Ionization, and radiation

Fig. 18.2. ADAS408 generates recombination, ionization and radiated power data from parametric representations of the various coefficients. Electron temperature and density ranges are specified on the processing screen along with atomic masses. This code can accept special filter files which describe the soft X-ray pass band of arbitrary window/detector combinations and modify the calculated radiated power. ADAS408 delivers output data in the ADAS data format adfl 1 - a principal data class accessed by plasma modeling codes...

Consider two electrons, one with kinetic energy 1 MeV, the other with 10 MeV. Which electron will lose more energy going through a 1-ram-thick plastic scintillator Consider both ionization and radiation loss. Composition of the scintillator is given in Prob. 6.4. For radiation loss, use... 

Modern commercial lasers can produce intense beams of monochromatic, coherent radiation. The whole of the UV/visible/IR spectral range is accessible by suitable choice of laser. In mass spectrometry, this light can be used to cause ablation, direct ionization, and indirect ionization (MALDI). Ablation (often together with a secondary ionization mode) and MALDI are particularly important for examining complex, intractable solids and large polar biomolecules, respectively. 

Does the employer comply with 29 CFR, Subpart G (OSHA standards for ventilation, noise, and ionizing and nonionizing radiation) [OSHA Reference. 120(g)(l)(iv)]... 

Another mode of initiation of polymerization being vigorously studied in numerous laboratories involves the use of ionizing radiation. In the primary process a molecule (not necessarily the monomer) is ionized and thus a positive ion and an electron are formed. The latter is eventually captured by another molecule yielding a negative ion. On recombination of these ions, enough... 

Because of these limitations to both the conventional internal ionization and external ionization techniques it has been impossible to obtain accurate kinetic data for the reactions of thermal energy ions. Such thermal energy data are desirable for applications in such areas as radiation chemistry, discharge and combustion phenomena, and upper atmosphere research. 

It is likely that the answers to these questions will come only from more selective and sophisticated experiments than have been done hitherto, although some useful directions have been established. The use of high-sensitivity electron spin resonance for the study in situ of anticipated radical species will likely be possible, if the background signals from other radiation-produced species are not too intense. Studies of the chemistry of implanted atoms and ions in solid organometallic substrates will make it possible to start with totally unbound atoms which suffer no Auger ionization and thus to simulate the extreme of the total recoil. Careful studies of the thermal annealing effects, especially in the presence of reactive atmospheres, will... 

The laser desorption experiments which we describe here utilize pulsed laser radiation, which is partially absorbed by the metal substrate, to generate a temperature jump in the surface region of the sample. The neutral species desorbed are ionized and detected by Fourier transform mass spectrometry (FTMS). This technique has... 

Total Ionization—The total electric charge of one sign on the ions produced by radiation in the process of losing its kinetic energy. For a given gas, the total ionization is closely proportional to the initial ionization and is nearly independent of the nature of the ionizing radiation. It is frequently used as a measure of absorption of radiation energy. 

Dose equivalent or rem is a special radiation protection quantity that is used, for administrative and radiation safety purposes only, to express the absorbed dose in a manner which considers the difference in biological effectiveness of various kinds of ionizing radiation. The ICRU has defined the dose equivalent, H, as the product of the absorbed dose, D, and the quality factor, Q, at the point of interest in biological tissue. This relationship is expressed as H = D x Q. The dose equivalent concept is applicable only to doses that are not great enough to produce biomedical effects. 

Since icosahedral carboranes are generally viewed as 3D energy sinks as well as polymer building blocks, the thermal and radiation stability that these units impart on the base rubbery material needs to be explored. While the thermal stability of these materials has been studied and reported by a number of workers, there is little reported work on the stability of these materials to ionizing radiation. A brief account of our work within this area is detailed below. 

The areas where the use of the track model has been found particularly expedient are (1) LET variation of product yields in the radiation chemistry of liquids (2) the yield of escaped ions and its variation with particle LET (3) energy loss in primary excitations and ionizations (4) radiation-induced luminescence and (5) particle identification. 

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