Emission Grid Research Articles

Electron beam generation with variable current amplitude during its pulse in a source with a grid plasma cathode

In electron sources with grid plasma cathodes, the boundary of the emission plasma is stabilized by a fine-structured grid, the cell size of which is comparable to the size of the Langmuir layer. The correct choice of the cell size of the emission grid allows to stabilize of the emission plasma boundary, reaching a wide range of the parameters adjustment of the generated electron beam with a weak dependence of these parameters on each other. Since the beam current amplitude is most often controlled by a proportional change of the discharge current in the plasma cathode, which allows to change the emission plasma concentration, this paper is investigated the possibility of generating the electron beam having variable amplitude by predicting the change in the discharge current amplitude during its pulse. The described advantage of plasma cathodes makes it possible to obtain electron beams with both a falling and a rising current amplitude of the beam during its pulse. The obtained regimes of electron beam generation open up new possibilities for using this source for both scientific and technological purposes.

A very-high resolution (20m) measurement-based dust emissions and dispersion modeling approach for the Oceano Dunes, California

This study shows the results from very high-resolution (20 m) dust emissions and transport simulations for the Oceano Dunes State Vehicular Recreation Area (ODSVRA), a coastal sand dune complex located in San Luis Obispo County, California. Field data from an enhanced observation period carried out in May–July 2013 helped estimate the emissions and flow conditions over the dune field. Emissions are based on a comprehensive emissions grid developed from in-situ measurements using the Portable In-Situ Wind ERosion Lab (PI-SWERL). PI-SWERL estimates the potential for a soil surface to produce PM10 dust emissions for a range of wind speeds. This approach provided a well-determined PM10 emissions field as a function of time and space. Wind and turbulence fields were estimated using the CALMET diagnostic meteorological model constrained with surface stations, upper air soundings, buoys, and the North American Reanalysis data. Hourly, three-dimensional wind flow and instability objective analysis fields were developed at 20 m resolution in order to consider the complex flow over realistic dune morphology, land use/land cover and terrain characteristics over and around the Oceano Dunes. The dust dispersion simulations were performed using a computationally efficient and vectorized Lagrangian Stochastic Particle Dispersion Model driven by the CALMET output and the PI-SWERL time-space variable emissions. The dispersion model is based on the Langevin formulation and includes the turbulent diffusion and stochastic particle motion (of millions of particles) in the inertial sub-range, and assuming particles as discrete units neglecting deposition. The model estimates diffusion of particles from an initial particle releases that scale according to the PI-SWERL time-variable emissions estimates. Results were then tested at two independent-downwind locations, with positive correlations for flow conditions (R2 = 0.89) and similar receptor PM10 concentrations (R2 = 0.85). Evaluations against those observations during mean flow conditions as well as for elevated dust events suggest that the model framework can capture the spatial and temporal characteristics of mean day-to-day and diurnal PM10 variability. In this study we describe the details of the model framework and its performance as well as its implementation to locate the dust sources that have the strongest impact in the receptor sites and to evaluate the impact of different dust reduction strategies used at the ODSVRA to mitigate PM10 at downwind receptors.

EDGAR v4.3.2 Global Atlas of the three major greenhouse gas emissions for the period 1970–2012

