scholarly journals The glow duration time influence on the ionization rate detected in the diodes filled with noble gases on mbar pressures

2003 ◽  
Vol 2 (5) ◽  
pp. 259-267 ◽  
Author(s):  
Olivera Stepanovic ◽  
Miodrag Radovic ◽  
Cedomir Maluckov
Keyword(s):  
Electrical Breakdown ◽  
Measuring Method ◽  
Stationary Regime ◽  
Ionization Rate ◽  
Relaxation Period ◽  
Breakdown Time ◽  
Duration Time ◽  
Current Duration ◽  
Helium Neon ◽  
Ionization Rates

The results of the glow current duration time (glowing-time) influence on the ionization rate detected in the gas filled diodes are presented. The electrical breakdown was detected as the minimal current impulse. After that diode glow from the minimal glowing-time (10-3 s), up to the maximal 103 s which overlap the time of the stationary regime formation in the gas diode tube. The diodes were with volumes of 300 cm3, but with a diode gap volume of about 1 cm3 and filled with helium, neon, argon or krypton, at the pressures of the order of mbar. The ionization rates were detected as the residual ionization after the glowing was interrupted, using the electrical breakdown time delay measuring method. The influence of the gap distance stationary current values and the relaxation period were also investigated. The result shows that the stationary regime in such a gas diode is established after the glowing time of 1-3 s, although the breakdown formative times were smaller then 1 ms.

Tunneling Ionization Study of Linear Molecules in Strong-Field Laser Pulses

2020 ◽  
Vol 65 (1-2) ◽  
pp. 57-68
Author(s):  
V. Petrović ◽  
◽  
H. Delibašić ◽  
I. Petrović ◽  
◽  
...  
Keyword(s):  
Ionization Potential ◽  
Strong Field ◽  
Laser Pulses ◽  
Ionization Rate ◽  
Rate Equations ◽  
Tunneling Ionization ◽  
Low Intensity ◽  
Linear Molecules ◽  
Experimental Findings ◽  
Ionization Rates

"We theoretically studied photoionization of atoms and molecules in the frame of Perelomov-Popov-Terent’ev (PPT) and Ammosov-Delone-Krainov (ADK) theories. Strong-field single ionization of two diatomic molecules, N_2 and O_2, are studied and compared to Ar and Xe atoms, using an 800 nm Ti:sapphire laser in the 3×〖10〗^13 to 1×〖10〗^15 Wcm^(-2) intensity range. To eliminate disagreement between theoretical and experimental findings in a low intensity fields (~6×〖10〗^13 Wcm^(-2)), we considered the influence of shifted ionization potential. Including these effects in the ionization rates, we numerically solved rate equations in order to determine an expression for the ionization yields. The use of modified ionization potential showed that the ionization yields will actually decrease below values predicted by original (uncorrected) formulas. This paper will discuss the causes of this discrepancy. Keywords: tunneling ionization, ionization rate, ionization yield, molecules. "

scholarly journals On the Cosmic Ray-Induced Ionization Rate in Molecular Clouds

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Ararat G. Yeghikyan
Keyword(s):  
Molecular Clouds ◽  
Column Density ◽  
Cosmic Ray ◽  
Ionization Rate ◽  
Electronic Interaction ◽  
Absorbing Medium ◽  
Be Star ◽  
Good Agreement ◽  
Ionization Rates

The transformation of the energy dependence of the cosmic ray proton flux in the keV to GeV region is investigated theoretically when penetrating inside molecular clouds ( mag). The computations suggest that energy losses of the cosmic ray particles by interaction with the matter of the molecular cloud are principally caused by the inelastic (electronic) interaction potential; the transformed energy distribution of energetic protons is determined mainly by the column density of the absorbing medium. A cutoff of the cosmic ray spectrum inside clouds by their magnetic fields is also phenomenologically taken into account. This procedure allows a determination of environment-dependent ionization rates of molecular clouds. The theoretically predicted ionization rates are in good agreement with those derived from astronomical observations of absorption lines in the spectrum of the cloud connected with the Herbig Be star LkH 101.

HIGH FREQUENCY GAS DISCHARGE BREAKDOWN IN NEON

1952 ◽  
Vol 30 (5) ◽  
pp. 565-576 ◽  
Author(s):  
A. D. MacDonald ◽  
D. D. Betts
Keyword(s):  
Kinetic Theory ◽  
Electric Fields ◽  
Cross Sections ◽  
Electrical Breakdown ◽  
Ionization Rate ◽  
Gas Discharge ◽  
Distribution Functions ◽  
Boltzmann Transport ◽  
Discharge Data ◽  
Confluent Hypergeometric Functions

Electrical breakdown of neon at high frequencies has been treated theoretically on the basis of the Boltzmann transport equation. Exciting and ionizing collisions are accounted for as energy loss terms in the Boltzmann equation and measured values of the ionization efficiency are used in the integral determining the ionization rate. Electrons are lost to the discharge by diffusion. The equations are treated separately for the cases in which the collision frequency is much less than or much greater than the radian frequency of the applied field. The electron energy distribution functions are expressed in terms of Bessel functions, confluent hypergeometric functions, and simple exponentials. The ionization rate and the diffusion coefficient are calculated using these distribution functions in kinetic theory formulas, and combined with the diffusion equation to predict breakdown fields. The theoretically predicted fields are compared with experiment at 3000 Mc. per sec. The breakdown equations, calculated from kinetic theory and using no gas discharge data other than collision cross sections, predict breakdown electric fields within the limits of accuracy determined by these cross sections over a large range of experimental variables.

