Oscillating electromagnetic field

Near the outlet from the torch, at the end of the concentric tubes, a radio high-frequency coil produces a rapidly oscillating electromagnetic field in the flowing gas. The applied high-frequency field couples inductively with the electric fields of the electrons and ions in the plasma, hence the name inductively coupled plasma or ICP. 

Electrons from a spark are accelerated backward and forward rapidly in the oscillating electromagnetic field and collide with neutral atoms. At atmospheric pressure, the high collision frequency of electrons with atoms induces chaotic electron motion. The electrons gain rapidly in kinetic energy until they have sufficient energy to cause ionization of some gas atoms. 

Suppose now that the system is subjected to an oscillating electromagnetic field with a representative Fourier component of the electric field F0( >] cos cot. The predominant term in the interaction energy V is usually the electric dipole term Ei , e.g. for an electron in an atom... 

Linear accelerator A long straight tube (or series of tubes) in which charged particles (ordinarily electrons or protons) gain in energy by the action of oscillating electromagnetic fields. 

Electric dipole radiation is the most important component involved in normal excitation of atoms and molecules. Ttu electric dipole operator has the form TejXf where e is the electronic charge in esu and xt is the displacement vector for the jth electron in the oscillating electromagnetic field. 

Electron spin may interact directly 22,67,123 with the oscillating electromagnetic field of a photon. In this case the transition operator,, /(t) of Section IV, does not commute with the symmetric group S f, so that direct transitions between pure singlet and pure triplet states are allowed. Selection rules for this type of transition may be derived, as has been done by Chiu,22 by noting that f(t) has components which transform as different representations of the double group SF 0 (see Sect. VIII). 

In spectroscopy, the response of a molecule to an oscillating electromagnetic field leads to absorption of energy, the details of which are revealed after solving an equation of the form ... 

Before we discuss how chlorophylls can transform light into chemical energy, let s review some of the basic properties of light. Light is an oscillating electromagnetic field (fig. 

It interacts with matter in packets, or quanta, called photons, each of which contains a definite amount of energy. The relationship between the energy e of a photon and the frequency v of the oscillating electromagnetic field is given by the equation... 

The effects of microwave heating on the tissue sections that result in epitope retrieval are exceedingly complex. A full understanding of the actions of microwaves at the molecular level to facilitate epitope retrieval is lacking. At least two mechanisms need to be considered heat and kinetic energy of the oscillating electromagnetic field. Both possibilities are discussed below. 

A 1- to 2-kW radio frequency power supply, either free-running or crystal-controlled, drives current through a water- or air-cooled copper tube that acts as the induction coil (often called a load coil). The oscillating current through the load coil produces an oscillating electromagnetic field. 

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