Moleküldissoziation durch hohe elektrische Felder

1964 ◽  
Vol 19 (1) ◽  
pp. 71-83 ◽  
Author(s):  
H. D. Beckey
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Charge Ratio ◽  
Mass Spectrometers ◽  
Basic Model ◽  
Internal Interaction ◽  
High Electric Fields ◽  
Very High ◽  
Field Dissociation ◽  
Positively Charged

It has been shown by different experiments using field ion mass spectrometers that molecules may be dissociated by very high electric fields (several 107 - 108 V/cm) immediately after field ionization. The large variety of field dissociation processes observed in field ion mass spectrometers is treated systematically. This is done by assuming a basic model underlying the effect of field dissociation. The rules derived from the model are confirmed experimentally by the field ion mass spectra of homologous series of organic substances.After derivation of the model it is shown that field dissociation of organic ions is dependent on factors such as: Charge distribution in the molecule rearranged by the electric field, interaction of the positively charged parts of the molecule with the external electric field, internal interaction of the field dissociating parts of the molecule.Each of these main factors in turn is dependent on further factors which will be discussed, the most important ones being the mass to charge ratio and the electronic structure of both the field ionized molecule and the subsequently formed fragments.

Effect of a High Electric Field on the Thermal and Phase Change Characteristics of an Impacting Drop

2019 ◽  
Author(s):  
Abhishek Basavanna ◽  
Prajakta Khapekar ◽  
Navdeep Singh Dhillon
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Phase Change ◽  
Electric Fields ◽  
High Speed ◽  
Impact Behavior ◽  
Liquid Drops ◽  
Active Interest ◽  
Post Impact ◽  
High Electric Fields

Abstract The effect of applied electric fields on the behavior of liquids and their interaction with solid surfaces has been a topic of active interest for many decades. This has important implications in phase change heat transfer processes such as evaporation, boiling, and condensation. Although the effect of low to moderate voltages has been studied, there is a need to explore the interaction of high electric fields with liquid drops and bubbles, and their effect on heat transfer and phase change. In this study, we employ a high speed optical camera to study the dynamics of a liquid drop impacting a hot substrate under the application of high electric fields. Experimental results indicate a significant change in the pre- and post-impact behavior of the drop. Prior to impact, the applied electric field elongates the drop in the direction of the electric field. Post-impact, the recoil phase of the drop is significantly affected by charging effects. Further, a significant amount of micro-droplet ejection is observed with an increase in the applied voltage.

scholarly journals Nanosecond air breakdown parameters for electron and microwave beam propagation

1988 ◽  
Vol 6 (1) ◽  
pp. 105-117 ◽  
Author(s):  
A. W. Ali
Keyword(s):  
Electric Fields ◽  
Drift Velocity ◽  
Collision Frequency ◽  
Short Pulse ◽  
Microwave Beam ◽  
Avalanche Ionization ◽  
Air Breakdown ◽  
High Electric Fields ◽  
Ionization Frequency ◽  
Very High

Air breakdown by avalanche ionization plays an important role in the electron beam and microwave propagations. For high electric fields and short pulse applications one needs avalanche ionization parameters for modeling and scaling of experimental devices. However, the breakdown parameters, i.e., the ionization frequency vs E/p (volt. cm−1. Torr−1) in air is uncertain for very high values of E/P. We review the experimental data for the electron drift velocity, the Townsend ionization coefficient in N2 and O2 and develop the ionization frequency and the collision frequency for momentum transfer in air. We construct the E/p vs Pτ diagram and show that our results are in better agreement with the most recent short pulse air breakdown experiments, compared to those predicted by the expression of Felsenthal & Proud (1965). This is because they extrapolate an expression for the drift velocity, linear in E/p, to high values of E/p. Experimentally the drift velocity varies as (E/p)½ in the region of E/p > 100.

OBIC Analysis of Different Edge Terminations of Planar 1.6 kV 4H-SiC Diodes

2007 ◽  
Vol 556-557 ◽  
pp. 1007-1010 ◽  
Author(s):  
Christophe Raynaud ◽  
Daniel Loup ◽  
Phillippe Godignon ◽  
Raul Perez Rodriguez ◽  
Dominique Tournier ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Breakdown Voltage ◽  
High Voltage ◽  
Semiconductor Devices ◽  
Optical Beam ◽  
Induced Current ◽  
Bipolar Diodes ◽  
High Electric Fields ◽  
Optical Beam Induced Current

High voltage SiC semiconductor devices have been successfully fabricated and some of them are commercially available [1]. To achieve experimental breakdown voltage values as close as possible to the theoretical value, i.e. value of the theoretical semi-infinite diode, it is necessary to protect the periphery of the devices against premature breakdown due to locally high electric fields. Mesa structures and junction termination extension (JTE) as well as guard rings, and combinations of these techniques, have been successfully employed. Each of them has particular drawbacks. Especially, JTE are difficult to optimize in terms of impurity dose to implant, as well as in terms of geometric dimensions. This paper is a study of the spreading of the electric field at the edge of bipolar diodes protected by JTE and field rings, by optical beam induced current.