Abstract. The Emissions Database for Global Atmospheric Research (EDGAR) compiles anthropogenic emissions data for greenhouse gases (GHGs), and for multiple air pollutants, based on international statistics and emission factors. EDGAR data provide quantitative support for atmospheric modelling and for mitigation scenario and impact assessment analyses as well as for policy evaluation. The new version (v4.3.2) of the EDGAR emission inventory provides global estimates, broken down to IPCC-relevant source-sector levels, from 1970 (the year of the European Union's first Air Quality Directive) to 2012 (the end year of the first commitment period of the Kyoto Protocol, KP). Strengths of EDGAR v4.3.2 include global geo-coverage (226 countries), continuity in time, and comprehensiveness in activities. Emissions of multiple chemical compounds, GHGs as well as air pollutants, from relevant sources (fossil fuel activities but also, for example, fermentation processes in agricultural activities) are compiled following a bottom-up (BU), transparent and IPCC-compliant methodology. This paper describes EDGAR v4.3.2 developments with respect to three major long-lived GHGs (CO2, CH4, and N2O) derived from a wide range of human activities apart from the land-use, land-use change and forestry (LULUCF) sector and apart from savannah burning; a companion paper quantifies and discusses emissions of air pollutants. Detailed information is included for each of the IPCC-relevant source sectors, leading to global totals for 2010 (in the middle of the first KP commitment period) (with a 95 % confidence interval in parentheses): 33.6(±5.9) Pg CO2 yr−1, 0.34(±0.16) Pg CH4 yr−1, and 7.2(±3.7) Tg N2O yr−1. We provide uncertainty factors in emissions data for the different GHGs and for three different groups of countries: OECD countries of 1990, countries with economies in transition in 1990, and the remaining countries in development (the UNFCCC non-Annex I parties). We document trends for the major emitting countries together with the European Union in more detail, demonstrating that effects of fuel markets and financial instability have had greater impacts on GHG trends than effects of income or population. These data (https://doi.org/10.5281/zenodo.2658138, Janssens-Maenhout et al., 2019) are visualised with annual and monthly global emissions grid maps of 0.1∘×0.1∘ for each source sector.

Crop residue open field burning in Pakistan; multi-year high spatial resolution emission inventory for 2000–2014

Over recent years, crop residue burning has become a widely practiced agricultural activity in developing countries due to varying economic and social reasons. To estimate current pollution generation from crop residue burning in Pakistan, an emission inventory was developed based on district level crop production data from 2000 to 2014. Spatial distribution of quantified emissions was achieved by using MODIS Active Fire Data (MOD/MYD14A1) at 1-day temporal and 1 × km spatial resolutions. The fire occurrences were extracted over agricultural land using land cover data provided by European Space Agency/Climate Change Initiative (ESA/CCI) at 300 m spatial resolution for 2000 to 2014. Results show that CO emissions have increased by 40% at an average annual rate of 2.7% from 1.16 Tg in 2000 to 1.63 Tg in 2014 and increase in emissions of CO2, CH4, NMVOCS, N2O, NH3, SO2, NOx, PM2.5, PM10, OC and BC ranged between 37%, to 63% during same period. Spatially, CO emissions were more significant in districts of Punjab and Sindh provinces with intensive agricultural activities as compared to other areas of Pakistan with highest emission grids located in Muzaffargarh, Jafferabad, and Noushahro Feroze districts. Crop residue burning exhibited similar trend with highest emissions in June followed by February and November over 15-year period. The emissions for most of the considered pollutants were comparable to the limited previous studies available. Finally, the study conducted provides better understanding regarding spatial and temporal patterns of crop residue burning across Pakistan and can be utilized for air quality modeling and management with higher accuracy.

