Positron Spectroscopy of Solids

The lifetime of a positron inside a solid is normally less than a fraction of nanosecond. This is a very short time on a human scale, but is long enough to enable the positron to visit an extended region of the material and to sense the atomic and electronic structure of the environment. It is possible to inject a positron in a sample to draw from it some signal providing information on the microscopic properties of the material. This idea has been successfully developed in a number of positron-based techniques of physical analysis, with resolution in energy, momentum or position. The complex of these processes is what is known as positron spectroscopy of solids.