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.

Comments

could be the end...

[astrophysics]

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.

You'd think they could say why

[hackman]

Seems strange that the article was so sketchy on why the damage was done. They sort of implied that the tank got overfilled, but then again they really avoided saying anything.

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

[Joe Decker]

Seems strange that the article was so sketchy on why the damage was done.

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:You'd think they could say why

[CaseyB]

That comment isn't offtopic at all. I think you moderators meant (-1, Too Damn Close to the Truth). The agressive witchhunt for scapegoats immediately after any sort of problem arises is very much an American phenomenon.

Supernovae

[the Atomic Rabbit]

...leaving the world far less capable of observing the next supernova neutrino burst, should it arrive before repairs or a replacement could be completed.

While the accident is a tragic blow to some valid and interesting research, no one should lose any sleep over the possibility of being unable to analyze the next big supernova before it can be repaired. After all, supernovae on the scale of SN1987A occur once every few hundred years (the last two occurred in 1054 and 1572.) I suspect repairing Super-K will take significantly faster than that.

Even in the minuscule chance that a big supernova will occur in the meantime, Super-K isn't the only neutrino observatory around. The Sudsbury Neutrino Observatory, a similar experiment, is online and producing some very good results.

Re:Supernovae

[the Atomic Rabbit]

Oh, and in case anyone is misled... the neutrino observatories are assuredly NOT there to catch supernovae. They mostly detect neutrinos coming from the Sun, which are produced during the solar fusion process. The data from Super-K and SNO is shedding light on some problems in solar physics and elementary particle physics.

I doubt any grad student is patient enough to work on an experiment that gets one event every five hundred years.

Re:Supernovae

[astrophysics]

While it's true there are multiple observatories, they aren't merely copies or bigger versions of each other. The different observatories are senstive to neutrions of different energies.

SuperK used ordinary (but pure) water. SNO used pure "heavy water", that is water where the hydrogen has a neutron. SNO has recently added salt to their heavy water, since comparing the reaction rates with and without the salt will provide a very interesting ratio for understanding the mass heirarchy of neutrinos. Other detectors have used other media for detecting neutrinos, such as gallium.

Re:Supernovae

[isaac_akira]

What makes you think supernovae follow any kind of cyclic schedule? Only two dates were mentioned.

As an example, say you know I ate a burrito yesterday and I ate a burrito today. That doesn't mean that I eat a burrito every... oh wait. But that's TOTALLY different!

Re:Supernovae

[the Atomic Rabbit]

Three dates, actually - the last big (naked-eye) supernova was in 1987. That was what made these neutrino observatories famous. IIRC, teams working at two different sites each detected a big burst of neutrinos, almost three hours before the supernova was sighted.

(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.

Re:Supernovae

[Paul Komarek]

Although the thesis sometimes feels like it takes 500 years...

-Paul Komarek

Re:Supernovae

[crumley]

Actually, the neutrino detectors weren't built to study the "Solar Neutrino Problem" either, although that has been a pleasant side effect.

I'm pretty sure that Super-K and the current generation of neutrino detectors were designed to study neutrinos. Earlier detector such as Kamiokande and Soudan were designed to look for proton decay.

Re:Supernovae

[Eric Sharkey]

While the accident is a tragic blow to some valid and interesting research, no one should lose any sleep over the possibility of being unable to analyze the next big supernova before it can be repaired. After all, supernovae on the scale of SN1987A occur once every few hundred years (the last two occurred in 1054 and 1572.) I suspect repairing Super-K will take significantly faster than that.

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:Supernovae

[efuseekay]

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.)

Good try, but not quite right either.

Neutrinos have very low crossectional area, so interact weakly with other stuff. Photons, however, interact strongly with electrons and protons and what have you. So during a SN collapse neutrinos escape first, while the other stuff begins to fall into the core of the dying star. Photons are generated during the collapse, but their escape from the SN is blocked by the collapsing matter. So photons have to "work" themselves via random scattering, which takes a lot more time, i.e. a few hours.

Re:Supernovae

[the Atomic Rabbit]

So photons have to "work" themselves via random scattering.

