High-energy Ion Research Articles

High-power and high-energy zinc ion cathodes through embedded CNTs current collectors in vanadium oxide

High-power and high-energy zinc ion cathodes through embedded CNTs current collectors in vanadium oxide

Dual-Loop Charge Management for Space-Based Gravitational Wave Detection

In space-based gravitational wave detection missions, inertial sensors act as the inertial reference, requiring the test mass (TM) to maintain exceptionally low residual acceleration noise. High-energy particles, cosmic rays, and ion pumps during ground tests can quickly lead to charge accumulation on the TM surface, necessitating a charge management system to regulate surface charges. To manage the TM surface potential, this paper develops a mathematical model of the charge management system using established ultraviolet (UV) discharge simulation methods. The model describes how photoelectron emission or absorption on the TM surface varies with UV light-emitting diodes (LEDs) power and bias voltage. For the first time, a dual-loop control method is implemented for charge control, highlighting its practical significance. The controller precisely regulates the TM surface potential and residual charges to specified values, achieving a control accuracy of 1.1×106e, meeting the stringent requirements of space-based gravitational wave detection missions. This approach offers a closed-loop charge management solution and provides valuable insights for designing future charge management systems.

The HEARTS EU Project and its Initial Results on Fragmented High-Energy Heavy Ion Single Event Effects Testing

The HEARTS EU Project and its Initial Results on Fragmented High-Energy Heavy Ion Single Event Effects Testing

Development of a high-resolution, high-dynamic-range charge detector for ion beam monitoring

We present an innovative charge detector with high resolution and wide dynamic range designed to fulfill the requirements of a monitoring system for a high energy ion beam. The detector prototype, constructed using Si photodiodes and a custom readout electronics, underwent extensive testing during HERD and AMS beam tests at CERN SPS facilities. Initial testing showcased the detector's exceptional performance, emphasizing both high resolution and a dynamic range capable of measuring nuclei with atomic numbers ranging from 1 to 80. The prototype's compatibility with fast, quasi real-time data analysis qualifies it as an ideal candidate for online applications. This article presents the results from the testing phase of the prototype, highlighting its capabilities and performance. Ongoing detector development, potential applications, and future developments aimed at enhancing the detector's functionality and versatility are also discussed.

Influence of energetic heavy ion sputtering on lifetime of alloy target

When energetic heavy ions are incident on negatively charged structure that collects and deposits ions, ion sputtering will occur. Metal wire is a structure commonly used for accelerating ions, the incidence of continuous high-throughput ions can cause surface loss of metal wire, affecting the service performance and lifespan of the metal wire. The SRIM software commonly used for calculating sputtering yield cannot consider the multi-body interaction problem contained in the alloy crystal structure. so, there is a significant error in calculating the sputtering yield of high-energy ions incident on alloy target. Based on the molecular dynamics method and Langevin temperature control model, the calculation model of ion sputtering parameters of energetic metal ions incident on alloy target is established in this work. The model is used to calculate the sputtering yield under the conditions of intact surface lattice of the target material and long-term incident surface lattice damage. The damages to the cathode metal wire under different incident ion fluences are further calculated, and the cross-sectional characterization of the metal wire is carried under typical working condition. The results show that the discrepancy between the experimental value and the theoretical value is less than 10%, which verifies the accuracy and applicability of the theoretical model. Based on this model, the search direction for sputtering resistant materials is proposed, meanwhile, a theoretical optimization is carried out to improve the service life of metal wire, and a method of using Ni-Ti alloy to improve the service life of metal wires is proposed, which is of great significance for predicting the service life of the metal wire under different conditions.

Laser Wakefield Acceleration of Ions with a Transverse Flying Focus.

