Search Results (166)

In recent years, 3D pixel sensors have been a topic of increasing interest within the High Energy Physics community. Due to their inherent radiation hardness, demonstrated up to a fluence of $3\times {10}^{16}$ 1 MeV equivalent neutrons per square centimeter, 3D pixel sensors have been used to equip the innermost tracking layers of the ATLAS and CMS detector upgrades at the High-Luminosity Large Hadron Collider. Additionally, the next generation of vertex detectors calls for precise measurement of charged particle timing at the pixel level. Owing to their fast response times, 3D sensors present themselves as a viable technology for these challenging applications. Nevertheless, both radiation hardness and fast timing require 3D sensors to be operated with high bias voltages on the order of ∼150 V and beyond. Special attention should therefore be devoted to avoiding problems that could cause premature electrical breakdown, which could limit sensor performance. In this paper, TCAD simulations are used to gain deep insight into the impact of surface isolation layers (i.e., p-stop and p-spray) used by different vendors on the high-voltage tolerance of small-pitch 3D sensors. Results relevant to different geometrical configurations and irradiation scenarios are presented. The advantages and disadvantages of the available technologies are discussed, offering guidance for design optimization. Experimentalmeasurements from existing samples based on both isolation techniques show good agreement with simulated breakdown voltages, thereby validating the simulation approach. Full article

In this study, we systematically analyzed selective lithium plating on graphite (Gr)–silicon (Si) composite anodes for lithium-ion batteries during fast charging, using electrochemical techniques. To achieve this, half-cells were first constructed with single Gr and Si electrodes, and lithium plating on each electrode was examined at different charging rates. It was observed that lithium plating on both electrodes began at a lower state of charge (SoC) as the charge rate increased. Furthermore, at a given charge rate, lithium plating occurred on the Si electrode at a lower SoC than on the Gr electrode. Based on the experimental findings, the lithium plating behavior of Gr and Si as a function of the charge rate was formulated to investigate the plating behavior of hypothetical composite electrodes with varying Gr–Si ratios. The lithium plating behavior observed on the actual composite electrode was consistent with that predicted from the hypothetical composite electrode, which was simulated using the same Gr–Si ratio based on the behaviors of the individual electrodes. By comparing the results from the single and composite electrodes, it is proposed that lithium plating occurs first on Si and then on Gr at low charge rates, whereas, at high charge rates, it proceeds first on Gr and then on Si. We discuss how to extrapolate the preferential plating signals—namely, plating onto Si at low charge rates and onto Gr at high charge rates—that are not directly evident in the signal from the actual composite electrode. Full article

When a semiconducting sample is illuminated by an intensity-modulated monochromatic light beam with photon energy exceeding the band gap, part of the absorbed energy is directly converted into heat through photon–lattice interactions. This gives rise to a heat source that closely follows the temporal profile of the optical excitation, known as the fast heat source. Simultaneously, another portion of the absorbed energy is used to generate electron-hole pairs. These charge carriers diffuse together and recombine via electron–electron and electron–hole interactions, transferring their kinetic energy to the lattice and producing additional heating of the sample. This indirect heating mechanism, associated with carrier recombination, is referred to as the slow heat source. In this study, we develop a model describing surface temperature variations on the non-illuminated side of a thermally thin semiconductor exposed to a rectangular optical pulse, explicitly accounting for the contribution of surface charge carrier recombinations. Using this model, we investigate the influence of surface recombination velocity and the material’s plasma properties on the time-domain temperature response for both plasma-opaque and plasma-transparent samples. Our results demonstrate that charge carrier recombinations can significantly affect the transient photoacoustic signal recorded using a minimum volume cell, highlighting the potential of time-resolved photoacoustic techniques for probing the electronic properties of semiconductors. Full article

