scholarly journals Analisis Karakteristik Fenomena Pre-Breakdown Voltage Berbasis Pengujian pada Media Isolasi Minyak

2018 ◽  
Vol 16 (3) ◽  
pp. 128
Author(s):  
I Made Yulistya Negara ◽  
Daniar Fahmi ◽  
Dimas Anton Asfani ◽  
Dwi Krisna Cahyaningrum
Keyword(s):  
High Resolution ◽  
Breakdown Voltage ◽  
High Voltage ◽  
Dielectric Breakdown ◽  
Laboratory Scale ◽  
Excitation Voltage ◽  
Measured Current ◽  
Breakdown Phenomenon ◽  
Dielectric Degradation

Pre-breakdown voltage is a phenomenon of dielectric breakdown affecting insulation’s performance. The faster pre-breakdown voltage of insulation, the more significant its dielectric degradation. In this paper, pre-breakdown voltage in oil insulation was investigated by using DC high voltage in laboratory scale. Under testing, the streamer development was recorded by using a high-resolution camera. The measured current was synchronized with an image that was picked up during the oil insulation testing. By this experiment, the characteristics of the current in phenomenon pre-breakdown voltage at oil insulation was studied. The results showed that the measured current of pre-breakdown phenomenon in oil insulation under 28 kV to 30 kV excitation voltage is in a range 100 mA - 150 mA.

scholarly journals Impulse Breakdown Characteristics of Main Gap in the Presence of a Local Discharge

2019 ◽  
Vol 6 (2) ◽  
pp. 413-423
Author(s):  
Abderrahmane Settaouti
Keyword(s):  
Breakdown Voltage ◽  
Electric Discharge ◽  
High Voltage ◽  
Discharge Channel ◽  
Dielectric Breakdown ◽  
Metallic Electrode ◽  
Factors Affecting ◽  
Electrode Location ◽  
The Third ◽  
Breakdown Mechanism

The characteristics of impulse breakdown voltages and the influence of the position of third electrode in air gap are investigated experimentally to study the parameters influencing the breakdown voltage in the presence of metallic objects around the high voltage power apparatus with air insulation. Experimental results show that the factors affecting the breakdown voltage are the shape and the size of the grounded electrode, the third metallic electrode location and the gap length. A comparison between negative and positive polarities of the applied voltages indicates an important influence of the polarity in the dielectric breakdown mechanism. The possible mechanism by which the local electric discharge initiates the main dielectric breakdown seems to be the high electric field around the local discharge channel and the streamers protruding from its surface.

Alternative approaches to ultra-high resolution imaging

1991 ◽  
Vol 49 ◽  
pp. 650-651
Author(s):  
J.M. Cowley
Keyword(s):  
High Resolution ◽  
High Voltage ◽  
High Resolution Electron Microscopy ◽  
Crystal Defects ◽  
High Resolution Imaging ◽  
General Applicability ◽  
Resolution Electron ◽  
Radiation Resistant ◽  
Resolution Imaging ◽  
Alternative Approaches

By extrapolation of past experience, it would seem that the future of ultra-high resolution electron microscopy rests with the advances of electron optical engineering that are improving the instrumental stability of high voltage microscopes to achieve the theoretical resolutions of 1Å or better at 1MeV or higher energies. While these high voltage instruments will undoubtedly produce valuable results on chosen specimens, their general applicability has been questioned on the basis of the excessive radiation damage effects which may significantly modify the detailed structures of crystal defects within even the most radiation resistant materials in a period of a few seconds. Other considerations such as those of cost and convenience of use add to the inducement to consider seriously the possibilities for alternative approaches to the achievement of comparable resolutions.

“High Resolution High Voltage Electron Microscopy”

1968 ◽  
Vol 26 ◽  
pp. 326-327
Author(s):  
Benjamin M. Siegel
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Voltage ◽  
Full Potential ◽  
Contrast Imaging ◽  
High Voltage Electron Microscopy ◽  
Low Contrast ◽  
Voltage Electron ◽  
Critical Areas ◽  
High Voltage Electron

The potential advantages of high voltage electron microscopy for extending the limits of resolution and contrast in imaging low contrast objects, such as biomolecular specimens, is very great. The results of computations will be presented showing that at accelerating voltages of 500-1000 kV it should be possible to achieve spacial resolutions of 1 to 1.5 Å and using phase contrast imaging achieve adequate image contrast to observe single atoms of low atomic number.The practical problems associated with the design and utilization of the high voltage instrument are, optimistically, within the range of competence of the state of the art. However, there are some extremely important and critical areas to be systematically investigated before we have achieved this competence. The basic electron optics of the column required is well understood, but before the full potential of an instrument capable of resolutions of better than 1.5 Å are realized some very careful development work will be required. Of great importance for the actual achievement of high resolution with a high voltage electron microscope is the fundamental limitation set by the characteristics of the high voltage electron beam that can be obtained from the accelerator column.

