A
solid-state nuclear track detector or
SSNTD (also known as an
etched track detector or a
dielectric track detector,
DTD) is a sample of a solid material (photographic
emulsion, crystal, glass or plastic) exposed to
nuclear radiation (
neutrons or
charged particles, occasionally also
gamma rays),
etched, and examined microscopically. The tracks of nuclear particles are etched faster then the bulk material, and the size and shape of these tracks yield information about the mass, charge, energy and direction of motion of the particles. The main advantages over other radiation detectors are the detailed information available on individual particles, the persistence of the tracks allowing measurements to be made over long periods of time, and the simple, cheap and robust construction of the detector.