This study employed a simple and cost-effective method for developing NiO with reduced optical band gaps that can be combined with nanostructured polyaniline (PANI). The composite systems were used as electrocatalytic and electrode materials in oxygen evolution reactions (OER) and in supercapacitor applications. We prepared the composite material in two stages: NiO was prepared with a reduced optical band gap by combining it with wheat peel extract. This was followed by the incorporation of PANI nanoparticles during the chemical oxidation polymerization process. A variety of structural characterization techniques were employed, including scanning electron microscopy (SEM), powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). A surface-modified NiO/PANI composite with enhanced surface area, fast charge transfer rate, and redox properties was produced. When NiO/PANI composites were tested in KOH electrolytic solution, 0.5 mL of wheat peel extract-mediated NiO/PANI demonstrated excellent electrochemical performance. It was found that the asymmetric supercapacitor (ASC) device had the highest specific capacitance of 404 Fg⁻¹ at a current density of 4 Ag⁻¹. In terms of energy density and power density, the ASC device was found to have 140 Whkg⁻¹ and 3160 Wkg⁻¹, respectively. The ASC device demonstrated excellent cycling stability and charge storage rates, with 97.9% capacitance retention and 86.9% columbic efficiency. For the OER process, an overpotential of 320 mV was observed at a current density of 10 mA/cm². It was found that the NiO/PANI composite was highly durable for a period of 30 h. A proposed hypothesis suggested that reducing the optical band gap of NiO and making its composites with PANI could be an appealing approach to developing next-generation electrode materials for supercapacitors, batteries, and fuel cells. Full article

FPGA-RICH is an FPGA-based online partial particle identification system for the NA62 experiment employing AI techniques. Integrated between the readout of the Ring Imaging Cherenkov detector (RICH) and the low-level trigger processor (L0TP+), FPGA-RICH implements a fast pipeline to process in real-time the RICH raw hit data stream, producing trigger primitives containing elaborate physics information—e.g., the number of charged particles in a physics event—that L0TP+ can use to improve trigger decision efficiency. Deployed on a single FPGA, the system combines classical online processing with a compact Neural Network algorithm to achieve efficient event classification while managing the challenging ∼10 MHz throughput requirement of NA62. The streaming pipeline ensures ∼1 $\mathsf{\mu }$s latency, comparable to that of the NA62 detectors, allowing its seamless integration in the existing TDAQ setup as an additional detector. Development leverages High-Level Synthesis (HLS) and the open-source hls4ml package software–hardware codesign workflow, enabling fast and flexible reprogramming, debugging, and performance optimization. We describe the implementation of the full processing pipeline, the Neural Network classifier, their functional validation, performance metrics and the system’s current status and outlook. Full article

In this paper, we present the analysis of functional alloy samples containing metals aluminum (Al), copper (Cu), lead (Pb), silicon (Si), tin (Sn), and zinc (Zn) using a Q-switched Nd laser operating at a wavelength of 532 nm with a pulse duration of 5 ns. Nine pelletized alloy samples were prepared, each containing varying chemical concentrations (wt.%) of Al, Cu, Pb, Si, Sn, and Zn—elements commonly used in electrotechnical and thermal functional materials. The laser beam is focused on the target surface, and the resulting emission spectrum is captured within the temperature interval of $9.0\times {10}^3$ to $1.1\times {10}^4$ K using a set of compact Avantes spectrometers. Each spectrometer is equipped with a linear charged-coupled device (CCD) array set at a 2 μs gate delay for spectrum recording. The quantitative analysis was performed using calibration-free laser-induced breakdown spectroscopy (CF-LIBS) under the assumptions of optically thin plasma and self-absorption-free conditions, as well as local thermodynamic equilibrium (LTE). The net normalized integrated intensities of the selected emission lines were utilized for the analysis. The intensities were normalized by dividing the net integrated intensity of each line by that of the aluminum emission line (Al II) at 281.62 nm. The results obtained using CF-LIBS were compared with those from the laser ablation time-of-flight mass spectrometer (LA-TOF-MS), showing good agreement between the two techniques. Furthermore, a random forest technique (RFT) was employed using LIBS spectral data for sample classification. The RFT technique achieves the highest accuracy of ~98.89% using out-of-bag (OOB) estimation for grouping, while a 10-fold cross-validation technique, implemented for comparison, yields a mean accuracy of ~99.12%. The integrated use of LIBS, LA-TOF-MS, and machine learning (e.g., RFT) enables fast, preparation-free analysis and classification of functional metallic materials, highlighting the synergy between quantitative techniques and data-driven methods. Full article

