The Super-Kamiokande detector in Japan, an underground tank that holds 50 million liters of water, captures neutrinos that emanate from a particle accelerator nearly 300 kilometers away. When a neutrino hits the detector, it can produce charged particles, whose high speed through the water emits a flash of light, triggering phototubes mounted in the walls of the Super-K tank. The experiment investigates muon neutrinos transforming into electron neutrinos.
A candidate electron neutrino appears in the Super Kamiokande particle detector in Japan like this. In July 2013 researchers announced they'd definitively measured muon neutrinos oscillating flavor into electron neutrinos.