On the correlation between electron mobility, free-ion yield, and electron thermalization distance in nonpolar dielectric liquids

1993 ◽  
Vol 71 (3) ◽  
pp. 287-293 ◽  
Author(s):  
Jean-Paul Jay-Gerin ◽  
Thomas Goulet ◽  
Isabelle Billard
Keyword(s):  
Electron Mobility ◽  
Point Of View ◽  
Thermal Electron ◽  
Polar Dielectric ◽  
Dielectric Liquids ◽  
Free Ion ◽  
Radiation Induced ◽  
Ionization Detectors ◽  
Nonpolar Dielectric ◽  
Liquid Ionization

The correlation between the thermal electron mobility, μe, the radiation-induced free-ion yield Gfi at zero applied electric field, and the most probable thermalization distance b of secondary electrons, is examined for 52 different pure non-polar dielectric liquids for which data have been reported in the literature. It is shown that, in liquids for which μe > 10−1 cm2 V−1 s−1, the variation of Gfi with μe is well represented by a relation of the type [Formula: see text] where n ≈ 0.31. The connection between Gfi and μe can be described through the product εsb, where εs is the static dielectric constant of the intervening liquid. In particular, 1/εsb is shown to correlate with both μe and Gfi. Analysis of these correlations allows us to estimate an upper limit of μe that can be attained in a room-temperature dielectric liquid, information of utmost importance from the point of view of application to liquid ionization detectors.

In situ TEM studies of irradiation effects for materials improvement

1991 ◽  
Vol 49 ◽  
pp. 452-453
Author(s):  
Charles W. Allen
Keyword(s):  
Nuclear Reactor ◽  
Austenitic Stainless Steels ◽  
High Energy ◽  
Point Of View ◽  
In Situ Tem ◽  
Irradiation Effects ◽  
Tem Analysis ◽  
Radiation Induced ◽  
Analytical Tools

Irradiation effects studies employing TEMs as analytical tools have been conducted for almost as many years as materials people have done TEM, motivated largely by materials needs for nuclear reactor development. Such studies have focussed on the behavior both of nuclear fuels and of materials for other reactor components which are subjected to radiation-induced degradation. Especially in the 1950s and 60s, post-irradiation TEM analysis may have been coupled to in situ (in reactor or in pile) experiments (e.g., irradiation-induced creep experiments of austenitic stainless steels). Although necessary from a technological point of view, such experiments are difficult to instrument (measure strain dynamically, e.g.) and control (temperature, e.g.) and require months or even years to perform in a nuclear reactor or in a spallation neutron source. Consequently, methods were sought for simulation of neutroninduced radiation damage of materials, the simulations employing other forms of radiation; in the case of metals and alloys, high energy electrons and high energy ions.

RADIATION HAZARDS IN THE FIELD OF PEDIATRICS

PEDIATRICS ◽  
1957 ◽  
Vol 20 (5) ◽  
pp. 921-940
Author(s):  
Meinhard Robinow ◽  
Frederic N. Silverman
Keyword(s):  
Radiation Injury ◽  
Radiation Safety ◽  
The United States ◽  
Point Of View ◽  
Public Understanding ◽  
X Rays ◽  
Tissue Destruction ◽  
Radiation Hazards ◽  
External Sources ◽  
Radiation Induced

The different types of injury from external sources of ionizing radiation are briefly described and the manifestations of radiation injury in the fetus, the infant and the child are reviewed. If radiation therapy for malignant disease is excluded from consideration, it is found that x-ray damage to skin, other tissue destruction, and growth impairment are relatively minor radiation hazards compared to the dangers of leukemia and other malignancy and of radiation-induced genetic damage. Consideration is given to somatic radiation injury as largely an individual problem and genetic injury as a population problem. This point of view is reflected in the differing recommendations concerning "permissible doses" for individuals and for populations. Medical radiation represents a major and presumably growing source of exposure to individuals and to the population in the United States. Various ways are shown in which excessive diagnostic exposure to x-rays, especially in children, can be reduced without interference with requirements of diagnosis. Control of avoidable radiation can be accomplished by combined attack from different fronts. The more important approaches to radiation safety are discussed. They include attention to technical detail, personnel monitoring, maintenance of radiation records, radiation safety through legislative control and public education. The responsibility of the physician in promoting public understanding of radiation hazards is emphasized.

Evaluation of Degradation due to Electron Irradiation of Si1-xCx S/D n-type MOSFETs

2014 ◽  
Vol 778-780 ◽  
pp. 1197-1200
Author(s):  
Masato Hori ◽  
Yuki Asai ◽  
Masashi Yoneoka ◽  
Isao Tsunoda ◽  
Kenichiro Takakura ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Electron Mobility ◽  
Field Effect Transistors ◽  
Drain Current ◽  
Oxide Semiconductor ◽  
Enhancement Effect ◽  
Device Performance ◽  
Irradiation Effects ◽  
Radiation Induced ◽  
Improve Device

To solve the problem of the limitation to improve device performance in standard Si integration technologies and to develop radiation-harsh devices, the irradiation effects of Si1-xCx source/drain (S/D) n-type metal oxide semiconductor field effect transistors (n-MOSFETs) have been investigated. It is shown that the drain current and the maximum electron mobility of Si1-xCx n-MOSFETs decrease by electron irradiation. The reduction of the device performance can be explained by the radiation-induced lattice defects in the devices. However, the electron mobility enhancement effect by adding C remained after an electron irradiation up to 5×1017 e/cm2.

Epithermal Electron Ranges and Thermal Electron Mobilities in Liquid Aromatic Hydrocarbons

1974 ◽  
Vol 52 (20) ◽  
pp. 3495-3506 ◽  
Author(s):  
Kyoji Shinsaka ◽  
Gordon R. Freeman
Keyword(s):  
Aromatic Hydrocarbons ◽  
Secondary Electron ◽  
Shielding Effect ◽  
Methyl Groups ◽  
Thermal Electron ◽  
Molecular Asymmetry ◽  
Trimethyl Benzene ◽  
Free Ion ◽  
Benzene Toluene ◽  
Ion Yields

Radiolysis free ion yields were measured as functions of electric field strength and temperature in benzene, toluene, 1,2-, 1,3-, and 1,4-dimethylbenzene, 1,2,3-, 1,2,4-, and 1,3,5-trimethylbenzene, 1,2,3,4- and 1,2,4,5-tetramethylbenzene, pentamethylbenzene, hexamethylbenzene, naphthalene, and anthracene. Secondary electron ranges bGP were estimated from the yields. The density-normalized ranges bGPd were almost constant, 34−38 × 10−8 g/cm2, from benzene up to the tetramethylbenzenes, then increased to 47 × 10−8 in pentamethyl- and 52 × 10−8 in hexamethylbenzene. In naphthalene and anthracene the normalized ranges were 32 and ∼20 × 10−8 g/cm2, respectively. Electron mobilities in the liquids at 293 K, and their activation energies, expressed in (cm2/V s, kcal/mol) were: benzene (0.114, 7.4); toluene (0.063, 3.4); 1,2-dimethylbenzene (0.018, 4.4); 1,3-dimethylbenzene (0.057, 4.5); 1,4-dimethylbenzene (0.062, —); 1,2,3-trimethylbenzene (0.022, 4.8); 1,2,4-trimethylbenzene (0.035, 4.3); 1,3,5-trimethyl-benzene (0.17, 3.2); 1,2,3,4-tetramethylbenzene (∼0.02, 5). The mobilities reflect migration retarding influences of the aromatic ring and molecular asymmetry, and a slight ring-shielding effect of methyl groups that tends to enhance the mobility.

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