photon (redirected from Gamma quantum)

photon /pho·ton/ (fo´ton) a particle (quantum) of radiant energy.

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pho·ton (ftn)

n.

The quantum of electromagnetic energy, generally regarded as a discrete particle having zero mass, no electric charge, and an indefinitely long lifetime.

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pho·tonic adj.

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Photon

A light particle.

Mentioned in: Positron Emission Tomography (PET)

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photon

[fō′ton]

Etymology: Gk, phos, light

the smallest quantity of electromagnetic energy. It has no mass and no charge but travels at the speed of light. Photons may occur in the form of x-rays, gamma rays, or quanta of light. The energy (E) of a photon is expressed as the product of its frequency (v) and Planck's constant (h), as in the equation E = hv. X-ray photons occur in frequencies of 10¹⁸ to 10²¹ Hz and energies that range upward from 1 KeV.

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photon (fō´ton),

n a bullet or quantum of electromagnetic radiant energy emitted and propagated from various types of radiation sources. The term should not be used alone but should be qualified by terms that will clarify the type of energy (e.g., light photon, radiographic photon).

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photon

a particle (quantum) of radiant energy.

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x-ray photon

a particle of x-ray energy.

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photon 

The basic unit of radiant energy defined by the equation

E = hν

where h is Planck's constant (6.62 ✕ 10⁻³⁴ joule ✕ second), ν the frequency of the light and E the energy difference carried away by the emission of a single photon of light. The term photon usually refers to visible light whereas the term quantum refers to other electromagnetic radiations. See quantum theory; wave theory; troland.