Showing papers on "Ion beam deposition published in 2023"
TL;DR: In this paper , a high-brightness and stable sodium ion source is developed, and the performance of Na ion beam optics is simulated by the COMSOL multiphysics. And the authors provide the basis and the design references for the Na-BES development on EAST.
Abstract: Abstract To upgrade the Li-BES to Na-BES on Experimental Advanced Superconducting Tokamak (EAST), a high-brightness and stable sodium (Na) ion source is developed, and the performance of Na ion beam optics is simulated by the COMSOL Multiphysics. The porous tungsten disk with 70% porosity and filled with albite Na 2 O·Al 2 O 3 ·6SiO 2 is successfully developed as the Na ion source. The extracted current density of the Na-beam increases with the extraction voltage, and its maximum current can reach 9 mA with the ion source diameter of 20 mm. The lifetime of the Na ion source is evaluated to be 63 mAh, which is much longer than that of the Li ion source. The simulation shows that the preferable distances among the ion source (or anode electrode), extractor and puller to get the well-focused beam are x puller - x extractor ∼ 0.06 m and x extractor - x ion source ∼ 0.02 m. Further simulation with these optimized distances determines the extraction voltage and ion source size for good beam performance. In addition, the simulation shows the beam divergence angle decreases by more than 40% by optimizing the Einzel voltage to 5 kV, suggesting an excellent focusing property of the Einzel lens. These works provide the basis and the design references for the Na-BES development on EAST.
TL;DR: In this paper , the development of silver ion-beam by Electron Cyclotron Resonance (ECR) plasma sputtering and synthesis of Ag nano-dot arrays by implantation of the Ag+ ions on a pre-fabricated silicon nano-template is reported.
01 Apr 2023-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: An adjustable radio frequency (RF) positive hydrogen ion source is designed in Huazhong University of Science and Technology (HUST) to provide ion beam with adaptive beam current and beam energy for neutral beam injection (NBI) related material research as discussed by the authors .
Abstract: An adjustable radio frequency (RF) positive hydrogen ion source is designed in Huazhong University of Science and Technology (HUST) to provide ion beam with adaptive beam current and beam energy for neutral beam injection (NBI) related material research. The ion source aims to produce 10–20 keV positive hydrogen ion beam with total current of 50–125 mA. This paper investigates the design of the RF ion source including RF driver via inductively discharge mechanism and the extractor which is designed and optimized, including ion beam optics simulation, thermal analysis and power supply analysis. The vacuum analysis of the source is carried out as well.
TL;DR: In this paper , a self-magnetically insulated ion diode was used to produce a pulsed beam of metallic ions from explosion emission plasma, which consisted in a bladed cathode and a removable perforated anode overlay made of VT-8 alloy.
Abstract:
A self-magnetically insulated ion diode was used to produce a pulsed beam of metallic ions from explosion emission plasma. The ratio of integral transferred charge for the Al, Ti and Mo ions amounted to at least 63% to the total beam charge. The ion diode had design features, which consisted in a bladed cathode and a removable perforated anode overlay made of VT-8 alloy. Analysis of the charge to mass characteristics of beam ions and the ion current density waveforms by the time of flight methodic with use of a Faraday cup showed the content of aluminum and titanium ions in the third to fourth states of ionization.
TL;DR: In this paper, 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.
Abstract: 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.
TL;DR: In this paper , the influence of the electrode structure on ion beam extraction in a cold-cathode ion source was investigated, and the authors found that the potential structure inside the plasma source, which is greatly influenced by the electrodes structure, plays a significant role in determining the amount and divergence of the extracted ion beam.
Abstract: In this study, we investigated the influence of the electrode structure on ion beam extraction in a cold-cathode ion source. Numerical simulations were performed for three typical structures of cold-cathode ion sources with different cathode and anode geometries using in- house 2-D ion ray-tracing code. We found that the potential structure inside the plasma source, which is greatly influenced by the electrode structure, plays a significant role in determining the amount and divergence of the extracted ion beam. The electrode structure influences the potential structure inside the plasma source and forms a radial electric field between the sheath edge and the extraction aperture. The radial electric field guides the ion beam to focus or diverge in this region, thus changing the characteristics of the ion beam extracted from the aperture. The simulation results reveal that the ion source with the cylindrical anode geometry extracts a higher current than those with other geometries due to its potential structure, which focuses the ion beam more efficiently. The simulation results are consistent with those of our experiments with a small-sized cold-cathode ion source.
01 Jan 2023
TL;DR: The high-density arc electron flow in arc discharge can generate more argon ions and metal ions, thereby increasing the sputtering rate and metal ionization rate in magnetron sputtering technology as discussed by the authors .
