JAP: Plasmas and Electrical Discharges

Schlieren imaging in a dielectric barrier discharge actuator for airflow control

A. Cristofolini, G. Neretti, F. Roveda, and C. A. Borghi
The operation of a surface dielectric barrier discharge actuator for airflow control has been experimentally investigated. The actuator is constituted by an electrode pair separated by a dielectric Teflon sheet. Several ac supply conditions have been utilized. An electrohydrodynamics interaction was ... [J. Appl. Phys. 111, 033302 (2012)] published Fri Feb 10, 2012.

Excitation wavelength dependence of water-window line emissions from boron-nitride laser-produced plasmas

M. Crank, S. S. Harilal, S. M. Hassan, and A. Hassanein
We investigated the effects of laser excitation wavelength on water-window emission lines of laser-produced boron-nitride plasmas. Plasmas are produced by focusing 1064 nm and harmonically generated 532 and 266 nm radiation from a Nd:YAG laser on BN target in vacuum. Soft x-ray emission lines in the ... [J. Appl. Phys. 111, 033301 (2012)] published Thu Feb 9, 2012.

Model for a transformer-coupled toroidal plasma source

Shahid Rauf, Ajit Balakrishna, Zhigang Chen, and Ken Collins
A two-dimensional fluid plasma model for a transformer-coupled toroidal plasma source is described. Ferrites are used in this device to improve the electromagnetic coupling between the primary coils carrying radio frequency (rf) current and a secondary plasma loop. Appropriate components of the Maxw ... [J. Appl. Phys. 111, 023306 (2012)] published Mon Jan 30, 2012.

Negative resistance phenomenon in dual-frequency capacitively coupled plasma-enhanced chemical vapor deposition system for photovoltaic manufacturing process

H. C. Kwon, Aman-ur-Rehman, I. H. Won, W. T. Park, and J. K. Lee
The validity of effective frequency concept is investigated for dual-frequency (DF) capacitively coupled plasma (CCP) discharges by using particle-in-cell/Monte Carlo collision simulations. This concept helps in analyzing DF CCP discharges in a fashion similar to single-frequency (SF) CCP discharges ... [J. Appl. Phys. 111, 023305 (2012)] published Thu Jan 26, 2012.

Spark discharge formation in an inhomogeneous electric field under conditions of runaway electron generation

Tao Shao (邵涛), Victor F. Tarasenko, Cheng Zhang (章程), Mikhail I. Lomaev, Dmitrii A. Sorokin et al.
In this article we report on work where the formation of a spark in nanosecond high-voltage discharges was studied in nitrogen, nitrogen-methane mixtures, and air at increased pressures under the conditions of runaway electron generation. Voltage pulses of amplitude ~90 and ~250 kV were applied to a ... [J. Appl. Phys. 111, 023304 (2012)] published Mon Jan 23, 2012.

Absorption spectroscopy measurements of argon metastable and resonant atom density in atmospheric pressure Ar-He surface-wave plasmas using a low pressure lamp

J. Munoz, J. Margot, and M. D. Calzada
The densities of metastable and resonant atom were measured in atmospheric pressure Ar-He surface-wave plasmas. Measurements were performed using an absorption spectroscopy method taking into account the Voigt profiles of the plasma lines. The density values of the argon P, P (metastable atoms) and ... [J. Appl. Phys. 111, 023303 (2012)] published Thu Jan 19, 2012.

Steady state discharge optimization in high-power impulse magnetron sputtering through the control of the magnetic field

J. Capek, M. Hala, O. Zabeida, J. E. Klemberg-Sapieha, and L. Martinu
High-power impulse magnetron sputtering (HiPIMS) is a pulsed DC sputtering technique utilizing high power density peaks of typically more than 100 W cm. The discharge operation at such elevated powers can be hindered by the magnetron configuration (size and magnetic field) and/or the target conditio ... [J. Appl. Phys. 111, 023301 (2012)] published Tue Jan 17, 2012.

Inducing phase locking of multiple oscillators beyond the Adler's condition

Wei Song, Jun Sun, Hao Shao, Ren-zhen Xiao, Chang-hua Chen et al.
To achieve phase locking of high power microwave oscillators on a relatively weak coupling strength, an inducing phase locking method is investigated. With an external signal injected from the end of relativistic backward wave oscillator, the frequency and phase of the output microwave is pulling in ... [J. Appl. Phys. 111, 023302 (2012)] published Tue Jan 17, 2012.

Numerical simulation of the pre-ionization processes during nanosecond-pulse discharge in nitrogen

D. Levko, V. Tz. Gurovich, and Ya. E. Krasik
The pre-ionization of nitrogen gas by high-voltage nanosecond pulse discharges is studied using one-dimensional particle-in-cell numerical simulations. The comparison between the various mechanisms of pre-ionization, i.e., by runaway electrons, x-rays, and ultraviolet radiation, is presented. It is ... [J. Appl. Phys. 111, 013306 (2012)] published Fri Jan 13, 2012.

Numerical simulation of runaway electrons generation in sulfur hexafluoride

D. Levko and Ya. E. Krasik
The results of the numerical simulation of the generation of runaway electrons in sulfur hexafluoride are presented. It is shown that the emission of the runaway electrons occurs from the cathode and its vicinity. The generation of these electrons is terminated because of the formation primarily by ... [J. Appl. Phys. 111, 013305 (2012)] published Thu Jan 12, 2012.

