Energy distribution of low‐energy electrons and free‐ion yields in irradiated liquid hydrocarbons

1992 ◽  
Vol 96 (9) ◽  
pp. 6531-6535 ◽  
Author(s):  
Robert Schiller
Keyword(s):  
Energy Distribution ◽  
Low Energy ◽  
Liquid Hydrocarbons ◽  
Free Ion ◽  
Low Energy Electrons ◽  
Ion Yields

Comparison between Molecular Structure Effects in Triplet Positronium Annihilation Rates and Radiolysis Free Ion Yields in Liquid Hydrocarbons

1972 ◽  
Vol 50 (16) ◽  
pp. 2697-2698 ◽  
Author(s):  
G. R. Freeman ◽  
J.-P. Dodelet
Keyword(s):  
Molecular Structure ◽  
Chain Length ◽  
Molecular Interaction ◽  
Half Life ◽  
Density Effect ◽  
Liquid Hydrocarbons ◽  
Positronium Annihilation ◽  
Free Ion ◽  
Alkane Chain ◽  
Ion Yields

Two seemingly unrelated phenomena in liquid hydrocarbons have similar trends in their dependences upon the molecular structure of the hydrocarbon. The phenomena are the annihilation half-life of triplet positronium and the radiolysis free ion yield. In n-alkanes the effect of increasing the molecular chain length, upon both phenomena, appears to be simply to increase the density of interacting sites. Branching the alkane chain decreases the strength of molecular interaction with both electrons and positronium, although the relative decrease is much greater for the former than for the latter. The effects of double bonds on the phenomena, after separating out the density effect, are different from each other.

Electron energy measurements in pulsating auroras

1981 ◽  
Vol 59 (8) ◽  
pp. 1106-1115 ◽  
Author(s):  
D. J. McEwen ◽  
E. Yee ◽  
B. A. Whalen ◽  
A. W. Yau
Keyword(s):  
Energy Distribution ◽  
Electron Energy ◽  
Equatorial Plane ◽  
Low Energy ◽  
Background Intensity ◽  
Energy Distributions ◽  
Electron Spectra ◽  
Energy Modulation ◽  
Low Energy Electrons ◽  
S Period

Electron spectra were obtained during two rocket flights into pulsating aurora from Southend, Saskatchewan. The first rocket launched at 1143:24 UT, on February 15, 1980 flew into an aurora of background intensity 275 R of N2+ 4278 Å and showing regular pulsations with about a 17 s period. Electron spectra of Maxwellian energy distributions were observed with an average E0 = 1.5 keV, rising to 1.8 keV during the pulsations. There was one-to-one correspondence between the electron energy modulation and the observed optical pulsations. The second rocket, launched at 1009:10 UT on February 23, flew into a diffuse auroral surface of intensity 800 R of N2+ 4278 Å and with somewhat irregular pulsations. The electron spectra were again of Maxwellian energy distribution with an average E0 = 1.8 keV increasing to 2.1 keV during the pulsations. The results from these flights suggest that pulsating auroras occurring in the morning sector may be quite commonly excited by low energy electrons. The optical pulsations are due to periodic increases in the energy of the electrons with the source of modulation in the vicinity of the geomagnetic equatorial plane.

Compton scattering in the optically thick uniform spherical corona around the neutron star in an X-ray binary in two conditions

2021 ◽  
Author(s):  
ChangSheng Shi
Keyword(s):  
Neutron Star ◽  
Energy Distribution ◽  
Compton Scattering ◽  
Physical Process ◽  
Low Energy ◽  
X Ray ◽  
Low Energy Electrons ◽  
Initial Seed

Abstract We consider the Compton scattering in the optically thick uniform spherical corona around a neutron star in an X-ray binary. In the scattering, the low energy seed photons (0.1 ∼ 2.5 keV) are scattered in low energy electrons (2.5 ∼ 10 keV) in the corona in two conditions, i.e. initial seed photons are scattered in a whole corona and scattered in every layer of the corona that are supposed to be divided into many layers. When the same number of input seed photons, the same corona parameters and the same energy distribution of all photons in the two conditions are considered, the approximately same number of output photons can be obtained, which means that there is approximately a transform invariance of layering the Comptonized corona. Thus the scattering in the layers of a multi-layered corona is approximately equal to the scattering in the whole corona by dividing the whole corona into several layers. It means that Compton scattering for the initial seed photons scattered in a whole optically thick spherical corona with uniformly distributed electrons also can be considered as that the multiple Compton scatterings take place in the layers of a multi-layered corona in order approximately, which can be used to explore some physical process in one part of a corona.

