Ion Injection Research Articles

LEBT Development for High-Current Multicharged Ion Injector Based on SC ECR Ion Source

LEBT Development for High-Current Multicharged Ion Injector Based on SC ECR Ion Source

Automated Control of Injection Times for Unattended Acquisition of Multiplexed Individual Ion Mass Spectra.

Charge detection mass spectrometry (CDMS) provides mass domain spectra of large and highly heterogeneous analytes. Over the past few years, we have multiplexed CDMS on Orbitrap instruments, an approach termed Individual Ion Mass Spectrometry (I2MS). Until now, I2MS required manual adjustment of injection times to collect spectra in the individual ion regime. To increase sample adaptability, enable online separations, and reduce the barrier for entry, we report an automated method for adjusting ion injection times in I2MS for image current detectors like the Orbitrap. Automatic Ion Control (AIC) utilizes the density of signals in the m/z domain to adjust an ensemble of ions down to the individual ion regime in real-time. The AIC technique was applied to both denatured and native proteins yielding high quality data without human intervention directly in the mass domain.

Diagnostics of highly charged plasmas with multicomponent 1+ ion injection.

We establish multicomponent 1+ injection into a charge breeder electron cyclotron resonance ion source and an associated computational procedure as a noninvasive probe of the electron density n_{e}, average electron energy 〈E_{e}〉, and the characteristic times of ionization, charge exchange, and ion confinement of stochastically heated, highly charged plasma. Multicomponent injection allows refining the n_{e}, 〈E_{e}〉 ranges, reducing experimental uncertainty. Na/K injection is presented as a demonstration. The 〈E_{e}〉 and n_{e} of a hydrogen discharge are found to be 600_{-300}^{+600}eV and 8_{-3}^{+8}×10^{11}cm^{-3}, respectively. The ionization, charge exchange, and confinement times of high charge state alkali ions are on the order of 1 ms-10 ms.

Injection of low-energy SiCH5+ ion-beam to Si substrate during chemical vapor deposition process using methylsilane

Silicon carbide (SiC) films produced on Si substrates by the thermal chemical vapor deposition (CVD) method using methylsilane (MS) were compared with those made by the mass-selected ion-beam deposition (MSIBD) method using MS-derived 100 eV SiCH5+ ions. We also investigated the effect of SiCH5+ ion injections during the CVD process. When the substrate was 550 °C, no distinct peaks were found in the Fourier transform infrared (FTIR) spectroscopy spectra of the samples obtained by both CVD and MSIBD. By contrast, an obvious FTIR peak due to the presence of SiC was observed when SiCH5+ ions were injected to a substrate in conjunction with MS. In the case of 650 °C, we found that the film thickness was significantly increased when additional SiCH5+ ions were injected during the CVD process using MS. These results suggest that the interaction between MS and SiCH5+ has some effects on the SiC film formation at the substrate temperatures 550 and 650 °C. When the substrate temperature was set at 750 °C, the effect of the SiCH5+ ion injection on the SiC film formation was negligibly small compared to that of CVD.

절연유 내 이온 주입을 통한 미세입자 크기별 제거 특성

Since contamination of insulating oil causes partial discharge and mechanical malfunction, it is necessary to remove internal fine particles. Currently an electrostatic filter method is being actively studied to remove particles inside the non-conductive liquids, however this method has the drawback of being time-consuming. Recently an electrostatic filter with ion injection has been created to deal with the issue of taking a long time, however there hasn’t been enough research on removing particles of various sizes. This study used an electrostatic filter with an ion injection to remove particles of various sizes. Up to 72% of the 100 mesh-sized particles were removed after using a needle-plate electrode for 180 seconds after adding PE particles to the transformer oil. This result can be applied to studies on electrostatic force-based removal of fine dielectric particles from non-conductive liquids.

