Ion Injection Research Articles

Mono-Energetic Proton Induced Damages in SiC Power MOSFETs

The mechanisms of single event burnout (SEB) are investigated for SiC MOSFETs by proton irradiation with varying energies. The material melting due to thermal runaway is observed at the damage region for the device with SEB. The proton energy is proved to be a key factor to affect SEB. The proton induced SEB cross-section is higher for higher energy proton irradiation. The information of the secondary ions is obtained through Monte Carlo simulations to explain this phenomenon. The occurrence of SEB depends on the LET value and range of the secondary ions. The relations between SEB and quasi-stationary avalanche characteristics for SiC MOSFET are verified by TCAD simulations. SEB phenomenon actually origins from the secondary breakdown caused by charged ion injection. So the drain bias voltage during irradiation is very important to determine whether SEB occurs.

Evidence of H+‐Band EMIC Waves in the Inner Radiation Belt Observed by Van Allen Probes During Magnetic Storms

AbstractElectromagnetic ion cyclotron (EMIC) waves play an important role in the losses of ring current ions and outer radiation belt relativistic electrons. While EMIC waves have been reported to occur frequently in the outer belt and slot region, there is little information about the occurrence of EMIC waves in the inner radiation belt. On basis of the magnetometer observations from Van Allen Probes, we analyze two representative events of H+‐band EMIC waves that occurred in the inner zone on December 21 and June 22, 2015. We find that these waves occurred synchronously accompanying with 5–35 keV proton dispersive injections at the dawn and night sectors. During the periods of EMIC waves, the perpendicular temperature of injected protons increased, while the corresponding parallel component decreased. By analyzing the relation between the temperature anisotropy and parallel plasma beta for the two cases, we suggest that the evident enhancements of the temperature anisotropy (T⊥/T∥) of 5–35 keV protons may provide the energy source to excite the H+‐band EMIC waves. A total of 16 left‐hand H+‐band EMIC wave events have been found in the inner radiation belt during the 4‐year (2013–2016) interval and all occur during magnetic storms. The statistical results implicated that left‐hand H+‐band EMIC waves in the inner radiation belt is associated with storm‐time ion injections.

Combined Optical, Gravimetric, and Electrical Operando Investigation of Structural Variations in Polymeric Mixed Conductors

AbstractBioelectronics based on organic mixed conductors offers tremendous application potential in biological interfacing, drug delivery systems, and neuromorphic devices. The ion injection and water swelling upon electrochemical switching can significantly change the molecular packing of polymeric mixed conductors and thus influence the device performance. Herein, we quantify ion and water injection, and analyze the change of microscopic molecular packing of typical polymeric mixed conducting materials, namely poly(3,4‑ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) and poly(2‐(3,3′‐bis(2‐(2‐(2‐methoxyethoxy)ethoxy) ethoxy)‐[2,2′‐bithiophen]‐5‐yl)thieno[3,2‐b]thiophene) (p(g2T‐TT)), by integrating electrochemical quartz crystal microbalance with dissipation monitoring, in situ charge accumulation spectroscopy, and electrical current‐voltage measurement. The penetration of ions and water can lead to viscous and disordered microstructures in organic mixed conductors and the water uptake property plays a more dominant role in morphological disruption compared with ion uptake is demonstrated. This study demonstrates the potential application of the combined optical, gravimetric, and electrical operando platform in evaluating the structural kinetics of organic mixed conductors and highlights the importance of concertedly tuning the hydration process, structural integrity, and charge transport properties of organic mixed conductors in order to achieve high performance and stable bioelectronic devices.