The extreme electric fields created in high-intensity laser-plasma interactions could generate energetic ions far more compactly than traditional accelerators. Despite this promise, laser-plasma accelerator experiments have been limited to maximum ion energies of ∼100 MeV/nucleon. The central challenge is the low charge-to-mass ratio of ions, which has precluded one of the most successful approaches used for electrons: laser wakefield acceleration. Here, we show that a laser pulse with a focal spot that moves transverse to the laser propagation direction enables wakefield acceleration of ions to GeV energies in underdense plasma. Three-dimensional particle-in-cell simulations demonstrate that this relativistic-intensity "transverse flying focus" can trap ions in a comoving electrostatic pocket, producing a monoenergetic collimated ion beam. With a peak intensity of 10^{20} W/cm^{2} and an acceleration distance of 0.44cm, we observe a proton beam with 23.1pC charge, 1.6GeV peak energy, and 3.7% relative energy spread. This approach allows for compact high-repetition-rate production of high-energy ions, highlighting the capability of more generalized spatiotemporal pulse shaping to address open problems in plasma physics.

Effect of Ion-Assisted Deposition Energy of RF Source on Optical Properties, Microstructure, and Residual Stress of HfO2 Thin Films

HfO2 thin films were prepared using radio frequency (RF) ion source-assisted deposition, and the effects of auxiliary ion energy on the microstructure, optical properties, and residual stress of the films were systematically studied. The experimental results showed that when the auxiliary ion energy increased, the extinction coefficient, compressive stress, and optical band gap were gradually increased. These changes were attributed to increased grain boundary defects, crystal structure disorder, and grain size decrease due to high-energy ion bombardment. The HfO2 films deposited at a lower ion energy (600 V) exhibited higher surface quality (RMS = 0.78 nm), better optical properties (k = 10⁻5), and lower residual stress (1.26 GPa).

Molecular Design and Mechanism Study of Non-Activated Collectors for Sphalerite (ZnS) Based on Coordination Chemistry Theory and Quantum Chemical Simulation.

Sphalerite flotation is generally achieved by copper activation followed by xanthate collection. This study aims to propose a design idea to find novel collectors from the perspective of molecular design and prove the theoretical feasibility that the collector can effectively recover sphalerite without copper activation. To address this, 30 compounds containing different structures of sulfur atoms and different neighboring atoms were designed based on coordination chemistry. Twelve potential collectors were screened, and their properties and interactions with a hydrated sphalerite (110) surface were evaluated. Compound 27 (C2H4S22-) showed the greatest reactivity, suggesting that the double-coordination structure of two sulfhydryl groups is an effective molecular structure for direct sphalerite flotation. The DFTB+ and MD results demonstrate that 1,2-butanedithiol (C4H10S2), having a similar coordination structure to compound 27, has the potential to replace the traditional reagent scheme of sphalerite flotation. The strong reagent-surface interaction is attributed to the overlap of Zn 3d with S 3p orbitals, the most negative electrostatic potential, the relatively high EHOMO and low average local ionization energy, and the eliminated steric hindrance effect. It is expected that this study can provide a design idea for the targeted design and development of novel reagents for complex sulfide ore flotation.

Study of the 3-(3,3-Dimethylbutanoyl)-4-hydroxy-6-neopentyl-2H-pyran-2-one by IR, Raman spectroscopy, and DFT

The heterocyclic structure of pyrones has a variety of biological activities and plays an important role in the creation of new drugs. Therefore, the study of the structure and spectra of pyrones is of considerable interest. In this work, we studied the IR and Raman spectra of 3-(3,3-Dimethylbutanoyl)-4-hydroxy-6-neopentyl-2H-pyran-2-one (1) in its crystalline state. The tautomerization of 1 was followed by a quantum-chemical method at the DFT/B3LYP/6-311G** level. The calculation for the 4-hydroxy enol tautomer (A) reproduces the experimental IR and Raman spectra of compound 1. The classification of the bands in the experimental vibrational spectra of 1 has been carried out. The intramolecular H-bond was characterized by IR spectroscopy. The free energies of the tautomers and their populations were calculated for two different solvents. It appears from our data that tipe A dominates. The content of tautomer B increases in the nonpolar solvent but does not exceed 13%. As can be seen from our calculations and experimental X-ray data, the pyran ring of the molecule is flat. HOMO and LUMO of molecule 1 are located on the pyran ring. During tautomeric transformations, there is a significant delocalization of charge and a change in the reactivity of the molecule. The reactivity of pyrone 1 was characterized using descriptors. The form B was found to have higher ionization energy, electron affinity, chemical potential, and electrophilic index than the A form. The dipole moment is higher for form A, and the softness of the two molecules is the same.