Electron velocity in Si and GaAs at very high electric fields

1980 ◽  
Vol 37 (9) ◽  
pp. 797-798 ◽  
Author(s):  
P. M. Smith ◽  
M. Inoue ◽  
Jeffrey Frey
Keyword(s):  
Electric Fields ◽  
Electron Velocity ◽  
High Electric Fields ◽  
Very High

scholarly journals Electric field and infrared radiation in the troposphere before earthquakes

2011 ◽  
Vol 11 (12) ◽  
pp. 3125-3133 ◽  
Author(s):  
V. A. Liperovsky ◽  
C.-V. Meister ◽  
V. V. Mikhailin ◽  
V. V. Bogdanov ◽  
P. M. Umarkhodgaev ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Force Balance ◽  
Earthquake Preparation ◽  
Charged Aerosols ◽  
Seismic Shock ◽  
Physical Effects ◽  
Infrared Emissions ◽  
Near Future ◽  
Positively Charged

Abstract. Some years ago, a model of the generation of local electric fields in the atmosphere a few days before earthquakes and up to a few days after the seismic shock was proposed. In the model, the generation of the electric fields occurs because of an increased ionisation intensity of the atmosphere in the presence of aerosols. The generation of the electric field is the result of the fact that the larger aerosols, which are mainly negatively charged, have a larger velocity of gravitational precipitation than the smaller, which are mainly positively charged aerosols. The ionisation in such atmospheric regions is caused by radon, the concentration of which increases in earthquake preparation regions. The formation of mosaic-likely distributed areas of electric fields with intensities of 3 × 102 – 105 Vm−1 and, on the other hand, large areas with increased electrical conductivity cause a series of physical effects, e.g. the occurrence of infrared emissions with a specific spectrum, which may be studied using earth-based, atmospheric and satellite observations. In the present paper, the model of the generation of local electric fields is further developed, improving the description of the force balance on the aerosols in the atmosphere. A recently proposed laboratory experiment is briefly discussed, which is carried out to prove the theoretically predicted intensification of infrared emissions some hours-days before earthquakes. Besides the experiment described, it will be operated on Kamchatka in the near future to scan mosaic-likely distributed regions of electric fields in the atmosphere during earthquake preparation times.

Calculations of Some Transport Coefficients in Simple Semiconductors at Low Temperatures and High Electric Fields

1971 ◽  
Vol 49 (7) ◽  
pp. 876-880 ◽  
Author(s):  
Jyoti Kamal ◽  
Satish Sharma
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Low Temperatures ◽  
Transport Coefficients ◽  
Drift Mobility ◽  
Temperature Dependent ◽  
Hall Constant ◽  
The Difference ◽  
High Electric Fields ◽  
Model Semiconductor

In this paper the authors have calculated Hall mobility, drift mobility, and Hall constant for a non-degenerate simple model semiconductor at low temperatures for an arbitrary electric field strength. Following Paranjape the modified distribution of phonons has been taken into account. The difference between the calculations of transport coefficients made by taking into account the modified phonon distribution and by not taking it into account is quite appreciable at high electric field. Calculations also show that for Ne = 1016/cm3 the mobility of electrons remains temperature dependent.

scholarly journals Reducing leakage current and dielectric losses of electroactive polymers through electro-annealing for high-voltage actuation

RSC Advances ◽  
2019 ◽  
Vol 9 (23) ◽  
pp. 12823-12835 ◽  
Author(s):  
Francesco Pedroli ◽  
Alessio Marrani ◽  
Minh-Quyen Le ◽  
Olivier Sanseau ◽  
Pierre-Jean Cottinet ◽  
...  
Keyword(s):  
Leakage Current ◽  
Electric Fields ◽  
High Voltage ◽  
Electroactive Polymers ◽  
Dielectric Losses ◽  
High Electric Fields ◽  
Very High

The electro-annealed polymer, the E-TH sample, shows a reduction in leakage current of 80% for very high electric fields.

Sign in / Sign up

Export Citation Format

Share Document