Hiroyuki Kyushima, an engineer at Hamamatsu Photonics K.K. who helped create a particle detector that enabled physicist Masatoshi Koshiba to win the Nobel Prize in physics in 2002, has developed an ultra-small photomultiplier tube together with his fellow workers.

"This is a break-proof, ideal PMT with functions comparable to those of the Super-Kamiokande," Kyushima, 56, said.

The original Kamiokande, short for the Kamioka Nucleon Decay Experiment neutrino physics laboratory, was built underground near the Kamioka section in the city of Hida, Gifu Prefecture, in the early 1980s under the leadership of Koshiba, 87, a professor of physics at the University of Tokyo at the time.