In other words, by interacting with matter. Forgive me, but I don't quite see what you're correcting.

The answer is obvious

[donglekey]

They should have used a surge protector, not just a power strip. Too late now!

Just speculation, but...

[sting3r]

One of my colleagues used to work at Fermi Lab and he mentioned once that the light sensors that were damaged are extremely sensitive to saline solutions (such as water that has any appreciable amount of non-neutral-pH molecules). His speculation was that the deionized water that they were using had developed impurities in it, possibly from rusting pipes or failed filters, and those impurities set off the chain reaction in question.

Naturally this is all speculation, but it sounded plausible to me. Does anyone with a stronger chemistry background than mine know if this is a likely cause?

-sting3r

Re:Just speculation, but...

[dragons_flight]

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.

Re:Just speculation, but...

[Paul Johnson]

More likely I think is a chain reaction from the shockwave of implosion. These photomultipliers are basically big vacuum tubes. If one breaks under water then the water is going to accelerate rapidly inwards, then stop suddenly when it meets other water coming the other way. This will generate a pressure pulse which would break nearby tubes, causing a chain reaction to spread across the entire system.

Paul.

Re:Just speculation, but...

[markmoss]

According to the article, they were refilling the tank after draining it when the glass bulbs started imploding in a chain reaction. The materials for neutrino detectors have to be _extremely_ pure, so I don't see any chance of having unintended impurities in sufficient concentration to react with glass.

On the other hand, extremely pure water is itself a strong solvent for many things. That may be why they had to periodically change the water in the first place, that it gradually picked up impurities from the tank. But dissolving glass doesn't seem likely unless they really had the wrong kind of glass to start with.

The one thing that's clear is the "chain reaction." The photomultipliers are glass vacuum turbes 20 inches long. In air, one of these breaking would be like a cherry bomb or maybe even a hand-grenade. Deep under water it would be much more violent due to the higher pressure, also water transmits shock waves better than air. So unless the bulbs were well protected, any accident or defective bulb that broke one would start a shock wave that might break more, etc.

I have two theories about why the researchers are reportedly closed mouthed about two simple questions: What broke the first one, and why weren't they protected against a foreseeable chain reaction implosion. Perhaps "Yoshi dropped a wrench, and we didn't think of that" is just too embarrassing. Or, if Japanese scientists are anything like the American ones I've known, more likely they said just what happened, in jargon that is utterly incomprehensible to the reporter, repeated until he gave up. And they weren't even trying to obfuscate!

Pick A Punchline...

[Bowie J. Poag]

Allrighty, step right up and pick the punchline that best matches this story:

#1: These photos are fake!! Theyre from the inside of Studio 54!! Look up in the balcony in the 4th image, you can see Liza Minelli smokin a bong!

#2: It should be easy to build another Super K detector. Just look for trailer parks...Super K's tend to spring up in low-income areas where Wal-Mart hasn't already established a commercial presence..

#3: So SuperK is handicapped...Does that make it "Special K" ?

hee hee

In other news...

[c_jonescc]

1,800 Japanese Grad students are looking for a new advisor, citing "extended duration of research project" as the reason. Each potential particle-physicist has a co-authorship of several papers, all shared with the other 1,799 students and their advisors. It is expected that many will go into theory soon, as the resulting projects can be finished this decade. One student was overheard saying "first I was put as 234th author on our last paper, and now the experiment is gone. I've had it, I'm going into astronomy, man! Or maybe condensed matter theory, but not this! Not anymore!"

Future Nytimes

[Henry V .009]

In other news:

Nov 12, 2050,

Scientists working with Japan's Super-Duper-Kamiokande anounce that they have lost containment on a micro black hole.

Apparently, an undergrad triped over the power cable.

Officials tell us that there is no need to panic. The mini black hole plunged straight to the center of the earth.

Happily, it will feed on the other mini black hole that was created when the first copy of Windows 2047 was burned onto CD and collapsed on its own data mass -- it was thought at the time that the universe was acting to protect both itself and the second law of Thermodynamics from Windows 2047's immense entropic mass.

There is some speculation that the black hole could actually provide enough energy to run Windows 2047, but Physicists are highly dubious.

