Reactive Gas Flow Research Articles

Concentration Impedance in Testing of Solid Oxide Cells Revisited

Concentration impedance in the context of solid oxide cells (SOC) has been discussed in the literature [1-6]. We divide the concentration impedance into diffusion impedance and conversion impedance. Diffusion impedance is defined as impedance due to a reactant concentration gradient caused by a slow (relative to the electrode reaction rate) diffusion through a porous boy of a stagnant gas layer. Conversion impedance is defined as impedance caused by a decrease in an electrode reactant concentration due the conversion of the reactant by electrode reaction. Mainly the diffusion impedance has been treated in spite of the fact that the conversion impedance often is of greater importance. Actually not all workers within the SOC field recognize the concept of conversion impedance. Other workers claim that the two kinds of concentration impedance cannot be distinguished. It is correct that the two phenomena will interact, and thus often it may be difficult to separate them, but we have tools that make it possible to distinguish between the two types of impedance. The diffusion impedance due to diffusion through a porous body, e.g. an electrode support layer, will not be sensitive to reactant gas flow rate, whereas the conversion impedance will be very sensitive to the reactant flow rate. Diffusion impedance results in the simple, clean case in a Warburg element, i.e. a 45 ° slope followed by a relative sharp decrease by decreasing low frequencies down to the x-axis in a Nyquist plot. In contrast to this, clean conversion impedance can always be modeled by a resistor in parallel with an ideal capacitor, which most often has a rather huge value in the order of 0.1 – 1 F cm-2. The paper and presentation will explain how the two types of concentration impedance may be extracted from impedance spectra in a manner that they are separated. Both simple examples and more difficult cases with very high fuel utilization at high current density, where the interaction between diffusion and conversion impedance is in particular strong, will be given. Special emphasis will be put on the case of plug flow condition, which is the relevant case for practical cells and stacks.

Approximate analytical solutions for heat fluxes in three-dimensional hypersonic flow over blunt bodies

Analytical expressions for the heat flux divided by its value at the stagnation point which depend on the geometric parameters invariant with respect to the choice of the coordinate system, as well as expressions depending on the geometry and the pressure on the surface which have a wider applicability range are obtained in the problem of three-dimensional hypersonic flow over blunt bodies at large and moderate Reynolds numbers. These formulas are derived by solving the thin viscous shock layer equations for a perfect gas using the integral method of successive approximations developed by the author. The accuracy and the range of applicability of the analytical solutions are estimated by comparing them with numerical solutions. On the basis of comparisons with numerical solutions for multicomponent chemically nonequilibrium air at altitudes from 90 to 50 km of the spacecraft reentry trajectory in the Earth’s atmosphere it is shown that the formulas obtained can be used for calculations of the heat flux on an ideal catalytic surface of bodies in hypersonic chemically reacting gas flow.

Measurement of high temperature emissivity and photothermal conversion efficiency of TiAlC/TiAlCN/TiAlSiCN/TiAlSiCO/TiAlSiO spectrally selective coating

A spectrally selective TiAlC/TiAlCN/TiAlSiCN/TiAlSiCO/TiAlSiO coating was deposited on stainless steel substrate by unbalanced magnetron sputtering system. Each individual layer of the tandem absorber was optimized by varying the reactive gas flow rates (C2H2, N2 and O2) and target power densities (Ti, Al and Si). The optimized tandem absorber shows a solar absorptance of 0.960 and an emittance of 0.15 at 82°C, measured using solar spectrum reflectometer and emissometer, respectively. In order to study the optical properties of the deposited tandem absorber at high operating temperatures the reflectance spectra of the tandem absorber were measured at temperatures ranging from 80°C to 500°C by UV–Vis–NIR spectrophotometer and FTIR spectrometers. The reflectance spectra of the as-deposited sample and after high temperature reflectance measurements did not show any significant changes. The thermal emittance of the tandem absorber at high temperatures (80–500°C) was studied in detail. At the temperature of 200°C, 300°C, 400°C and 500°C the tandem absorber shows the emittance of 0.152–0.157, 0.181–0.19, 0.214–0.246 and 0.251–0.275, respectively with an absorptance of ~0.930. These results show the good selectivity of the tandem absorber even at high operating temperatures (e.g., 500°C) with a photothermal conversion efficiency of 88%, thus demonstrating that the tandem absorber is suitable for solar thermal power generation applications. Reflectance and roughness data of the absorber coating post annealing in air up to 600°C for 2h, carried out independently, corroborated the present results.

