Radiation, interaction

Table 5. Ionizing Radiation Interactions with Polymeric Substrates. ...

Light-scattering processes involve the interaction of light with gases or particles in such a manner that the direction or frequency of the light is altered. Absorption processes occur when the electromagnetic radiation interacts with gases or particles and is transferred internally to the gas or particle. 

High-energy radiation interacts with a material by three principal mechanisms [25-28] ... 

This treatment differs from the usual approach to molecule-radiation interaction through the inclusion of the contribution from the electric field from the beginning and by not treating it as a perturbation to the field free situation. The notation 7/ei(r R, e(f)) makes the parametric dependence of the electronic Hamiltonian on the nuclear coordinates and on the electric field explicit. 

Radiation, Secondary—A particle or ray that is produced when the primary radiation interacts with a material, and which has sufficient energy to produce its own ionization, such as bremsstrahlung or electrons knocked from atomic orbitals with enough energy to then produce ionization (see Delta Rays). 

The method by which incident radiation interacts with the medium to cause ionization may be direct or indirect. Electromagnetic radiations (x rays and gamma photons) are indirectly ionizing that is, they give up their energy in various interactions with cellular molecules, and the energy is then utilized to produce a... 

As radiation interacts in the scintillation crystal, energy is transferred to bound electrons of the crystal s atoms. If the energy that is transferred is greater than the ionization energy, the electron enters the conduction band and is free from the binding forces of the parent atom. 

Radiation interactions with a crystal center cause electrons to be raised to an excited state. 

In practice, surface modifications are restricted to sensors of the ATR- or FEWS-type. For other transducer layouts, the sample - radiation interaction is less localised, making a modification difficult to impossible. Depending on the analytes and the environment of the sensor, two basic surface modification strategies can be used to enhance the function of vibrational spectroscopic optical chemical sensors. The functional layers can either be... 

The low BE region of XPS spectra (<20 — 30 eV) represents delocalized electronic states involved in bonding interactions [7]. Although UV radiation interacts more strongly (greater cross-section because of the similarity of its energy with the ionization threshold) with these states to produce photoelectrons, the valence band spectra measured by ultraviolet photoelectron spectroscopy (UPS) can be complicated to interpret [1], Moreover, there has always been the concern that valence band spectra obtained from UPS are not representative of the bulk solid because it is believed that low KE photoelectrons have a short IMFP compared to high KE photoelectrons and are therefore more surface-sensitive [1], Despite their weaker intensities, valence band spectra are often obtained by XPS instead of UPS because they provide... 

When radiolysing a solution, the radiation interacts mainly with solvent molecules, since the solution consists mainly of the latter and the radiation interacts with the molecules unselectively. Consequently, the radiation chemistry of a solution is the combination of the production of initial intermediates from the solvent, which will be the same as in pure solvents, and the reaction of those intermediates with the solute. 

Kr Cosmic radiation interacting with the atmosphere. 104 to 108 years... 

In spectroscopy we study the effect of interaction of electromagnetic radiation on matter. For examples X-rays are produced by bombandment of metal targets with high speed electrons. So the different types of electromagnetic radiation interact with the matter and give different types of spectroscopy. 

Expressed in its simplest form, high energy Ionising radiation Interacts with materials to produce ionisation and excitation (In almost equal amounts) and lattice defects. (1 ) The resulting species can further react to give free radicals,... 

The primary event which takes place when high energy radiation, such as gamma radiation, interacts with a polymer molecule involves the ejection of an electron, with formation of the polymer cation radical, as shown in Equation (1) ... 

IEC 60544-1, Electrical insulating materials - Determination of the effects of ionizing radiation - Part 1 Radiation interaction and dosimetry, 1994. 

The second section, Radiation Interactions, contains nine chapters ranging from preliminary aspects of radiation-induced polymer modifications to industrial applications, and includes topics related to IR, UV,... 

In all studies involving methods based on absorption or scattering of light, X rays, or neutrons, the characteristic time scales on which radiation interacts with the substance are many orders of magnitude shorter than those of atomic motions. Therefore, it is not the motions themselves but the disordering which arises due to molecular dynamics that should be investigated. 

There is a variety of exposure technologies, each with a fundamental resolution limit resulting from radiation interactions with both the hardware and the resist. From a practical standpoint, factors such as alignment tolerance and resist swelling usually degrade resolution to a point where minimum feature sizes are larger than theoretically expected. Nevertheless, examining the fundamental resolution limits of the various techniques can be instructive. 

Emitted y radiation interacts with electrons of the surrounding matter. If the frequency of the emitted radiation exceeds the energy level corresponding to the ionization potential of the element, the electron may be expelled from its localized... 

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