Slashdot checked a story??

[Gorimek]

The apocalypse is near, and chrisd is it's harbinger. Calling the place the story is about is a dead giveaway. A real slashdot editor would never do that.

Re:Slashdot checked a story??

[dragons_flight]

Calling the place the story is about is a dead giveaway.

Not only is it entirely atypical behavior for slashdot, one has to wonder why it is that chrisd didn't trust the New York Times? Did he think SuperK would give him more details than were already in the story?

Reports of its demise have been....

[wholesomegrits]

Premature at best.

It's a real shame, the loss the Japan lab, but I can't help but think that the lab being built in Western South Dakota will be even more important. I cannot find a decent date on completion, but this page explains a newer, better neutrino detection lab being constructed right now.

The location even better (8,000 feet deep, insulated from nearly every form of interference) and the site has fanstastic support from the state and federal government. The Japan lab isn't the only one in existance -- there are others in Ontario and the South Dakota lab has had facilities in operation since 1967.

The articles, both the Slashdot commentary and the NYTimes article, predict a savage demise. But other labs, especially the South Dakota lab, offer a huge potential to pickup the slack.

Bin Laden lauds neutrino detector blast

[serutan]

Bakhrubabad, Afghanistan - Speaking from his hidden mountain stronghold, Osama bin Laden praised the destruction of the Super-Kamiokande neutrino detector Tuesday. The terrorist leader said neutrinos are "...an abomination on the face of God," and termed the search for neutrinos "...idolatry, which will be smashed beneath the fist of righteousness." Bin Laden, who once called neutrinos "little messengers of Allah" abruptly reversed his stand upon learning that a steady stream of neutrinos was constantly penetrating every cell in his body. He now vows "not to rest until the last neutrino has been obliterated from the face of the earth."

Ashcroft: Supernova could explode this week

[MillionthMonkey]

The FBI is warning again that a supernova may explode and send a massive number of energetic neutrinos toward U.S. interests worldwide, possibly this week, and that the world's neutrino telescopes should be on the highest alert.

Attorney General John Ashcroft said the warning -- the second this month -- was based on credible information, described by others as coming from sources outside the solar system. The information did not specify the type of supernova or whether the progenitor star would have a binary companion, Ashcroft said.

Ashcroft tried to walk a fine line between giving the public prompt and necessary warnings and not causing panic.

The alert "gives people a basis for continuing to live their lives the way they would otherwise live them, with this elevated sense of alertness or vigilance that comes from knowing that the planet could be vaporized any second," Ashcroft told a news conference.

FBI Director Robert Mueller said the previous supernova warning may have helped avert an explosion. Ashcroft said the absence of a supernova should not lull people "into a false sense of indifference."

"It's important for the American people to understand that these (alerts) are to be taken seriously," said Ashcroft, who canceled plans to travel Monday to Toronto to address a conference of near-earth asteroid experts.

Officials said the warning was based in part on intelligence that terrorists may set off a supernova within 1000 light years of the earth, in the aftermath of the Afghan bombings by U.S. and British forces.

"There certainly is intelligence that causes you to be concerned, and possibly that al-Qaida may be behind it," said one senior U.S. official, speaking only on condition of anonymity.

Ashcroft said that all neutrino observatories were advised to go on the highest alert. Federal agencies, meanwhile, were increasing security and authorities were boosting their efforts to keep suspected neutrinos from entering U.S. airspace- either by coming down from above or by emerging from the ground after a trip through the center of the earth.

Here's why (a guess)

[Anonymous Coward]

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.

Re:Here's why (a guess)

[Anonymous Coward]

Cute theory, but there weren't any light bulbs in the tank. Many, many photomultiplier tubes, but no light bulbs.

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:Here's why (a guess)

[hackman]

Yeah, ok you guys got me. Scientifically speaking if the news was really new then they may not have actually known yet what the cause was. It's hard to tell on some of these /. stories when they actually occurred, sometimes it's way later that it gets posted. I guess I could have checked.

And that light-bulb idea sounds pretty plausible actually, although a bit beyond common reason. I'm an engineer but I have absolutely no idea how those things are constructed...