A statistical interpretation of the electrical breakdown of liquid dielectrics

1962 ◽  
Vol 269 (1337) ◽  
pp. 233-248 ◽  
Keyword(s):  
Short Duration ◽  
Electrical Breakdown ◽  
Short Pulse ◽  
Time Lag ◽  
Step Function ◽  
Time Lags ◽  
Statistical Interpretation ◽  
Breakdown Time ◽  
Formative Time ◽  
Statistical Time

Previous investigators, when measuring the electric strength of hydrocarbon liquids with short-duration rectangular pulses, have assumed that the statistical component of the breakdown time was insignificant com pared with the formative time. In the present investigation, however, the time to breakdown was measured directly by the use of step-function pulses, and clear evidence for a statistical time lag was found. The formative time was ~ 0.1 us, being less than that given by previous estimates. A statistical interpretation of short-pulse measurements is presented and this provides a consistent explanation of the results of other workers. Furthermore, by using an experimentally derived equation for the variation of the mean rate of breakdown f ( E ) with applied stress E , it has been shown that the form of the relationship between strength and pulse duration obtained by other workers agrees with that obtained by a statistical analysis. Experiments on air-saturated n -hexane with both short-duration and step-function pulses support the statistical ideas presented and indicate that electrode conditions are extremely important. It was found that strength and time to breakdown were affected by the number of breakdown measurements on a sample. Experiments with gas-free n -hexane and non-uniform fields have demonstrated the importance of air content when long duration pulses are used. It was found that, although the statistical time lag was insignificant, formative time lags as long as 10 ys occurred with a point cathode-sphere anode configuration.

Statistical analysis of the electrical breakdown time delay distributions in krypton

2006 ◽  
Vol 13 (8) ◽  
pp. 083502 ◽  
Author(s):  
Čedomir A. Maluckov ◽  
Jugoslav P. Karamarković ◽  
Miodrag K. Radović ◽  
Momčilo M. Pejović
Keyword(s):  
Statistical Analysis ◽  
Time Delay ◽  
Electrical Breakdown ◽  
Breakdown Time

The Rate of Ionization of Some Aromatic Hydrocarbons in Ethanolic Dimethyl Sulfoxide

1974 ◽  
Vol 52 (7) ◽  
pp. 1059-1061 ◽  
Author(s):  
A. Albagli ◽  
J. R. Jones ◽  
Ross Stewart
Keyword(s):  
Dimethyl Sulfoxide ◽  
Aromatic Hydrocarbons ◽  
Sodium Ethoxide ◽  
Ionization Rate ◽  
Unit Slope ◽  
Straight Line ◽  
Ionization Rates

The rates of detritiation of triphenlymethane, 9-phenylxanthene, fluorene, 9-ethylfluorene, 9-phenylfiuorene, and 2,3-benzofluorene have been measured in ethanolic dimethyl sulfoxide (DMSO) containing sodium ethoxide. When the logarithm of the ionization rate is plotted against the logarithm of the ionization rate of DMSO a straight line of near-to-unit slope is obtained in each case. There are significant differences, however, between relative ionization rates and equilibrium acidities.

The application of convolution-based statistical model on the electrical breakdown time delay distributions in neon

2004 ◽  
Vol 11 (11) ◽  
pp. 5328-5334 ◽  
Author(s):  
Čedomir A. Maluckov ◽  
Jugoslav P. Karamarković ◽  
Miodrag K. Radović ◽  
Momčilo M. Pejović
Keyword(s):  
Time Delay ◽  
Statistical Model ◽  
Electrical Breakdown ◽  
Breakdown Time

scholarly journals HEPPA III intercomparison experiment on electron precipitation impacts:  Estimated ionization rates during a geomagnetic active period in April 2010

2021 ◽  
Author(s):  
Hilde Nesse Tyssøy ◽  
Miriam Sinnhuber ◽  
Timo Asikainen ◽  
Stefan Bender ◽  
Mark A. Clilverd ◽  
...  
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Ionization Rate ◽  
Data Sets ◽  
Active Period ◽  
Medium Energy ◽  
Model Driven ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Ionization Rates

<p>Precipitating auroral and radiation belt electrons are considered an important part of the natural forcing of the climate system.  Recent studies suggest that this forcing is underestimated in current chemistry-climate models. The HEPPA III intercomparison experiment is a collective effort to address this point. Here, eight different estimates of medium energy electron (MEE) (>30 keV) ionization rates are assessed during a geomagnetic active period in April 2010.  The objective is to understand the potential uncertainty related to the MEE energy input. The ionization rates are all based on the Medium Energy Proton and Electron Detector (MEPED) on board the NOAA/POES and EUMETSAT/MetOp spacecraft series. However, different data handling, ionization rate calculations, and background atmospheres result in a wide range of mesospheric electron ionization rates. Although the eight data sets agree well in terms of the temporal variability, they differ by about an order of magnitude in ionization rate strength both during geomagnetic quiet and disturbed periods. The largest spread is found in the aftermath of the geomagnetic activity.  Furthermore, governed by different energy limits, the atmospheric penetration depth varies, and some differences related to latitudinal coverage are also evident. The mesospheric NO densities simulated with the Whole Atmospheric Community Climate Model driven by highest and lowest ionization rates differ by more than a factor of eight. In a follow-up study, the atmospheric responses are simulated in four chemistry-climate models and compared to satellite observations, considering both the model structure and the ionization forcing.</p>

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