delayed neutron
neutron emitted after a nuclear fission event, as a fission product daughter after beta decay, any time from a few milliseconds to a few minutes after the fission event
en-GB/dɪˈleɪd ˈnjuːtɹɒn/
en-US/dɪˈleɪd ˈnutˌɹɑn/
neutron emitted after a nuclear fission event, as a fission product daughter after beta decay, any time from a few milliseconds to a few minutes after the fission event