• Radiation Oncology Journal
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• v.1 no.1
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• pp.11-19
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• 1983

Interaction between high energyelectrons and matters had many complex reactions and the high energy electrons lost their energies with collision and scattering, therefore, electrons distribution in matters was shown as various situation by scattering, exciting and ionizing with moleculars. We experimentally studies with 13 MeV Linear Accelerator and thermoluminescence dosimeter using aluminium and Teflon, etc., and measured energy loss of electrons, electron range, electron scattering and dose distribution in matter. We compared the results with theoretical formular, between 4-qw MeV, the energy loss of electrons was decreased by 2 MeV per $1g/cm^2$ but under 1MeV it was rapidly decreased. Electron range in matter reached to $0.5/cm^2$ per 1MeV of incident energy at 6-12MeV. The dose distribution in matter was increased slightly to some depth by total distribution i.e., the combined intensity of primary and secondary radiant and it was rapidly decreased near the maximum range of electrons. Energy loss of electrons and electron range measured by experiment were coincided with theoretical equations of L. Landau and Feather under 5 and 3% errors respectively. The dose distribution of electrons in matter was similar to L.V. Spencer formular, however, we had found that it was quite different in accordance with the field size and that new formular of dose distribution was induced as empirical function contained experimental factors according to field size.

• Korean Journal of Materials Research
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• v.23 no.9
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• pp.517-524
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• 2013

The electrical and optical properties of fluorine-doped tin oxide films grown on polyethylene terephthalate film with a hardness of 3 using electron cyclotron resonance plasma with linear microwave of 2.45 GHz of high ionization energy were investigated. Fluorine-doped tin oxide films with a magnetic field of 875 Gauss and the highest resistance uniformity were obtained. In particular, the magnetic field could be controlled by varying the distribution in electron cyclotron deposition positions. The films were deposited at various gas flow rates of hydrogen and carrier gas of an organometallic source. The surface morphology, electrical resistivity, transmittance, and color in the visible range of the deposited film were examined using SEM, a four-point probe instrument, and a spectrophotometer. The electromagnetic field for electron cyclotron resonance condition was uniformly formed in at a position 16 cm from the center along the Z-axis. The plasma spatial distribution of magnetic current on the roll substrate surface in the film was considerably affected by the electron cyclotron systems. The relative resistance uniformity of electrical properties was obtained in film prepared with a magnetic field in the current range of 180~200A. SEM images showing the surface morphologies of a film deposited on PET with a width of 50 cm revealed that the grains were uniformly distributed with sizes in the range of 2~7 nm. In our experimental range, the electrical resistivity of film was able to observe from $1.0{\times}10^{-2}$ to $1.0{\times}10^{-1}{\Omega}cm$ where optical transmittance at 550 nm was 87~89 %. These properties were depended on the flow rate of the gas, hydrogen and carrier gas of the organometallic source, respectively.

• Journal of the Korean Vacuum Society
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• v.1 no.1
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• pp.83-87
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• 1992

Rencently, angle-resolved ultraviolet photoemission measurements of the Fermi surface contours for Mo(011) and W(011) are reported. The electron contour of W(011) is expanded upon hydrogen adsorption, which implies that the surface states consisting of electron pockets are shifted to higher binding energy. This phenomena can be explained by the band flattening. We explained here the reconstruction of W(011) surface induced by adsorption of hydrogen in terms of band flattening of surface states with a combination of S. E. Trullinger long range dipole-dipole interaction force and Kohn anomaly.

• Proceedings of the KIEE Conference
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• 1985.07a
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• pp.215-218
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• 1985

In this paper, The electron drift velocity was measured from an experimental study of the open end heat pipe system by induced current method as alkali metal vapour was generated in ordinary region of a drift tube. The test condition was alkali metal vapour range from 3.6 to 20.1(Torr), temperature of 667 to 755(K), and E/N of $1{\times}10^{-16}$ to $1{\times}10^{-15}(v.cm^2)$. The results of this study were obtained essentially the same as the extrapolated prediction curve for electron drift velocity in the alkali metal Vapour of J. Lucas et 31 with range of E/N: $1{\times}10^{-17}$ to $1{\times}10^{-16}(v.cm^2)$, and the electron drift velocity was obtained the result an increase in alkali to E/N range from E/N $2.8{\times}10^{-17}$ to $5.6{\times}10^{-16}(v.cm^2)$ (E/N From 2.8 to 50 Td).