Mechanisms to control laser-plasma coupling in laser wakefield electron acceleration

Experimental results, supported by precise modeling, demonstrate optimization of a plasma-based injector with intermediate laser pulse energy ($<1\text{ }\text{ }\mathrm{J}$), corresponding to a normalized vector potential ${a}_{0}=2.15$, using ionization injection in a tailored plasma density profile. An increase in electron bunch quality and energy is achieved experimentally with the extension of the density downramp at the plasma exit. Optimization of the focal position of the laser pulse in the tailored plasma density profile is shown to efficiently reduce electron bunch angular deviation, leading to a better alignment of the electron bunch with the laser axis. Single peak electron spectra are produced in a previously unexplored regime by combining an early focal position and adaptive optic control of the laser wavefront by optimizing the symmetry of the prefocal laser energy distribution. Experimental results have been validated through particle-in-cell simulations using realistic laser energy, phase distribution, and temporal envelope, allowing for accurate predictions of difficult to model parameters, such as total charge and spatial properties of the electron bunches, opening the way for more accurate modeling for the design of plasma-based accelerators.

Quantum and quasi-classical effects in the strong field ionization and subsequent excitation of nitrogen molecules.

The processes leading to the N2 + lasing are rather complex and even the population distribution after the pump laser excitation is unknown. In this paper, we study the population distribution at electronic and vibrational levels in N2 + driven by ultra-short laser pulse at the wavelengths of 800 nm and 400 nm by using the quantum-mechanical time-domain incoherent superposition model based on the time-dependent Schrödinger equation and the quasi-classical model assuming instantaneous ionization injection described by density matrix. It is shown that while both models provide qualitatively similar results, the quasi-classical instantaneous ionization injection model underestimates the population inversions corresponding to the optical transitions at 391 nm, 423 nm and 428 nm due to the assumption of quantum mixed states at the ionization time. A fast and accurate correction to this error is proposed. This work solidifies the theoretical models for population at vibrational states in N2 + and paves the way to uncover the mechanism of the N2 + lasing.

Kinetic analysis of redox processes in Salen-type polymers at sub-zero temperatures

• Injection of counter ion into polymer film limits the redox processes. • The kinetic parameters strongly depends on the structure of the polymer and electrolyte composition. • Solvated counterions injection with small activation energy possible even at the temperatures as low as –40 °C. Batteries and supercapacitors are widely used in various types of portable electronic devices and electric vehicles. Typically, they retain energy and power density at room temperature and at temperatures up to +60° C. However, at sub-zero temperatures, the energy as well as the power density of the power sources dramatically decline due to the sluggish kinetics, mostly connected with solvation/desolvation processes. One of the approaches to solving the problem is using organic electrode materials, among which NiSalen-type polymers may be considered as one of the prospective. Here, we investigate the kinetic restrictions of the redox processes in such polymers at sub-zero temperatures. Temperature-dependent relationships of the kinetic parameters of charge/discharge of poly[Ni(Salen)], poly[Ni(CH 3 Salen)] and poly [Ni(CH 3 Saltmen)] were determined in electrolyte solutions based on acetonitrile and ethyl acetate with Et 4 NBF 4 , LiClO 4 and LiTFSI salts. It was shown that injection of counter ions into the polymer film limits the redox processes, and the activation energy of the process depends on the film structure as well as electrolyte composition. Proper combination of the electrolyte and polymer ensures low-activation process of counter ion injection, which corresponds to the absence of desolvation stage. As a result, fast charge and discharge of such materials is possible at the temperatures as low as –40 °C.

Development of a novel high-performance readout circuit for α and β energy spectrum measurement