Optimal conditions for efficient ion acceleration and neutron production in deuterium gas-puff z-pinches

Abstract Deuterium gas-puff z-pinches are researched primarily as efficient sources of DD fusion neutrons. The first experiment with a deuterium gas jet was carried out in 1978 (J. Shiloh, A. Fisher, and N. Rostoker, Phys. Rev. Lett. 40, 515518, 1978). Since then, several D2 gas-puff experiments have been performed on various pulsed-power generators. The highest, so far published, DD neutron yields of 4×1013 were observed on the Z-machine at Sandia National Laboratories around 2005 (C.A. Coverdale, et al. Phys. Plasmas 14, 022706, 2007). More recently, z-pinch experiments with a plasma shell on a deuterium gas puff were carried out on GIT-12 higher-impedance pulsed-power generator at 3 MA currents. On GIT-12, unique results were high neutron and ion energies, which approached 60 MeV. Comparison of deuterium gas-puff experiments on different generators allows the identification of the parameters essential for optimizing neutron production. These parameters include the optimal mass, preionization, short deuterium gas-injection time, and zippering towards a cathode. Neutron yields appear to depend not only on a current, but also on other parameters of a generator, such as an impedance and the energy stored in a capacitor bank. Our conclusions regarding the optimal conditions were tested on the Hawk generator (NRL, Washington, DC). At a current of 0.7 MA, Hawk accelerated deuterons up to 15 MeV producing one neutron pulse with the yield of the order of 1010 and a broad energy spectrum in the axial and radial direction. These results show that ion acceleration mechanisms in deuterium gas-puff z-pinches could be very efficient and attractive, with a variety of potential applications in high-energy-density physics, materials science, and controlled thermonuclear fusion research.

Charge-exchange measurements of high-energy fast ions in LHD using negative-ion neutral beam injection

A new sightline geometry for the fast-ion D-alpha (FIDA) diagnostic on the Large Helical Device (LHD) has been confirmed to measure signals for high-energy fast ions produced by negative-ion neutral beam injection. The newly installed sightline uses a 180 keV tangential negative-ion neutral beamline as the active source. Due to the small angle between the beamline and FIDA sightline, the relative velocity between fast ions and injected neutrals is small. This allows for high-energy fast ions just below the beam injection energy to produce measurable Doppler-shifted FIDA emission. Experiments were conducted at LHD in order to compare the new sightline, which views a high-energy negative-ion tangential beamline, and the old sightline, which views a low-energy perpendicular positive-ion neutral beamline. The measured FIDA signal is validated against predictions from the synthetic fast-ion diagnostic code FIDASIM with a distribution function modelled by the 5D transport code GNET. The results of the experiment confirm that reducing the viewing angle with a tangential active beam allows FIDA diagnostic to view high-energy fast ions with a sufficient signal-to-noise ratio.

Observational Signatures of AGN Feedback in the Morphology and the Ionization States of Milky Way-like Galaxies

We make an in-depth analysis of different active galactic nuclei (AGN) jet models’ signatures, inducing quiescence in galaxies with a halo mass of 1012 M ⊙. Three jet models, including cosmic-ray-dominant, hot thermal, and precessing kinetic jets, are studied at two energy flux levels each, compared to a jet-free, stellar feedback-only simulation. Each of our simulations is idealized isolated galaxy simulations with AGN jet powers that are constant in time and generated using GIZMO and with FIRE stellar feedback. We examine the distribution of Mg ii, O vi, and O viii ions, alongside gas temperature and density profiles. Low-energy ions, like Mg ii, concentrate in the interstellar medium (ISM), while higher energy ions, e.g., O viii, prevail at the AGN jet cocoon’s edge. High-energy flux jets display an isotropic ion distribution with lower overall density. High-energy thermal or cosmic-ray jets pressurize at smaller radii, significantly suppressing core density. The cosmic-ray jet provides extra pressure support, extending cool and warm gas distribution. A break in the ion-to-mass ratio slope in O vi and O viii is demonstrated in the ISM-to-circumgalactic medium (CGM) transition (between 10 and 30 kpc), growing smoothly toward the CGM at greater distances.