The fast development of portable electronics demands electrodes for supercapacitors that are compatible with miniaturized device applications. In this study, an orderly aligned coaxial bilayer nanotube array made of transition metal/transition metal oxides was adopted as a nanostructure-integrated electrode for applications as miniaturized micro-supercapacitors. Using Ni and NiO as our model materials, the corresponding Ni/NiO-CBNTA electrodes were fabricated using templated growth and post-thermal oxidation. The Ni shells served as parts of the 3D nano-architectured collector, providing a large specific surface area, and the pseudocapacitive NiO layers were directly attached and electrically connected to the collector without any additives. The vertical growth of orderly aligned Ni/NiO-CBNTAs successfully avoided the underutilization of capacitive nanomaterials and allowed the electrolyte to be fully accessed, which manifested full charge storage capabilities under the miniaturizing. It was demonstrated that Ni/NiO-CBNTAs can serve as miniaturized electrodes with an improved specific capacitance of 1125 F/g ≅ 3 A/g, which is comparable to that obtained in a massive load electrode prepared by the conventional slurry-coating technique. Full article

Charge transfer dynamics fundamentally influence energy conversion efficiency in excited electronic states, directly impacting photoelectric conversion, molecular electronics, and catalysis. The core hole clock (CHC) technique enables the precise measurement of interfacial charge transfer time, providing insights into the electronic structure and dynamics of organic and inorganic coupled systems. Among these materials, poly(3-hexylthiophene) (P3HT), a p-type semiconductor known for its high charge mobility, serves as an ideal model for charge transfer studies. This review discusses recent advancements in understanding charge transfer dynamics in P3HT-based composites through the application of the CHC technique. The studies are categorized into two main areas: (1) P3HT combined with carbon-based nanomaterials and (2) P3HT combined with 2D materials. These findings highlight the effectiveness of the CHC technique in probing interfacial charge transfer and emphasize the critical role of nanomaterial interfaces in modulating charge transfer, which is essential for advancing organic electronic devices and energy conversion systems. Full article

Dual-ion batteries (DIBs) were demonstrated as a promising technology for large-scale energy storage due to their low cost, recyclability, and impressively fast charge capability. Graphite as a commonly used cathode material in DIBs, however, suffers from poor compatibility with commercial Li-ion electrolytes and graphite anodes, making it difficult to directly utilize the well-established infrastructure for Li-ion batteries. Herein, we report a small aromatic amine molecule 4,4′,4″-tris(diphenylamino)triphenylamine (N4) functioning as a compatible anion host in the EC-containing Li-ion electrolyte. With an average discharge voltage of 3.6 V (vs. Li⁺/Li), the N4 electrode delivers a reversible specific capacity of 108 mAh/g, which is much higher than 29 mAh/g for the graphite cathode at the same condition. The high capacity retention of 91.3% was achieved after 500 cycles at 1 A/g. The N4 electrode also exhibited good rate performance. Via different characterization techniques like Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, the energy storage mechanism of N4 was revealed as a conversion between amine and quaternary amine cations, accompanied by PF₆⁻ (de-)insertion. As consequences, the assembled N4||graphite DIB w showed a high discharge capacity of 90 mAh/g within 1.5–4.1 V, and good cycling stability with a 98% capacity retention after 40 cycles. Decent rate performance was achieved in the N4||graphite DIB as well. This work provides new insights into designing a compatible anion host for affordable DIBs. Full article

