Aug 2026· Al-Noor Journal of Engineering Management and Computer Science· 0 citations· 5 references
Abstract
This research investigated the effect of both the applied voltage and the anode area on the electrical and plasma properties of a DC glow discharge in low-pressure argon gas. The electrical properties included current-voltage (I-V) curves and Paschen's curves, while the plasma parameters included electron temperature and number density. The plasma was generated between two copper electrodes separated by a constant distance of (4 cm), using anodes of different diameters of (2, 4, 5, and 6 cm). The plasma was characterized by optical emission spectroscopy (OES), which was used to estimate the electron temperature (Te) and number density (ne). The experimental results showed that the discharge operates within an anomalous glow regime. Furthermore, decreasing the anode area led to a higher breakdown voltage required to initiate the discharge, while increasing the anode area resulted in higher spectral emission line intensity, electron temperature, and number density. When the anode diameter changed from (2-6) cm, the electron temperature ranged from (0.389-0.393) eV, while the electron density ranged from (3.26×10¹⁵ - 9.23×10¹⁵) cm⁻³. These results confirm the influential role of anode geometry in the distribution of the electric field and the processes of ionization and excitation, and thus in determining the electrical and plasma characteristics of the discharge.
The fabrication and experimental study of a nanoscale field-emission diode based on tantalum are described. The cathode and anode with an interelectrode gap were shaped using a focused ion beam in an SEM/FIB system. Current–voltage measurements were carried out in a pressure range from 10−6 mbar to atmospheric pressure. At pressures above 1 mbar, a sharp decrease in emission current was observed, which may be explained by the adsorption of residual atmosphere gases onto the cathode upon vacuum degradation and removal of the anode voltage, leading to a local change in the work function of the emission centers. At atmospheric pressure, cathode destruction was observed, presumably caused by a microplasma discharge and subsequent ion bombardment.
I. Evsikov, G. D. D. R. C. Memsec, B. V. Lobanov et al.· International Vacuum Nanoele...· 0 citations
The results of the experiments with potentially “clean” electrical discharge source of extreme ultraviolet (EUV) radiation with wavelength below 10 nm are presented. The operation of the source is based upon the use of the early stage of vacuum discharge with external triggering. The main feature of the stage under consideration is the presence of the voltage across the discharge gap. The phenomenon involves the acceleration of the electrons, emitted by trigger plasma under the action of the applied electrical field, evaporation, and finally, ionization of the anode material driven by the accelerated electrons. No plasma pinching and electrode melting take place. The operation of such a discharge as an EUV source was demonstrated in the spectral range 10–20 nm for 10 kV. A more advanced discharge circuit proposed in the present work made it possible to increase the working voltage from 10 to 34 kV. This step has allowed to operate at shorter wavelength regions. The use of rare earth metals (Nd, Sm, Tb) as anode materials allowed us to get radiation with spectral maxima at 8.3, 7.5, and 6.8 nm, respectively.
P. Antsiferov, L. Stepanov· Journal of Applied Physics· 0 citations
Laser-assisted spark switches are promising devices for generating fast and controllable electrical discharges in high-voltage systems. In this study, the characteristics of plasma generated by an excimer laser in a spark gap were investigated using optical emission spectroscopy and electrical diagnostics. Copper emission lines were analyzed using the Boltzmann plot method to determine the plasma temperature. The electron temperature was estimated to be approximately 25 167 K (≈2.17 eV). The spectroscopic analysis also included oxygen emission lines, with the O,I line near 480 nm exhibiting a typical full width at half-maximum of approximately 0.1 nm under the plasma conditions generated by the excimer laser. The breakdown behavior of the spark gap was analyzed using Paschen’s law. For an electrode gap of 3 mm at atmospheric pressure, the calculated breakdown voltage was approximately 8.7 kV, which is in good agreement with the experimental observations. Electrical measurements showed that laser irradiation significantly influenced the discharge dynamics by reducing the delay time and stabilizing the breakdown process. Plasma conductivity was evaluated using both macroscopic and microscopic approaches. The calculated macroscopic conductivity was 2059.37 S/m, whereas the microscopic conductivity derived from the plasma parameters was 2065.21 S/m. The close agreement between these values confirms the consistency of the theoretical models and the reliability of the experimentally determined plasma parameters. Overall, the results demonstrate that excimer laser irradiation effectively initiates and controls spark discharges while producing plasma conditions suitable for spectroscopic diagnostics.