Abstract: Charged particle flow includes ion beam flow and electron flow. The high-energy ion beams can take part in ion implantation, ion beam sputtering, and ion beam mixing on the material surface. Ion sources that generate high-energy ions include ion implanter, Hall ion source, Kaufman ion source, anode layer ion source, hollow cathode Hall ion source, and radio frequency ion source. The high-density arc electron flow in arc discharge can generate more argon ions and metal ions, thereby increasing the sputtering rate and metal ionization rate. In magnetron sputtering technology the electron flow has three functions: cleaning, ionization, and deposition. The flow can improve the film quality. High-density electron flow can be generated by hollow cathode guns, hot-wire arc guns, and various cathode arc sources.
TL;DR: In this paper , an ion beam system based on Kaufman ion source is designed, which can meet the ground calibration of space low-energy ion detection instrument in the low energy range of 100-1,000 eV.
Abstract: Abstract Low-energy ion detection in space is one of the most important interests of space exploration. An accurate calibration of this type of instrument is necessary to ensure the effectiveness and scientificness of the obtained data. And the ion source is the most critical equipment in a calibration facility. In this study, an ion beam system based on Kaufman ion source is designed, which can meet the ground calibration of space low-energy ion detection instrument in the low-energy range of 100–1,000 eV. The experimental research shows that when the beam intensity of the ion source is about 100 mA, the Faraday Cup collects about 1 mA of current, and the generated ion beam fluctuates less than 5% within 60 min, which can meet the ground calibration requirements of space low-energy ion detection instruments.
TL;DR: In this article , the authors present the results of studies of the processes of compensation of the surface charge of an insulated collector upon interaction with a beam of metal ions with energies up to 50-150 keV.
Abstract: The interaction of ion beams with dielectric materials is an urgent problem, both from the point of view of practical application in ion implantation processes and for understanding the fundamental processes of charge compensation and the effective interaction of beam ions with a target surface. This paper presents the results of studies of the processes of compensation of the surface charge of an insulated collector upon interaction with a beam of metal ions with energies up to 50–150 keV. At low pressure (about 10−6 torr), removing the collector from the region of extraction and beam formation makes it possible to reduce the floating potential to a value of 5–10% of the total accelerating voltage. This phenomenon allows for the efficient implantation of metal ions onto the surface of alumina ceramics. We have shown that the sheet resistance of dielectric targets depends on the material of the implanted metal ions and decreases with an increase in the implantation dose by 3–4 orders of magnitude compared with the initial value at the level of 1012 Ω per square.
TL;DR: In this paper , the effect of a 445 nm, high power diode laser, directed on the cathode of a SNICS ion source on the extracted beam currents of Cl , Br and I - ion beams was measured.
Abstract: Abstract We have measured the effect of 445 nm, high power diode laser, directed on the cathode of a SNICS ion source on the extracted beam currents of Cl - , Br - and I - ion beams. Beam current enhancement factors up to 9 were observed in Cs-depleted operation mode of the ion source. The photo-assisted enhancement is shown to scale with the laser power and depend strongly on the neutral Cs flux into the ion source. The effect of the laser diminishes with increasing Cs oven temperature. We present a qualitative model, supported by cathode current measurement, arguing that photoelectron emission and Cs coverage of the cathode surface could explain the observations.
15 May 2023
TL;DR: In this article , an ion beam system based on Kaufman ion source is designed, which can meet the ground calibration of space low-energy ion detection instrument in the low energy range of 100-1000eV.
Abstract: Low energy ion detection in space is one of the important directions of space science detection. An accurate calibration of this type of instrument is necessary to ensure the effectiveness and scientificity of the obtained data. And the ion source is the most critical equipment in a calibration facility. In this study, an ion beam system based on Kaufman ion source is designed, which can meet the ground calibration of space low-energy ion detection instrument in the low-energy range of 100-1000eV. The experimental research shows that when the beam intensity of the ion source is about 100mA, the Faraday Cup collects about 1mA of current, and the generated ion beam fluctuates less than 5% within 60 minutes, which can meet the ground calibration requirements of space low-energy ion detection instruments.
21 Mar 2023-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this paper , two methods of molecular beam production were studied: extraction of molecular ion beams from the ion source, and formation of molecular ions from the mass-separated ion beam in a gas-filled radio-frequency quadrupole ion trap.