Battery charging systems are crucial for energy storage in off-grid photovoltaic (PV) installations. Since the power generated by a PV panel is conditioned by climatic conditions and load characteristics, a maximum power point tracking (MPPT) technique is required to maximize PV power and accelerate battery charging. On the other hand, a battery must be carefully charged, ensuring that its charging current and voltage limits are not exceeded, thereby preventing premature degradation. However, the voltage generated by the PV panel during MPPT operation fluctuates, which can harm the battery, particularly during periods of intense radiation when overvoltages are likely to occur. To address these issues, the design and construction of an enhanced solar battery charger utilizing a single-ended primary-inductor converter (SEPIC) and soft computing (SC)-based control is presented. A control strategy is employed that integrates voltage stabilization and MPPT functions through two dedicated fuzzy logic controllers (FLCs), which manage battery charging using a three-mode scheme: MPPT, Absorption, and Float. This approach optimizes available PV power while guaranteeing fast and safe battery charging. The developed charger leverages the SEPIC’s notable features for PV applications, including a wide input voltage range, minimal input current ripple, and an easy-to-drive switch. Moreover, unlike most PV charger control strategies in the literature that combine improved traditional MPPT methods with classical proportional integral (PI)-based control loops, the proposed control adopts a fully SC-based strategy, effectively addressing common drawbacks of conventional methods, such as slowness and inaccuracy during sudden atmospheric fluctuations. Simulations in MATLAB/Simulink compared the FLCs’ performance with conventional methods (P&O, IncCond, and PID). Additionally, a low-power hardware prototype using an Arduino Due microcontroller was built to evaluate the battery charger’s behavior under real weather conditions. The simulated and experimental results both demonstrate the robustness and effectiveness of the solar charger. Full article

The general-purpose Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) at CERN is used to study the production of new particles in proton–proton collisions at an LHC center of mass energy of 13.6 TeV. The detector includes a magnet based on a 6 m diameter superconducting solenoid coil operating at a current of 18.164 kA. This current creates a central magnetic flux density of 3.8 T that allows for the high-precision measurement of the momenta of the produced charged particles using tracking and muon subdetectors. The CMS magnet contains a 10,000 ton flux-return yoke of dodecagonal shape made from the assembly of construction steel blocks distributed in several layers. These steel blocks are magnetized with the solenoid returned magnetic flux and wrap the muons escaping the hadronic calorimeters of total absorption. To reconstruct the muon trajectories, and thus to measure the muon momenta, the drift tube and cathode strip chambers are located between the layers of the steel blocks. To describe the distribution of the magnetic flux in the magnet yoke layers, a three-dimensional computer model of the CMS magnet is used. To validate the calculations, special measurements are performed, with the flux loops wound in 22 cross-sections of the flux-return yoke blocks. The measured voltages induced in the flux loops during the CMS magnet ramp-ups and -downs, as well as during the superconducting coil fast discharges, are integrated over time to obtain the initial magnetic flux densities in the flux loop cross-sections. The measurements obtained during the seven standard ramp-downs of the magnet were analyzed in 2018. From that time, three fast discharges occurred during the standard ramp-downs of the magnet. This allows us to single out the contributions of the eddy currents, induced in steel, to the flux loop voltages registered during the fast discharges of the coil. Accounting for these contributions to the flux loop measurements during intentionally triggered fast discharges in 2006 allows us to perform the validation of the CMS magnet computer model with better precision. The technique for the flux loop measurements and the obtained results are presented and discussed. The method for measuring magnetic flux density in steel blocks described in this study is innovative. The experience of 3D modeling and measuring the magnetic field in steel blocks of the magnet yoke, as part of a muon detector system, has good prospects for use in the construction and operation of particle detectors for the Future Circular Electron–Positron Collider and the Circular Electron–Positron Collider. Full article