Ag polycrystal and monocrystal by high sensitivity-low energy ion scattering

Low energy ion scattering is a qualitative and quantitative surface analysis technique. Its supreme surface sensitivity and straightforward quantification (using a well-defined reference) make it a convenient tool for the study of surface composition and a useful method for surface characterization in cooperation with other surface analysis methods such as XPS and SIMS. Silver (100) monocrystal was analyzed by the primary beam of helium ions. The wide energy range from 1.0 to 4.5 keV covers three distinguished regions. On the low energy side, the charge exchange processes are dominated by Auger neutralization (AN), while collision-induced (CI) processes rule a high energy range. Both mechanisms are mixed in the intermediate region between 1.2 and 2.1 keV (for perpendicular incidence and 145° scattering geometry). The results can serve both as a reference and as an insight into neutralization probability changes (as dependence on primary energy). The neutralization strength is reflected by the characteristic velocity. It was evaluated for AN and CI regions to 0.75 × 105 and 0.38 × 105 ms−1, respectively. The CI reionization energy threshold is around 1700 eV for both Ag (100) and polycrystalline Ag. The reference measurement on polycrystalline copper relates the presented data to those received by other Qtac100 instruments with different sensitivities.

Performance of the prototype beam drift chamber for LAMPS at RAON with proton and 12C beams

Beam Drift Chamber (BDC) is designed to reconstruct the trajectories of incident rare isotope beams provided by RAON (Rare isotope Accelerator complex for ON-line experiments) into the experimental target of LAMPS (Large Acceptance Multi-Purpose Spectrometer). To conduct the performance test of the BDC, the prototype BDC (pBDC) is manufactured and evaluated with the high energy ion beams from HIMAC (Heavy Ion Medical Accelerator in Chiba) facility in Japan. Two kinds of ion beams, 100 MeV proton, and 200 MeV/u 12C, have been utilized for this evaluation, and the track reconstruction efficiency and position resolution have been measured as the function of applied high voltage. This paper introduces the construction details and presents the track reconstruction efficiency and position resolution of pBDC.

Boron doped Ti2Nb10O29 nanosheets core/shell arrays as advanced high-energy anode for fast lithium ions storage

Titanium niobium oxide (Ti2Nb10O29, TNO) as anode for high-energy lithium ion batteries (LIBs) typically suffers from sluggish kinetics and reaction activity because of its inferior electronic/ionic conductivity and easy aggregation feature. Herein, we present a novel synergistic strategy to tackle such problems of TNO by combining boron (B) doping and porous carbon nanosheet (PCN) arrays support. Experiment results and theoretical calculations demonstrate that the doped B substantially ameliorates the intrinsic electronic/ionic conductivity of TNO, increases the oxygen vacancy content in TNO, and accelerates lithium ion diffusion. Meanwhile, high-conductive PCN arrays as growth skeleton can avoid the agglomeration of B-TNO particles. As a result, the as-prepared PCN/B-TNO anode delivers an impressive specific capacity of 303 mAh g−1 at 1 C and 104 mAh g−1 at 20 C, superior to the PCN/TNO anode. Additionally, PCN/B-TNO anode also possesses a prominent long-time durability (85 % capacity retention after 2000 cycles). Our work paves a new way of rationally constructing high-energy anodes for fast energy storage and release.