Commissioning Results of the New Compact ECR Ion Source for Electrostatic Storage Ring at KACST

A compact microwave ECR ion source with low operating power was tested and commissioned for the ion injector line in the multipurpose low-energy ELASR storage ring facility at King Abdulaziz City for Science and Technology (KACST) in Riyadh. The compact ECR ion source can deliver singly charged ions with an energy of up to 50 keV and a beam current of up to 50 μA or up to 500 µA with a larger extraction aperture. The plasma in the ECR chamber is driven by a simple transmitter antenna, making the overall size of the ion source only 6 cm in diameter, which is relatively small when compared with other ECR systems. Additionally, the source operates without a high-voltage platform, which significantly reduces the overall footprint and simplifies the system operation. In this paper, the mechanical design and modeling of the ECR ion source are introduced, and the layout of the first part of the beam line is presented along with the numerical simulation results. In addition, the experimental results obtained for the first generated ion beam and commissioning of the ECR ion source are introduced and discussed.

Wafer Type Ion Energy Monitoring Sensor for Plasma Diagnosis

We propose a wafer-type ion energy monitoring sensor (IEMS) that can measure the spatially resolved distribution of ion energy over the 150 mm plasma chamber for the in situ monitoring of the semiconductor fabrication process. The IEMS can directly be applied to the semiconductor chip production equipment without further modification of the automated wafer handling system. Thus, it can be adopted as an in situ data acquisition platform for plasma characterization inside the process chamber. To achieve ion energy measurement on the wafer-type sensor, the injected ion flux energy from the plasma sheath was converted into the induced currents on each electrode over the wafer-type sensor, and the generated currents from the ion injection were compared along the position of electrodes. The IEMS operates without problems in the plasma environment and has the same trends as the result predicted through the equation.

The Effect of Energetic Ion Dispersionless Injections on the Ring Current Dynamics

AbstractEnergetic particle injections, usually observed as sudden flux enhancements of charged particles from tens to hundreds of keV, are one of the main mechanisms for ring current enhancement. In this study, we statistically analyzed the influence of dispersionless injections on Earth's ring current based on the measurements of radiation belt storm probes ion composition experiment onboard Van Allen Probes from 2013 to 2019. We identified 813 dispersionless proton injection events, which are mainly in the pre‐midnight sector. With a greater SuperMAG electrojet index (SME), the observed injections extend to lower L shells. Meanwhile, Helium (He+) and oxygen (O+) ions experience almost simultaneous injections with protons. Superposed epoch results show that ion energy densities enhance significantly after injections. As SMEmax increases, the ring current energy densities of all three species are increasing, and the magnitude of the enhancements, defined as the ratio of the energy densities after and before the injection, hardly changes for protons (∼2.0) and He+ ions (∼2.0) but increases for O+ ions (2.6 and 3.0 for SMEmax < 1,000 nT and SMEmax ≥ 1,000 nT, respectively), suggesting the contribution of O+ ions to ring current becomes more significant during super substorms. With proton injections, the dawn‐dusk electric field is enhanced sharply to twice as large as before. Simultaneously, there is a dip followed by gradual dipolarization of the magnetic fields. Moreover, particle anisotropies increase following ion injections, which may generate electromagnetic ion cyclotron waves. These statistical results indicate that ion injections during substorms contribute significantly to the ring current.

Role of impact ionization and self-consistent tunnel injection in Schottky-barrier diodes operating under strong reverse-bias conditions

This work shows that for a correct analysis of Schottky barrier diodes operating under strong reverse-bias conditions, it is necessary to account for the self-consistency between the shape of the energy barrier and carrier concentration in the depletion region since the full-depletion approximation fails to estimate the current. This happens for very high applied voltages, at which impact ionization by electrons and holes must also be considered. Two example GaN diodes with different doping concentrations and barrier heights are analyzed. The results are relevant to regions of the diodes where a very high tunnel injection takes place, like the contact edge or surface inhomogeneities.

Soil Microbial Fuel Cell Based Self-Powered Cathodic Biosensor for Sensitive Detection of Heavy Metals.