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.195.1-195.1
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• 2016

Currently, as Plasma application is expanded to the industrial and medical industrial, low temperature plasma applications became important. Especially in medical and biology, many researchers have studied about generated radical species in atmospheric pressure low temperature plasma directly adapted to human body. Therefore, so measurement their plasma parameter is very important work and is widely studied all around world. One of the plasma parameters is electron density and it is closely relative to radical production through the plasma source. some kinds of method to measuring the electron density are Thomson scattering spectroscopy and Millimeter-wave transmission measurement. But most methods have very expensive cost and complex configuration to composed of experiment system. We selected Michelson interferometer system which is very cheap and simple to setting up, so we tried to measuring electron density by laser interferometer with laser beam chopping module for measurement of temporal phase difference in plasma jet. To measuring electron density at atmospheric pressure Ar plasma jet, we obtained the temporal phase shift signal of interferometer. Phase difference of interferometer can occur because of change by refractive index of electron density in plasma jet. The electron density was able to estimate with this phase difference values by using physical formula about refractive index change of external electromagnetic wave in plasma. Our guiding laser used Helium-Neon laser of the centered wavelength of 632 nm. We installed chopper module which can make a 4kHz pulse laser signal at the laser front side. In this experiment, we obtained more exact synchronized phase difference between with and without plasma jet than reported data at last year. Especially, we found the phase difference between time range of discharge current. Electron density is changed from Townsend discharge's electron bombardment, so we observed the phase difference phenomenon and calculated the temporal electron density by using phase shift. In our result, we suggest that the electron density have approximately range between 1014~ 1015 cm-3 in atmospheric pressure Ar plasma jet.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.12 no.1
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• pp.88-93
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• 1999

This paper describes the electron transport characteristics in $SiH_4$ gas calculated for the range of E/n:0.5~300(Td) and Pressure:0.5, 1, 2.5(Torr) by the Monte carlo simulation and Boltzmann equation method using a set of electron collision cross sections determined by the reported results. The motion has been calculated to give swarm parameters for the electron drift velocity, longitudinal and transverse diffusion coefficients, the electron ionization coefficients, characteristics energy and the electron energy distribution function. The electron energy distributions function has been analysed in $SiH_4$ at E/N: 30, 50(Td)for a case of the equilibrium region in the mean electron energy and respective set of electron collision cross sections. The results of Monte carlo simulation and Boltzmann equation have been compared with experimental data by ohmori ad Pollock.

• Proceedings of the KIEE Conference
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• 2006.10b
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• pp.159-162
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• 2006

In this paper energy distribution function in $SiH_4$ has been analysed over the E/N range 0.5${\sim}$300Td and Pressure value 0.5, 1.0, 2.5 Torr by a two-term approximation Boltzmann equation method and by a Monte Carlo simulation. The motion has been calculated to give swarm parameters for the electron drift velocity, diffusion coefficient, electron ionization, mean energy and the electron energy distribution function. The electron energy distribution function has been analysed in $SiH_4$ at E/N=30, 50Td for a case of the equilibrium region in the mean electron energy and respective set of electron collision cross sections. The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.1
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• pp.19-23
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• 2014

This paper describes the electron transport characteristics in $SF_6$-He gas calculated E/N values 0.1~700[Td] by the Monte Carlo simulation and Boltzmann equation method using a set of electron collision cross sections determined by the authors and the values of electron swarm parameters obtained by TOF method. This study gained the values of the electron swarm parameters such as the electron drift velocity, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients for $SF_6$-He gas at a range of E/N. A set of electron collision cross section has been assembled and used in Monte Carlo simulation to predict values of swarm parameters. The result of Boltzmann equation and Monte Carlo Simulation has been compared with experimental data by Ohmori, Lucas and Carter. The swarm parameter from the swarm study are expected to sever as a critical test of current theories of low energy scattering by atoms and molecules.

• Bulletin of the Korean Chemical Society
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• v.7 no.3
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• pp.194-196
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• 1986

The effect of the non-Coulombic long-range forces and the next nearest neighbor interactions on the lattice properties of alkali halide crystals is calculated using the Electron Gas model and Electron Gas Drude model. It is found that these often neglected interactions make changes in the lattice properties that are indeed small, but by no means negligible.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.155-158
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• 1998

This paper is calculated at electron swarm simulation by Back Prolongation of Boltzmann equation for range of E/N values from 0.1~200[Td], pressure P= 1.0[Torr], temperature T=300[ 。K], the electron swarm parameter(drift velocity, longitudinal . transverse diffusion coefficients, characteristic energy, etc) in He gas is used by electron collision cross section, particularly explicate the simulation technique, and consider electrical conduction characteristic of He gas.