Hybrid gas phase Ti-B-C-N coatings doped with Al

Deposition of Multicomponent hard coatings (Ti-B-C-N) on the molybdenum high-speed tool steels (AISI M52) has been achieved by mixed vapor deposition technique to improve the mechanical properties of the surface. The Ti-B-C-N coating samples were produced by a hybrid gas phase process, were in this technique, the coating materials that supplied in the gas phase were produced from powders that vaporized by thermal energy (that is, PVD- Reactive Evaporation Process), while the reactor that used to deposit Ti-Base coatings is a hot-wall chemical vapor deposition (HWCVD) system equipment. The resulting coating exhibit different amounts of the Titanium oxide phase, which is characterized by the low mechanical and thermal properties. These phases (Ti-O) will have determinant effect on the coated high speed steel tools. The alloying of transition metal nitrides and borides (TiN, BN, and TiB) with stable oxide-forming elements (for example, Cr, Al, Si and Ni) will have the effect of decreasing crystallinity, promoting nanocrystalline structure and increasing oxidation resistance. Ti-Base hard film was characterized by XRD technique, and Scanning Electron Microscopy (SEM). Mechanical characterization of the hard films has been performed by using The Ball-on-disk wear tests. With different deposition temperatures (550–950 °C) and at the same reactive gas flow rate 2.5SLPM (Standard Litter Per Minute), Al doping in the Ti-B-C-N coating has proven a great success by producing a new film microstructure (free of Ti-O phases) which contains fine fiber structure as a strengthening second phase in the Ti-B type structure with a sufficient amorphous phase (B-N) as a matrix. Maximum hardness of 4230 HV is achieved, with better thermal stability during the process of the wear test than the uncoated H.S.S samples. Also a great enhancement in the wear resistance values for this coating film (Volume loss = 1.8291*10−7 mm3) was reported.

Investigation of GDL compression effects on the performance of a PEM fuel cell cathode by lattice Boltzmann method

Abstract Proton exchange membrane (PEM) fuel cells with a great potential for application in vehicle propulsion systems will have a promising future. However, to overcome the exiting challenges against their wider commercialization further fundamental research is inevitable. The effects of gas diffusion layer (GDL) compression on the performance of a PEM fuel cell is not well-recognized; especially, via pore-scale simulation technique capturing the fibrous microstructure of the GDL. In the current investigation, a stochastic microstructure reconstruction method is proposed which can capture GDL microstructure changes by compression. Afterwards, lattice Boltzmann pore-scale simulation technique is adopted to simulate the reactive gas flow through 10 different cathode electrodes with dissimilar carbon paper GDLs produced from five different compression levels and two different carbon fiber diameters. The distributions of oxygen mole fraction, water vapor mole fraction and current density for the simulated cases are presented and analyzed. The results of simulations demonstrate that when the fiber diameter is 9 μm adding compression leads to lower average current density while when the fiber diameter is 7 μm the compression effect is not monotonic.

In situ assessment of target poisoning evolution in magnetron sputtering

We present an experimental approach for the in situ monitoring of target poisoning through roughness evolution during reactive sputtering by laser reflectometry. Aluminum (Al) and Titanium (Ti) targets were reactively sputtered in the presence of Nitrogen (N2) and Oxygen (O2), separately. From the hysteresis loops of reactive gas flow and discharge voltage, the threshold flow rates of N2 and O2 were determined for partial and complete poisoning of the targets, respectively. These targets were then sputtered up to 60min in metallic and poisoning modes at different flow rate of the reactive gases. For given time intervals, the eroded regions of the cylindrical sputtering targets were hit by a laser beam and reflected images were captured on a screen. Based on ray tracing optics, the reflected intensity distribution of the laser was utilized for the assessment of the poisoned surface. The mean tilt angle of the surface roughness for both nitride and oxide formation on the Al and Ti targets was measured from the reflected intensity profiles. A change in surface roughness of poisoned targets was observed after different sputtering times. As a proof of concept, the deposition rate and de-poisoning time were measured at different poisoning levels. The change in surface roughness of the targets was found to be in good agreement with depoisoning time. This in situ method can be applied for the assessment of target poisoning evolution during reactive sputtering.

