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.
You'd think they could say why (Score:5, Insightful)
Why would a research instution hide the reason for the damage, afraid that they are going to cripple someone's career? It certainly is a tragedy, but the fact that they are not disclosing the real reason for the damage makes it more interesting somehow.
Thumbs up for cool Neutrino detectors though, it has been an unexplained scientific phenomena for a long time now. I hope they can fix it (and have the $$ too).
Brett
Re:You'd think they could say why (Score:3, Insightful)
Doesn't to me. Premature guessing as to the cause before investigation could be potentially damaging to any funding sources. The funding politics of large science projects can be quite complex. Completely normal.
Re:Next Supernova (Score:5, Insightful)
Tom.
Re:Here's why (a guess) (Score:2, Insightful)
You are right, there are no light bulbs inside, BTW, do you know how a photomultiplier tube works? The impact of a single photon releases an electron, this electron is attracted (by a big voltage difference) to an electrode. At the impact of this electron some more electrons are released, again attracted by a big voltage difference to the next electrode and so on. At each impact the number of electrons is multiplied, so that at the end you can measure a significant current from the impact of a single photon. Conditions to make this work are a vacuum inside a transparant enclosure (= a glass bulb).
Re:Just curious (Score:2, Insightful)
Re:Here's why (a guess) (Score:2, Insightful)
PMTs are remarkably robust. When we were building SNO, we tested a bunch of PMTs. Amongst other tests, we pressurized a tank to over 80 PSI and tried to smash the tubes inside using a rod that pushed through a pressure fitting.
The outcome of this test was that mostly the PMTs did not implode. There was a strong tendency for the rod to simply punch a rod-sized (about 1 cm) hole in the target tube. Putting a blunt block on the end of the rod did eventually produce an instance where the target tube smashed. The adjacent tubes, which were mounted in closer proximity to the target tube than they are in the real detector (and much closer than the tubes are in SuperK) were not damaged, despite being visibly twisted in their mountings.
Caveate: the tubes used in SuperK are about twice the size of those used in SNO, and therefore correspondingly more fragile. But having handled these tubes a good deal, I can say that it takes more than a small bang to break them. Whatever happened at SuperK (the NYT story is weirdly uninformative, to the extent that I wonder if they don't have all the major facts wrong) it is unlikely to be as simple as a chain reaction of imploding tubes.
--Tom
Re:Supernovae (Score:3, Insightful)
Two things:
Deterministic probability doesn't work. A rate of 1/500 years means that in any given year, there's a 0.2% chance of a near-by supernova. The fact that there was one recently doesn't rule out that the next one could happen tomorrow. If you're going to watch for a SN, it's better to be ready for it as much of the time as possible. The fact that it's so rare makes it more important to be ready for it, not less. If one happened every day, no one would care about missing one.
SuperK was much more sensitive than the detectors used to detect the 1987A supernova. In other words, it doesn't need a "big" (nearby) supernova in order to be able to see it. A supernova which is further away, and not visible to the naked eye, would still produce a detectable neutrino pulse which would provide more scientific information than the 1987A observation with comparatively crude equipment. SuperK was even sensitive enough to detect extragalactic supernovae in the neighboring Andromeda galaxy. The ability to increase the volume of space you're observing means that you've greatly increased the observation rate as well. It's still a rare event, but it's no longer miniscule.
Re:Just curious (Score:2, Insightful)
"Science is like sex. Sometimes something useful comes out, but that's not why we're doing it."
--Richard Feynman
We never know exactly what good will come of some obscure avenue of research. It may not produce anything truly significant or profitable. Still, curiosity about the world around us is a core element of our humanity. Would you take that away from us?