A one-dimensional kinetic theory of sheaths surrounding planar, electron-emitting surfaces is presented which accounts for plasma electrons lost to the surface and temperature emitted electrons. It shown that ratio electron significantly affects sheath potential when within an order magnitude temperature. The goes zero as equals temperature, can occur in afterglow rf some low-temperature sources. These results were validated by particle cell simulations. was tested making measurements a...

The pursuit of climate neutrality requires global systemic actions involving the use solutions aimed at reducing emissions. Changes must be introduced in all sectors affecting change, namely power engineering and district heating, construction, transport, industry, as well agriculture forestry. Analyzing structure final energy consumption EU by sector, it can stated that households account for 27% total consumption. Comprehensive are needed to increase efficiency buildings. aim this paper...

Measurements of the electrical resistivity thin copper films sputtered onto silicon dioxide, in real time, are reported. The is shown to strongly depend on film’s thickness for thicknesses below bulk mean free path (39 nm). Model fits combined with ex situ atomic force microscopy and transmission electron suggest that average grain size plays a dominant role during growth. Furthermore, observations made relaxation after growth (by sputtering) terminated, at room temperature. Both magnitude...

As the size of a positively biased electrode increases, nature interface formed between and host plasma undergoes transition from an electron-rich structure (electron sheath) to intermediate containing both ion electron rich regions (double layer) ultimately forms electron-depleted (ion sheath). In this study, measurements are performed further test how electron-collecting impacts discharge is immersed in. This accomplished using segmented disk in which individual segments individually...

What effect does a dielectric material surrounding small positively biased electrode have on the ion flow and sheath structure near electrode? Measurements of velocity distribution function plasma potential electrodes were made using laser-induced fluorescence an emissive probe. The results compared with 2D particle-in-cell simulations. Both measurements simulations showed that when positive was surrounded by material, ions accelerated toward to approximately 0.5 times sound speed before...

Spatially resolved electric fields in the sheath region near a metal–dielectric junction were measured radio-frequency-driven argon plasma. The determined by observing Stark shifted transitions to 13d[3∕2]1 Rydberg state laser-induced fluorescence-dip spectroscopy. Calibration of shifts for experimentally obtained separate apparatus. Maps illustrate that structure formed around depended on both surface material and configuration surface.

We discuss the application of laser-collisional induced fluorescence (LCIF) technique to produce two-dimensional maps both electron densities and temperatures in a helium plasma. A collisional–radiative model (CRM) is used describe evolution electronic states after laser excitation. generalizations time dependent results which are useful for simplifying data acquisition analysis. LCIF measurements performed plasma containing ranging from ~109 electrons cm−3 approaching 1011 comparison made...

Electron sheaths form near the surface of objects biased more positive than plasma potential, such as a Langmuir probe collecting electron saturation current. Generally, formation requires that electron-collecting area be sufficiently smaller ( times) ion-collecting area. They are commonly thought to local phenomena collect random thermal current, but do not otherwise perturb plasma. Here, using experiments on an electrode embedded in wall helium discharge, particle-in-cell simulations, and...

Temporal measurement of electron density, metastable-atom and reduced electric field are used to infer the dynamic behavior excitation rates describing electron-atom collision-induced in positive column a 1 Torr argon plasma by invoking plausible assumptions regarding shape energy distribution function performed Adams et al (2012 Phys. Plasmas 19 023510). These inferred predict 420.1 nm 419.8 emission ratio, which agree with experimental results when applicable. Thus observed ratio is...

We examine the effects of an externally applied magnetic field (0–150 G) on argon discharge generated capacitively at 13.56 MHz, in a Gaseous Electronics Conference reference cell. Dependence electrical characteristics are measured as functions field, rf power and pressure. At fixed voltage decreases with increasing field. Likewise, impedance is capacitive but becomes more resistive electron mobility limited by The impact found to diminish cyclotron frequency smaller than that collision...

A review of work centered on the utilization multi-dimensional optical diagnostics to study phenomena arising in radiofrequency plasma discharges is given. The range from passive techniques such as emission more active utilizing nanosecond lasers capable both high temporal and spatial resolution. In this review, emphasis placed observations that would have been difficult, if not impossible, make without use diagnostic techniques. Examples include sheath structure around an electrode...

The electron spatial distribution within a magnetic cusp and surrounding regions were measured noninvasively using laser-collision induced fluorescence. density profiles used to infer the plasma leak width. Leak widths found scale with hybrid gyroradius. scaling constant of proportionality was increase pressure, consistent theoretical predictions.

In this letter, we study Ta/parylene-F (PA–F) buried interfaces using x-ray photoelectron spectroscopy. We found that the Ta–F bond was formed at Ta/PA–F interface after depositing a layer of thin Ta film (<50 Å). For Ar+ or O2 plasma pretreated PA–F surface, in addition to bond, Ta–C observed metallization. The may be responsible for enhancement adhesion.

