terahertz radiation
(noun)
Electromagnetic waves with frequencies around one terahertz.
Examples of terahertz radiation in the following topics:
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Microwaves
- The boundaries between far infrared light, terahertz radiation, microwaves, and ultra-high-frequency radio waves are fairly arbitrary.
- EHF runs the range of frequencies from 30 to 300 gigahertz, above which electromagnetic radiation is considered as far infrared light, also referred to as terahertz radiation.
- The sun also emits microwave radiation, although most of it is blocked by Earth's atmosphere.
- The Cosmic Microwave Background Radiation (CMBR) is microwave radiation that permeates all of space, and its discovery supports the Big Bang theory of the origin of the universe.
- Cosmic background radiation of the Big Bang mapped with increasing resolution.
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Photon Energies of the EM Spectrum
- The electromagnetic (EM) spectrum is the range of all possible frequencies of electromagnetic radiation.
- The electromagnetic (EM) spectrum is the range of all possible frequencies of electromagnetic radiation .
- Generally, electromagnetic radiation is classified by wavelength into radio waves, microwaves, terahertz (or sub-millimeter) radiation, infrared, the visible region humans perceive as light, ultraviolet, X-rays, and gamma rays.
- The behavior of EM radiation depends on its wavelength.
- Also, radiation from various parts of the spectrum has many other uses in communications and manufacturing.
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Therapeutic Uses of Radiation
- Radiation therapy uses ionizing radiation to treat conditions such as hyperthyroidism, cancer, and blood disorders.
- Radiation therapy involves the application of ionizing radiation to treat conditions such as hyperthyroidism, thyroid cancer, and blood disorders.
- Ionizing radiation works by damaging the DNA of exposed tissue, leading to cellular death.
- Radiation therapy is in itself painless.
- Radiation therapy of the pelvis.
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Medical Imaging and Diagnostics
- Radiation therapy uses ionizing radiation to treat conditions such as hyperthyroidism, cancer, and blood disorders.
- Radiation therapy involves the application of ionizing radiation to treat conditions such as hyperthyroidism, thyroid cancer, and blood disorders.
- Ionizing radiation works by damaging the DNA of exposed tissue, leading to cellular death.
- Radiation therapy is in itself painless.
- Radiation therapy of the pelvis.
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Planck's Quantum Hypothesis and Black Body Radiation
- A black body emits radiation called black body radiation.
- Planck described the radiation by assuming that radiation was emitted in quanta.
- A black body in thermal equilibrium (i.e. at a constant temperature) emits electromagnetic radiation called black body radiation.
- Max Planck, in 1901, accurately described the radiation by assuming that electromagnetic radiation was emitted in discrete packets (or quanta).
- Contrary to the common belief that electromagnetic radiation can take continuous values of energy, Planck introduced a radical concept that electromagnetic radiation was emitted in discrete packets (or quanta) of energy.
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Radiation
- In these examples, heat is transferred by radiation.
- There is a clever relation between the temperature of an ideal radiator and the wavelength at which it emits the most radiation.
- The rate of heat transfer by emitted radiation is determined by the Stefan-Boltzmann law of radiation:
- If you knock apart the coals of a fire, there is a noticeable increase in radiation due to an increase in radiating surface area.
- A black object is a good absorber and a good radiator, while a white (or silver) object is a poor absorber and a poor radiator.
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Biological Effects of Radiation
- Ionizing radiation is generally harmful, even potentially lethal, to living organisms.
- Ionizing radiation is generally harmful, even potentially lethal, to living organisms.
- Although radiation was discovered in the late 19th century, the dangers of radioactivity and of radiation were not immediately recognized.
- Other conditions, such as radiation burns, acute radiation syndrome, chronic radiation syndrome, and radiation-induced thyroiditis are deterministic, meaning they reliably occur above a threshold dose and their severity increases with dose.
- Two pathways of exposure to ionizing radiation exist.
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Radiation Detection
- A radiation detector is a device used to detect, track, or identify high-energy particles.
- A radiation detector is a device used to detect, track, or identify high-energy particles, such as those produced by nuclear decay, cosmic radiation, and reactions in a particle accelerator.
- Modern detectors are also used as calorimeters to measure the energy of detected radiation.
- Gaseous ionization detectors use the ionizing effect of radiation upon gas-filled sensors.
- Scintillators are used by the American government, particularly Homeland Security, as radiation detectors.
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A Physical Aside: Multipole Radiation
- It is possible to calculate the radiation field to higher order in $L/(c\tau)$.This is necessary if the dipole moment vanishes, for example.
- where $k\equiv\omega/c$$n=0$ gives the dipole radiation, $n=1$ gives the quadrupole radiation and so on.
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A Physical Aside: Intensity and Flux
- Blackbody radiation is a radiation field that is in thermal equilibrium with itself.
- In general we will find it convenient to think about radiation that is in equilibrium with some material or its enclosure.
- Using detailed balance between two enclosures in equilibrium with each other and the enclosed radiation we can quickly derive several important properties of blackbody radiation.
- The intensity ($I_\nu$) of blackbody radiation does not depend on the shape, size or contents of the enclosure.