Soil microbial fuel cells (SMFCs) are an innovative device for soil-powered biosensors. However, the traditional SMFC sensors relied on anodic biosensing which might be unstable for long-term and continuous monitoring of toxic pollutants. Here, a carbon-felt-based cathodic SMFC biosensor was developed and applied for soil-powered long-term sensing of heavy metal ions. The SMFC-based biosensor generated output voltage about 400 mV with the external load of 1000 Ω. Upon the injection of metal ions, the voltage of the SMFC was increased sharply and quickly reached a stable output within 2~5 min. The metal ions of Cd2+, Zn2+, Pb2+, or Hg2+ ranging from 0.5 to 30 mg/L could be quantified by using this SMFC biosensor. As the anode was immersed in the deep soil, this SMFC-based biosensor was able to monitor efficiently for four months under repeated metal ions detection without significant decrease on the output voltage. This finding demonstrated the clear potential of the cathodic SMFC biosensor, which can be further implemented as a low-cost self-powered biosensor.

A comparison of energetic particle energization observations at MMS and injections at Van Allen Probes

In this study, we examine particle energization and injections that show energetic electron enhancements at both MMS in the magnetotail and Van Allen Probes in the inner magnetosphere. Observing injections along with a corresponding flow burst allows us to better understand injections overall. Searching for suitable events, we found that only a small number of events at MMS had corresponding injections that penetrated far enough into the inner magnetosphere to observe with Van Allen Probes. With the four suitable events we did find, we compared the energy spectra at the two spacecraft and mapped the boundary of where the injection entered the inner magnetosphere. We found that, among these injections in the inner magnetosphere, the electron flux did not increase above ∼400 keV, similar to previous results, but the corresponding signatures in the tail observed increased fluxes at 600 keV or higher. There does not appear to be a comparable flux increase at Van Allen Probes and MMS for a given event. None of our injections included ion enhancements at Van Allen Probes, but one included an ion injection at geosynchronous orbit in the GOES spacecraft. All of our injections were dispersed at Van Allen Probes, and we were therefore able to map an estimate of the injection boundary. All of the injections occurred in the premidnight sector. Although we found some events where particle energizations in the tail are accompanied by inner magnetospheric injections, we do not find a statistical link between the two.

The 18–19 March 2022 series of 3He-rich events observed by Solar Orbiter at 0.36 au compared with EUV, X-ray, and radio observations

Context. During the first close perihelion pass of Solar Orbiter, a series of impulsive 3He-rich solar particle events was observed on 18–19 March 2022 from a distance of 0.36 au. In addition to the energetic particle, radio, and X-ray data from Solar Orbiter, the events were observed in radio and/or extreme ultraviolet by STEREO-A, SDO, Wind, and Parker Solar Probe. Aims. Observations of the event series along with remote sensing of flaring and radio emission with only small timing delays due to the close distance allow the association with energetic particles to be determined with much higher accuracy than previously possible from 1 au. Methods. By comparing the onsets of type-III bursts with the arrival of electrons of tens of keV at Solar Orbiter only a few minutes later, it can be seen that, overall, each of the more intense type-III bursts was associated with an electron and ion injection. Extreme ultraviolet data show that the times of the type-III bursts coincide with emission from a small (approximately Earth-sized) loop to the west of a nearby active region. Results. The energetic particle spectra and abundances show typical properties of impulsive 3He-rich flares and, when combined with the remote sensing observations, establish that the particle-accelerating mechanism in this series of events operates near the solar surface in association with magnetic loops, and in the absence of other phenomena such as jets and small coronal mass ejections.

Abnormal Sub‐Auroral Ion Drifts (ASAID) Developed in Various Inner‐Magnetosphere Configurations at Geomagnetically Quiet Times

