notesonly.in

Example: Detecting an electron antineutrino from a nuclear reactor using inverse beta decay. Step 1: Reactor emits antineutrinos with typical energy ~3 MeV. Step 2: In the detector, an antineutrino interacts with a proton: \(\bar ν_e + p \rightarrow n + e^+\). Step 3: The positron (e+) quickly annihilates with an electron, producing two 511 keV gamma rays that create a prompt light signal. Step 4: The neutron is captured on a nucleus (often Gd) after ~200 µs, releasing a gamma cascade that gives a delayed light signal. Step 5: The coincidence of prompt and delayed signals within a short time window identifies the antineutrino event. Step 6: By counting such events and knowing the detector size, one can estimate the antineutrino flux and verify the reactor's power.