scholarly journals Transport Coefficients for Low Energy Electrons in Crossed Electric and Magnetic Fields

1965 ◽  
Vol 18 (3) ◽  
pp. 237 ◽  
Author(s):  
RL Jory
Keyword(s):  
Distribution Function ◽  
Magnetic Fields ◽  
Energy Distribution ◽  
Cross Section ◽  
Transport Coefficients ◽  
Low Energy ◽  
Electric And Magnetic Fields ◽  
Experimental Parameters ◽  
Low Energy Electrons ◽  
Momentum Transfer Cross Section

Experimental results are given for the ratio W xl W. of transverse to longitudinal drift velocity for electron swarms in nitrogen moving in crossed electric and magnetic fields. The results, obtained by Huxley's method, cover the range 0�04 < Elp < 8�0 V cm-1 torr-1 at 293�K. The apparatus and experimental procedures which have been developed permit accurate measurements to be made so that significant tests of the method have been possible over wide ranges of the experimental parameters. Information concerning the variation of the momentum transfer cross section with electron energy, and concerning the energy distribution function, can be obtained by comparing a quantity

Electronic Properties of Wide Bandgap Materials

1997 ◽  
Vol 483 ◽  
Author(s):  
J.E. Yater ◽  
A. Shih ◽  
R. Abrams
Keyword(s):  
Energy Distribution ◽  
Electron Distribution ◽  
Secondary Electron ◽  
Impact Ionization ◽  
Incident Beam ◽  
Wide Bandgap ◽  
Low Energy ◽  
Internal Gain ◽  
Low Energy Electrons ◽  
The Impact

AbstractSecondary electron emission spectroscopy is used to investigate the generation and transport of impact-ionized electrons in wide bandgap material. Secondary electron yield and energy distribution measurements from C(100) and CVD diamond samples are analyzed to obtain information about the internal gain and electron energy distribution following impact ionization, as well as the effects of the transport process on the internal electron distribution. By studying the emission from surfaces having a negative electron affinity (NEA), the total transmitted intensity and the full energy spectrum of the internal electrons are revealed in the measurements. Energy spectra measured from the diamond samples contain a low-energy peak whose energy position and width are independent of incident beam energy. This suggests that the peak represents the electron distribution produced by impact-ionization events. A large percentage of the total emitted electrons lie within this peak, indicating that the impact-ionization process is very efficient at generating low-energy electrons. Very high yields are measured from both samples, establishing the presence of high internal gain and efficient electron transport in the material. From the linear slope of the yield curves, the escape depth of the low-energy electrons is deduced to be much larger than ˜ 0.1 μm in both diamond samples.

The effect of pressure on the radiation-induced conductance of liquid hydrocarbons

1969 ◽  
Vol 47 (6) ◽  
pp. 885-892 ◽  
Author(s):  
D. W. Brazier ◽  
G. R. Freeman
Keyword(s):  
Solid Phase ◽  
The Other ◽  
Electron Localization ◽  
Cavity Model ◽  
Liquid Hydrocarbons ◽  
Appreciable Increase ◽  
Free Ion ◽  
Radiation Induced ◽  
Phase Glass ◽  
Ion Yields

An attempt was made to test the cavity model of electron localization in liquid hydrocarbons by measuring the effect of pressures up to 4000 bars on the radiation induced conductance of n-pentane, n-hexane, n-octane, cyclopentane, methylcyclohexane, and 2,2-dimethylbutane at 30°. Measurements at 3 and 56° were also made on n-hexane and n-octane. The relative induced conductance, i.e. the ratio of the induced conductance at pressure p to that at 1 bar, decreased with increasing pressure. The amount of decrease was slightly greater at low than at high temperatures. The behavior of 2,2-dimethylbutane was complex and is not understood. For the other liquids, it was concluded that the free ion yields remained constant or decreased somewhat with increasing pressure. An appreciable increase in the free ion yields, which is a possible implication of the cavity model of electron localization, did not occur. Therefore, either (a) the cavity model of electron localization in hydrocarbons is wrong, or (b) application of pressures up to 4000 bars did not appreciably alter the cavity concentrations in the liquids. Perhaps the cavity concentration is greatly reduced only by pressures great enough to cause a solid phase (glass or crystal) to form.

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