Effect of explosive emission on runaway electron generation

D. Levko, S. Yatom, V. Vekselman, J. Z. Gleizer, V. Tz. Gurovich et al.
The results of numerical simulations of the generation of runaway electrons in a nitrogen-filled coaxial diode with electron emission governed by field emission that transfers to explosive emission with a variable time delay are presented. It is shown that the time when the explosive emission turns ... [J. Appl. Phys. 111, 013304 (2012)] published Wed Jan 11, 2012.

X-band microwave generation caused by plasma-sheath instability

Y. Bliokh, J. Felsteiner, and Ya. Z. Slutsker
It is well known that oscillations at the electron plasma frequency may appear due to instability of the plasma sheath near a positively biased electrode immersed in plasma. This instability is caused by transit-time effects when electrons, collected by this electrode, pass through the sheath. Such ... [J. Appl. Phys. 111, 013302 (2012)] published Fri Jan 6, 2012.

Numerical simulations of runaway electron generation in pressurized gases

D. Levko, S. Yatom, V. Vekselman, J. Z. Gleizer, V. Tz. Gurovich et al.
The results of a numerical simulation of the generation of runaway electrons in pressurized nitrogen and helium gases are presented. It was shown that runaway electrons generation occurs in two stages. In the first stage, runaway electrons are composed of the electrons emitted by the cathode and pro ... [J. Appl. Phys. 111, 013303 (2012)] published Fri Jan 6, 2012.

Stability and properties of stationary state of one dimensional space charge limited current

A. Rokhlenko and J. L. Lebowitz
A linear stability analysis of the planar one dimensional space charge limited flow shows that the classical Child's solution is stable in time. Small perturbations of the flow are accompanied by high frequency oscillations that decay exponentially. These oscillations should appear when the flow reg ... [J. Appl. Phys. 111, 013301 (2012)] published Tue Jan 3, 2012.

Estimation of electron temperature and density of the decay plasma in a laser-assisted discharge plasma extreme ultraviolet source by using a modified Stark broadening method

Qiushi Zhu, Takahiro Muto, Junzaburo Yamada, Nozomu Kishi, Masato Watanabe et al.
In order to investigate the plasma expansion behaviors and the electrical recovery process after the maximum implosion in our tin fueled laser-assisted discharge plasma (LDP) 13.5 nm EUV source, we developed and evaluated a cost-efficient spectroscopic method to determine the electron temperature T ... [J. Appl. Phys. 110, 123302 (2011)] published Fri Dec 30, 2011.

Chemical bond modification in porous SiOCH films by H and H/N plasmas investigated by in situ infrared reflection absorption spectroscopy

Hiroshi Yamamoto, Kohei Asano, Kenji Ishikawa, Makoto Sekine, Hisataka Hayashi et al.
The modification of porous low-dielectric (low-k) SiOCH films by ashing plasma irradiation and subsequent exposure to air was investigated by in situ characterizations. Porous blanket SiOCH film surfaces were treated by a H or H/N plasma in a 100-MHz capacitively coupled plasma reactor. The individu ... [J. Appl. Phys. 110, 123301 (2011)] published Wed Dec 28, 2011.

Physics and modelling of microwave streamers at atmospheric pressure

Bhaskar Chaudhury, Jean-Pierre Boeuf, Guo-Qiang Zhu, and Olivier Pascal
Breakdown in a microwave field leads to the formation of plasmoids that expand in a direction parallel to the incident electric field and form microwave streamers. A two-dimensional model based on solutions of Maxwell's equations coupled with a quasineutral description of the plasma is used to study ... [J. Appl. Phys. 110, 113306 (2011)] published Mon Dec 12, 2011.

Effects of radiofrequency on dust particle dynamics in a plasma reactor

C. Horn, M. Davoudabadi, and B. Shotorban
A numerical solution is obtained for the electron and ion number densities, and electric field of an rf argon plasma in a low pressure reactor utilizing a one-dimensional model. These variables are used to solve the equations describing the dynamical behavior of a dust particle under the influence o ... [J. Appl. Phys. 110, 113305 (2011)] published Fri Dec 9, 2011.

Electron density measurements in a pulse-repetitive microwave discharge in air

M. Nikolic, S. Popovic, L. Vuskovic, G. C. Herring, and R. J. Exton
We have developed a technique for absolute measurements of electron density in pulse-repetitive microwave discharges in air. The technique is based on the time-resolved absolute intensity of a nitrogen spectral band belonging to the Second Positive System, the kinetic model and the detailed particle ... [J. Appl. Phys. 110, 113304 (2011)] published Wed Dec 7, 2011.

Langmuir probe diagnostics of electron energy distributions with optical emission spectroscopy in capacitively coupled rf discharge in nitrogen

E. Abdel-Fattah, M. Bazavan, and H. Sugai
Measurements with a rf compensated Langmuir probe and optical emission spectroscopy are carried out in capacitively coupled rf (13.56 MHz) pure nitrogen N discharges at fixed rf voltage over a wide range of pressure, 30 to 400 mTorr. The electron energy probability function (EEPF) measured below 100 ... [J. Appl. Phys. 110, 113303 (2011)] published Mon Dec 5, 2011.

Analysis of pulsed high-density HBr and Cl plasmas: Impact of the pulsing parameters on the radical densities

P. Bodart, M. Brihoum, G. Cunge, O. Joubert, and N. Sadeghi
The dynamic of charged particles in pulsed plasma is relatively well known since the 1990s. In contrast, works reporting on the impact of the plasma modulation frequency and duty cycle on the radicals' densities are scarce. In this work, we analyze the impact of these modulation parameters on the ra ... [J. Appl. Phys. 110, 113302 (2011)] published Fri Dec 2, 2011.