A

David

Darling

thermal neutron

A thermal neutron is a neutron of very slow speed and consequently of low energy. Their energy is of the same order as the thermal energy of the atoms or molecules of the substance through which they are passing; i.e. about 0.025 electron volts, which is equivalent to an average velocity of about 2,200 meters per second. Thermal neutrons are responsible for numerous types of nuclear reactions, including nuclear fission.