Gridded maps of geological methane emissions and their isotopic signature

Abstract. Methane (CH4) is a powerful greenhouse gas, whose natural and anthropogenic emissions contribute ∼20 % to global radiative forcing. Its atmospheric budget (sources and sinks), however, has large uncertainties. Inverse modelling, using atmospheric CH4 trends, spatial gradients and isotopic source signatures, has recently improved the major source estimates and their spatial–temporal variation. Nevertheless, isotopic data lack CH4 source representativeness for many sources, and their isotopic signatures are affected by incomplete knowledge of the spatial distribution of some sources, especially those related to fossil (radiocarbon-free) and microbial gas. This gap is particularly wide for geological CH4 (geo-CH4) seepage, i.e. the natural degassing of hydrocarbons from the Earth's crust. While geological seepage is widely considered a major source of atmospheric CH4, it has been largely neglected in 3-D inverse CH4 budget studies given the lack of detailed a priori gridded emission maps. Here, we report for the first time global gridded maps of geological CH4 sources, including emission and isotopic data. The 1∘×1∘ maps include the four main categories of natural geo-CH4 emission: (a) onshore hydrocarbon macro-seeps, including mud volcanoes, (b) submarine (offshore) seeps, (c) diffuse microseepage and (d) geothermal manifestations. An inventory of point sources and area sources was developed for each category, defining areal distribution (activity), CH4 fluxes (emission factors) and its stable C isotope composition (δ13C-CH4). These parameters were determined considering geological factors that control methane origin and seepage (e.g. petroleum fields, sedimentary basins, high heat flow regions, faults, seismicity). The global geo-source map reveals that the regions with the highest CH4 emissions are all located in the Northern Hemisphere, in North America, in the Caspian region, in Europe and in the East Siberian Arctic Shelf. The globally gridded CH4 emission estimate (37 Tg yr−1 exclusively based on data and modelling specifically targeted for gridding, and 43–50 Tg yr−1 when extrapolated to also account for onshore and submarine seeps with no location specific measurements available) is compatible with published ranges derived using top-down and bottom-up procedures. Improved activity and emission factor data allowed previously published mud volcanoes and microseepage emission estimates to be refined. The emission-weighted global mean δ13C-CH4 source signature of all geo-CH4 source categories is about −49 ‰. This value is significantly lower than those attributed so far in inverse studies to fossil fuel sources (−44 ‰) and geological seepage (−38 ‰). It is expected that using this updated, more 13C-depleted, isotopic signature in atmospheric modelling will increase the top-down estimate of the geological CH4 source. The geo-CH4 emission grid maps can now be used to improve atmospheric CH4 modelling, thereby improving the accuracy of the fossil fuel and microbial components. Grid csv (comma-separated values) files are available at https://doi.org/10.25925/4j3f-he27.

Hydrogen is essential for sustainability

Summary Sustainable energy conversion requires zero emissions of greenhouse gases and criteria pollutants using primary energy sources that the earth naturally replenishes quickly, like renewable resources. Solar and wind power conversion technologies have become cost effective recently, but challenges remain to manage electrical grid dynamics and to meet end-use requirements for energy dense fuels and chemicals. Renewable hydrogen provides the best opportunity for a zero emissions fuel and is the best feedstock for production of zero emission liquid fuels and some chemical and heat end-uses. Renewable hydrogen can be made at very high efficiency using electrolysis systems that are dynamically operated to complement renewable wind and solar power dynamics. Hydrogen can be stored within the existing natural gas system to provide low cost massive storage capacity that (1) could be sufficient to enable a 100% zero emissions grid; (2) has sufficient energy density for end-uses including heavy duty transport; (3) is a building block for zero emissions fertilizer and chemicals; and (4) enables sustainable primary energy in all sectors of the economy.

The reaction of arc discharge parameters to the selection of electrons from the emission plasma in an electron accelerator with a grid plasma cathode

In the electrode system of an electron source with a plasma cathode, which allows the generation of a pulse-periodic electron beam of a large cross section from vacuum to the atmosphere through the outlet foil window, investigations have been made of the effect of electron extraction from the emission plasma on the parameters of a low-pressure arc discharge in which this plasma is generated. The work of the plasma cathode in different modes of electron beam generation is compared, namely, with the use of both a wide-aperture two-electrode electron-optical system (EOS) characterized by high beam current losses on the ribs of the support grid and a multi-aperture two-electrode EOS, when a metal mask is installed on the emission mesh with a configuration of holes that repeats the configuration of the holes in the support grid, and the electron beam is a superposition of electron beamlets formed by separate emission structures, the plasma boundary of which is also stabilized by a fine-structure metal mesh. Under the experimental conditions, the selection of electrons from the emission plasma leads to an increase in the voltage in the interelectrode gap between the cathode and the hollow anode of the plasma emitter, whose “voltage-addition” depends on the conditions of generation of the emission plasma (pressure and type of working gas, the ratio of the anode area of the discharge to the emission area), the area of the emission structures and the cell size of the used emission grid.

