Calculations on the effect of supply frequency on the positive column of a low-pressure Hg-Ar AC discharge

Drop, P C; Polman, J.

doi:10.1088/0022-3727/5/3/316

Cited by 31 publications

(5 citation statements)

References 5 publications

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“…These time constants include ambipolar diffusion time (τ D ) and energy relaxation time (τ E ). In the present discharge, τ E ≈ 2 µs, and τ D ≈ 5 ms [6].…”

Section: Applying Waveforms With Different Frequenciesmentioning

confidence: 49%

“…Drop et al [6] studied the effect of excitation AC discharge frequency on the positive column of a low-pressure Ar-Hg (P Ar = 3 Torr, P Hg ≈ 6 × 10 −3 Torr, I eff = 0.4 A). They measured the plasma electron density for three frequencies (50 Hz, 500 Hz, 32 kHz) and concluded that the efficiency of UV emission has a minimum value at 500 Hz.…”

Section: Introductionmentioning

confidence: 99%

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The influence of electrical waveform on the electron density and collision frequency of low-pressure gas discharge plasma

Ebrahimi

Sohbatzadeh

Zakeri-Khatir

2019

J. Phys. D: Appl. Phys.

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In this experimental research, the effect of electrical waveforms including direct current (DC), sinusoidal, sawtooth, triangular, modified sinusoidal and square wave on the plasma electron density and collision frequency of the positive column of low-pressure gas discharge (PAr = 10 Torr, PHg = 6 × 10−3 Torr, R = 18 mm, Irms = 400 mA) was examined. Time-resolved plasma electron density and collision frequency were measured by fast time-resolved microwave interferometry with simultaneous current and voltage measurements. In the case of direct current excitation, the striation with 800 Hz fluctuation was observed. In a sine wave, the striation was observed at 50 Hz while it was disappeared at 5 kHz. In the square waveform, the collision frequency that keeps the plasma density constant could be controlled by tuning the excitation frequency. It was also found that a rapid change in the electrical current signal, like the sawtooth waveform, causes a total reduction in the electron density and collision frequency. Studying the rectangular pulse periods, showed that the maximum density and collision frequency, as well as their evolutions, could be controlled. Regarding the obtained results, it was concluded that one could effectively control (increase or reduce) the electron density and collision frequency with respect to the critical time intervals for practical applications such as plasma antennas and plasma RCS reduction.

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“…These time constants include ambipolar diffusion time (τ D ) and energy relaxation time (τ E ). In the present discharge, τ E ≈ 2 µs, and τ D ≈ 5 ms [6].…”

Section: Applying Waveforms With Different Frequenciesmentioning

confidence: 49%

Section: Introductionmentioning

confidence: 99%

The influence of electrical waveform on the electron density and collision frequency of low-pressure gas discharge plasma

Ebrahimi

Sohbatzadeh

Zakeri-Khatir

2019

J. Phys. D: Appl. Phys.

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“…At frequencies above 20 kHz the recom bination of ions and electrons in the discharge is very low, so no reignition energy is needed during opera tion. 1,2 This same phenomenon at the lamp elec trodes sustains the electron density during the transi tion from cathode to anode function, thereby saving additional energy relative to 50 or 60 Hz 3,4 . There fore, in addition to improved ballast efficiency, the discharge itself is more effective in the high frequency mode, contributing to an increased efficacy for the FL.…”

Section: Advantages Of High Frequency Operationmentioning

confidence: 96%

“…For preheat times less than 0.4 s, the determination of the preheat current becomes rather uncertain, because perturbations like the inhomogeneous heating of the electrode can influ ence the results. IEC standards for FL high frequency operation, i.e., IEC 81, give the minimum preheat time t H for a certain preheat current I min by the formula t H = a(I 2 (1)…”

mentioning

confidence: 99%

Specifications for the Operation of Preheated Cathode Fluorescent Lamps on Electronic Ballasts

Heidemann

Denz

Roche

1994

Journal of the Illuminating Engineering Society

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IntroductionAll fluorescent lamps (FL), including the well known straight lamps and the newly developed compact fluo rescent lamps (CFL), display a negative voltage-current characteristic, requiring a device to limit the lamp cur rent when the FL is connected to a voltage source. Otherwise an ever increasing power dissipation would destroy the lamp. This current limiting device can be a resistor in series with the lamp. However for achiev ing low power dissipation and high efficiency an induc tive ballast is typically used. Whereas pure magnetic (in ductive) ballasts need additional starting elements such as glow switches or transformers, electronic control gear (ECG) incorporates all the equipment necessary for starting and operating a FL. During operation, ECGs generate high frequency voltages, most commonly in the range of 25-50 kHz, compared to conventional ballasts, which operate lamps at 50 or 60 Hz. This dif ference in the frequency of lamp operation is the main reason for nearly all the advantages of ECGs.

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“…Ein Vergleich zwischen Gleichstrom-und Wechselstromentladung kann unter diesen Umstiinden n b fiir eine ganz bestimmte Entladung mit einem ganz bestimmten Vorschaltgerat erfolgen, und die Ausdehnung der Amsagen auf Entladungen, die mit anderen Vorschaltgeriiten betrieben wurden, sind nicht immer sinnvoll. Erst in neuerer Zeit wurde von POLMAN u. Mitarbeitern auch theoretisch versucht, die Wechselstromentladung im Hg-k-System zu erfassen, wobei den Rechnungen ein sinusformiger Entladungsstrom zugrunde gelegt wurde [6].…”

Section: Introductionunclassified

Zeitaufgelöste Bestimmung der Plasmaparameter im Ar‐Hg‐Plasma

Zahn¹,

Schaal²

1973

Contrib Plasma Phys

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Bei Kulturen von Candida guilliermondii, Stamm H 17, wurden n‐Alkane definierter Kettenlängen, die Alkangemische Mepasin I und II sowie in Kontrollen Acetat und Glucose als C‐Quellen angeboten. Im Kulturfiltrat konnten gaschromatographisch Glutar‐, Adipin‐, Pimelin‐ und Azelainsäure nachgewiesen werden. Die Beziehungen zwischen den Substraten mit gerad‐ oder ungeradzahliger C‐Kettenläge und den gebildeten Dicarbonsäuren werden erörtert.

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Calculations on the effect of supply frequency on the positive column of a low-pressure Hg-Ar AC discharge

Cited by 31 publications

References 5 publications

The influence of electrical waveform on the electron density and collision frequency of low-pressure gas discharge plasma

The influence of electrical waveform on the electron density and collision frequency of low-pressure gas discharge plasma

Specifications for the Operation of Preheated Cathode Fluorescent Lamps on Electronic Ballasts

Zeitaufgelöste Bestimmung der Plasmaparameter im Ar‐Hg‐Plasma

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