What is Thermal Neutron Detection?

Neutrons do not produce ionization directly in scintillation crystals but can be detected through their interaction with the nuclei of a suitable element. In a 6LiI(Eu) scintillation crystal, for example, neutrons interact with 6Li nuclei to produce an alpha particle and a triton (tritium nucleus), which both produce scintillation light that can be detected. Another Li-containing scintillator is CLYC.

Also enriched 6Li containing glass can be used, doped with Ce as an activator. Alternatively, Boron or Gadolinium containing inorganic scintillators can be used but these scintillators are not common. One alternative technique is to construct a large area thermal neutron detector using 6LiF/ZnS(Ag)screens. These can then be read out via green wavelength shifters by PMTs or SiPMs.