Improvement of Thin Film Adhesion Due to Bombardment by Fast Argon Atoms

A new hollow cathode sputtering system is used for beam-assisted deposition of thin films on dielectric substrates. A copper target placed at the hollow cathode bottom is uniformly sputtered by argon ions from the glow discharge plasma filling the cathode. Through an emissive grid, sputtered copper atoms leave the cathode together with accelerated argon ions. On their way to the substrate, the ions—due to charge exchange collisions—turn into fast argon atoms bombarding the growing film. With increasing argon ion energy, continuous bombardment results in the film adhesion improvement and reduction of the deposition rate down to zero, at an energy of about 2 keV. The pulsed bombardment does not influence the film deposition rate, and results in a monotonic growth of the film adhesion up to 20 MPa when increasing the fast atom energy up to 10 keV.

Optimizing critical source control of five priority-regulatory trace elements from industrial wastewater in China: Implications for health management.

Anthropogenic emissions of toxic trace elements (TEs) have caused worldwide concern due to their adverse effects on human health and ecosystems. Based on a stochastic simulation of factors' probability distribution, we established a bottom-up model to estimate the amounts of five priority-regulatory TEs released to aquatic environments from industrial processes in China. Total TE emissions in China in 2010 were estimated at approximately 2.27 t of Hg, 310.09 t of As, 318.17 t of Pb, 79.72 t of Cd, and 1040.32 t of Cr. Raw chemicals, smelting, and mining were the leading sources of TE emissions. There are apparent regional differences in TE pollution. TE emissions are much higher in eastern and central China than in the western provinces and are higher in the south than in the north. This spatial distribution was characterized in detail by allocating the emissions to 10 km × 10 km grid cells. Furthermore, the risk control for the overall emission grid was optimized according to each cell's emission and risk rank. The results show that to control 80% of TE emissions from major sources, the number of top-priority control cells would be between 200 and 400, and less than 10% of the total population would be positively affected. Based on TE risk rankings, decreasing the population weighted risk would increase the number of controlled cells by a factor of 0.3-0.5, but the affected population would increase by a factor of 0.8-1.5. In this case, the adverse effects on people's health would be reduced significantly. Finally, an optimized strategy to control TE emissions is proposed in terms of a cost-benefit trade-off. The estimates in this paper can be used to help establish a regional TE inventory and cyclic simulation, and it can also play supporting roles in minimizing TE health risks and maximizing resilience.

Impact of Emissions, Meteorology and Grid Resolution on Changes in HMs and PAHs Concentrations between 2005 and 2010 in Italy

A dynamical evaluation of the Flexible Air quality Regional Model (FARM) system was conducted to assess its ability to predict changes in heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) concentrations over Italy between the years of 2005 and 2010. Several simulations were performed to relate variations in the PAHs and HMs concentrations to changes in the emission inventories, meteorology or grid resolution. The results generally indicate that these concentrations have decreased through the years and the magnitude of decrease is dependent on the specific chemical species. The changes in emissions have determined the major variations of all chemicals, whereas the meteorology has caused significant changes in the concentrations of reactive species, such as benzo[a]pyrene (BaP), in high-resolution simulations, especially over complex topography. The analyses also show that while the total emitted mass of pollutants is important, its geographical distribution is fundamental to estimating changes in concentration.