A novel high-performance readout circuit with multi-Junction field-effect transistors (Multi-JFETs) and high-speed integrated operational amplifiers as the core was designed. By coupling the circuit to a large area passivated ion injection planar silicon (PIPS) detector, excellent α and β energy spectrum can be obtained. Therefore, it can be applied to radon monitor, radioactive aerosol monitor and other equipment to achieve high precision information on radioactive substances in the environment. The input stage of the circuit adopts the parallel structure of JFETs to achieve the matching between the amplifier circuit with the detector junction capacitance. The bias circuit adopts JFETs to form a constant current source while using the gate-source self-biased parallel structure to obtain large transconductance gain and good amplification linearity. The main amplifier circuit adopts a high-speed and low-noise operational amplifier with the advantages of high open-loop gain and stable quiescent point. The performance of this readout circuit was tested, in which the rise time of the signal is 35 ns, the sensitivity of charge-voltage conversion is better than 0.979 mV/fC when the input capacitance is less than 100 pF, and the equivalent noise charge is 1.55 fC, noise slope is 0.00366 fC/pF. By coupling the readout circuit to a PIPS detector with a sensitive area of 450 mm2, the signal-to-noise ratio of the output signal is 116:1 for the 241Am alpha source and 20:1 for the 90Sr-90Y beta particles. The energy spectrum measurement of the 238Pu source was performed, providing FWHM is 16.90 keV@5499 keV.

The Omnitrap Platform: A Versatile Segmented Linear Ion Trap for Multidimensional Multiple-Stage Tandem Mass Spectrometry.

Multidimensional multiple-stage tandem processing of ions is demonstrated successfully in a novel segmented linear ion trap. The enhanced performance is enabled by incorporating the entire range of ion activation methods into a single platform in a highly dynamic fashion. The ion activation network comprises external injection of reagent ions, radical neutral species, photons, electrons, and collisions with neutrals. Axial segmentation of the two-dimensional trapping field provides access to a unique functionality landscape through a system of purpose-designed regions for processing ions with maximum flexibility. Design aspects of the segmented linear ion trap, termed the Omnitrap platform, are highlighted, and motion of ions trapped by rectangular waveforms is investigated experimentally by mapping the stability diagram, tracing secular frequencies, and exploring different isolation techniques. All fragmentation methods incorporated in the Omnitrap platform involving radical chemistry are shown to provide complete sequence coverage for partially unfolded ubiquitin. Three-stage (MS3) tandem mass spectrometry experiments combining collision-induced dissociation of radical ions produced by electron meta-ionization and further involving two intermediate steps of ion isolation and accumulation are performed with high efficiency, producing information rich spectra with signal-to-noise levels comparable to those obtained in a two-stage (MS2) experiment. The advanced capabilities of the Omnitrap platform to provide in-depth top-down MSn characterization of proteins are portrayed. Performance is further enhanced by connecting the Omnitrap platform to an Orbitrap mass analyzer, while successful integration with time-of-flight analyzers has already been demonstrated.

Stabilisation of a clay soil by injection of different ions

In this research study the effects of calcium and magnesium ions on stabilisation of a clay soil were studied by conducting a set of laboratory tests. A special apparatus was employed for carrying out the tests under constant voltage and time. During the tests, solutions of calcium chloride (CaCl2) or magnesium chloride (MgCl2) with different concentrations were injected into the soil samples. The electro-osmotic and electrokinetics methods were used for stabilisation of the soil and the results were compared with each other. In the electro-osmotic technique, distilled water was used as pore fluid, but in the electrokinetic method, calcium chloride or magnesium chloride solutions with various concentrations were injected into the pores of soil samples. The results revealed an increase in strength of the soil in both methods. In the electrokinetic method, the amount of increase in strength was a function of concentration of the solution that was used. The results also indicated that a solution of calcium chloride is more effective in increasing the strength, discharge flow and electro-osmotic permeability than a magnesium chloride solution at various concentrations. In addition, the variations of these properties are a function of the concentration of the given solution.