B

Re:Here's why (a guess)

[radtea]

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:Here's why (a guess)

[Peter Harris]

Nah. They just detected a 50kg "Bastardino". These hardly ever interact with matter, but when they do you want to get out of the f**king way. Creating a sensitive and expensive instrument to detect such exotic particles is just asking for trouble in my opinion ;)

Just an irrational and uneducated guess.

Re:Neutrinos

[mmontour]

...have no charge and no mass...

No charge - correct. However, as the article mentions, recent experiments indicate that neutrinos have some mass. They also have spin 1/2, like electrons.

are very fast

This is related to mass. If they had zero mass, they would travel at the speed of light (like photons, which have no rest mass). However, if they do have mass, then they have to travel at slightly less than the speed of light.

Supernova observations can be used to estimate neutrino mass, by measuring the time difference between the arrival of visible light from the supernova, and the arrival of a neutrino pulse. Over those vast distances, even a very small difference in speed could lead to a significant difference in arrival times.

and pass through the planet so fast most detection has to be done underground...

This is a bit off. The interesting item is that most neutrinos pass right through the planet without interacting with any atoms. Because they interact so weakly with matter, a detector will only see a very small number of events caused by neutrinos, even though there are bazillions of neutrinos passing through it every second.

However, a detector on the surface of the earth would also see events not from neutrinos, but from other cosmic radiation like muons (actually, muons generated in the upper atmosphere by cosmic radiation). Going deep underground blocks out all particles except neutrinos, enabling the experimenters to get accurate measurements.

Insurance

[trenton]

My $10k motorcycle has full insurance because it's borrowed against; my crap 87 Chevy has comprehensive and liabilty because it's a good idea; my apartment has renters.

If this thing costs $30 million to fix, don'tcha think someone should have it insured against everything? Poor planning.

*trenton

Re:Insurance

[cperciva]

Who exactly is going to sell insurance on a neutrino detector? As a general rule, insurance companies want to have some understanding of the likely risk involved in whatever they are insuring; neutrino detectors (and interplanetary probes) don't satisfy this criterion, so any insurance policy you could get would come at a very high cost.

Re:Insurance

[Caid Raspa]

In some countries (including the one I'm living in), the parliament has passed laws that forbid any insurance on state property. I'm not sure if Japan is one of those, but this might be the reason.

Re:Insurance

[CrazySailor]

In the US, the government is considered "self-insured" and is not permitted to purchase policies from commercial providers. Any adequately large business may do this as well. It comes into play when I'm on travel and not permitted to purchase the various damage waivers on rental cars. The travel office refuses to reimburse them.

Re:Insurance

[dattaway]

From what I read, the insurance company paid the guy with a check, but he was arrested for arson after he cashed it.

It would seem insurance companies not only make their business covering risks, but providing a service of advice and checks to make sure what you have is secure. For example, the company I work at has fire insurance. The insurance company works closely with us to make sure we have safe procedures when we need to work with welders, contractors, what happens if we need to service the fire system, etc. They make rules to help us have safer procedures so accidents are much less likely to happen. If we don't follow those rules, they will take steps to terminate our contract. Same with bad drivers. Traffic tickets are their check to make sure drivers are following customary procedures.

I'd imagine with a neutrino detector, an insurance company would consult with the researchers on proper procedures for enforcing safe conditions when working around the system. Insurance can be a win-win situation for both sides. They consult for a more reliable business and when things don't work out, they help get you going again for the next round.

More wild speculation

[Tsar]

A few random thoughts:

I don't know how much their missions overlap, but does this put any more urgency on getting the Ice Cube neutrino scope up and running?

Whilst I'm here, I've been mulling over some possible reasons for the accident:

• SuperK Technicians ignored the pump signs warning not to "top off"
• They accidentally filled it with heavy water
• Water level was correct, but wash cycle was accidentally bumped from "Delicates" to "Heavy Duty"
• Weekend Sumo Bellyflop contest got a bit too rowdy this week
• Detector tubes? We thought you ordered defective tubes!
• Drunken revelry, celebrating yet another discovery of the Higgs boson

Re:Next Supernova

[tomknight]

Why isn't there a moderation category "-1, unbelievebly stupid"?