Optimizing the Spatial Resolution for Urban CO2 Flux Studies Using the Shannon Entropy

The ‘Hestia Project’ uses a bottom-up approach to quantify fossil fuel CO2 (FFCO2) emissions spatially at the building/street level and temporally at the hourly level. Hestia FFCO2 emissions are provided in the form of a group of sector-specific vector layers with point, line, and polygon sources to support carbon cycle science and climate policy. Application to carbon cycle science, in particular, requires regular gridded data in order to link surface carbon fluxes to atmospheric transport models. However, the heterogeneity and complexity of FFCO2 sources within regular grids is sensitive to spatial resolution. From the perspective of a data provider, we need to find a balance between resolution and data volume so that the gridded data product retains the maximum amount of information content while maintaining an efficient data volume. The Shannon entropy determines the minimum bits that are needed to encode an information source and can serve as a metric for the effective information content. In this paper, we present an analysis of the Shannon entropy of gridded FFCO2 emissions with varying resolutions in four Hestia study areas, and find: (1) the Shannon entropy increases with smaller grid resolution until it reaches a maximum value (the max-entropy resolution); (2) total emissions (the sum of several sector-specific emission fields) show a finer max-entropy resolution than each of the sector-specific fields; (3) the residential emissions show a finer max-entropy resolution than the commercial emissions; (4) the max-entropy resolution of the onroad emissions grid is closely correlated to the density of the road network. These findings suggest that the Shannon entropy can detect the information effectiveness of the spatial resolution of gridded FFCO2 emissions. Hence, the resolution-entropy relationship can be used to assist in determining an appropriate spatial resolution for urban CO2 flux studies. We conclude that the optimal spatial resolution for providing Hestia total FFCO2 emissions products is centered around 100 m, at which the FFCO2 emissions data can not only fully meet the requirement of urban flux integration, but also be effectively used in understanding the relationships between FFCO2 emissions and various social-economic variables at the U.S. census block group level.

Milling of Dielectric Ceramics by Fast Argon Atoms

A new method for dielectric materials milling has been developed. Instead of well-known ion milling used for metals the dielectrics were processed by broad beams of fast argon atoms. The fast atoms were produced due to charge exchange collisions of accelerated ions. Plasma emitter of the ions was generated in hollow cathode glow discharge. Emissive grid of a circular cross-section beam source consisted of six segments. Energy of the fast atoms ranged from 1 to 3 keV. The beam source was used for production of contoured grooves on flat surfaces of hard ceramic materials. On the surface of movable seal ring made of α-corundum were produced grooves with depth of 20±0.5 μm and roughness of Ra ≈ 0.4 µm. The rate of α-corundum etching amounted to 3 μm/h.

HTAP_v2.2: a mosaic of regional and global emission grid maps for 2008 and 2010 to study hemispheric transport of air pollution

Abstract. The mandate of the Task Force Hemispheric Transport of Air Pollution (TF HTAP) under the Convention on Long-Range Transboundary Air Pollution (CLRTAP) is to improve the scientific understanding of the intercontinental air pollution transport, to quantify impacts on human health, vegetation and climate, to identify emission mitigation options across the regions of the Northern Hemisphere, and to guide future policies on these aspects. The harmonization and improvement of regional emission inventories is imperative to obtain consolidated estimates on the formation of global-scale air pollution. An emissions data set has been constructed using regional emission grid maps (annual and monthly) for SO2, NOx, CO, NMVOC, NH3, PM10, PM2.5, BC and OC for the years 2008 and 2010, with the purpose of providing consistent information to global and regional scale modelling efforts. This compilation of different regional gridded inventories – including that of the Environmental Protection Agency (EPA) for USA, the EPA and Environment Canada (for Canada), the European Monitoring and Evaluation Programme (EMEP) and Netherlands Organisation for Applied Scientific Research (TNO) for Europe, and the Model Inter-comparison Study for Asia (MICS-Asia III) for China, India and other Asian countries – was gap-filled with the emission grid maps of the Emissions Database for Global Atmospheric Research (EDGARv4.3) for the rest of the world (mainly South America, Africa, Russia and Oceania). Emissions from seven main categories of human activities (power, industry, residential, agriculture, ground transport, aviation and shipping) were estimated and spatially distributed on a common grid of 0.1° × 0.1° longitude-latitude, to yield monthly, global, sector-specific grid maps for each substance and year. The HTAP_v2.2 air pollutant grid maps are considered to combine latest available regional information within a complete global data set. The disaggregation by sectors, high spatial and temporal resolution and detailed information on the data sources and references used will provide the user the required transparency. Because HTAP_v2.2 contains primarily official and/or widely used regional emission grid maps, it can be recommended as a global baseline emission inventory, which is regionally accepted as a reference and from which different scenarios assessing emission reduction policies at a global scale could start. An analysis of country-specific implied emission factors shows a large difference between industrialised countries and developing countries for acidifying gaseous air pollutant emissions (SO2 and NOx) from the energy and industry sectors. This is not observed for the particulate matter emissions (PM10, PM2.5), which show large differences between countries in the residential sector instead. The per capita emissions of all world countries, classified from low to high income, reveal an increase in level and in variation for gaseous acidifying pollutants, but not for aerosols. For aerosols, an opposite trend is apparent with higher per capita emissions of particulate matter for low income countries.