Model-based Analysis of Carbon Corrosion in Start-up/Shutdown, Fuel Starvation, and Voltage Reversal of a Polymer Electrolyte Fuel Cell

Support carbon corrosion has been identified as a major degradation source in a polymer electrolyte fuel cell. Start-up/Shutdown (SUSD) [1], fuel starvation [1], and voltage reversal [2] are widely-known conditions that can trigger non-negligible carbon corrosion in the anode or cathode. SUSD carbon corrosion is associated with current reversal while there is no external load. As a comparison, fuel starvation due to nitrogen blanketing and/or water droplets in an operating cell also can result in similar current reversal. The region with current reversal, i.e., a proton flux from the cathode to the anode, features extremely severe hydrogen depletion in the anode and occurrence of carbon corrosion in the opposite cathode. Differently, the voltage reversal occurs in one or a few cells (not all) in a stack. Those cells show negative cell voltages under extended reversal, but the overall current is flowing as usual thanks to the other normal cells in the stack. The voltage reversal leads to carbon corrosion in the anode, as compared to carbon corrosion in the cathode for current reversal. The local potential for carbon corrosion could be much more severe in an extended voltage reversal than that in SUSD.This paper/presentation will elucidate the fundamental differences of these three carbon corrosion scenarios with model simulation and analysis. The models [3, 4] will also be used to perform comprehensive parametric studies, aiming to understand the impacts from key design and operating parameters including pseudo-capacitance, selective oxygen evolution reaction (OER) catalysis, reactant gas flow rate, temperature, membrane hydration state, and current load drawn from the stack. It is anticipated to shed light on the otherwise confusing carbon corrosion scenarios in a polymer electrolyte fuel cell and the fundamental ideas for alleviation strategies. For example, in the fuel starvation induced carbon corrosion, the simulation indicates that the decreasing cell voltage due to diluted hydrogen concentration appears to limit the local potential in the cathode and associated carbon corrosion. In the SUSD carbon corrosion, pseudo-capacitance from Pt oxidation may raise another concern in parallel to carbon corrosion. In general, a reduced temperature or enhanced OER activity is helpful in reducing carbon corrosion. Figure 1

Relation between growth rate and structure of graphene grown in a 4″ showerhead chemical vapor deposition reactor

The chemical vapor deposition (CVD) growth of graphene on copper is controlled by a complex interplay of substrate preparation, substrate temperature, pressure and flow of reactive gases. A large variety of recipes have been suggested in literature, often quite specific to the reactor, which is being used. Here, we report on a relation between growth rate and quality of graphene grown in a scalable 4″ CVD reactor. The growth rate is varied by substrate pre-treatment, chamber pressure, and methane to hydrogen (CH4:H2) ratio, respectively. We found that at lower growth rates graphene grains become hexagonal rather than randomly shaped, which leads to a reduced defect density and a sheet resistance down to 268 Ω/sq.

New chemical-DSMC method in numerical simulation of axisymmetric rarefied reactive flow

The modified quantum kinetic (MQK) chemical reaction model introduced by Zakeri et al. is developed for applicable cases in axisymmetric reactive rarefied gas flows using the direct simulation Monte Carlo (DSMC) method. Although, the MQK chemical model uses some modifications in the quantum kinetic (QK) method, it also employs the general soft sphere collision model and Stockmayer potential function to properly select the collision pairs in the DSMC algorithm and capture both the attraction and repulsion intermolecular forces in rarefied gas flows. For assessment of the presented model in the simulation of more complex and applicable reacting flows, first, the air dissociation is studied in a single cell for equilibrium and non-equilibrium conditions. The MQK results agree well with the analytical and experimental data and they accurately predict the characteristics of the rarefied flowfield with chemical reaction. To investigate accuracy of the MQK chemical model in the simulation of the axisymmetric flow, air dissociation is also assessed in an axial hypersonic flow around two geometries, the sphere as a benchmark case and the blunt body (STS-2) as an applicable test case. The computed results including the transient, rotational and vibrational temperatures, species concentration in the stagnation line, and also the heat flux and pressure coefficient on the surface are compared with those of the other chemical methods like the QK and total collision energy (TCE) models and available analytical and experimental data. Generally, the MQK chemical model properly simulates the chemical reactions and predicts flowfield characteristics more accurate rather than the typical QK model. Although in some cases, results of the MQK approaches match with those of the TCE method, the main point is that the MQK does not need any experimental data or unrealistic assumption of specular boundary condition as used in the TCE method. Another advantage of the MQK model is the significant reduction of computational cost rather than the QK chemical model to reach the same accuracy because of applying more proper collision model and consequently, decrease of the particles collision number.