Tom.

Re:Neutrinos

[Anonymous Coward]

> 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 ;-)

another detector

[firebat162]

the school i'm at (UBC) is co-sponsoring a neutrino detector in sudbury: http://www.physics.ubc.ca/~kutter/

Just curious

[SweenyTod]

Pardon my lack of scientific knowledge and enthusiam, but what exactly will finding one of these suckers do or, besides cost a ton of cash?

How will knowing they're out there and finding one will benefit people, besides in the science for science's sake sort of reasoning (not that I'm automatically opposed to that).

Re:Just curious

[Anonymous Coward]

You're pardoned but what would you have said to JJ Thomson when he was trying to discover the electron with cathode ray tubes? That was in the late 1800s. Would he have told you that finding electrons will benefit ordinary people? Would he tell you that with the understanding of electrons cathode ray tubes will be used for computer displays and for televisions one hundred years later?

Re:Just curious

[PurpleFloyd]

A quote for you:

"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?

Re:Just curious

[kindbud]

(not that I'm automatically opposed to that)

Of course you are, why else would you ask this question in the first place?

If you try to measure benefit in dollars, you will surely be disappointed. Try asking a better question.

Re:Just curious

[Fnkmaster]

Mostly indirect, but most of the effort to confirm or dispute parts of the rag-tag-whole that is known as the Standard Model hangs around neutrino research. Mostly because neutrinos are still quite a big question mark for EXACTLY this reason (they are hard and expensive to find and detect).

Nobody is going to be building "neutrino guns" or "neutrino death rays" any time soon, and this is basic research, not applied research. But if inconsistencies or discrepancies in the Standard Model are discovered that relate to neutrino behavior it is possible that will eventually lead us to a Grand High Pooba Ultimate Theory of Everything. Or at least get us a couple of steps closer.

Such understanding may allow us to make big spaceships that cross the galaxy in months rather than millenia or smash planets with large pseudo-scientific beam weapons. Err.. well, maybe not, but I'm quite sure we haven't seen an end to the totally inconceivable but infinitely useful devices that come out of better scientific understanding, and basic research comes into the picture somewhere. My point is that rather being some weird peripheral piece of basic research, neutrino detection work is hot on the trail of figuring stuff out that WILL change our understanding of the universe and therefore will likely result in very cool devices and gadgets 50 years from now that we can't even imagine today.

Whoa, dude...

[phillymjs]

Bill: "I'm Bill S. Preston, Esquire."
Ted: "And I'm Ted "Theodore" Logan."
Bill, Ted: "And together, we're WYLD PHYSICISTS!"
Bill: "Ok, the maintenance dudes are done. I'm gonna refill the water tank."

<cacophony of pops as the light detectors implode>

Ted: "Strange things are afoot at the Super-K."
Rufus: [reassuringly to the camera]: "They do get better."

~Philly

What did they expect?

[sysadmn]

It serves them right for adding that big red "SELF DESTRUCT" button. Of course, it didn't help that the Mad Scientist (er, Project Director) just stood there boasting about taking over the world instead of firing the dang thing.

Incorrect

[DoctorNathaniel]

Neutrino observatories ARE there to catch supernovae, although this is not their primary reason for existance.

SNO is indeed on the case for supernovae explosions, but the fact of the matter is that one observatory simply isn't enough; because of unvavoidable detector downtimes (maintanence, calibration, equipment failures, instrumental problems, etc etc) you can't run 24/7/365 with these guys. Also important is that one really wants both detectors live: you want verification that there really IS a supernova in progress before you swing the Hubble around to look for it.

Add to that the complimentary advantages of the detectors (angular resolution and high statistics in SK, antineutrino detection and energy resolution in SNO) and you really really don't want SK going down if you're a neutrino astrophysicsist interested in supernovae.

--Nathaniel, recent PhD with SNO

This sounds suspiciously like....

[Unknown Bovine Group]

This sounds suspiciously like the plot of Half-Life.

They probably can't say why. Yet.

[DoctorNathaniel]

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.

