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SuperK Neutrino Detector Severely Damaged.
Eric Sharkey writes "The Super-Kamiokande neutrino detector, which announced the discovery of neutrino oscillation and mass in 1998 (covered by Slashdot at the time), has been severely damaged. The NY Times (free reg, blah blah) has an article here. Most of the phototubes have been destroyed. Repair estimates top $30M, leaving the world far less capable of observing the next supernova neutrino burst, should it arrive before repairs or a replacement could be completed." CD: I called the lead of the project and he was in the tank checking out the damage. The webpage for the Super-Kamiokande is here. There are pictures for you to peruse.
Of course this is just wild speculation, but...
A couple of Japanese colleges say that SuperK was previously being targeted for budget cuts, and was fighting to maintain funding. They were concerned that if it would indeed take tens of millions of USDs to fix, then it may be cut. That would be a real dissappiontment.
Let's hope SuperK comes back on line, and that we don't have a galactic supernova go off while SuperK is being fixed.
I don't know about physically damaging the detectors, but I do know that the machine is extermely sensitive to ionization with regards to it's being able to function properly.
The photocollectors measure Cerenkov radiation given off by high energy electrons and muons travelling through or being created in the tank. The mountain blocks the majority of external particles, so most are created when nuetrinos interact with Hydrogen nuclei. You don't get a lot of Cerenkov light from an event, and ionized impurities dissipate the light, so in order to work effectively, the water needs to be very pure.
I've never heard that detectors can be physically damaged by impure water, but I've never heard that they can't either. At the very least you already need pure water to gather data effectively regardless of any actual damage to equipment that impurities might cause.
Right, pressure: a bulb imploding under a significant depth of water (say, at the bottom of the tank, I doubt it is artificially pressurised in any way, the volume would be too large for that to be an economically feasible structure) will create a shockwave within the water - which may have enough energy in turn to cause a neighbouring bulb to implode, etc, etc, bringing about a cascade failure of the bulbs.
Which is why deep water divers have to be carefull with their lights while working under pressure - if one implodes, the shockwave is like a small bomb going off. Remember, water is much more dense than air, any shockwaves will have significantly more energy, particularly at a depth of 40 meters.
All it would take is for one bulb to be broken somewhere in the depths of the tank (through physical impact or corrosion, etc) to set off a large number of them. Despite it's size, these are delicate instruments.
Just a rational, educated guess.
(No, neutrinos can't travel faster than the speed of light, just very close to it. The neutrinos produced by the core of the collapsing star escape easily through the stellar atmosphere since they interact weakly with matter, whereas the light took significantly longer to escape - think of how light travels more slowly in a block of glass. So the neutrinos reached us first.)
It was all tremendously exciting stuff, as you might imagine. Unbelievable serendipity.
If this thing costs $30 million to fix, don'tcha think someone should have it insured against everything? Poor planning.
*trenton
Too big to fail? Does that make me to small to succeed?
> The interesting item is that most neutrinos pass right through the planet without ;-)
> interacting with any atoms.
That is only the moderately interesting item. Now the really spectacular item is that these particles come to us in real time straight out of the core of a collapsing star, nary even noticing the star's outer layers
the school i'm at (UBC) is co-sponsoring a neutrino detector in sudbury: http://www.physics.ubc.ca/~kutter/
This thing collapsed just hours ago. Remember that work was being done in an underground lab. There are probably no more than 2 dozen people on site (a remote part of Japan) at one time, and they just had their detector implode. Give them some time to figure out what's going on down there. Heck, they might not really understand it for a few weeks. Science is like that.
The chain-reaction-implosion mechanism is a plausable one, but it still requires something to make it happen.. these tubes have been sitting under a lot of hydrostatic pressure (more than during the accident) for years now. Other phototube experiments have been doing similar things, none of which have ever seen this happen.
The failure mode for the tubes is likely to be leackage at the base (the back) which slowly degrades the vacuum inside... no implosion.
There was likely a large pressure change that happened all at once. I'd be looking for a rockburst: a small seizmic event in which the external rock pressure (which is very large) caused the wall to buckle and throw debris.
---Nathaniel, glad it didn't happen to HIS neutrino experiment.
This is midly off-topic, but I'd love to hear an answer if anyone's got one.
Has anything come out of the Sudbury Neutrino Observatory? Net resources seem to be over my head.
The Sudbury Neutrino Observatory put 1000 tons of heavy water into a geodesic dome two miles deep in an abandoned nickel mine, up in Northern Ontario.
I last heard news about SNO about 6 years ago when they were building it, but haven't heard a thing since.
Anyone got any updates?
<a href=http://www.sno.phy.queensu.ca/>SNO</a>