Neutron detection is the effective detection of neutrons entering a well-positioned detector. There are two key aspects to effective neutron detection: hardware and software. Detection hardware refers to the kind of neutron detector used (the most common today is the scintillation detector) and to the electronics used in the detection setup. Further, the hardware setup also defines key experimental parameters, such as source-detector distance, solid angle and detector shielding. Detection software consists of analysis tools that perform tasks such as graphical analysis to measure the number and energies of neutrons striking the detector.

Atomic and subatomic particles are detected by the signature they produce through interaction with their surroundings. The interactions result from the particles' fundamental characteristics.

As a result of these properties, detection of neutrons fall into several major categories:

Gas proportional detectors can be adapted to detect neutrons. While neutrons do not typically cause ionization, the addition of a nuclide with high neutron cross-section allows the detector to respond to neutrons. Nuclides commonly used for this purpose are helium-3, lithium-6, boron-10 and uranium-235. Since these materials are most likely to react with thermal neutrons (i.e., neutrons that have slowed to equilibrium with their surroundings), they are typically surrounded by moderating materials to reduce their energy and increase the likelihood of detection.

Further refinements are usually necessary to differentiate the neutron signal from the effects of other types of radiation. Since the energy of a thermal neutron is relatively low, charged particle reactions are discrete (i.e., essentially monoenergetic and lie within a narrow bandwidth of energies) while other reactions such as gamma reactions will span a broad energy range, it is possible to discriminate among the sources.

As a class, gas ionization detectors measure the number (count rate), and not the energy of neutrons.

Helium-3 is an effective neutron detector material because it reacts by absorbing thermal neutrons, producing a ¹H and ³H ion. Its sensitivity to gamma rays is negligible, providing a very useful neutron detector. Unfortunately the supply of ³He is limited to production as a byproduct from the decay of tritium (which has a 12.3 year half-life); tritium is produced either as part of weapons programs as a booster for nuclear weapons or as a byproduct of reactor operation.

As elemental boron is not gaseous, neutron detectors containing boron may alternately use boron trifluoride (BF₃) enriched to 96% boron-10 (natural boron is 20% ¹⁰B, 80% ¹¹B). Boron trifluoride is highly toxic. The sensitivity of this detector is around 35-40 CPS/nv (counts per second per neutron flux) the sensitivity of boron-lined detectors is approximately 4 CPS/nv. This is because in boron-lined detectors, neutrons react with boron to produce ion pairs inside the boron layer and so charged particles produced (alpha particles and lithium ions) may lose some of their energy inside that layer. This means that low-energy charged particles may be unable to reach the ionization chamber's gas environment resulting in a lower number of ionizations produced. In BF₃ gas-filled detectors, on the other hand, neutrons react with ¹⁰B atoms inside the detector gas volume, so charged particles produced are more likely to deposit their energy in the gas volume, producing more ionizations and therefore higher signal.