A dense plasma structure was observed to form near the extraction aperture of a helium RF cathode. Laser collision-induced fluorescence used generate two-dimensional spatial maps electron density and effective temperature within over range operating conditions. The reached densities nearly an order magnitude higher than surrounding bulk plasma. sharp change in at boundary suggests presence double layer sheath. Higher electrons were also periphery structure. Variations with extracted current...

Development and application of laser-collision induced fluorescence (LCIF) diagnostic technique is presented for the use interrogating argon plasma discharges. Key atomic states utilized LCIF method are identified. A simplified two-state collisional radiative model then used to establish scaling relations between LCIF, electron density, reduced electric fields (E/N). The procedure generate, detect calibrate in controlled environments discussed detail. emanating from an discharge densities...

Two-dimensional maps of the sheath electric fields formed around a metal-dielectric interface were measured in radio frequency (rf) argon plasma using laser-induced fluorescence-dip spectroscopy. Experimentally determined Stark shifts Rydberg 13d[3∕2]1 state used to quantify as functions rf cycle, voltage, and pressure. Both structure discharge characteristics region above electrode depend on conditions configuration surface. Dissimilar materials placed adjacent each other result with...

Plasma and sheath structure around a rf excited stepped electrode is investigated. Laser-induced fluorescence dip spectroscopy used to spatially resolve fields in an argon discharge while optical emission laser-induced are measure the spatial of surrounding for various conditions step-junction configurations. The presence step perturbs as well excitation region above step.

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation J. P. Sheehan, E. V. Barnat, B. R. Weatherford, I. D. Kaganovich, N. Hershkowitz; Emissive sheath measurements in the afterglow of a radio frequency plasma. Physics Plasmas 1 January 2014; 21 (1): 013510. https://doi.org/10.1063/1.4861888 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends...

This paper deals with the issue of air cooling in outdoor areas human habitation. An analysis parameters during summer season was carried out to determine thermal comfort zone for a part northern platform local station Rzeszow (Poland). The capacity required calculated using and heat gains vicinity research object. Ten potential air-cooling systems were proposed zones. differed terms equipment, primary energy source, medium, recipients. They divided into three categories: compressor,...

Nonuniformities in both sheath electric field and plasma excitation were observed around dissimilar metals placed on a rf electrode. Spatial maps of the obtained by laser-induced fluorescence-dip (LIF-dip) spectroscopy show that structure was function electrode metal. In addition to electric-field measurements, LIF, optical emission, Langmuir probe measurements nonuniform metals. The degree spatial extent discharge nonuniformities dependent conditions history metal surfaces.

The radial distribution of the measured voltage drop across a sheath formed between 300mm electrode and an argon plasma discharge is shown to depend on excitation radio frequency, under constant power pressure conditions. At lower frequency 13.56MHz, uniform electrode, while at higher frequencies 60 162MHz becomes radially nonuniform. magnitude spatial extent nonuniformity become greater with increasing frequency.

Laser-induced fluorescence-dip spectroscopy was used to measure the spatial distribution of electric fields around a biased cylindrical probe in an argon rf discharge. Two-dimensional maps field profiles were obtained as functions pressure, discharge power, bias, and phase cycle. Analysis radial dependence indicated that ion density decreased vicinity for all cases, contrary orbit motion limited regime typically employed Langmuir analysis. We also observed perturbation plasma by presence...

The spatial structure and temporal evolution of the electric fields in a sheath formed dual frequency, 300 mm capacitive argon discharge are measured as functions relative mixing between low frequency current high current. It is found that overall (potential across thickness sheath) dominated by lower component while (smaller) oscillations these quantities dictated higher component. Comparisons profiles made for Lieberman's Robiche et al model with particle cell calculation.

A retarding field analyzer is used to obtain a measure of the energy ions extracted from direct current discharge driven by low-frequency (100–100 kHz) asymmetrically pulsed bias. Measurements are made illustrate effects pulse’s shape (frequency and duty) on distribution in energies plasma. Ion distributions computed quasistatic treatment ion’s response measured wave form electrode. Comparisons between calculated ion demonstrate effectiveness technique calculate distribution. Expressions...

A one-dimensional model is used to describe the evolution of charged particles in a plasma sheath driven by an asymmetrically pulsed dc bias frequency range 100 kHz 10 MHz. The temporal-spatial obtained through simultaneous solution Poisson's equations, ionic fluid equations and Boltzmann treatment electrons. Calculations are performed demonstrate effects inertia restructuring have on temporal dependence current energy ions arriving at electrode. scale observed depend bulk density plasma....