“Getting High Resolution Out of A High Voltage Microscope”

1980 ◽  
Vol 38 ◽  
pp. 822-825
Author(s):  
David J. Smith
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Voltage ◽  
Theoretical Limit ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Technological Advances ◽  
Potential Improvement ◽  
Lower Voltage

The initial attractions of the high voltage electron microscope (HVEM) stemmed mainly from the possibility of considerable increases in electron penetration through thick specimens compared with conventional 100KV microscopes, although the potential improvement in resolution associated with the decrease in election wavelength had been fully appreciated for many years (eg. Cosslett, 1946)1, even if not realizable in practice. Subsequent technological advances enabled the performance of lower voltage machines to be brought closer to the theoretical limit, to be followed in turn by more recent projects which have been successful, eventually, in achieving even higher resolution with dedicated higher voltage instruments such as those at Kyoto (500KV)2, Munich (400KV)3, Ibaraki (1250KV)4 and Cambridge (600KV)5. It does not necessarily follow however that the performance of journal high voltage microscopes can be easily upgraded, retrospectively, to the same level, as will be discussed in detail below.

scholarly journals High-Resolution Photoabsorption Spectrum of Cs+ (5p61So + 5p5ns, nd) Between 504A and 600A using a Laser Ionized Cs Vapor Column

1984 ◽  
Vol 86 ◽  
pp. 124-124
Author(s):  
T.J. McIlrath ◽  
V. Kaufman ◽  
J. Sugar ◽  
W.T. Hill ◽  
D. Cooper
Keyword(s):  
High Resolution ◽  
Laser Pulse ◽  
High Voltage ◽  
Power Output ◽  
Random Phase ◽  
Grazing Incidence ◽  
Fano Resonances ◽  
Line Shapes ◽  
Phase Calculation ◽  
Photoabsorption Spectrum

Rapid ionization of Cs vapor in a heat pipe at 0.05 torr was achieved by pumping the 6s 2S½ – 7p 2P½ transition (f=0.007)1 with a flash-pumped dye laser at 4593.2A and I MW power output. Photoabsorptian initiated at the end of the laser pulse(≃ 0.5/s) showed the 5p5ns and nd series below and above the 5p52P3/2 threshold at 535.4A. Broad Beutler - Fano resonances appeared in the d series above threshold. The spectrum was recorded photographically on a 10.7m grazing incidence spectrograph using a continuum background generated by a BRV high-voltage spark source with a uranium anode. We will compare the line-shapes and the quantum defect (Lu-Fano2) plot with the predictions of a relativistic random phase calculation.

On the Breakdown Voltage Temperature Dependence of High-Voltage Power Diode Passivated with Diamond-Like Carbon

2021 ◽  
Author(s):  
Luigi Balestra ◽  
Susanna Reggiani ◽  
Antonio Gnudi ◽  
Elena Gnani ◽  
Jagoda Dobrzynska ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Breakdown Voltage ◽  
High Voltage ◽  
Diamond Like Carbon ◽  
Power Diode

scholarly journals Design of a Low on Resistance High Voltage (120V) Novel 3D NLDMOS with Side Isolation Based on 0.35um BCD Process Technology

2018 ◽  
Vol 201 ◽  
pp. 02004
Author(s):  
Shao-Ming Yang ◽  
Gene Sheu ◽  
Tzu Chieh Lee ◽  
Ting Yao Chien ◽  
Chieh Chih Wu ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
High Voltage ◽  
High Performance ◽  
Power Device ◽  
Simulation Tool ◽  
Process Technology ◽  
Surface Field ◽  
Kirk Effect ◽  
Tcad Simulation ◽  
Reduced Surface

High performance power device is necessary for BCD power device. In this paper, we used 3D Synopsis TCAD simulation tool Sentaurus to develop 120V device and successfully simulated. We implemented in a conventional 0.35um BCDMOS process to present of a novel high side 120V LDMOS have reduced surface field (RESURF) and Liner p-top structure with side isolation technology. The device has been research to achieve a benchmark specific on-resistance of 189 mΩ-mm2 while maintaining horizontal breakdown voltage and vertical isolation voltage both to target breakdown voltage of 120V. In ESOA, we also proposed a better performance of both device without kirk effect.

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