Dynamic Reaction Cell-ICP-MS as a Powerful Tool for Quality Control of a Se-Enriched Dietary Supplement

The aim of this work was to evaluate different approaches employing a reaction cell to circumvent spectral interferences over 80Se+ to increase the sensitivity in the determination of Se by inductively coupled plasma mass spectrometry (ICP-MS). Different gases (NH3, CH4, and O2) were employed, and the operating conditions were optimized by a central composite design, evaluating the effect of the reaction gas flow rate and the rejection parameter q (Rpq) on the limit of detection (LOD) of the method. All reaction gases studied reduced the interference by 40Ar2 + over 80Se+, reducing the LOD when compared to the LOD obtained with ICP-MS operating in the standard mode (LOD = 0.2 μg kg−1). A better LOD (0.01 μg kg−1) was obtained with CH4, while 0.1 μg kg−1 was the LOD with NH3. The use of O2 as a reaction gas enabled the determination of Se at m/z 96 (80Se16O+) with adequate analytical performance (LOD = 0.03 μg kg−1). The accuracy of the method was evaluated by analyzing the certified reference material (CRM) Selm-1, and the results obtained ranged from 99 to 104% of the certified value. In addition, Se dietary supplements of four different brands and commercial yeast were analyzed, and the major sources of uncertainty were studied. The dietary supplements followed the criteria adopted by Brazilian legislation, although the uncertainty study highlighted the great variation in the Se content of each brand. Clearly, the manufacturing process of dietary supplements needs more rigorous quality control, considering that this product can affect the health of consumers.

Titanium-Base Nanostructure Coatings for AISI M52 Tool Steel by Gas-Phase Mix Process

Deposition of Multicomponent hard coatings (Ti-B-N-C) on the molybdenum high-speed tool steel (AISI M52) has been achieved by mixed vapor deposition technique to improve the mechanical properties of the surface. In this technique the coating materials that were supplied in the gas phase were produced from powders that vaporized by thermal energy (that is, PVD- Reactive Evaporation Process), while the reactor that used to deposit Ti-Base coatings is hot-wall chemical vapor deposition (HWCVD) system equipment. This combination results in technical and financial advantages. The structure of deposited Ti-Base hard film was characterized by XRD technique, Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray spectroscopy (EDX). Mechanical characterization of the hard films has been performed by using Vickers micro hardness tester and The Ball-on-disk wear tests. With different reactive gas flow rates that ranged from 500 to 3000Sccm(standard Cubic Centimeter per Minute), the film showed amorphous matrix with crystalline Nano fibers of Ti-B phase which led to achieve higher hardness of 2051HV and better wear resistance with relatively good COF values of 0.61 than the uncoated tools.

Synthesis and characterization of the mechanical and optical properties of Ca-Si-O-N thin films deposited by RF magnetron sputtering

Ca-Si-O-N thin films were deposited on commercial soda-lime silicate float glass, silica wafers and sapphire substrates by RF magnetron co-sputtering from Ca and Si targets in an Ar/N2/O2 gas mixture. Chemical composition, surface morphology, hardness, reduced elastic modulus and optical properties of the films were investigated using X-ray photoelectron spectroscopy, scanning electron microscopy, nanoindentation, and spectroscopic ellipsometry. It was found that the composition of the films can be controlled by the Ca target power, predominantly, and by the reactive gas flow. Thin films in the Ca-Si-O-N system are composed of N and Ca contents up to 31eq. % and 60eq. %, respectively. The films thickness ranges from 600 to 3000nm and increases with increasing Ca target power. The films surface roughness varied between 2 and 12nm, and approximately decreases with increasing power of Ca target. The hardness (4–12GPa) and reduced elastic modulus (65–145GPa) of the films increase and decrease with the N and Ca contents respectively. The refractive index (1.56–1.82) is primarily dictated by the N content. The properties are compared with findings for bulk glasses in the Ca-Si-(Al)-O-N systems, and it is concluded that Ca-Si-O-N thin films have higher values of hardness, elastic modulus and refractive index than bulk glasses of similar composition.