Interplanetary Ion Flux Dropouts Across Multiple 3He-Rich Events

Solar Orbiter, a joint ESA/NASA mission, is studying the Sun and inner heliosphere in greater detail than ever before. Launched in February 2020, Solar Orbiter has already completed its first three orbits, reaching perihelia of 0.5 au from the Sun in June 2020, February and August 2021. During the first 2 years in orbit, Solar Orbiter observed multiple 3He-rich Solar Energetic Particle (SEP) events inside 1 au. Even though these events were small, their spectral forms, 3He content, and association with energetic electrons and type III bursts convincingly identifies them as 3He-rich SEP events with properties similar to those previously observed at 1 au, and promising new insights as Solar Orbiter moves much closer to the Sun in 2022. In May 2021, we observed six 3He-rich SEP events in close succession within 48 h when Solar Orbiter was at 0.95 au. These events were likely released from the same active region at the Sun, and the particles arrived at Solar Orbiter in two batches with various abundances and intensities, showing strong anisotropies throughout. Multiple ion flux dropouts were also observed with these six 3He-rich SEP events. The fact that we observed so many ion injections in such a short period of time indicates the 3He enrichment and acceleration mechanism can produce SEP from the same region very efficiently and with varying enrichment levels and intensities. In addition, we report for the first-time dropout features that spanned multiple ion events simultaneously. This implies the field line random walk that we observe at 1 au still maintains magnetic connections to a small region back at the Sun up to the entire duration of these events (∼48 h).

Intercalation of Small Organic Molecules into Ti3C2Tx MXene Cathodes for Flexible High‐Volume‐Capacitance Zn‐Ion Microsupercapacitor

AbstractThe delamination of 2D Ti3C2Tx MXene endows the injection of various ions and small organic molecules into its layers, thus leading to a tunable distance between layers and adjustable electrochemical properties. A suitable selection of intercalators needs to be considered according to the relevant metal‐ion‐based energy storage device because of the different radii of metal ions such as Li+, Na+, Mg2+ Zn2+, etc. Herein, the intercalation of N,N‐dimethylacetamide (DMAC), acetonitrile (ACN), dimethyl sulfoxide (DMSO), LiCl (H2O) into Ti3C2Tx cathodes and their electrochemical performance comparisons by fabricating Zn‐ion microsupercapacitors (MSCs) is reported. Studies found that an increased calculated interlayer space of 3.42, 7.47, 7.79, 8.3 Å is obtained for the H2O, DMSO, ACN, DMAC intercalated Ti3C2Tx cathodes, and a decreased calculated binding energy of −0.03, −0.78, −1.91, and −3.06 eV is obtained for the Ti3C2Tx‐H2O, Ti3C2Tx‐DMSO, Ti3C2Tx‐ACN, and Ti3C2Tx‐DMAC, respectively. The highest interlayer space, lowest binding energy, and amide groups make the DMAC intercalated Ti3C2Tx‐based MSC exhibit volumetric capacitance of 1873 F cm−3 at a scan rate of 5 mV s−1, much higher than 1103 F cm−3 for Ti3C2Tx‐H2O, 1313 F cm−3 for Ti3C2Tx‐ACN, 544 F cm−3 for Ti3C2Tx‐DMSO. The superior flexibility that results in invariable capacitance under 5000 bending cycles, together with the lighting test of the fabricated MSC, demonstrates its application in the wearable integrated system.

Interaction Between Proton Aurora and Stable Auroral Red Arcs Unveiled by Citizen Scientist Photographs

AbstractWe utilized citizen scientist photographs of subauroral emissions in the upper atmosphere and identified a repeatable sequence of proton aurora and subauroral red (SAR) arc during substorms. The sequence started with a pair of green diffuse emissions and a red arc that drifted equatorward during the substorm expansion phase. Simultaneous spectrograph and satellite observations showed that they were subauroral proton aurora, where ion precipitation created secondary electrons that illuminated aurora in green and red colors. The ray structures in the red arc also indicated existence of low‐energy electron precipitation. The green diffuse aurora then decayed but the red arc (SAR arc) continued to move equatorward during the substorm recovery phase. This sequence suggests that the SAR arc was first generated by secondary electrons associated with ion precipitation and may then transition to heat flux or Joule heating. Proton aurora provides observational evidence that ion injection to the inner magnetosphere is the energy source for the initiation of the SAR arc.

Almost perfect sequence modulated multiplexing ion mobility spectrometry.