An electron source with a multiaperture plasma emitter and beam extraction into the atmosphere

The results of investigating the emission properties of a multiaperture plasma emitter with grid stabilization of the emission-plasma boundary in an electron source with ejection of a generated electron beam from the accelerating gap into the atmosphere through a thin foil. A stainless-steel foil mask with 344 circular holes is laid on an emission grid with dimensions of 750 × 150 mm. The holes form a discrete emission structure of the plasma emitter, from which electrons are emitted under the action of an accelerating voltage. The alignment of the holes in the mask of the emission structure and in the bearing grid of the output foil window, which has the same number of holes with a larger diameter, and the attainment of a coaxial plane–parallel geometry of the accelerating gap allows minimization of the beam loss in the bearing grid of the output foil window. An electron beam is a superposition of elementary beams that are formed by individual emission structures, whose plasma boundaries are stabilized with a fine-structure metal grid. The coefficient of the current extraction into the atmosphere reached 75% of the emission current. In experiments at an accelerating voltage of 200 kV, an emission current of 16 A, and a pulse duration (FWHM) of 40 μs, a beam with an average power of ∼4 kW was ejected into the atmosphere. This value is more than 60% of the beam power in the accelerating gap at a geometrical transparency of the bearing grid of the output foil window of 56%. A further increase in the power was limited by the power of the high-voltage power-supply unit.

Synthesis of Superhard Coatings Using Pulsed Beams of High-Energy Gas Molecules

It is proposed to use for synthesis of superhard and fracture tough nanocomposite coatings on dielectric products with deep cavities a source of metal atoms accompanied by pulsed beams of high-energy neutral gas molecules. Slow and fast particles are produced by one and the same plasma emitter of ions and trajectories of their movement from a common emissive grid to the product surface coincide.

Deposition of wear-resistant coatings using a combined source of metal atoms and fast gas molecules

A source of metal atoms accompanied by fast gas atoms has been developed and studied. The fast particles are produced due to charge exchange collisions of ions accelerated by potential difference between a plasma emitter inside the source and an emissive grid. The metal atoms are produced due to sputtering a target placed at the hollow cathode bottom by ions with energy up to 3 keV from the plasma emitter. Sputtered atoms cross the emitter and the grid, together with accelerated ions enter the chamber and deposit on the products. Two different discharge modes can be used to produce the plasma emitter and bombard the growing nitride coating interruptedly by atoms and molecules with energy variable from 10 to 300 eV.