Platinum and Other Transition Metal Nanoclusters (Pd, Rh) Stabilized by PAMAM Dendrimer as Excellent Heterogeneous Catalysts: Application to the Methylcyclopentane (MCP) Hydrogenative Isomerization.

Pt, Rh, and Pd nanoclusters stabilized by PAMAM dendrimer are used for the first time in a gas flow reactor at high temperature (150-250 °C). Pt nanoclusters show a very high activity for the hydrogenation of the methylcyclopentane (MCP) at 200-225 °C with turnover freqency (TOF) up to 334 h-1 and selectivity up to 99.6% for the ring opening isomerization at very high conversion (94%). Rh nanoclusters show different selectivity for the reaction, that is, ring opening isomerization at 175 °C and cracking at higher temperature whereas Pd nanoclusters perform ring enlargement plus dehydrogenation, while maintaining a high activity. The difference in these results as compared to unsupported/uncapped nanoparticles, demonstrates the crucial role of dendrimer. The tunability of the selectivity of the reaction as well as the very high activity of the metal nanoclusters stabilized by dendrimer under heterogeneous conditions open a new application for dendrimer catalysts.

Structure and properties of Hf-O-N films prepared by high-rate reactive HiPIMS with smoothly controlled composition

Hafnium oxynitride ceramics were prepared in the form of thin films by high-power impulse magnetron sputtering of Hf in various Ar+O2+N2 gas mixtures. Smooth composition control was achieved by maximizing the degree of dissociation in plasma, suppressing the importance of the difference between reactivities of undissociated O2 and N2. The application potential of the films was further enhanced by extremely high deposition rates (e.g. 230nm/min for stoichiometric HfO2; achieved by feedback pulsed reactive gas flow control), low deposition temperatures (<140°C) and not using any substrate bias. We focus on the relationships between elemental composition, phase structure, and optical, electrical, mechanical and hydrophobic properties of the materials. We quantify the evolution of smoothly controlled film properties along the transition from an oxide to a nitride, such as increasing extinction coefficient, decreasing electrical resistivity, increasing hardness or increasing water droplet contact angle.

Impact of elevated CO2 concentrations on carbonate mineral precipitation ability of sulfate-reducing bacteria and implications for CO2 sequestration

Interest in anthropogenic CO2 release and associated global climatic change has prompted numerous laboratory-scale and commercial efforts focused on capturing, sequestering or utilizing CO2 in the subsurface. Known carbonate mineral precipitating microorganisms, such as the anaerobic sulfate-reducing bacteria (SRB), could enhance the rate of conversion of CO2 into solid minerals and thereby improve long-term storage of captured gasses. The ability of SRB to induce carbonate mineral precipitation, when exposed to atmospheric and elevated pCO2, was investigated in laboratory scale tests with bacteria from organic-rich sediments collected from hypersaline Lake Estancia, New Mexico. The enriched SRB culture was inoculated in continuous gas flow and batch reactors under variable headspace pCO2 (0.0059 psi to 20 psi). Solution pH, redox conditions, sulfide, calcium and magnesium concentrations were monitored in the reactors. Those reactors containing SRB that were exposed to pCO2 of 14.7 psi or less showed Mg-calcite precipitation. Reactors exposed to 20 psi pCO2 did not exhibit any carbonate mineralization, likely due to the inhibition of bacterial metabolism caused by the high levels of CO2. Hydrogen, lactate and formate served as suitable electron donors for the SRB metabolism and related carbonate mineralization. Carbon isotopic studies confirmed that ∼53% of carbon in the precipitated carbonate minerals was derived from the CO2 headspace, with the remaining carbon being derived from the organic electron donors, and the bicarbonate ions available in the liquid medium. The ability of halotolerant SRB to induce the precipitation of carbonate minerals can potentially be applied to the long-term storage of anthropogenic CO2 in saline aquifers and other ideal subsurface rock units by converting the gas into solid immobile phases.

