Measurement of the fluorescence yield of electrons in air
The fluorescence yield of electrons in air is measured with the AIRFLY
experiment. At accelerators in Argonne, USA and Frascati, Italy electrons with
MeV energies are injected into different gases (nitrogen, nitrogen-oxygen
mixtures, air). This yields nitrogen molecules in excited states. During their
transition to the ground state fluorescence light is emitted. The intensity of
this light is investigated as function of various parameters, like pressure,
temperature, and humidity.