Tuning the bandgap and photoluminescence properties of Ge/Al2O3 multilayer thin films using annealing and ion beam irradiation

Abstract The present work reports high energy ion beam irradiation induced modifications in Ge/Al2O3 multilayers (MLs). Ge and Al2O3 multilayer thin films were deposited using the electron beam evaporation technique. Afterward, the as-deposited films were annealed using Rapid thermal annealing (RTA) at different temperatures ranging from 500 to 800°C under high vacuum. At a constant fluence of 5×1012 ions /cm2, the annealed films were subjected to irradiation with 80 MeV Ag ions. X-ray diffraction patterns show the crystalline nature of films that were annealed above 500°C, and the increase in crystallite size of Ge nanocrystals from 4.5 to 5.7 nm is observed for annealed samples. After Ag ion irradiation, the crystallinity of the films deteriorates. The crystallinity and optical bandgap are found to vary with Ag ion irradiation. The band gap of annealed films decreased from 1.1 to 0.97 eV with increase in crystallite size. The band gap of irradiated samples increased than that of pristine films. In addition, photoluminescence (PL) measurements were carried out to investigate the luminescence characteristics of annealed and irradiated multilayer films, and a wide emission band in the visible region was observed. The basic mechanism for tailoring the optical band gap and PL emission using RTA and ion irradiation is discussed.


Boron trace amount measurement in LaB6 hollow cathode discharge using an improved actinometry method based on OES

Abstract The erosion of hollow cathode critical structures is inevitable for the high-temperature and high-energy ion environment. As the amount of erosion product is very small in a short time, it is difficult to achieve online monitoring by traditional methods. This paper established an improved actinometry method based on optical emission spectroscopy (OES) to achieve online monitoring of the density of boron (B) erosion products from the lanthanum hexaboride (LaB6) cathode emitter without damaging the cathode structure. In this method, the intensity of spectral lines generated by the transitions of xenon (Xe) from its ground state and metastable state was collected. Then, the electron temperature can be calculated using the collisional-radiative model of Xenon spectral lines. Further, the number density of B is obtained through the ratio of spectral lines excited from the ground state of B and Xe, and thereby the rate of production of B erosion products from the emitter per unit time is determined. The erosion rate of the cathode under different operating conditions was measured. It was found that the erosion of the cathode emitter was closely related to the flowrate and low-frequency current oscillations of the cathode. Therefore, it is necessary to avoid low-frequency current oscillations and appropriately increase the gas flowrate of the cathode to improve the lifespan of the cathode emitter.

Monte Carlo study of high-energy light ions for minibeam radiation therapy approach

Monte Carlo study of high-energy light ions for minibeam radiation therapy approach

Molten Salt Synthesis and Growth Mechanism of Single Crystal Ni-Rich Layered Oxides As Cathode Materials

Responding to the growing demand for high-energy lithium ion batteries (LIBs), it is crucial to develop advanced materials which offer higher energy density than currently available commercial materials. The class of Ni-rich layered oxide has attracted great interest owing to their prime advantage of high reversible capacity.[1] However, conventional polycrystalline cathodes suffer from intergranular cracking that occurs within secondary particles during repeated cycling, leading to the loss of contact between active materials and an increase in the exposed fresh surfaces to further parasitic reactions with electrolytes.[2-3] Consequently, this phenomenon results in a significant impedance rise and rapid deterioration in performance.In response to the challenge of intergranular cracking, the utilization of a single crystal morphology has been proposed as a promising solution. Studies have demonstrated that eliminating grain boundaries allows a single crystal cathode to maintain structural integrity, suppress the formation of intergranular cracks, and ultimately enhance cycle stability.[4-5] Nevertheless, ongoing debates persist regarding gas evolution and rate performances. One reason for this lies in the diverse characteristics of single crystal particles, such as particle size and shape, the degree of agglomeration, and cation disorder, all of which exert a complex influence on their properties. To effectively manage these features, a comprehensive understanding of the synthesis process and the identification of critical factors that affect the properties of single crystal Ni-rich cathodes are necessary.In this study, we elucidated the synthesis mechanism of single crystal LiNi0.95Co0.05O2 (SC95) using the molten salt synthesis (MSS) method, employing a combination of lithium hydroxide (LiOH) and lithium sulfate (Li2SO4) as a salt mixture. Through a comparative analysis of the MSS process against the solid-state synthesis, we closely examined the mechanisms governing crystal growth and morphology evolution during MSS. By conducting a comprehensive analysis, including in situ heating XRD, SEM, and EPMA, we demonstrated that the unique synthesis behavior of MSS stemmed from both the formation process of a layered structure and the grain growth of SC95 proceeded through a liquid-solid phase reaction. The maintenance of the salt mixture in a molten state during the reaction facilitated the uniform coverage of the precursor, resulting in a homogeneous reaction and effective dispersion of SC95. Based on these findings, we successfully prepared discrete micron-sized SC95 particles with monodisperse particle size distribution. The SC95 cathode exhibited superior cyclability over 150 cycles with a capacity retention of 89 % at a 1 C rate. This study provides valuable insights necessary for designing highly dispersed single crystal Ni-rich cathodes.