AbstractUtilizing multi‐point observations, we investigate a series of inner‐magnetosphere configurations formed at Kp ≤ 3+ when the magnetosphere‐ionosphere (M‐I) conjugate Abnormal Sub‐Auroral Ion Drifts (ASAID) developed near the plasmapause. We analyze the development of ASAID by adopting the recent theories of (1) fast‐time short‐circuiting explaining SAID development and (2) Larmor radius effects explaining ASAID development. The earthward ASAID electric field developed (1) by short‐circuiting when the reconnection‐related earthbound hot ring current (RC) electrons became stopped and ions kept moving earthward and started their usual Larmor rotations, and (2) because of the larger Larmor radius of the hot RC ions creating excess positive charges in the nearby cold‐inner‐edge plasmasheet plasma and deficit negative charges inside the hot RC region. Respective new findings include the observations of (1a) earthward hot RC ion injections across and near the ASAID channel in the inner magnetosphere and (1b) the localized increase of energetic proton differential fluxes (good proxy for hot RC ions) in the topside ionosphere within the ASAID channel, and (2a) M‐I conjugate ASAID and ASAID‐SAID series created by their respective single intrusion and repeated intrusions of hot RC ions into the cold plasmasheet plasma. New findings also include (3) the specifications of plasma waves such as Kelvin‐Helmholtz surface waves and electromagnetic ion cyclotron (EMIC) waves developed in the inner‐magnetosphere during plasmasheet rippling, and (4) the development of multiple ASAID channels in the hot zone impacted by EMIC waves.

Erasing of the Free Induction Decay by Incoherent Ionization Injection

Erasing of the Free Induction Decay by Incoherent Ionization Injection

Computational and experimental study of an ion injector of a weakly divergent ion beam for implementing a method for removing space debris objects by an ion beam

Attention to the method of removing large space debris objects by impacting them with an ion beam has not waned over the past 10 years. The application of this method to the space debris removal from the protected area of the Geostationary Earth Orbit (GEO) seems to be the most effective. This is due to a low energy consumption for removing an object to a safe orbit with ΔV≃11 m/s, which allows the removal of several objects by a single spacecraft. A service spacecraft can be developed for this purpose based on the TelSat geostationary communication satellite technology. At the same time, one of the problematic issues remains that is the development of an injector of a weakly divergent ion beam. The ion beam divergence during injection into the vacuum occurs under the insuperable influence of the ambipolar electric field acting in the beam volume. At the same time, the beam behavior depends on the initial divergence angle stipulated by the conditions of beam formation by the electrostatic acceleration system. This paper considers the results of calculated and experimental studies for the peculiarities of the formation of an ion beam in an ion extraction system with slit and round apertures. The dependence of the initial divergence half-angle on the beam perveance for both geometries was defined. In the operation of the injector designed for the space debris removal, it is necessary to ensure stability of the geometry of the ion-extraction system, which is subject to uneven thermal loading. The resulting thermomechanical deformations of the grids in the technology of ion thrusters are parried by giving the grids a plate shape. Therefore, flat grids made of a carbon-carbon composite material of a new type were used in experiments, which avoided noticeable deformations. The results of experimental investigation of the prototype of ion injector with two configurations of carbon grids (with round and slit perforation) and with the initial divergence half-angle of 2°-4° are given in this paper. The thrust control of an ion beam by changing of the screen grid potential under the condition of a constant beam perveance is considered. It is shown that such regulation is associated with a change in the Mach number, which affects the beam divergence. As an example, the calculation of the dependence of the coefficient k on the distance to the removing object is given, which is considered to be a spent satellite SUPERBIRD-A.

Insights into the effect of hollow cathode with external injection of fast ions in a sputter-type negative ion source

In sputter-type negative ion sources, the negative ion currents and ionization efficiencies are very dependent upon the creation of a sputter crater and formation of an intense plasma glow. This effect has many similarities with the well-known phenomena of hollow cathode discharges (HCDs). This paper discusses the phenomenological model related to conventional HCDs, including modes with injection of external energetic particles. We propose that HCDs play a major role in sputter-type negative ion sources. In this study, we evaluate the phenomenology of a discharge with a hollow cathode and derive an analytical formula that defines the neutral particle density inside the cathode cavity and substantiates how the classic HCD occurs in sputter-type negative ion sources. The cathode pit geometry was revealed by optical microscopy. Volt–ampere characteristics were investigated in order to compare it to typical discharges with hollow cathodes. In sputter-type negative ion sources, known as SNICS, discharge characteristics and observed light glow inside the cathode pit after its formation were very similar to data published on HCDs. The HCD phenomenon explains how the cathode current increases by orders of magnitude after creation of the cathode pit. The HCD effect in SNICS and similar sputter sources compliments existing mechanisms of negative ion production, especially ion pair production close to the cathode surface due to low energy ionization based on the collision–radiation model. The wealth of information accumulated over the last century on HCDs can be used to describe and explain the phenomenology of physics and operation of sputter negative ion sources.

