Fermilab History and Archives Project

Fixed Target Program - Neutrino Area

How do scientists learn about the elusive neutrino? This is a composite photograph showing one of the events found in the Fermilab 15-ft. Bubble Chamber during a run in which the Chamber was filled with neon and hydrogen, exposed to a beam of neutrinos, and recorded by Experiment #28A. A neutrino interaction is indicated at the vertex of the event.

View 1 above is a photograph of the entire event. View 2 is a close-up of the vertex of the event shown in the rectangle outlined in View 1. View 3 is a schematic explanation of the event.

These events are interpreted by the experimenters as involving the production of a new particle in the neutrino interaction, a particle which then decays into a neutral K meson, a positron and an invisible neutrino. The original neutrino turns into a muon.