Radiation effects electrical properties

A role is also played by the temperature and frequency dependence of the photocurrent, the variable surface sensitivity at various parts of the cathode and the vector effect of polarized radiation [40]. All the detectors discussed below are electronic components whose electrical properties vary on irradiation. The effects depend on external (photocells, photomultipliers) or internal photo effects (photoelements, photodiodes). 

Vannikov, A. V., and N. A. Bakh The effect of iodine on the electrical properties of products of radiation-thermal modification of polyethylene. Dokl. Akad. Nauk. 149, 357 (1963). 

After 14 years on the faculty of Imperial College, Jacobs moved from London, England, to London, Ontario, where his research program focused on the optical and electrical properties of ionic crystals, as well as on the experimental and theoretical determination of thermodynamic and kinetic properties of crystal defects.213 Over the years his research interests have expanded to include several aspects of computer simulations of condensed matter.214 He has developed algorithms215 for molecular dynamics studies of non-ionic and ionic systems, and he has carried out simulations on systems as diverse as metals, solid ionic conductors, and ceramics. The simulation of the effects of radiation damage is a special interest. His recent interests include the study of perfect and imperfect crystals by means of quantum chemical methods. The corrosion of metals is being studied by both quantum chemical and molecular dynamics techniques. 

The electrical properties of insulators for superconducting magnets are of crucial importance in relation to the operational reliability of fusion reactors [81], In the present section, the characteristics in original electrical properties of polymers at cryogenic temperatures are briefly introduced and then the effects of radiation on these properties are surveyed. 

Both transient and permanent changes in the electrical properties of polymers are induced by the action of radiation [85]. The transient effects are sensitively affected by the kind of radiation and its intensity, because the magnitude and the distribution of any space charge in materials depend on generation and recombination rates of charged species. Although the transient effects are currently interesting topics, only the permanent effects by radiation on electrical properties are taken up in this section from the viewpoint of practical uses. 

Banford et al. studied the radiation effects on electrical properties of low-density polyethylene (LDPE) at 5 K with the use of a 60Co gamma source and a thermal nuclear reactor [86]. They reported that both the electrical conductivity and the dielectric breakdown strength of LDPE at 5 K were not significantly affected by radiation absorbed doses up to 10s Gy, but an erratic pulse activity under high applied fields was observed in the sample irradiated at 106 Gy. 

The aim of this chapter is to provide an understanding of how carbon black particle size and shape translate into dispersion quality and other performance attributes in plastics applications. While this chapter focuses on carbon black s effectiveness as a pigment, some attention will also be paid to some of the other plastics performance properties it influences, such as stability against UV radiation, effects on mechanical properties, and electrical conductivity. At its conclusion, this chapter will help the reader select an appropriate carbon black grade for specific plastics applications. 

In addition to this major use to improve mechanical properties, high aspect ratio flake-type fillers have been added to polymers for a variety of other purposes. They include improved thermal stability (3), high voltage resistance (4), electrical conductivity, radiation shielding (5) and optical and aesthetic effects (6). 

Loy, W. E., Jr., Effects of Gamma Radiation on Some Electrical Properties of TFE-Fluorocarbon Plastics, paper in Materials in Nuclear Applications, ASTM-STP-276, pp. 68-78 (1959)... 

Singh, V., Shashank, N., Kumar, D., Nahar, R.K. 2012. Effect of heavy ion irradiation on the electrical properties of rf-sputtered HfO, thin Aims for advanced CMOS devices. Radiation Effects and Defects in Solids,... 

When electrical conductivity is used as a method of (radiation) reaction monitoring in systems containing nanoparticles, or if they are expected to form during the reaction, various effects are possible. Up to now there are very few publications on conductivity monitoring of reactions in such systems, while the litertaure on changes due to radiation-induced reactions in nanoparticle containing compounds seems to be nonexistent. Because of that the publications on electrical properties of various polymer nanocomposites are used as a main source of presented information. 

Specific influences of nanoparticles on electric properties of nanomaterials and possible effects on reaction monitoring, especially in a radiation environment have to be considered in advance, but in most cases monitoring of electrical conductivity will provide valuable information on reaction and/or structural changes. 

The effects of a total dose of ionizing radiation from a cobalt-60 source may be measured by Method 1019.5 of MIL-STD-883F. Although this method is intended for radiation effects on semiconductor devices, the radiation sources, doses, and procedures can be used to evaluate the effects on exposed adhesives, provided that changes in bond strength or other physical or electrical properties are measured. 

To make a practical photodetector, it is not sufficient to study and evaluate the interaction of radiation with materials giving rise to a photoeffect. As with all types of sensors, internal noise limits the ability to detect a very small signal in the detector output. Thus accompanying the study of photoeffects in materials is one of noise in materials. Since the effects of greatest utility are those in which the signal is manifested as a change in the electrical properties of the material. Section 2.2 presents a description of electrical noise in photosensitive materials. 

The above characteristics make these systems very promising for radiation effect studies and in particular for metrological applications such as the measurement of the Rydberg constant directly in frequency units. One can indeed expect very narrow resonances between circular states, with spectral lines only quadratically sensitive to stray electric fields and frequencies depending only slightly upon the atomic ion core properties and being easily related to the hydrogen frequencies via the determination of very small quantum defects corrections. 

The interaction of resonant radiation with atoms or molecules present in a discharge can induce variations in the electrical properties (impedance) of the discharge. This effect, known as the optogalvanic (OG) effect, has been shown to be a powerful and inexpensive technique for the spectroscopic investigation of atomic and molecular species. 

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