Relaxor ferroelectric film capacitors exhibit high power density with ultra-fast charge and discharge rates, making them highly advantageous for consumer electronics and advanced pulse power supplies. The Aurivillius-phase bismuth layered ferroelectric films can effectively achieve a high breakdown electric field due to their unique insulating layer ((Bi₂O₂)²⁺ layer)). However, designing and fabricating Aurivillius-phase bismuth layer relaxor ferroelectric films with optimal energy storage characteristics is challenging due to their inherently stable ferroelectric properties. In this work, lead-free CaBi_4-xLa_xTi₄O₁₅ films were synthesized using the sol–gel technique and a weakly coupled relaxor design. On one hand, the introduction of La³⁺ ions weaken the dipole–dipole interactions, thereby enhancing the relaxor behavior. Alternatively, the expansion of grain size is restricted to enhance the number of grain boundaries, which possess improved insulating properties. This leads to a higher breakdown electric field. The results indicate that CaBi_4-xLa_xTi₄O₁₅ (x = 1.0) films exhibit excellent recoverable energy storage density (70 J/cm³) and high energy efficiency (73%). Moreover, the film exhibited good temperature stability and frequency stability. This study not only identifies a promising material for dielectric film capacitors but also demonstrates that the energy storage capabilities of Aurivillius-phase bismuth layer ferroelectric films can be effectively modulated through a design incorporating weakly coupled relaxor characteristics. Full article

Fast electrochemical phenomena occurring in supercapacitors are hard to analyze by ex situ or in situ techniques because many of them are meta-stable (the supercapacitor relaxes once it is not further polarized). In a steady state, one observes the effect of charge storage but not necessarily the mechanism. This is a problem for Raman spectroscopy, too, even though Raman spectra of the electrodes of supercapacitors are commonly recorded ex situ or in a steady state in situ. Raman operando is desired, but it represents a technological challenge since the electrochemical events in a supercapacitor are very fast (occurring within seconds), and in contrast, Raman requires from seconds to minutes to collect enough photons for reliable spectra. This work presents the development of electrodes made of thin layers of iron oxide grown solvothermally on Si wafers, with a porosified surface and resistivity of 0.005 Ωcm, to study their performance as electrodes in supercapacitors and analyze their energy storage mechanisms by cyclic voltammetry and Raman operando. Being flat and containing just iron oxide and silicon, these electrodes allow for studying interfacial phenomena with minor interferents. Full article

Electric mobility is attracting significant attention in the current era due to its environmental benefits, sustainable transportation options, and the absence of carbon emissions. However, challenges such as the high price of batteries, inefficient charging techniques, and compatibility linking the charging station with electric vehicles (EVs) must be addressed. This article reviews advancements and identifies challenges in charging infrastructure for electric mobility. This study incorporates and analyzes an integrated review of approximately 223 research articles. Current research trends and states of charging infrastructure are prepared as per the Web of Science (WoS) database from 2013 to 2023. In light of recent extensions in wireless power transfer technology, including capacitive, inductive, and magnetic gear topology, are presented to advance the charging infrastructure. Different charging tactics based on power source, such as level-1 AC, level-2 AC, level-3 DC fast, and level-3 DC ultra-rapid charging, related to charging infrastructure are addressed. The vehicle-to-grid (V2G) integration methodology is addressed to construct a smart city by presenting the transfer of power and related data through linkage and moving systems. The exploration of artificial intelligence, global connectivity of electric vehicles (EVs), sun-to-vehicle (S2V), and vehicle-to-everything (V2X) techniques with EVs is conducted to enhance and progress the charging infrastructure. Key barriers associated with charging infrastructure are identified. Full article

As reliance on sustainable energy grows, the demand for efficient, high-performance energy storage systems becomes increasingly critical, especially in uninterruptible power supplies (UPS), where reliability and fast transitions are essential. Supercapacitors, with their high power density and rapid charging capabilities, are emerging as strong alternatives to lithium-ion batteries in UPS systems. This paper presents a novel real-time estimation technique for monitoring supercapacitor parameters within a UPS, focusing on the dynamic behavior of these parameters and their evolution over the system’s lifecycle. The proposed estimator demonstrates exceptional accuracy, achieving less than 1% error within 120 ms of startup and nearly zero error thereafter. The estimator’s performance remains robust even as supercapacitor parameters change due to aging effects over the lifespan. The UPS system features a modular design, enabling scalability to accommodate higher power requirements or longer backup durations and adaptability to various supercapacitor types. Experimental results highlight the system’s robustness in both charging and backup modes, emphasizing the potential of supercapacitors as key components in future UPS systems. Full article