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This paper is aimed at expressing the expanded combined measuring uncertainty of capacitive divider with concentrated capacitance on a high-voltage scale. The tested capacitive divider is constructed to have a minimal measuring uncertainty. Measuring uncertainty of type A is expressed by means of the statistical processing of an experimentally determined random variable of pulse voltage amplitude and random variable of step voltage amplitude uncertainty budget of type B was derived from: 1) the influence of uncertainty values of a high-voltage and low-voltage capacitances on the transmission ratio; 2) the influence of frequency on the transmission ratio; and 3) measuring uncertainty type B of the used instrument. The experiments were performed under well-controlled conditions. Measuring uncertainty of type B for the first budget component is obtained theoretically using the Monte Carlo method, for the second budget component by using experimental-analytical method, while for the third budget component it is taken from the instructions manual of the manufacturer. The Gaussian distribution is attributed to the influential effects of the instruments measuring uncertainty type B. The results obtained show that most impact on measuring uncertainty of type B has the measuring uncertainty type B of the used instrument and the measuring uncertainty type B of divider by the influence of frequency. Values of expanded combined measuring uncertainty for 95% of coverage probability are 5.2% for frequencies equal to 50 MHz, 6.1% for frequencies equal to 1 GHz, and 7.1% for frequencies equal to 4 GHz. Comparing to our results for relative error of capacitive divider for measuring fast pulse voltages, it is shown that the tested capacitive divider has very good characteristics.

The aim of this paper is to investigate the justification and the limitation of the geometrical similarity law application on the electrical breakdown of SF6 gas. For this purpose, the measurements of the dielectric breakdown voltage for similar systems insulated with SF6 gas were done. The applied dc voltage source had an 8 V/s rate of rise. Standard double exponential overvoltage pulse (rise time T-1 = 1.2 mu s, fall time T-2 = 50 mu s) of the amplitude U-1(max) = 320 V, U-2(max) = 4.80 kV, and U-3(max) = 640 kV was used. On the basis of the obtained experimental results and theoretical considerations, the conditions under which the geometrical similarity laws are applicable on discharges in gases are determined. It was concluded that there is no correlation between the geometrical similarity of the electrode surface topography and corresponding breakdown voltages. It was shown that the extension of the similarity law, introducing the electron mean free path as a linear dimension of the system, gives a good quantitative agreement. Also, in case of the pulse breakdown voltage, it is necessary to apply the breakdown possibility rise law.

Devices with micrometer and submicrometer gaps can face a serious challenge due to electrical breakdown during manufacturing, handling, and operation. Therefore, it is necessary to be aware of the breakdown voltage at different gaps. Since the Paschens law is not valid for gaps smaller than several micrometers, modified Paschen curve should be used to predict breakdown voltage for microdevices. One of the possible mechanisms responsible for the reduction of the maximum operation voltage at small gaps is the field emission (FE). In this paper, particle-in-cell/Monte Carlo collision simulations, including the ejection of electrons from the cathode due to a high electric field, have been carried out to estimate the significance of the FE effect on the breakdown voltage in microgaps.

Devices with micrometer and submicrometer gaps can face a serious challenge due to electrical breakdown during manufacturing, handling, and operation. Therefore, it is necessary to be aware of the breakdown voltage at different gaps. Since the Paschens law is not valid for gaps smaller than several micrometers, modified Paschen curve should be used to predict breakdown voltage for microdevices. One of the possible mechanisms responsible for the reduction of the maximum operation voltage at small gaps is the field emission (FE). In this paper, particle-in-cell/Monte Carlo collision simulations, including the ejection of electrons from the cathode due to a high electric field, have been carried out to estimate the significance of the FE effect on the breakdown voltage in microgaps.

This paper aims to find the possibility of stabilizing the gas-filled surge arrester's (GFSA) static working point in gamma- and X-radiation fields by an appropriate choice of constructive parameters. The observed effects on Some commercial components have been compared to the originally developed GFSA model with the aim of improving the characteristics of the commercial components. The type of noble gas, the pressure in the gas chamber, the inter-electrode gap value, the electrode material, and the manner of electrode surface processing are used as variable parameters. The obtained results are significant for a better understanding of the prebreakdown effects in gases at low pressures, but also have practical importance for the manufacturer of GFSAs.

