explain the operation of a solid state detector what type of

explain the operation of a solid state detector. what type of radiation are these detectors normally used for? what advantage do they have over other detector types?

Solution

Solid state detectors are usually made from semiconductors like silicon and germanium. The property of semiconductor enables them as a better detecting medium. Semiconductors have low energy gap between the conduction band and the valence band which is used to detect any type of radiation present in the medium. On receiving the energy required in overcoming band gap (energy gap) there is flow of current observed in the semiconductor, this micro current is amplified and analyzed.
One such mechanism used in solid state detector is the use of p-n junction across which a pulse of current develops when exposed to ionizing radiation. Another mechanism is generation of pairs of charge carriers in the semiconductor when exposed to ionization energy. The migration of these charge carriers under the influence of a applied voltage cause a pulse current which is amplified and analyzed.
These detectors are normally used to detect charged particles like alpha, beta, gamma radiation from nuclear material and X-ray. Any kind of radiation that can provide the required energy gap for the semiconductor conduction can be detected.
These detectors have following advantage:
1.   It does not affect the detecting medium. Hence the motion of the tracking element remains the same.
2.   Detection with a higher and better resolution than the conventional ones.
3.   With wide range of semiconductors it can detect wide range of wavelength radiation.
4.   It is cheap and compact
5.   It does not require any kind of extra installation like gas chamber or vacuum to operate. Although reduced temperature does enhances the resolution of detection.