Super Kamiokande (Super K for short) is a real piece of scientific equipment, a particle detector, located underneath 1km of rock at the heart of Mount Ikenoyama in Gifu prefecture in western Japan. It is a massive cylinder as tall as a 14 story building (40m) and the same in diameter. Looking into this cathedral sized cylinder are 11,146 electronic eyes called photo multiplier tubes (PMTs) attached to the walls. Essentially inverse light bulbs, turning light into electricity rather than the other way around, each of these PMTs are whopping 50cm (20″) in diameter.
This vast space is filled with over 33 Olympic sized swimming pools worth (50,000 tonnes) of ultra pure water. The water is so pure in fact that if you were to put your hand in it you would lose all of the naturally occurring salts and oils in your skin leaving it bone dry. The reason for this is we require light to be able to travel the entire distance through the water to reach our electronics on the walls. Any impurities dissolved, like the stuff you see on the back of your bottle of mineral water, would scatter the light on it’s journey to the walls and reduce the amount we see.
So light from particles in this huge amount of ultra pure water enter our inverse light bulbs and is turned into electricity which we then channel to our computers to build up a picture of what is going on in Super K.
Next Blog: Faster than light.