• Title/Summary/Keyword: Electron density

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Measurement of electron density of atmospheric pressure Ne plasma jet by laser heterodyne Interferometer with voltage

  • Lim, Jun Sup;Hong, Young June;Choi, Eun Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.140.1-140.1
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    • 2015
  • Currently, As Plasma application is expanded to the industrial and medical industrial, Low temperature plasma characteristics became important. Especially in Medical industrial, Low temperature plasma directly adapted to human skin, so their plasma parameter is important. One of the plasma parameters is electron density, some kinds of method to measuring electron density are Thomson scattering spectroscopy and Millimeter-wave transmission measurement. But most methods is expensive to composed of experiment system. Heterodyne interferometer system is cheap and simple to setting up, So we tried to measuring electron density by Laser heterodyne interferometer. To measuring electron density at atmospheric pressure, we need to obtain the phase shift signal. And we use a heterodyne interferometer. Our guiding laser is Helium-Neon laser which generated 632 nm laser. We set up to chopper which can make a laser signal like a pulse. Chopper can make a 4 kHz chopping. We used Needle jet as Ne plasma sources. Interference pattern is changed by refractive index of electron density. As this refractive index change, phase shift was occurred. Electron density is changed from Townsend discharge's electron bombardment, so we observed phenomena and calculated phase shift. Finally, we measured electron density by refractive index and electron density relationship. The calculated electron density value is approximately 1015~1016 cm-3. And we studied electron density value with voltage.

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Structure Factor와 Electron Density간의 관계

  • 서일환
    • Korean Journal of Crystallography
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    • v.11 no.4
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    • pp.241-246
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    • 2000
  • Structure factor는 위치를 포함한 electron density를 알면 계산되고 역으로 electron density는 phase를 포함한 structure factor를 알면 작도할수 있으므로 structure factor와 electron density는 서로 Fourier transform이다.

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A Study on the characteristics of Electron Energy Distribution function of the Radio-Frequency Inductively Coupled Plasma (고주파 유도결합 플라즈마의 전자에너지 분포함수 특성에 관한 연구)

  • 황동원;하장호;전용우;최상태;이광식;박원주;이동인
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 1998.11a
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    • pp.131-133
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    • 1998
  • Electron temperature, electron density and electron energy distribution function were measured in Radio-Frequency Inductively Coupled Plasma(RFICP) using a probe method. Measurements were conducted in argon discharge for pressure from 10 mTorr to 40 mTorr and input rF power from 100W to 600W and flow rate from 3 sccm to 12 sccm. Spatial distribution of electron temperature, electron density and electron energy distribution function were measured for discharge with same aspect ratio (R/L=2). Electron temperature was found to depend on pressure, but only weakly on power. Electron density and electron energy distribution function strongly depended on both pressure and power. Electron density and electron energy distribution function increased with increasing flow rate. Radial distribution of the electron density and electron energy distribution function were peaked in the plasma center. Normal distribution of the electron density, electron energy distribution function were peaked in the center between quartz plate and substrate. These results were compared to a simple model of ICP, finally, we found out the generation mechanism of Radio-Frequency Inductively Coupled Plasma.

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Measurement of electron density of atmospheric pressure Ar plasma jet by using Michelson interferometer

  • Lim, Jun-Sup;Hong, Young June;Choi, Eun Ha
    • 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.

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Gas and Magenetic Field Effect to Low Pressure Plasma

  • Bae, In-Sik;Na, Byeong-Geun;Seol, Yu-Bin;Yu, Sin-Jae;Kim, Jeong-Hyeong;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.557-557
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    • 2013
  • Plasma hardly grows in lowpressure because of lack of collision. But low pressure plasma has useful properties because it has typically low electron density. In here, thermal electron is used to make breakdown in low pressure easily. We changed magnetic field strength and gas to control electron density or temperature. IV characteristic and electron density of the discharge are examined and the characteristic of the discharge in presence of magnetic field is also examined. Results showed that depending on the ionization cross section of the gas, electron density is changed and proper strength of magnetic field is required for high electron density.

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A Study on the Characteristics of the Radio-Frequency Inductive Discharge Plasma (고주파 유도방전 플라즈마 특성에 관한 연구( I ))

  • 박성근;박상윤;박원주;이광식;이동인
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 1996.11a
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    • pp.63-66
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    • 1996
  • Electron temperature and electron density were measured in a radio-frequency(rf) inductively coupled plasma using probe measurements. Measurements were made in an argon discharge for pressures from 10 to 100mTorr and input rf power from 100 to 800W. Spatial distribution Electron temperature and electron density were measured for discharge with same aspect ratio. Electron temperature and Electron density were found to depend on both pressure and power. Electron density was creased with increasing pressure, but peaked in a 70mTorr discharge. Radial distribution of the electron density was peaked in the plasma fringes. These results were compared to a simple model of inductively coupled plasmas.

