SuperK Neutrino Detector Severely Damaged. 191
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.
could be the end... (Score:5, Interesting)
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.
Re:Just speculation, but... (Score:3, Interesting)
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.
Here's why (a guess) (Score:5, Interesting)
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.
Re:Supernovae (Score:4, Interesting)
(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.
Insurance (Score:2, Interesting)
If this thing costs $30 million to fix, don'tcha think someone should have it insured against everything? Poor planning.
*trenton
Re:Neutrinos (Score:2, Interesting)
> 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
another detector (Score:3, Interesting)
They probably can't say why. Yet. (Score:3, Interesting)
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.
SNO? (Score:2, Interesting)
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>
Why I left Super-K this summer (Score:1, Interesting)
When our group got to Japan, they had just drained the tank, and external hydrostatic pressures caused the floor and walls of the tank to start bulging in, and while we were inside the tank on Tuesday, August 27, 2001, our second day of work, we heard huge CRACK and reverberation sounds, which we later learned were the bolts holding the concrete liner to the rock breaking. it was unreal.
People started looking around to see who was making the noise. I followed a sharp guy out of the tank, while a lot of other people waited around the exit, I guess waiting for official word to leave. I sat in the jeep in a dark, radioheadish mine tunnel, continuing to hear loud, ominous crashes and bangs.
The next day everyone said "IT'S FINE, they FIXED IT, IT'S PERFECTLY SAFE, the Japanese engineers said I'TS PERFECTLY SAFE," and even "Don't you trust me?" but after asking many different people, I couldn't get a real explanation of what had happened, or even a feeling that anyone
knew what had happened. A friend's father, a mining engineer, was unimpressed with their solution to the problem (drilling holes in the
bottom of the tank to relieve the pressure) saying it would allow greater
pressures to build up elsewhere, later, and unexpectedly, and that unless the source of the water was found and pumped, there was no reason to think the situation was stabilized. He said it at least would need monitoring for a few days before people went in the tank again, which made sense to
me. My mom, who drills oil wells, was also concerned and wondered why they didn't have instrumentation to monitor what was going on outside the tank. at one point the japanese engineering company responsible for the
tank determined that there were 2m of water built up around the outside walls, and they determined this by hitting the wall with sticks and listening to the sounds.
When the bolts started breaking and it was scary as hell I realized I had never been shown an evacuation procedure ("getting the hell out" is what it is, I later learned, and that involves changing boots into slippers, crawling out of a slippery tunnel, getting out of a tyvek clean
suit, climbing down a ladder and putting on normal shoes, then sitting in
the car waiting for someone to come drive us out.)
I realized I had never been shown the location of a first aid kit, fire extinguisher, emergency breathing apparatus, emergency food and water (we
were 2km into a mine, after all)
So, a friend and I decided to take responsibility for our safety and we flew
home the next day.
The End.