Навчально-науковий інститут "Фізико-технічний факультет"
Постійне посилання на розділhttps://ekhnuir.karazin.ua/handle/123456789/49
Переглянути
26 результатів
Результати пошуку
Документ Experimental Study of a Low-Pressure Glow Discharge in Air in Large-Diameter Discharge Tubes: I. Conditions for the Normal Regime of a Glow Discharge(Plasma Physics Reports, 2000-12) Lisovskiy, V.; Yakovin, S.The initiation and characteristics of a low-pressure glow discharge in air in large-diameter discharge tubes are studied. A deviation from the Paschen law is observed: the breakdown curves Udc(pL) shift toward the higher values of Udc and pL as the interelectrode distance L increases. It is shown that the normal regime of a glow discharge is accompanied by gas ionization in the anode sheath. This takes place only for pL values lying to the right of the inflection point in the breakdown curve. The cathode-sheath characteristics in the normal and abnormal regimes of an air discharge for a duralumin cathode are determined. The axial profiles of the ion density, electron temperature, and plasma potential, as well as the anode voltage drop, are measured at various air pressures.Документ Scaling Law for a Low-Pressure Gas Breakdown in a Homogeneous DC Electric Field(Journal of Experimental and Theoretical Physics Letters, 2000-02) Lisovskiy, V.; Yakovin, S.Gas breakdown in nitrogen, air, and oxygen in a dc electric field at various interelectrode distances L is studied experimentally. A scaling law for a low-pressure gas breakdown Udc=f(pL,L/R) is deduced. According to this scaling law, the breakdown voltage Udc is a function not only of the product of the gas pressure p and the gap length L, but also of the ratio of the gap length L to the chamber radius R. It is shown that, for any dimensions of the cylindrical discharge chamber (in the range of L/R under investigation), the ratio of the breakdown electric field to the gas pressure p at the minimum of the ignition curve remains constant: (Edc/p)min = const. A method for calculating the ignition curve in a cylindrical discharge chamber with arbitrary values of L and R is proposed.Документ Характеристики катодного слоя тлеющего разряда низкого давления в аргоне и азоте(Письма в Журнал Технической Физики, 2000-10) Лисовский, В.; Яковин, С.Экспериментально определены характеристики катодного слоя тлеющего разряда в аргоне и азоте в широком диапазоне давлений газа. Получено, что нормальный режим горения может наблюдаться только при наличии ионизации в анодном слое (справа от точки перегиба кривой зажигания тлеющего разряда). Показана некорректность одного способа определения нормального катодного падения напряжения.Документ Модифицированный закон Пашена для зажигания тлеющего разряда в инертных газах(Журнал Технической Физики, 2000-06) Лисовский, В.; Яковин, С.Экспериментально и теоретически исследован пробой инертных газов в однородном постоянном электрическом поле при различных расстояниях между электродами L и радиусах разрядных трубок R. Показано, что при любых геометрических размерах разрядной камеры и материалах катода в минимуме кривых зажигания отношение напряженности пробойного электрического поля к давлению газа сохраняется постоянным. Получен модифицированный закон Пашена, согласно которому пробойное напряжение является функцией не только произведения давления газа на величину расстояния L, но и функцией отношения L/R.Документ Low-pressure gas breakdown in uniform dc electric field(JOURNAL OF PHYSICS D: APPLIED PHYSICS, 2000-11) Lisovskiy, V.; Yakovin, S.; Yegorenkov, V.This paper studies in experiment and theory the breakdown of argon, nitrogen, air and oxygen in a uniform dc electric field at different discharge gaps L, discharge tube radii R and cathode materials. At arbitrary geometric dimensions of the cylindrical discharge vessel and cathode materials the ratio of the breakdown electric field value to the gas pressure p at the minimum of the breakdown curves is shown to remain constant, (Edc/p)min ≈ constant. A modified breakdown law for the low-pressure dc discharge Udc = f (pL, L/R) is obtained. That is, the breakdown voltage Udc is shown to depend not only on the product pL, but also on the ratio L/R. A method is presented enabling one to predict a dc breakdown curve in the cylindrical discharge vessel possessing arbitrary L and R values from the measured data on the dc breakdown.