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A Measurements of Radio-Frequency Induction Discharge Plasma using probe method (고주파 유도방전 플라즈마의 푸로우브법에 의한 계측)

  • Park, Sung-Gun;Park, Sang-Yun;Ha, Chang-Ho;Park, Won-Zoo;Lee, Kwang-Sik;Lee, Dong-In
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1657-1659
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    • 1997
  • Electron temperature and electron density were measured in a radio-frequency inductively coupled plasma (RFICP) using a probe measurements. Measurement was conducted in an argon discharge for pressures from 10 [mTorr] to 40 [mTorr] and input rf power from 100 [W] to 800 [W], Ar flow rate from 5 [sccm] to 30 [sccm], Spatial distribution electron temperature and electron density were measured for discharge with same aspect ratio (R/L=2). Electron temperature and electron density were discovered depending on both pressure and power, Ar flow rate. Electron density was increased with increasing input power and in creasing pressure, increasing Ar flow rate. Radial distribution of the electron density was peaked in the plasma center. Normal distribution of the electron density was peaked in the center between quartz plate and substrate. From these results, We found out the generation mechanism of Radio-Frequency Inductively Coupled Plasma.

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Study on Argon Metastable Density in ICP by Using Laser Induced Fluoresce

  • Seo, Byeong-Hun;Yu, Sin-Jae;Kim, Jeong-Hyeong;Seong, Dae-Jin;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.219.2-219.2
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    • 2014
  • Characteristics of Argon metastable density with electron density have been studied by using Laser induced fluorescence (LIF) in ICP. Two different evolutions of measured metastable densities with electron density depending on a measurement position are addressed. The experimental result is explained by using a zero dimensional global model and is due to electron kinetic properties in the positions that can be seen from electron energy probability functions measured by Langmuir probe. The underlying physics on metastable density with electron density and an experimental method of LIF are presented in detail.

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Measurement of Electron Energy Distribution of the Radio-Frequency Inductively Coupled Plasma (고주파 유도결합 플라즈마의 전자에너지 분포 계측 (II))

  • Hwang, Dong-Won;Ha, Chang-Ho;Jeon, Yong-Woo;Choi, Sang-Tae;Park, Won-Zoo;Lee, Kwang-Sik;Lee, Dong-In
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1803-1805
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    • 1998
  • Electron temperature, electron density and electron energy distribution function were measured in Radio-Frequency Inductively Coupled Plasma(RFICP) using a probe method. Measurements were conducted in argon discharge for pressure from 10 mTorr to 40 mTorr and input rf power from 100W to 600W and flow rate from 3 sccm to 12 sccm. Spatial distribution electron temperature and electron density and electron energy distribution function were measured for discharge with same aspect ratio(R/L=2). Electron temperature was found to depend on pressure, but only weakly on power. Electron density and electron energy distribution function strongly depended on both pressure and power. Electron density and electron energy distribution function increased with increasing flow rate. Radial distribution of the electron density and electron energy distribution function were peaked in the plasma center. Normal distribution of the electron density electron energy distribution function were peaked in the center between quartz plate and substrate. These results were compared to a simple model of ICP, then we found out the generation mechanism of Radio-Frequency Inductively Coupled Plasma.

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Time-dependent Characteristics of Pulse Modulated rf Plasma (펄스모듈레이션 된 고주파 플라즈마의 시변특성)

  • Lee Sun-Hong;Park Chung-Hoo;Lee Ho-Jun
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.11
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    • pp.566-571
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    • 2004
  • Pulse modulation technique provide additional controling method for electron temperature and density in rf and microwave processing plasma. Transient characteristics of electron density and temperature have been measured in pulse modulated rf inductively coupled argon plasma using simple probe circuit. Electron temperature relaxation is clearly identified in the after glow stage. Controllability of average electron temperature and density depends on the modulation frequency and duty ratio. Numerical calculation of time-dependent electron density and temperature have been performed based on the global model. It has been shown that simple langmuir probe measurement method used for continuous plasma is also applicable to time-dependent measurement of pulse modulated plasma.