The application of MOSFETs as detectors or device components in pulse power technique requires an investigation of their characteristics in radiation fields. Computing possibilities of the renowned programs FOTELP and PENELOPE for determining the energy deposited in MOISFET structure and dose distribution within microscopic dimensions of the dosimeter sensitive volume were presented in this paper. Based on the obtained results, qualitative conclusions were drawn about the values of energy deposited in different material zones having various dimensions. The difference between the two codes used for calculations in materials physics and semiconductor technics, basically originates from the different physical models for numerical simulation of photon, positron, and electron transport through various materials.

The application of MOSFETs as detectors or device components in pulse power technique requires an investigation of their characteristics in radiation fields. Computing possibilities of the renowned programs FOTELP and PENELOPE for determining the energy deposited in MOISFET structure and dose distribution within microscopic dimensions of the dosimeter sensitive volume were presented in this paper. Based on the obtained results, qualitative conclusions were drawn about the values of energy deposited in different material zones having various dimensions. The difference between the two codes used for calculations in materials physics and semiconductor technics, basically originates from the different physical models for numerical simulation of photon, positron, and electron transport through various materials.

This paper aims to find the possibility of stabilizing the gas-filled surge arresters (GFSA) static working point in gamma- and X-radiation fields by an appropriate choice of constructive parameters. The observed effects on Some commercial components have been compared to the originally developed GFSA model with the aim of improving the characteristics of the commercial components. The type of noble gas, the pressure in the gas chamber, the inter-electrode gap value, the electrode material, and the manner of electrode surface processing are used as variable parameters. The obtained results are significant for a better understanding of the prebreakdown effects in gases at low pressures, but also have practical importance for the manufacturer of GFSAs.

The application of MOSFETs as detectors or device components in pulse power technique requires an investigation of their characteristics in radiation fields. Computing possibilities of the renowned programs FOTELP and PENELOPE for determining the energy deposited in MOISFET structure and dose distribution within microscopic dimensions of the dosimeter sensitive volume were presented in this paper. Based on the obtained results, qualitative conclusions were drawn about the values of energy deposited in different material zones having various dimensions. The difference between the two codes used for calculations in materials physics and semiconductor technics, basically originates from the different physical models for numerical simulation of photon, positron, and electron transport through various materials.

The application of MOSFETs as detectors or device components in pulse power technique requires an investigation of their characteristics in radiation fields. Computing possibilities of the renowned programs FOTELP and PENELOPE for determining the energy deposited in MOISFET structure and dose distribution within microscopic dimensions of the dosimeter sensitive volume were presented in this paper. Based on the obtained results, qualitative conclusions were drawn about the values of energy deposited in different material zones having various dimensions. The difference between the two codes used for calculations in materials physics and semiconductor technics, basically originates from the different physical models for numerical simulation of photon, positron, and electron transport through various materials.

The connection between nonhomogeneities of the electric field and the value of the breakdown voltage [direct current (dc), pulls] in gases (N-2, SF6) under low pressure and small inter-electrode gap was investigated in this paper. The obtained. results show that the values of. the breakdown voltages for nonhomogenous fields are considerably higher than the values for homogenous fields. It was also established that there is some disagreement between experimentally and theoretically (numerically) obtained values of the do breakdown voltages for nonhomogenous fields. These results could be explained by the small distance effect and by the combination of the gas and vacuum breakdown mechanisms.

The aim of this paper is to discuss the area left of the Paschen minimum, i.e., the area where the anomalous Paschen effect occurs. The experimental results and numerical simulation suggest a slightly different explanation of the anomalous Paschen effect. That is to say, that the anomalous Paschen effect is the result of the breakdown in a nonhomogenous electric field (edge electrode lines).