Abstract: The use of radioactive molecules for fundamental physics research is a developing interdisciplinary field limited dominantly by their scarce availability. In this work, radioactive molecular ion beams containing actinide nuclei extracted from uranium carbide targets are produced via the Isotope Separation On-Line technique at the CERN-ISOLDE facility. Two methods of molecular beam production are studied: extraction of molecular ion beams from the ion source, and formation of molecular ions from the mass-separated ion beam in a gas-filled radio-frequency quadrupole ion trap. Ion currents of U$^+$, UO$_{1-3}^+$, UC$_{1-3}^+$, UF$_{1-4}^+$, UF$_{1,2}$O$_{1,2}^+$ are reported. Metastable tantalum and uranium fluoride molecular ions are identified. Formation of UO$_{1-3}^+$, U(OH)$_{1-3}^+$, UC$_{1-3}^+$, UF$_{1,2}$O$_{1,2}^+$ from mass-separated beams of U$^+$, UF$_{1,2}^+$ with residual gas is observed in the ion trap. The effect of trapping time on molecular formation is presented.
TL;DR: In this article , an ion beam was produced using a needle emitter equipped with a thermocouple, and sharpened glass rod externally wetted with propylammonium nitrate (PAN).
Abstract: Ionic liquid ion sources generate ion beams from ionic liquids by vacuum electrospray. Electrospray characteristics generally depend on the physical properties of the liquids used. A key factor affecting physical properties is temperature. In this study, ion beam production was investigated using a protic ionic liquid, propylammonium nitrate (PAN), at temperatures ranging from 22 to 60 °C. An ion beam was produced using a needle emitter equipped with a cartridge heater, thermocouple, and sharpened glass rod externally wetted with PAN. The experimental results showed that the heating of the emitter increased the ion beam current. This will be due to an increase in the conductivity and a decrease in the viscosity of PAN with increasing temperature. Furthermore, the abundance of larger cluster ions increased, whereas that of smaller cluster ions decreased with increasing temperature. It turned out, however, that higher heating of the emitter stopped ion beam production. Two hypotheses for the beam stop are proposed and discussed.
TL;DR: In this paper , a Hall magnetohydrodynamic converter of the ion beam kinetic energy into electrical energy is described, where the decelerated electrode imitating the substrate is located in the field of action of a magnetic field with an induction of 0.45 T.
Abstract: The features of the method for the formation of dense low-energy ion beams in the system consisting of ion source-ion decelerator are considered. According to this method, a wide ion beam is formed using an ion source with an ion energy of 500 eV and higher, and then the ions are decelerated just before landing on the substrate surface by an electric field created in the ion decelerator. In the considered ion decelerator, the electric field that slows down the ions is created in a gas discharge in E × B fields due to the Hall effect. The decelerated electrode imitating the substrate is located in the field of action of a magnetic field with an induction of 0.45 T. The ion decelerator is characterized as a Hall magnetohydrodynamic converter of the ion beam kinetic energy into electrical energy. The analysis of plasma processes in the converter has been carried out on the basis of the model of the ion-vacuum regime of a discharge in E × B fields for estimating the expected properties of the converter and their verification based on experimental results. In experiments, an ion source of the Kaufman type formed an argon ion beam with a density of 0.5-2 mA/cm2 and ion energy of 300-1500 eV was used. The voltage-current characteristics of the converter are given. The ratio of electron and ion components of the current in the circuit of the decelerated electrode was determined when the beam space charge neutralizer in the form of a heated filament was switched on and off. Using a Langmuir probe and a thermionic probe, the distributions of the ion beam current density and the potential of the plasma surrounding the ion beam in the beam transport space has been studied. A significant influence of the potential of the decelerator electrode on the plasma potential in the region of ion beam transport is shown. The features of the discharge in a specific design of the ion decelerator for a deceleration degree of ions to an energy of 50-75 eV are revealed.
TL;DR: In this article , a variable-focusing retarding field energy analyzer (RFEA) has been developed and tested with an Ar+ beam and an oxygen ion beam extracted from a 2.45 GHz microwave ion source, which is developed as a candidate ion source for SIMS applications.
Abstract: The energy spread (ΔE) of an ion source is an important parameter in the production of a finely focused primary ion beam applied in secondary ion mass spectrometry (SIMS). A variable-focusing retarding field energy analyzer (RFEA) has been developed and tested with an Ar+ beam and an oxygen ion beam extracted from a 2.45 GHz microwave ion source, which is developed as a candidate ion source for SIMS applications. The simulation results show that the relative resolution ΔE/E of the designed RFEA reaches 7 × 10−5. The experimental results indicate that a focusing electrode can improve the ΔE measurement results, which is consistent with the simulation results. The ion energy distributions of the Ar+ beam and oxygen ion beam are of Gaussian distribution with the value of ΔE of 3.3 and 2.9 eV, respectively. These results indicate that the designed RFEA is reliable for measuring the ion beam energy spread. The developed RFEA is also used to study the plasma behavior in different settings, which reveals that plasma stability is critical to making a low energy spread ion beam. This paper will present the simulation, design, and test of the variable-focusing RFEA. Preliminary ion beam quality studies with this instrument will also be discussed.