“photoionization”的概念、定义、翻译、参考文献-科学参考

photoionization

Physics

The ionization of an atom or molecule as a result of irradiation by electromagnetic radiation. For a photoionization to occur the incident photon of the radiation must have an energy in excess of the ionization potential of the species being irradiated. The ejected photoelectron will have an energy, E, given by E=hf − I, where h is the Planck constant, f is the frequency of the incident radiation, and I is the ionization potential of the irradiated species.

Astronomy

The loss of an electron by an atom, ion, or molecule by the absorption of a photon. For an electron in the ground state, a photon can remove an electron if the photon’s energy equals the ionization potential of the atom or molecule. Lower-energy photons may ionize the atom or molecule if it has electrons in an excited energy level. Photoionization is of importance primarily in stellar interiors and atmospheres, where the number of photons is high.

Chemistry

The ionization of an atom or molecule as a result of irradiation by electromagnetic radiation. For a photoionization to occur the incident photon of the radiation must have an energy in excess of the ionization potential of the species being irradiated. The ejected photoelectron will have an energy, E, given by E = hf – I, where h is the Planck constant, f is the frequency of the incident radiation, and I is the ionization potential of the irradiated species.

Electronics and Electrical Engineering

Ionization of an atom or molecule that results from exposure to electromagnetic radiation. The mechanism of photoionization is the same as that operating in the photoelectric effect, but in photoionization an electron is ejected from a single atom or molecule, such as occur in the gaseous state. The incident radiation, of frequency ν, can be considered to consist of discrete photons of energy hν, where h is the Planck constant. Photoionization can only occur when the photon energy, hν, exceeds the first ionization potential, I₁; there is thus a photoionization threshold of frequency below which the effect does not occur.

单词	photoionization
释义	photoionization Physics The ionization of an atom or molecule as a result of irradiation by electromagnetic radiation. For a photoionization to occur the incident photon of the radiation must have an energy in excess of the ionization potential of the species being irradiated. The ejected photoelectron will have an energy, E, given by E=hf − I, where h is the Planck constant, f is the frequency of the incident radiation, and I is the ionization potential of the irradiated species. Astronomy The loss of an electron by an atom, ion, or molecule by the absorption of a photon. For an electron in the ground state, a photon can remove an electron if the photon’s energy equals the ionization potential of the atom or molecule. Lower-energy photons may ionize the atom or molecule if it has electrons in an excited energy level. Photoionization is of importance primarily in stellar interiors and atmospheres, where the number of photons is high. Chemistry The ionization of an atom or molecule as a result of irradiation by electromagnetic radiation. For a photoionization to occur the incident photon of the radiation must have an energy in excess of the ionization potential of the species being irradiated. The ejected photoelectron will have an energy, E, given by E = hf – I, where h is the Planck constant, f is the frequency of the incident radiation, and I is the ionization potential of the irradiated species. Electronics and Electrical Engineering Ionization of an atom or molecule that results from exposure to electromagnetic radiation. The mechanism of photoionization is the same as that operating in the photoelectric effect, but in photoionization an electron is ejected from a single atom or molecule, such as occur in the gaseous state. The incident radiation, of frequency ν, can be considered to consist of discrete photons of energy hν, where h is the Planck constant. Photoionization can only occur when the photon energy, hν, exceeds the first ionization potential, I₁; there is thus a photoionization threshold of frequency below which the effect does not occur.
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