Elsa Moghadasinejad, A. Dezfuli, N. Morshedian et al.· Journal of laser application...· 0 citations
This study analyses the physical and optical properties of jet plasma at atmospheric pressure (APPJ) using optical emission spectroscopy (OES), focusing on the effect of argon gas flow rate. The results show that increasing the gas flow rate from 2 to 4 litres/minute results in an increase in the spectral emission intensity due to increased ionisation within the plasma. Using the Boltzmann method, it was noted that the electron temperature decreased from 0.609 to 0.526 electron volts, while the electron density increased as the gas flow rate was increased. This reflects an altered relationship between ionisation and energy loss. With higher gas flow, the plasma becomes more concentrated, but its temperature decreases. In this case, it becomes more manageable, ideal for advanced use.
Sarah Faris Khaleel, K. Aadim· Iraqi Journal of Science· 0 citations
This study investigates the generation and detailed characterization of an Argon-based Atmospheric Pressure Plasma Jet (AAPPJ) through systematic electrical and optical diagnostics. Electrical measurements yielded an RMS voltage of 0.79 kV and an RMS current of 5.91 mA, corresponding to a power output of 4.64 W. Analysis of the voltage–current waveforms revealed non-linear discharge behavior indicative of complex plasma dynamics. Optical Emission Spectroscopy (OES) identified emission lines from neutral (Ar I) and singly ionized (Ar II) argon species. Using the Boltzmann plot method, electron excitation temperatures were estimated to be 0.274 eV (Ar I) and 0.302 eV (Ar II). The corresponding electron densities were calculated as 1.043 × 1012 cm−3 and 1.001 × 1013 cm−3 , respectively. These findings reveal electron densities in the order of 1012 cm−3–1013 cm−3 , consistent with typical atmospheric pressure plasma jets. The close agreement between the excitation temperatures suggests a relatively stable plasma operating under weak non-local thermodynamic equilibrium (non-LTE) conditions. Overall, the study highlights the importance of precise electrical and optical diagnostics in understanding the characteristics of plasma discharge
Shaleen Kumar Dhital, Bhesh Bahadur Thapa, R. B. Tyata· Journal of Sciences and Engi...· 0 citations
This research investigates the influence of cathode surface roughness on DC breakdown voltages and pre-discharge currents in pressurized synthetic air. A physics-based computational model is presented for predicting breakdown voltages in insulating gases under high-voltage stress. The model combines electron ionization and attachment processes along the discharge path to calculate the evolution of the primary electron avalanche. The model considers gas pressure, gap distance, electrode geometry and electric field distortions due to electron avalanches, and had been validated with a huge number of experimental breakdown measurement series with smooth electrode geometries in synthetic air. In the present work this model is extended to include the influence of electrode surface roughness on breakdown behavior. To accomplish this, cathodes with varying roughness levels were characterized using laser scanning microscopy and corresponding local field enhancements at the surfaces are calculated by numeric simulation. Those, locally non-uniform electric field distributions were used as input for the computational model to predict breakdown voltages. Finally, breakdown and pre-discharge measurements of sphere spark gaps with different electrode surfaces are presented and compared to the model predictions. Validations against these experiments at pressures up to 1.5 MPa show strong agreement between measured and calculated breakdown voltages. The results demonstrate that cathode surface features in the micrometer scale can significantly reduce the insulation strength of pressurized synthetic air and that the proposed model is able to predict this effect.
Tobias Köstner, Maximilian Kuhn, M. Rossner et al.· Electrical Insulation Confer...· 0 citations