An Artificial Autonomic Nervous System That Implements Heart and Pupil as Controlled by Artificial Sympathetic and Parasympathetic Nerves

AbstractThe autonomic nervous system maintains homeostasis in organisms through complex neural pathways and responds adaptively to changes in the external and internal environment. The fabrication of an artificial autonomic nervous system is reported that replicates combined effects of sympathetic and parasympathetic nerves on cardiac activity and pupillary control, to mimic the regulation of autonomic nervous system to external changes. The artificial autonomic nerve‐controlled pupil contraction and relaxation, modulating the rate of heartbeats for normal cardiac rhythm and arrhythmia as reflected by blink rates of a signal indicator. These functions are switched by using a parallel‐channeled synaptic transistor with a special n‐i‐p heterostructure that has a 2D h‐BN insulator in the middle to provide barrier against ion injection into the 2D MoS2 bottom n‐channel and enable short‐term plasticity as induced by acetylcholine, and the electrochemical doping reaction occurred at the P3HT nanowire p‐channels on top to enable relatively long‐term plasticity as induced by noradrenaline. Low‐energy consumption down to femtojoule and an ultrahigh paired‐pulse facilitation index up to ≈455% are demonstrated. An artificial neural network based on device characteristics achieves a high recognition accuracy for electrocardiogram patterns. This study extends insights into artificial nerves‐inspired biological signal processing and recognition.

Corrosion resistance of Al2O3/FeAl coatings doped with Er2O3 in liquid Pb-15.7Li

Al2O3/FeAl coatings doped with Er2O3 were prepared on CLAM steel by ECX (electrochemical deposition in ionic liquids) and ion injection. The corrosion resistance of samples doped with Er2O3 was investigated in static liquid Pb-15.7Li at 550 °C for 1000 h. After the corrosion test, compared with the sample without Er2O3, the surface of the coating doped with Er2O3 was uniform and smooth, only a few corrosion products could be detected. Such results could be attributed to that: owing to the addition of Er2O3, the inward diffusion of Li and O ions along the coating grain boundaries was moderated, the formation of corrosion products and the growth of oxide layer was reduced. As a consequence, the corrosion resistance of Al2O3/FeAl coatings in liquid Pb-15.7Li was improved by doping Er2O3.

Boosted Output Voltage of BiSbTe‐Based Thermoelectric Generators via Coupled Effect between Thermoelectric Carriers and Triboelectric Charges

AbstractThe present work demonstrates the very first approach to enhancing the output voltage of a thermoelectric generator by introducing highly charged polyimide‐based dielectrics. High charge density over 320 µC m−2 in C60‐containing block polyimide (PI‐b‐C60) having excellent charge retention characteristics is obtained through an ion injection process, attached at the cooling part of a thermoelectric generator consisting of Cu/p‐type BiSbTe/Au/Cr/SiO2/Si. This significantly increases the electric potential difference across the thermoelectric generator (TEG) from 4.2 to 8.2 mV at the temperature difference of 20 K, and this increase can be maintained over 1 day. Density functional theory studies support that the enhancement depends on the dielectric constant and the insulating properties of the dielectric. Finally, a TEG consisting of 81 p‐type BiSbTe legs with PI‐b‐C60 generates an output voltage of 0.632 V, and the charged energy of the 10 mF‐capacitor is boosted by 30 s. These results demonstrate the possibility of large‐area TEG fabrication without the need for modification of the TE materials by introducing a new mechanism which is based on the coupling effect between thermoelectric carriers and triboelectric charges.

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.