Nano-Level Homogeneity of SiGe-Cu Composite Anodes

Employing alloy anodes based on Si, Ge, Sn, etc. can increase the energy density of lithium-ion batteries (LIBs) by their high gravimetric capacity.1 Their large volumetric expansion during lithiation, however, leads to cracks and solid electrolyte interphase (SEI) breakdown, followed by pulverization.2 Alloy engineering, creating composite alloys via ball milling of e.g. an active Si-phase embedded in an inactive matrix to buffer volume expansion, is one alternative approach/remedy.3-6 But the homogeneity of the alloy created varies with the processing conditions, such as the ball milling material (steel/WC/ZrO2), speed and duration, as well as the diameter and number of balls.As proof-of-concept and to learn more about the dependency on high-energy ball milling conditions, we have here synthesized SiGeCu (SGC) composite alloy anodes. Cu forms in situ Cu3Ge, which enhances electrical conductivity and acts as the buffer phase for SiGe. Atom probe tomography (APT) is used to quantify the nano-level homogeneity, and this is correlated vs. the electrochemical performance in LIB half-cells of Li/1 M LP57 + 10% FEC/SGC, with the composite anode subject to different ball milling durations. The shorter duration (40 h) leads to formation of an isolated Si-phase (Figure 1a) and this half-cell has quite different characteristics as compared to the half-cell when only SiGe and Cu3Ge phases are formed (longer duration, 60 h) (Figure 1b) – especially w r t the reproducibility of the capacity, proving the role and importance of nano-level homogeneity.Figure 1: a) the isolated Si-phase as revealed by APT, and b) cycling data for the Li/1 M LP57 + 10% FEC/SGC half-cells – two for each ball-milling duration produced SGC. References (1) Wang, X.; Tang, S.; Guo, W.; Fu, Y.; Manthiram, A. Advances in Multimetallic Alloy-Based Anodes for Alkali-Ion and Alkali-Metal Batteries. Materials Today 2021, 50 (November), 259–275.(2) Eshetu, G. G.; Zhang, H.; Judez, X.; Adenusi, H.; Armand, M.; Passerini, S.; Figgemeier, E. Production of High-Energy Li-Ion Batteries Comprising Silicon-Containing Anodes and Insertion-Type Cathodes. Nat Commun 2021, 12 (1), 1–14.(3) Ruttert, M.; Siozios, V.; Winter, M.; Placke, T. Mechanochemical Synthesis of Fe-Si-Based Anode Materials for High-Energy Lithium Ion Full-Cells. ACS Appl Energy Mater 2020, 3 (1), 743–758.(4) Nuhu, B. A.; Bamisile, O.; Adun, H.; Abu, U. O.; Cai, D. Effects of Transition Metals for Silicon-Based Lithium-Ion Battery Anodes: A Comparative Study in Electrochemical Applications. J Alloys Compd 2023, 933.(5) Liu, H.; Long, Y.; Chen, Y.; Wang, Z.; Zhang, C.; Hu, R.; Zhang, X.; Yu, P. Tuning Inactive Phases in Si-Ti-B Ternary Alloy Anodes to Achieve Stable Cycling for High-Energy-Density Lithium-Ion Batteries. ACS Appl Mater Interfaces 2021, 13 (48), 57317–57325.(6) Zhang, X.; Wang, L.; Zheng, T.; Lam, K. Si/CrSi2 Alloy Anodes Synthesized by a High-Energy Ball-Milling for Lithium-Ion Batteries: Microstructure, Electrochemistry, and Carbon Coating. Energy Fuels 2023, 37 (15), 11419–11431. Figure 1