Discharge characteristics under non-uniform electric field in He, Ar and air at low pressures

Ōkubo, H.; Yuasa, S.; Ota, K.; Hayakawa, Naoki; Hikita, Masayuki

doi:10.1109/94.625362

Cited by 16 publications

(4 citation statements)

References 6 publications

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“…In many atmospheric pressure plasmas being utilized in various industrial processes, gases such as argon or helium are often introduced for assisting stable plasma generation and/or for other particular processes. In general, helium has lower breakdown voltage characteristics in the Ͼ10 Torr cm range of the Paschen curve [1][2][3] and a lower gas temperature 4 than argon, which is consistent with our experimental results. The low breakdown voltage is beneficial because it helps by preventing arc production and system overloading.…”

Section: Introductionsupporting

confidence: 82%

Control of radio-frequency atmospheric pressure argon plasma characteristics by helium gas mixing

2006

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The control of plasma characteristics is one of the important issues in many atmospheric pressure plasma applications. In order to accomplish this control, a feasibility study was performed by investigating the role of helium gas in an argon glow plasma that were produced in ambient air by 13.56 MHz radio-frequency power. Optical emission spectroscopy was used to measure rotational temperature and emission spectra acquired between 300 and 840 nm. Based on electrical and optical measurements, parameters such as gas temperature, breakdown voltage, power coupling efficiency, spatial uniformity of rotational temperature, and the sum of the emission intensity were controlled by varying the argon and helium gas mixing ratio. The addition of helium gas ͑from 0 to 10 ᐉpm͒ to the argon flow ͑of 10 ᐉpm͒ lowered the breakdown voltage ͑from 430 to 300 V pk ͒ and the rotational temperature ͑from 465 to 360 K͒. However, an excessive addition of helium resulted in a reduction of the spatial uniformity and efficiency of power coupling. When the ratio of helium to argon flow was between 0.3 and 0.5, a high spatial uniformity with a relatively low gas temperature and breakdown voltage was achieved. This suggests that mixing of the supply gas is a useful way of controlling the plasma characteristics that may be utilized for applications with specific required discharge conditions.

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Section: Introductionsupporting

confidence: 82%

Control of radio-frequency atmospheric pressure argon plasma characteristics by helium gas mixing

2006

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“…It is well recognized that the physical phenomena that determine the collision-dominated nature of electrical discharges at low pressure influence the inception and temporal characteristics of PD events [2,3]. Hence, detection systems typically tuned to detect specific frequency ranges for terrestrial equipment can be ineffective with respect to detection of PD events at low pressures.…”

Section: Introductionmentioning

confidence: 99%

Development of procedures for partial discharge measurements at low pressures in air, argon and helium

Grosjean

Schweickart

Kasten

et al. 2008

IEEE Trans. Dielect. Electr. Insul.

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Partial discharge (PD) characteristics in air, argon and helium at pressures between 101 kPa (760 Torr) to about 0.27 kPa (2 Torr) under 60 Hz ac energization were studied with various electrode arrangements. Measurements are presented for two representative electrode configurations, (1) needle-plane, with 20 mm spacing and a dielectric barrier, and (2) a twisted pair of insulated conductors. Typical PD currentpulse waveforms are presented. Difficulties in adhering to measurement guidelines defined by the IEC 60270 standard are described, and suggested modifications of the standard procedures are presented for measurement and calibration for low-pressure PD.Index Terms -Partial discharge, experimental setup, partial discharge current-pulse waveform, rise time, partial discharge measurement requirements, guidelines, low pressure.

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“…With the decrease of insulation distance, the time to tracking failure is increased at low pressure, but reduced at atmospheric pressure. The discharge is caused by electron emission from the electrode due to the electric field [18], which, according to Paschen's Law relates to the function of ambient pressure and insulation distance. At both low and atmospheric pressures, with the decrease of insulation distance, the electric field strength is enhanced and increases the electron emission rate.…”

Section: Tracking Failurementioning

confidence: 99%

Effects of low pressure on tracking failure of printed circuit boards

Liu

2008

IEEE Trans. Dielect. Electr. Insul.

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In general, printed circuit boards (PCBs) used in power devices and system operation in low pressure environments are more susceptible to damage from surface discharges. Additionally, repetitive operation of power systems is an important factor leading to tracking failure. Whether the tracking phenomenon at low pressures is different from that at atmospheric pressure needs better understanding to ensure reliable applications. In this paper, studies of tracking failure of PCBs in a low-pressure chamber, are reported for an electrode configuration comprising a pointed end of track close to the side of a track. Test samples were made by printing these tracks onto a glass-cloth epoxy-resin laminate. Experiments were carried out using repetitive unipolar pulses to simulate voltage surges. The ambient pressure was reduced from atmospheric pressure to a very low pressure (0.6 kPa). The time to failure and the cumulative charge passing before failure were recorded as function of the pressure, temperature, pulse interval and insulation distance. The results obtained indicate that the low pressure enhances the breakdown endurance of PCBs and the breakdown phenomena at low pressure are different from those at atmospheric pressure. With the decrease of the pressure, the cumulative charge is increased but the tracking failure is delayed. At low pressures, increasing temperature has little effect on the cumulative charge, but has significant influence on the time to tracking failure.

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Discharge characteristics under non-uniform electric field in He, Ar and air at low pressures

Cited by 16 publications

References 6 publications

Control of radio-frequency atmospheric pressure argon plasma characteristics by helium gas mixing

Control of radio-frequency atmospheric pressure argon plasma characteristics by helium gas mixing

Development of procedures for partial discharge measurements at low pressures in air, argon and helium

Effects of low pressure on tracking failure of printed circuit boards

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