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Asked by Omdididom to Chris, Josh, Rebecca, Rob, Susan on 19 Jun 2015. This question was also asked by hazel, Ruben Unt Jacob, pippa.
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Susan Cartwright answered on 19 Jun 2015:
Oh yes. It was before I joined, but the great Super-Kamiokande disaster is the stuff of particle physics folklore.
Super-K uses over 11000 photomultiplier tubes (PMTs) to detect signals. PMTs look a bit like giant lightbulbs, and inside them they have a vacuum, so if the glass breaks they implode.
Well, on November 12, 2001, one PMT imploded. We don’t know why: probably the glass had some tiny crack or flaw that gave way under the water pressure. The implosion caused a shock wave in the water, and the shock wave was powerful enough to crack two more PMTs – which caused a stronger shock wave, and so on. Within about 4 minutes, all the PMTs that were underwater, which was about 6600 (the remaining 5000 or so were above water, because when this happened the detector was being refilled after routine maintenance) were broken glass at the bottom of the tank. There was absolutely nothing anyone could do but watch. (Incidentally, each PMT cost about £2000.)
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Rebecca Dewey answered on 19 Jun 2015:
Not really. Things have not worked very well on several occasions (like the pictures didn’t look very good or there was no difference between two conditions when I was hoping to see a difference). But nothing horribly wrong!
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Rob Temperton answered on 21 Jun 2015:
God yes! Accidents happen. I have get to witness the level of damage that Susan describes at the Super-K, but I came scarily close to breaking a 18 tesla superconducting magnet. It was whilst it was very new and before all the safety procedures where properly in place but I basically walked too close to it with a metal object whilst setting up my experiment. Luckily, no one got hurt and it wasn’t damaged, but it was very scary at the time!
Rob
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Josh Meyers answered on 22 Jun 2015:
Things go wrong in my experiments all the time. Its by getting things wrong that I learn and become a better scientist.
The only difference is, because my experiments are computational, there’s no explosion!
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