Multiplexing ion mobility spectrometry with multiple ion injection pulses was used to achieve a high duty cycle and thus improve the signal-to-noise (S/N) ratio while maintaining high resolving power compared with the traditional single-pulse signal averaging method. Historically, an ion mobility spectrum was reconstructed by various multiplexing methods including Fourier transform ion mobility spectrometry (FT-IMS), Hadamard transform ion mobility spectrometry (HT-IMS), and linear frequency modulation correlation ion mobility spectrometry (LFM-CIMS) sequence or Barker code. To achieve an artifact-free multiplexing ion mobility spectrum, an almost perfect sequence (APS) with correlation technique was proposed to modulate the Bradbury-Nielson ion gate and was compared with FT-IMS, HT-IMS, LFM-IMS, and the traditional single-pulse signal averaging method. Experimental results showed that there are no artifact peaks in the APS-IMS spectra except an inverted mirror peak, and the S/N ratio was improved 5-8 times with a repetition time of 40-60 ms, corresponding to the improvement in the duty cycle. With the same duty cycle and similar acquisition time, APS-IMS showed a higher S/N ratio than HT-IMS for its unique autocorrelation response. The APS-IMS technique offered a higher duty cycle and relatively shorter modulation period compared with reported multiplexing methods and is suitable to track rapidly changing signals without losing information and adding extra transformation artifact peaks.

Improving the Surface Friction and Corrosion Resistance of Magnesium Alloy AZ31 by Ion Implantation and Ultrasonic Rolling

The use of the magnesium alloy AZ31 is common in aviation and biomedicine; however, this alloy has poor friction and corrosion resistance. Here, mechanical grinding, ultrasonic rolling, and ultrasonic rolling + ion implantation were performed on the magnesium alloy surface to study the effect of the treatment process on the friction and corrosion resistance of the magnesium alloy surface. The results show that the surface roughness of the magnesium alloy treated by ultrasonic rolling + ion injection is reduced more than mechanical grinding and ultrasonic rolling. The friction coefficient is the lowest, the wear resistance is the best, and new phase nitrogen compounds appear on the surface. The results of SBF (simulated body fluid) solution immersion showed that the sample treated via this composite process had the lowest corrosion rate, which was 62.45% and 58.47% lower than that of the mechanically ground samples. The surface was relatively intact after the corrosion test, and the corrosion resistance was the best. These results can provide a new strategy for magnesium alloy surface protection.

Systematic Engineering of Metal Ion Injection in Memristors for Complex Neuromorphic Computing with High Energy Efficiency

Neuromorphic electronics attract significant attention as a new computing architecture. Despite much effort for achieving practical neuromorphic systems, it is still challenging to construct a synapse array ideal for complex neural networks. Herein, a novel strategy for developing a highly integrated crossbar array of a one‐selector–one‐memory (1S–1R) synapse by systematically engineering ion injection is demonstrated. In the proposed synapse, an electrochemical metallization (ECM) memristor consisting of unstable filaments and a typical ECM device with stable filaments act as a selector with a low leakage current and a stable memory device, respectively. To overcome the voltage‐matching issues in constructing the 1S–1R synapse with high integration density, ion injection related with the electrical properties is optimized in the ECM devices via the distribution of active metal nanoparticles at the interface. The developed synapse possesses a high on/off ratio, superior selectivity, low operating current, and stable multilevel conductance, compared to the previously reported devices. High feasibility for complex neuromorphic systems is demonstrated, and the neural network based on the developed synapse array exhibits reliable parallel computation with high energy efficiency. This promising concept of realizing complex neuromorphic electronics is a fundamental building block for the practical artificial intelligence.

Low-energy ion irradiation effects on chlorine desorption in plasma-enhanced atomic layer deposition (PEALD) for silicon nitride

Precise control of silicon nitride (SiN) film quality is required for SiN plasma-enhanced atomic layer deposition (PEALD) processes. In this study, we examined the interactions of SiCl4 adsorbed Si surfaces with incident ions in the desorption/nitridation half-cycle of typical SiN PEALD with nitrogen plasma irradiation. Reactions of low-energy ion beams with Cl-terminated Si surfaces were investigated with in situ X-ray photoelectron spectroscopy. It was found that N2 + ion injection in the incident energy range of 30–100 eV formed a SiN x (x ≈ 1.33) layer on a Cl-terminated Si surface at room temperature. It was also confirmed that, although low-energy ion injection tends to remove Cl atoms from the surface, some Cl atoms are pushed into a deeper layer by knock-on collisions caused by incident ions. This observation indicates that the complete removal of Cl atoms from the surface by N2 + ion irradiation only is not feasible.

