One method for detecting of antineutrino is to observe the inverse of positron decay, typically in a detector containing huge amounts of water where protons are readily available. (See, for example, the Super-Kamiokande detector in the chapter-opening photo.) In such a detecor, the antineutrino interacts with a proton (a hydrogen nucleus), producing a neutron and either a positron or electron.
(a) Write this reaction and determine what the charged particle is.
(b) Is this reaction endothermic or exotheric?
(c) Following the reaction, there will be two separate -producing events: one for the neutron and one for the positron. If both are slowed to near zero kinetic energy before their capture/decay, write down these reactions. Remember that the neutron is in the presence of a lot of protons and the positron near a lot of electrons.
(d) Essentially this detection method measures the energies of these gamma rays. What energies should the detector be set for?