erwin

Peter Erwin — Fri, 12 Dec 2008 13:45:24 +0000

The national helium reserve was set up in the 30’s to keep Nazi Germany from using it in dirigibles, as seen with the Hindenberg

According to Wikipedia, the National Helium Reserve was set up in 1925 (which is of course before the Nazis came to power). It was created primarily as a source for US airships. The US government later decided not to sell helium to Nazi Germany, forcing the latter to rely on hydrogen for the Hindenburg and other German airships. (The situation, as I understand it, is that private industry wasn’t willing to go into the helium extraction business, so the US government decided to set up an entity to promote it.)

By: Lab Lemming

Lab Lemming — Wed, 10 Dec 2008 20:50:38 +0000

“Should I ferret away He in my cellar rather than Iridium and Osmium for my old age?”

Leave the Os in the cellar, keep the He in the attic.

As for the waste, 15% of the actinides should eventually end up as He, but for Th you’ll have to wait a while…

By: What 10 Megajoules Worth of Damage To the LHC Looks Like | Bite-Dose

What 10 Megajoules Worth of Damage To the LHC Looks Like | Bite-Dose — Wed, 10 Dec 2008 20:20:47 +0000

By: Sili

Sili — Wed, 10 Dec 2008 17:55:52 +0000

the interconnect bus subsequently vaporized

I <3 Physics – as the kids might say.

On the subject of Helium – where’ll we get it once the wells run dry? Should I ferret away He in my cellar rather than Iridium and Osmium for my old age?

By: Roman

Roman — Wed, 10 Dec 2008 16:13:59 +0000

The report says:
“Overall, the discharge cross-section will be eventually increased 40-fold, thus allowing to cope with a helium discharge twice as high as that of the 09.19 incident while keeping overpressure within allowed limits.”
Does this mean that the original discharge cross-section was at least 20-fold under designed?