Photonics Dictionary

Gamma ray radiation released when matter and antimatter, such as electron and positron, unite and eliminate each other, transforming completely into energy. The resulting gamma ray spectrum depends...

Backscatter refers to the phenomenon in which radiation or waves are scattered backward, opposite to the direction of the incident beam. This occurs when the incident radiation encounters a target or...

Radiography using the emission of gamma rays to form an image of the structure penetrated by the radiation.

The spontaneous emittance of electromagnetic radiation by the nucleus of certain radioactive elements during their quantum transition between two energy levels. The radiation emitted has a wavelength...

An instrument used to detect and measure the energy distribution of gamma rays. It has been used to chart the radioactivity at the lunar surface.

An acronym of gamma ray amplification by stimulated emission of radiation. It is a gamma ray laser that operates between energy levels established by metastable isomeric transitions in the nucleus.

The use of photographic emulsions to detect and determine the amounts of ionizing radiation, such as x-rays and gamma rays, in an area. This is accomplished by exposing the emulsion to the radiation...

A medical imaging device that uses a ring of crystal/photomultiplier tube assemblies encircling the patient to detect gamma rays emitted by positrons colliding with electrons.

Basically, a hydrogen atom with two alterations, positronium is the lightest atom in the universe and has an extremely light positron in its nucleus that replaces hydrogen's proton so that its atomic...

The film used in photographic dosimetry to record the types and amounts of ionizing radiation, such as x-rays and gamma rays, present in an area for a set interval of time. The negative produced by...

An instrument used to detect radioactive materials: alpha particles or helium nuclei; beta particles or free electrons; and gamma rays, which are x-rays of very short wavelength. They may be detected...

A scintillation crystal, also known simply as a scintillator, is a material that emits light when it interacts with ionizing radiation such as gamma rays, x-rays, or charged particles. The emitted...

A scintillation detector is a radiation detection device that utilizes scintillation crystals to detect and measure ionizing radiation, such as gamma rays, x-rays, or charged particles. It consists...

A ruggedized scintillation counter used in oil well logging. The cylindrical housing contains a gamma ray source, a crystalline scintillator and a photomultiplier tube. As the sonde is drawn through...

A spectral signature, in the context of remote sensing and spectroscopy, refers to the unique pattern or characteristic spectral response of a material or object across different wavelengths of the...

A printing process of electrostatic electrophotography that uses a photoconductive insulating medium, in conjunction with x-rays or gamma rays, to produce latent electrostatic-charge patterns for...