3 – SOLID STATE NUCLEAR TRACK DETECTORS

Since its discovery in 1958 ( Young, 1958 ; Silk and Barnes, 1959 ), the technique now generally known as Solid State Nuclear Track Detection (SSNTD) has, over the last few decades, become a popular and well-established method of measurement in a large number of fields involving different aspects of radioactivity or nuclear interactions. The reasons for its widespread use include the basic simplicity of its methodology and the low cost of its materials, combined with the great versatility of its possible applications—as will become clear in what follows. Other important factors include the small geometry of the detectors, and their ability—in certain cases—to preserve their track record for almost infinite lengths of time (indeed, mineral grains in geological and planetary materials less than a millimeter across can, by suitable treatment, be made to reveal the billions of years old record of their radiation history). The fact that the detectors, in themselves, do not need any electronic/electrical instrumentation means that they can be deployed under field conditions and in remote, fairly inaccessible places for long durations of time without the need of human intervention or backup, except for initial placement and final retrieval; and their ruggedness is of great merit in making this possible.