Neutron microscopes use neutrons focused by small-angle neutron scattering to create images by passing neutrons through an object to be investigated. The neutrons that aren't absorbed by the object hit scintillation targets where induced nuclear fission of lithium-6 can be detected and be used to produce an image.
Neutrons have no electric charge, enabling them to penetrate substances to gain information about structure that is not accessible through other forms of microscopy. As of 2013, neutron microscopes offered four-fold magnification and 10-20 times better illumination than pinhole neutron cameras. The system increases the signal rate at least 50-fold.
Neutrons interact with atomic nuclei via the strong force. This interaction can scatter neutrons from their original path and can also absorb them. Thus, a neutron beam becomes progressively less intense as it moves deeper within a substance. In this way, neutrons are analogous to x-rays for studying object interiors.
Darkness in an x-ray image corresponds to the amount of matter the x-rays pass through. The density of a neutron image provides information on neutron absorption. Absorption rates vary by many orders of magnitude among the chemical elements.
While neutrons have no charge, they do have spin and therefore a magnetic moment that can interact with external magnetic fields.