Radiology - Technology Information Portal
Friday, 29 March 2024
• Welcome to Radiology-TIP.com!
     • Sign in / Create account
 
 'Electromagnetic Radiation' 
SEARCH   
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
Searchterm 'Electromagnetic Radiation' found in 1 term [
] and 5 definitions [
], (+ 9 Boolean[
] results
Result Pages :
Electromagnetic Radiation
(EMR) Electromagnetic radiation consists of an electric and a magnetic field component. All EMR travels in a vacuum at the speed of light. EMR is classified related to the frequency//length of the wave.
An EM wave consists of discrete packets of energy, named photons (quantization). The energy of the photons depends on the frequency of the wave. Planck-Einstein equation:
E = h * f
E (energy); h (Planck's constant); f (frequency)
EMR types include in order of increasing frequency//decreasing wavelength: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, x-rays and gamma rays. EMR contains energy and momentum, which may be imparted when it interacts with matter.

See Gamma Radiation.
• 
View NEWS results for 'Electromagnetic Radiation' (1).Open this link in a new window.
Annihilation
Annihilation in general refers to the transition of a particle and its antiparticle by collision into something different, depending on their energies and based on the conservation of energy and momentum. The electromagnetic radiation emitted is the result of the annihilation (combination and disappearance) of an electron and a positron. Two gamma rays of 0.511 MeV energy, assuming very low-energy particles, are emitted perpendicular to each other.
Gamma Quantum
A gamma quantum is a distinct photon of electromagnetic radiation with the highest energy, shortest wavelength. The energy of a single photon is above 100 keV, the wavelength is below about 10 picometers. Gamma photons are generated by processes within the atomic nuclei.

See also Quantum.
Gamma Radiation
Gamma radiation is electromagnetic radiation emitted in decay of radionuclides. Also called gamma ray and sometimes shortened to gamma (e.g., gamma-emitting radionuclides).
Photoelectric Effect
The photoelectric effect describes the following interaction of electromagnetic radiation with a metallic surface: a photon with an energy (frequency) above the binding energy of an electron gets absorbed and the electron is emitted. The positive energy difference is transferred to the electrons kinetic energy. If the photons energy is not high enough for the electron to overcome its binding forces, the photon will be re-emitted. It is not the intensity of a photon beam (amount of photons) which allows the photoelectric effect; it is the energy (frequency) of a single photon which will allow the emission of a single photoelectron.
The discovery and study of the photoelectric effect leads to a new quantized understanding in physics. Albert Einstein was awarded the Noble prize for physics in 1921 'for his services to theoretical physics and especially for his discovery of the law of the photoelectric effect'.
The photoelectric effect is the most important effect in medical radiography. E.g. it is photoelectric absorption that is responsible for most of the absorption in a mammogram which creates the contrast in the image.

See also Photon, Electron.
Result Pages :
 
Share This Page
Facebook
Twitter
LinkedIn

Look
      Ups
Radiology - Technology Information Portal
Member of SoftWays' Medical Imaging Group - MR-TIP • Radiology-TIP • Medical-Ultrasound-Imaging
Copyright © 2008 - 2024 SoftWays. All rights reserved.
Terms of Use | Privacy Policy | Advertising
 [last update: 2023-11-06 02:01:00]