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David Hall
2001-Nov-15, 11:42 AM
When I go to work, I try to take the time to read the English newspaper we get there. I was shocked to read this news story today. Looks like quite a setback.

http://www.yomiuri.co.jp/newse/20011113wo71.htm

Here's another site that looks a bit more current:

http://www.physicscentral.com/news/

frenchy
2001-Nov-15, 06:04 PM
That's bad!
Neutrino science seems to be well funded in Japan so I hope this will only be temporary, 20 mil$ doesn't sound too bad (compared to the cost of space observatories amongst other things). Of course it's going to take quite some time to repair.
There is shortage of new neutrino experiments coming along like SNO and Borexino. SuperK might lose its edge over its competitors though.

Fingers crossed...

Donnie B.
2001-Nov-15, 07:38 PM
It is bad.

But on the lighter side, they have apparently created the world's largest demonstration model of a nuclear chain reaction. Move over, ping-pong balls on mousetraps... /phpBB/images/smiles/icon_cry.gif

<font size=-1>[ This Message was edited by: Donnie B. on 2001-11-15 14:39 ]</font>

Mr. X
2001-Nov-15, 09:38 PM
On 2001-11-15 13:04, frenchy wrote:
That's bad!
Neutrino science seems to be well funded in Japan so I hope this will only be temporary, 20 mil$ doesn't sound too bad (compared to the cost of space observatories amongst other things). Of course it's going to take quite some time to repair.
There is shortage of new neutrino experiments coming along like SNO and Borexino. SuperK might lose its edge over its competitors though.

Fingers crossed...

Frenchy, on an unrelated note, if you are from where I think you are, did you go to Poly? Or did you leave too early?

You can private message me an answer or post it here, and sorry for disrupting the thread, won't happen again.

Chip
2001-Nov-15, 09:53 PM
On 2001-11-15 06:42, David Hall wrote:
When I go to work, I try to take the time to read the English newspaper we get there. I was shocked to read this news story today. Looks like quite a setback.

http://www.yomiuri.co.jp/newse/20011113wo71.htm

Here's another site that looks a bit more current:

http://www.physicscentral.com/news/



Those "photomultiplier tubes" are difficult and expensive to replace. $3000.00 each! /phpBB/images/smiles/icon_frown.gif

DStahl
2001-Nov-16, 07:13 AM
So the shockwave from the first tubes that blew caused the next echelon of bursts, etc? Geez. Has a similar accident ever happened at any other facility using photomultiplier tubes underwater, anyone know?

David Hall
2001-Nov-21, 03:18 PM
I saw an article in one of today's papers about the accident. They interviewed one of the main researchers at the Super-K site. They theorize that one of the tubes near the bottom was defective in some way, and that when subjected to the high water pressure it burst. The inrush from the implosion created a shock wave that burst the ones next to it, and so forth. The only tubes to survive were the ones near the top of the chamber, where the water pressure became less and the shock wave wasn't so strong.

Here's the full interview. I'm not sure how long the link will remain good for though.

http://spin.asahi.com/english/national/K2001112100450.html

ToSeek
2002-Jan-10, 05:33 PM
Here's a follow-up report on the accident:

http://www.newscientist.com/news/news.jsp?id=ns99991774

(I had some problems with the link, so I hope it works.)

David Hall
2002-Jan-11, 02:26 PM
Hmm, so they're going to start it up again with only the remaining tubes. I wonder if they are going to keep them in their original locations or if they are going to move them all down to the bottom (for example).

I guess they can't call it 'Super K' any more. It's just 'K' now. /phpBB/images/smiles/icon_razz.gif

Interesting to note the way purified water leaches out sodium ions from glass. And I also wonder exactly how they arranged it to walk over the glass tubes. I suppose the mats they used were spread out over several tubes at once to distribute the weight evenly. Sounds like a risky procedure to me. Direct contact with sensitive equipment is usually a bad idea. I wonder why they didn't have some better means available, like removable catwalks.

Thanks for the update.

Donnie B.
2002-Jan-11, 03:48 PM
As a guess, I'd say if they're planning to move any tubes at all, they'll distribute them evenly around the walls rather than concentrating them in one spot. Better coverage, and easier to extrapolate the results to the "fully-loaded" case.

Another possibility would be to leave them as is, map the areas of damage, and let the computers apply a correction to the new data.

I still think the whole episode is a tragedy... and possibly a travesty, if poor mantenance procedures were responsible. "Isoruko, this is coming out of your paycheck!"