Документ Alpha–gamma transition in RF capacitive discharge in low-pressure oxygen(www.elsevier.com/locate/vacuum, 2004-01) Lisovskiy, V.; Yegorenkov, V.We report the recorded current–voltage characteristics of a RF capacitive discharge in oxygen. Low-frequency oscillations of the plasma potential in a kilohertz frequency range are observed to accompany the transition of the discharge from a weak- (a-) to a strong-current (g-) regime in the low-pressure range. The weak-current regime of the RF capacitive discharge is observed within the pressure range limited not only from the medium pressure side but also from the lower-pressure one. Electron temperature and plasma density are registered with a probe technique.Документ Electron drift velocity in NH3 in strong electric fields determined from rf breakdown curves(JOURNAL OF PHYSICS D: APPLIED PHYSICS, 2005-03) Lisovskiy, Valeriy; Martins, Sofia; Landry, Karine; Douai, David; Booth, Jean-Paul; Cassagne, ValerickWe report measurements of the breakdown curves of a radio-frequency capacitive discharge in low pressure ammonia. The electron drift velocity was determined from the location of turning points in the breakdown curves in the range of E/p = 42–713 Vcm−1 Torr−1. We compare our results to values calculated from the published cross-sections in the range E/p = 1–5000 Vcm−1 Torr−1 and find good agreement.Документ Extinction of RF capacitive low-pressure discharges(EUROPHYSICS LETTERS, 2005-08) Lisovskiy, Valeriy; Booth, Jean-Paul; Martins, Sofia; Landry, Karine; Douai, David; Cassagne, ValerickBreakdown and extinction curves have been measured for RF capacitive low-pressure discharges in nitrogen and hydrogen at a frequency of 13.56 MHz and discharge gaps between 6 and 25 mm. In particular, the low-pressure, high-voltage region of the extinction curves is reported for the first time. The shape of the extinction curves was found to be similar to that of the breakdown curves. At sufficiently large gaps (L > 10 mm) the RF extinction voltage was found to be multi-valued in the low-pressure region, as is observed for the breakdown voltage. In this region, extinction can occur when the voltage is increased because the width of the two sheaths occupies the whole discharge space.Документ The effect of discharge chamber geometry on the ignition of low-pressure rf capacitive discharges(PHYSICS OF PLASMAS, 2005-09) Lisovskiy, V.; Martins, S.; Landry, K.; Douai, D.; Booth, Jean-Paul; Cassagne, V.; Yegorenkov, V.This paper reports measured and calculated breakdown curves in several gases of rf capacitive discharges excited at 13.56 MHz in chambers of three different geometries: parallel plates surrounded by a dielectric cylinder (“symmetric parallel plate”), parallel plates surrounded by a grounded metallic cylinder (“asymmetric parallel plate”), and parallel plates inside a much larger grounded metallic chamber (“large chamber”). The breakdown curves for the symmetric chamber have a multivalued section at low pressure. For the asymmetric chamber the breakdown curves are shifted to lower pressures and rf voltages, but the multivalued feature is still present. At higher pressures the breakdown voltages are much lower than for the symmetric geometry. For the large chamber geometry the multivalued behavior is not observed. The breakdown curves were also calculated using a numerical model based on fluid equations, giving results that are in satisfactory agreement with the measurements.Документ Double layer onset inside the near-electrode sheath of a RF capacitive discharge in oxygen(www.elsevier.com/locate/vacuum, 2006-04) Lisovskiy, V.; Yegorenkov, V.This paper reports the axial profiles of the electron temperature Te in the RF capacitive discharge in oxygen recorded with a probe technique. We observed the Te peaks near the boundaries of the sheaths as well as inside the near-electrode sheath. The Te peak inside the sheath is, probably, due to the formation of the double layer at the anode phase of this near-electrode sheath. The assumption of a double layer formation is also supported by the photos of the sheath glow making evident the bright region inside the sheath. The results of our measurements agree with our fluid simulation satisfactorily.
- «
- 1 (current)
- 2
- 3
- »