Costly Accident At Neutrino Super-Lab
Researchers on Tuesday were investigating an accident that damaged thousands of expensive and hard-to-replace light sensors at a Japanese neutrino physics lab near Tokyo.
The accident at the Super-Kamiokande laboratory, a huge underground chamber built a kilometer below ground, has rendered it unusable for the time-being and may cost more than $16 million to repair, an official at the Education, Science and Technology ministry said.
"This is a terrible thing for science," the official said. "There is only one other facility like this in the world, so this is likely to slow research into neutrinos altogether."
Neutrinos are ghostly particles which, although they bombard the earth constantly in mind-boggling numbers, pass almost seamlessly through matter and are nearly-impossible to detect without super-sensitive equipment.
The Super-Kamiokande facility has been acclaimed by scientists throughout the world for its 1998 discovery that neutrinos possess mass. Neutrinos come into being when cosmic rays hit the earth's upper atmosphere.
At stake in the study is the structure of matter itself, as well as cosmological puzzles such as whether the mass of the universe – and hence its own gravity – would be sufficient to stop its expansion.
The centerpiece of the Super-Kamiokande facility is a neutrino-detection apparatus that relies on more than 11,000 tubes called photomultipliers that line a massive tank of purified water.
The laboratory had just replaced about 100 of the failed sensors, which detect an elusive flash that occurs when a neutrino – one among billions – happens to make contact with another particle. The other sensors were damaged when technicians were refilling the water tank.
Researchers in the control room next to the apparatus felt the floor tremble and heard explosions from the next room, Kyodo news agency said.
As a result of the accident, the Education ministry official said, more than half the sensors appear to have been damaged.
"It's very hard to estimate the cost or how long it will take before we can use the facility again," he added. "All the damaged sensors will have to be remade and replaced."
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