CoronaChargingFoam: An OpenFOAM based solver for multi-physical simulations of direct unipolar diffusion charging of aerosol particles

Diffusion charging of ultrafine aerosol particles is widely used in various fields and understanding the multi-physical phenomena during the charging processes is critical to the optimization of chargers and prediction of particle evolution in particulate systems. In this work, a numerical algorithm of unipolar aerosol diffusion charging is coupled with corona discharge, a combination of electric field, current continuity and heat transfer, and fluid flow enabling the modelling of multi-physics in direct charging processes. The governing equations are discretized based on the finite volume schemes. Methods of numerically calculating the ion-particle attachment coefficients are proposed and a class named niMixedFvPatchField describing the boundary condition of ion injection on the anode is defined on the basis of OpenFOAM libraries. Iteratively strategies are applied to uncouple the governing equations and the PISO (Pressure Implicit with Splitting of Operators) algorithm is used to solve the aerosol flow equations. A new solver labelled as coronaChargingFoam in the OpenFOAM framework is developed to implement the numerical algorithm and it is further validated by comparing four test cases: Laplacian electric field, electric field-charge coupling effect, ion-particle attachment coefficients, and charging efficiencies. Acceptable agreement level in all these comparisons verifies the fidelity of the solver implementation. Program summaryProgram Title: coronaChargingFoamCPC Library link to program files:https://doi.org/10.17632/vrfky24b8m.1Licensing provisions: GNU General Public License (either version 3 or any later version)Programming language: C++External routines/libraries: OpenFOAM (http://www.openfoam.org)Nature of problem: coronaChargingFoam solves the problem of aerosol charging dynamics in direct unipolar diffusion chargers in which the equations of diffusion charging are coupled with corona discharge, a combination of electric field, current continuity and heat transfer, and fluid flow enabling the modelling of multi-physics in direct charging processes.Solution method: coronaChargingFoam employs the Finite-volume method to discretize the governing equations. Iteratively strategies are applied to uncouple the multi-physical equations and the PISO algorithm is used to solve the flow fields. Simpson method and Fibonacci approach are employed in the calculation of ion-particle attachment coefficients. A new class, niMixedFvPatchField, is defined to describe the ion-injection boundary condition on the anode.Additional comments including restrictions and unusual features: The current version of the solver can only be applied in diffusion charging for monodisperse aerosol particles. This restriction will be relaxed in near future by adopting models for polydisperse particles and incorporating field charging mechanism.

Electrostatic Tuning of Ionic Charge in SiO2 Dielectric Thin Films

Dielectric thin films are a fundamental part of solid-state devices providing the means for advanced structures and enhanced operation. Charged dielectrics are a particular kind in which embedded charge is used to create a static electric field which can add functionality and improve the performance of adjacent electronic materials. To date, the charge concentration has been limited to intrinsic defects present after dielectric synthesis, unstable corona charging, or complex implantation processes. While such charging mechanisms have been exploited in silicon surface passivation and energy harvesters, an alternative is presented here. Solid-state cations are migrated into SiO2 thin films using a gateless and implantation-free ion injecting method, which can provide greater long-term durability and enable fine charge tailoring. We demonstrate the migration kinetics and the stability of potassium, rubidium, and caesium cations inside of SiO2 thin films, showing that the ion concentration within the film can be tuned, leading to charge densities between 0.1–10 × 1012 q cm−2. A comprehensive model of ion injection and transport is presented along a detailed investigation of the kinetics of alkali cations. Integrating ionic charge into dielectrics to produce controlled electric fields can enable new architectures where field effect is exploited for improved electron devices.