Re:They probably can't say why. Yet.

[Eric Sharkey]

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.

This isn't quite true. Most of the tubes have been underwater for years, but this summer the tank was drained, dead tubes were replaced with new ones, and the tank was in the process of being refilled when the accident occurred. It was only about 2/3 full when it happened. I don't know yet if the first tube to go was brand new or not, but it's conceivable that as the water level was rising, pressure was increasing on a new tube that had a manufacturing defect and it imploded.

Although the most common failure mode is slow leakage, it only takes 1 / 11000 to implode and cause this kind of chain reaction.

(Loved your egg sandwhich paper, BTW.)

Will it come back up? I hope so. But it's hard.

[DoctorNathaniel]

Although news has been sketchy, I am hopeful that they had the phototubes insured. (Any other financial cost will be small compared to the PMTs.) Even if they didn't, I think it's not too unlikely that Japan and the US will re-fund the experiment. SK has done some really amazing work, and is committed to a long-term project with KEK (the K2K long-baseline experiment). I can't imagine that they would simply dump this very productive and valuable resource. But then, who am I to predict the whims of politicians?

However, even if money is no object, timeline could be. These 20-inch PMTs are not exactly off-the-shelf items, and Hamamatsu(the company that provides them for SK and many other experiments around the world) has substantial lead times in getting their production lines up. All told, even under the best of conditions, the process could take 2 years, by which time SK will be in severe competition with a lot of other experiments: Borexino, KamLand, MINOS, etc. etc.

They MIGHT use the time to build super-duper-K.. putting a magnet in the water to look for lepton charge sign from atmospheric neutrinos, but that seems a bit farfetched and difficult.

---Nathaniel, messenger of doom

P.S. I call dibs on the SK linac when it gets scraped!

Ice Cube

[DoctorNathaniel]

Oh, I forgot to mention: IceCube (and AMANDA) are not really in the same buisiness as Super-K. The really big ice experiments are looking for cosmogenic neutrinos, and very-high energy atmospheric neutrinos, not the same energy band as SK. SK in addition does a lot of work on solar neutrinos and other physics besides; the ice cube is not really in competition... although it is extremely cool. Not to say cold.

--- Nathaniel
Who has worked in Sudbury (SNO) and Minnesota (MINOS) and wants no part of AMANDA (south pole)

+1 Funny on the MQR standard

[MarkusQ]

Nah. They just detected a 50kg "Bastardino".

*laugh* Good thing it wasn't the Basterdino's super-sym partner (the Basterdon). Last I heard, it was suspected to mass about as much as a Mastodon (within a factor of Pi times some magic number).

-- Markus

SNO?

[AndyMan!]

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>

Sounds like...

[Tom7]

Super Kamiokande sounds like one sweet Nintendo game! Hook me up!

Next generation Kamiokande

[ErfC]

Actually, the next neutrino detector at the Kamioka site will be called "Hyper-Kamiokande".

I'm not kidding. See, for example, this article.

Re:Devastating....

[Enoch Root]

Yeah. If they keep this up, they'll need to undiscover the atom.

Re:Strange! Neutrino detector destruction NHK TV!

[zorgon]

Damn! It's those aliens. Again. You'd thought they would have been satisfied after replacing those Senators with zombies and ensuring cancellation of the SSC (not to mention Apollo 18-20) and destroying all those Mars probes, but no, now they have to destroy innocent neutrino detectors in order to conceal the signatures of their fusion reactors in orbit while they are carrying out their surveillance. What a nuisance.

Article dated tomorrow...

[evilviper]

Alright, I confess, I was the one that caused the rip in space and time... I was overclocking my CPU to incredible speeds, when I got to the point that the instructions were being executed before they reached the processor. Now the two universes are coliding, now is not now, it's next week, and yesterday will be here tomorrow. Surprisingly, people honestly believe that lotter numbers for next week's game are showing up early simply because of time zones... And no body suspects a thing (except for those Unix people who get an error when the source files are than the current date-it's obvious that the early Unix developers had the forsight to impliment this feature purely to detect just such a rip in the fabric of time).

Appologies to bbspot.com