The aim of this paper is to present the influence of electrode system parameters on electrical breakdown of gas (electrode effect) with the purpose to improve the gas-filled surge arresters (GFSAs) protective characteristics with the most optimal way. The influence of the electrode parameters on the pulse shape characteristics is examined. As variable parameters, the electrode material and the manner of electrode surface processing are used. The originally developed GFSA model with a composite electrode system enables a high degree of over-voltage protection without environmental contamination.

The aim of this paper is to present the influence of electrode system parameters on electrical breakdown of gas (electrode effect) with the purpose to improve the gas-filled surge arresters (GFSAs) protective characteristics with the most optimal way. The influence of the electrode parameters on the pulse shape characteristics is examined. As variable parameters, the electrode material and the manner of electrode surface processing are used. The originally developed GFSA model with a composite electrode system enables a high degree of over-voltage protection without environmental contamination.

In this paper, we present temperature stability investigations of different overvoltage protection components employed in low-voltage applications. The following components have been examined: transient suppresser diodes, metal-oxide varistors (MOVs), gas-filled surge arresters (GFSAs), and polycarbonate capacitors. The aim of the research presented here is to identify the effectiveness of the overvoltage protection as a function of temperature. Experimental results,show that GFSAs have rather stabile operational characteristics in a wide temperature range (from -90degreesC to +210degreesC). As for MOVs they exhibit certain improvement of their protective characteristics at higher temperatures. Experimental results are backed tip by I theoretical explanations.

This paper presents an alternative approach aimed toward improvement of protective characteristics of gas-filled surge arresters (GFSA). Although so far GFSA with built-in radioactive sources proved to have superior protective characteristics, environmental concerns often challenge functional benefits. Experimental results show that a hollow cathode used in GFSA (no radioactive sources), offers significant improvement of protective characteristics as compared to classical designs. A number of theoretical predictions and conclusions are confirmed experimentally.

In this paper, we present temperature stability investigations of different overvoltage protection components employed in low-voltage applications. The following components have been examined: transient suppresser diodes, metal-oxide varistors (MOVs), gas-filled surge arresters (GFSAs), and polycarbonate capacitors. The aim of the research presented here is to identify the effectiveness of the overvoltage protection as a function of temperature. Experimental results,show that GFSAs have rather stabile operational characteristics in a wide temperature range (from -90degreesC to +210degreesC). As for MOVs they exhibit certain improvement of their protective characteristics at higher temperatures. Experimental results are backed tip by I theoretical explanations.

This paper presents an alternative approach aimed toward improvement of protective characteristics of gas-filled surge arresters (GFSA). Although so far GFSA with built-in radioactive sources proved to have superior protective characteristics, environmental concerns often challenge functional benefits. Experimental results show that a hollow cathode used in GFSA (no radioactive sources), offers significant improvement of protective characteristics as compared to classical designs. A number of theoretical predictions and conclusions are confirmed experimentally.

The aim of this paper is to determine how to improve the protective characteristics of gas filled surge arresters (GFSA) on the best way. In this order there were big number of examinations of construction factors influence on following GFSA characteristics: 1) static breakdown voltage, 2) dynamic breakdown voltage, 3) volt-second characteristic. Influence of radiation sources close to GFSA electrodes is one very important construction factor. In GFSA model used in this research are built in alpha (241Am) and beta(90Sr) sources, respectively. During examination due to detail analysis influence of radiation sources on GFSA characteristics were changed type of gas and gas pressure in chamber. Also, we presented an alternative method for improvement of GFSA protective characteristic without the use of radioactive sources. With the application of hollow cathode improvement of protective characteristic is obtained. On the base of experimental results we can conclude that built in radioactive sources significantly improve the protective characteristics of GFSA. This is especially obvious in decreasing of response time more then three times e.g. from 100 ns to 30 ns. On the lower pressure the alfa emitters application is more useful and on the higher pressure the beta emitters application is more useful because of the greater cross section for ionization by beta particles. Hollow cathode method is less efficient then the radioactive filling method, but also less risk for the environment. We believe that the future prospects should be to investigate the possibility of combined use of short-living radioactive isotope and hollow cathode effect. The measuring methodology was based on the computer controlled high quality instrumentation and statistics experiment organization. This approach assures the high accuracy, reliability and repeatability of performed measurement.