Impact on the Gas Barrier Property of Silicon Oxide Films Prepared by Tetramethylsilane-Based PECVD Incorporating with Ammonia

The gas barrier property of a silicon oxide (SiOx) film synthesized from plasma-enhanced chemical vapor deposition using the tetramethysilane (TMS)-oxygen gas mixture was modified by introducing ammonia gas in the glow discharge. The change in the glow discharge with the ammonia gas incorporation was monitored by an optical emission spectrometer (OES). Structures, chemical bond configurations, and material properties of the resulting films were investigated. The introduced ammonia gas in the TMS-oxygen plasma resulted in emission lines dominated by the N2 and CN species with the suppression of the OH and oxygen-related radicals, thereby introducing nitrogen and carbon atoms in the deposited film. A silicon oxynitride (SiOxNy) film had the best surface morphology and the lowest residual internal stress was achievable by controlling the reactant gas flow ratio of the ammonia and oxygen. The barrier property to the water vapor permeation of the silicon oxide film (~1.65 g/m2/day) deposited onto the polyethylene terephthalate (PET) substrate was thus greatly improved to 0.06 g/m2/day for the film synthesized from an adequate TMS-oxygen-ammonia gas mixture.

Моделирование течения многокомпонентного химически активного газа на примере пиролиза углеводородов

Моделирование течения многокомпонентного химически активного газа на примере пиролиза углеводородов

Effect of Composition on Designed Tandem Absorber to Achieve Selective Properties for High Temperature Solar Thermal Applications

We have designed a tandem absorber comprising of five layers namely:TiAlC / TiAlCN / TiAlSiCN / TiAlSiCO / TiAlSiO on stainless steel substrate by DC unbalanced magnetron sputtering system.Tandem absorber shows a high absorptance of 0.961 with an emittance of 0.15 by careful optimization of flow rates and thicknesses of the individual layers. Further, the detailed effects of reactive gas flow rates and thicknesses of each individual layers on the optical properties were studied. Growth rate and thicknesses of each individual layers of the tandem absorber were studied by cross-section FESEM images. The tandem absorber shows long term thermal stability when annealed in vacuum at 600°C for more than 750 h under cyclic heating conditions, indicating suitability of the tandem absorber for solar thermal high temperature applications.

反応性大電力パルススパッタリング（R-HiPIMS）における遷移領域制御技術

This is to review a novel approach stabilizing reactive mode at transition regime in reactive high-power impulse magnetron sputtering (R-HiPIMS). The proposed method is based on a real-time monitoring of peak discharge current. To stabilize the process conditions at a given set point, a feedback control system, which automatically regulates the pulse frequency, and thereby the average sputtering power, was implemented to maintain a constant maximum discharge current. As a representative result, the variation of the pulse current waveforms over a wide range of reactive gas flows and pulse frequencies during a R-HiPIMS of Hf in an Ar-N2 atmosphere illustrates that the discharge current waveform is an excellent indicator of the process conditions. Applicability of the proposed method was successfully demonstrated.

Confirmation of40Ar+related product ions in the octopole reaction cell of an ICP-QMS/QMS with18O2enriched oxygen as the reaction cell gas

40Ar+ related product ions in an octopole reaction cell (ORC) were observed with an inductively coupled plasma tandem quadrupole mass spectrometer (ICP-QMS/QMS). In order to simplify the ion composition of the plasma, the carrier gas was directly connected to the torch injector, i.e. without introduction of the sample solution. The m/z of the first QMS was set to 40 permitting the passage of 40Ar+. Isotope enriched oxygen gas (18O2) was used as the reaction gas in order to separate the spectra of O3+ and Ar2O2+. The intensities of the ions produced in the ORC were measured by the second QMS. As the products of the reactions among 40Ar+ ions and 18O2 molecules in the ORC, the following ions were observed: 18O+, 18O2+, 18O3+, 18O4+, 40Ar18O+, 40Ar18O2+, 40Ar218O2+, and 40Ar18O22+. At a reaction gas flow rate of 0.3 mL min−1, the ionic species with the highest signal intensity was 18O2+, followed by 40Ar+ and 18O+. The maximum signal intensities of different product ions were obtained at different flow rates of the reaction gas. A lower flow rate of the reaction gas benefited the production of 40Ar18O+ and 18O3+, while a higher flow rate of the reaction gas benefited the production of 40Ar18O2+ and 40Ar218O2+. The maximum transfer efficiency from 40Ar+ to the resulting ionic species was 91%, 2.0%, and 0.12% for 18O2+, 18O+, and 40Ar18O+, respectively. The maximum transfer efficiency to the other investigated ionic species was less than 0.023%. By using 18O2 as the reaction gas, the mechanisms of 40Ar+ resulted ionic species interfering with the measurement of 32S16O+ were confirmed. The results showed that the contributions of 16O3+ and 40Ar2O2+ were almost equivalent to each other.