High-Resolution Mapping of Carbon Flows in Urban Systems: A Case Study in Guangyuan, an Earthquake-Affected Mountainous City of China

Being different from inventoried data, spatialized maps of carbon dioxide (CO2) flow at high resolution in urban areas are essential for carbon cycle research and carbon reduction management. In this research, Guangyuan, a mountainous city located in southwestern China, which was heavily affected by the 2008 earthquake, was used as a studying case. In this city, gridded data of vertical carbon flows at 1-km resolution was extracted based on point emission sources and other supporting data in Guangyuan. Among the 16,020 grids, 4,465 performed as CO2 emission sources while the other 11,555 as sinks. On the whole, Guangyuan City served as a carbon sink in 2010, with the total net flow of 0.44 Mt CO2 being sequestered and stored by vegetations. The overall pattern of emission sources and sinks matched well with local land-use patterns. The hotspots of CO2 emissions appeared in the built- up areas along local valleys, as well as low mountainous areas. On the contrary, large areas of carbon sinks were mainly distributed in the mountainous areas of northwest and northeast parts of Guangyuan. With regard to the distribution of gridded emissions, an evidently clustered characteristic was identified. The proportion of the largest individual emission grid accounted for 12.01% of the total emission. The cumulative percentage of gridded emissions indicated that supervision of 0.06% of the total area could enable effective management of approximately 60% of the total emissions in Guangyuan. Thus, the spatialized gridded data of carbon flows produced in this research can provide significant policy implications for urban planning and regional carbon flow mitigation.

Effect of electron extraction from a grid plasma cathode on the generation of emission plasma

The paper describes the operating mode of a plasma electron source based on a low- pressure arc discharge with grid stabilization of the plasma emission boundary which provides a considerable (up to twofold) increase in discharge and beam currents at an Ar pressure in the vacuum chamber p = 0.02-0.05 Pa, accelerating voltages of up to U = 10 kV, and longitudinal magnetic field of up to Bz = 0.1 T. The discharge and beam currents are increased on electron extraction from the emission plasma through meshes of a fine metal grid due to the energy of a high-voltage power supply which ensures electron emission and acceleration. The electron emission from the plasma cathode and arrival of ions from the acceleration gap in the discharge changes the discharge plasma parameters near the emission grid, thus changing the potential of the emission grid electrode with respect to the discharge cathode. The load is not typical and changes the voltage polarity of the electrode gap connected to the discharge power supply, which is to be taken into account in its calculation and design. The effect of electron emission from the plasma cathode on the discharge system can not only change the discharge and beam current pulse shapes but can also lead to a breakdown of the acceleration gap and failure of semiconductor elements in the discharge power supply unit.

Equipment for deposition of thin metallic films bombarded by fast argon atoms

Deposition of thin metallic films on dielectric substrates using a source of metal atom flow combined with a flow fast argon atoms has been investigated and the investigation results are presented. The fast atoms are produced due to charge-exchange collisions in a vacuum chamber of argon ions, which are accelerated by potential difference between the hollow-cathode glow-discharge plasma and an emissive grid and enter the chamber through the grid. The metal atoms produced due to ion sputtering of a metallic foil placed on the inner surface of the hollow cathode enter the chamber through the same grid. Substrate pretreatment and pulse-periodic bombardment of the growing film by ∼1-keV argon atoms both ensure adhesion of copper to glass up to 2 × 107 Pa. The use of a hollow substrate holder, whose inner surface is also covered with the same foil, makes it possible to exclude losses of the depositing metal and allows recommendation of the equipment for beam-assisted deposition of precious metal films.

Gas discharge source of metal vapor and fast gas atoms

A source of metal atom flow coinciding in time and space with a flow of fast gas atoms has been studied and the study results are presented. The fast particles are produced due to charge exchange collisions of ions accelerated by potential difference between a plasma emitter inside the source and secondary plasma inside a process vacuum chamber. The emitter is the glow discharge plasma, whose electrons are confined in an electrostatic trap formed by a cold hollow cathode and an emissive grid the latter being negative both to the cathode and the chamber. The metal atoms are produced due to sputtering a target placed at the hollow cathode bottom by ions from the plasma emitter with energy up to 3 keV. Sputtered atoms cross the emitter, together with accelerated ions enter the chamber through the emissive grid and deposit on pieces placed therein. When a mixture of argon and nitrogen is used, the metal nitride coatings are being synthesized and interruptedly bombarded during the synthesis by atoms and molecules with energy variable from ∼10 to ∼300 eV.