Charged Particles Research Articles

Existence of quantum states for Klein–Gordon particles based on exact and approximate scenarios

Abstract In the present study, Kummer’s eigenvalue spectra from a charged spinless particle located at spherical pseudo-dot of the form r 2 + 1/r 2 is reported. Here, it is shown how confluent hypergeometric functions have principal quantum numbers for considered spatial confinement. To study systematically both constant rest-mass, m 0 c 2 and spatial-varying mass of the radial distribution m 0 c 2 + S(r), the Klein–Gordon equation is solved under exact case and approximate scenario for a constant mass and variable usage, respectively. The findings related to the relativistic eigenvalues of the Klein–Gordon particle moving in the spherical space show the dependence of mass distribution, so it has been obtained that the energy spectra has bigger eigenvalues than m 0 c 2 = 1 fm−1 in exact scenario. Following analysis also shows eigenvalues satisfy the range of E < m 0 c 2 through approximate scenario.

Performance of Iron Phosphate Glass Containing Various Heavy Metal Oxides for Particulate Nuclear Radiation Shielding.

Employees may be exposed to different kinds of ionizing radiation at work. When ionizing radiation interacts with human cells, it can cause damage to the cells and genetic material. Therefore, one of the scientists' primary objectives has always been to create the best radiation-shielding materials. Glass could offer promising shielding material resulting from the high flexibility of composition, simplicity of production, and good thermal stability. The melt-quenching technique was used to create a glass having the following formula: 50% P2O5+20% Na2O+20% Fe2O3+10% X, where X = As2O3, SrO, BaO, CdO, and Sb2O3 mol %. The impact of the different heavy metal additions on the structure of the glass networks was studied using FTIR spectroscopy. Glass's ability to attenuate neutrons and/or charged particles has been theoretically investigated. The performance of the developed glass as a shield was examined by a comparison against commercial glass (RS 253 G18), ordinary concrete (OC), and water (H2O). For charged particle radiations (Electrons, Protons, and Alpha), the shielding parameters like the mass stopping power, the projected range, and the effective atomic number were evaluated, where S5/Sb glass achieves the best performance. In the case of Neutrons, the results values reveal that S3/Ba glass ( ΣR = 0.105) is the best-modified glass for neutron shielding. Among all the investigated glasses, S5/Sb glass composition has a smaller range and provides superior protection against charged particles. In contrast, the S3/Ba glass composition is a superior choice for shielding against neutron radiation.

Pharmaceutical Applications and Advances with Zetasizer: An Essential Analytical Tool for Size and Zeta Potential Analysis

Abstract: Zetasizer is an advanced device that measures various properties of particles or molecules suspended in a liquid medium. It is extensively used for evaluating the size of nanoparticles, colloids, and biomolecular particles, and for determining particle charge. There are several analytical techniques by which the size, zeta potential, and molecular weight can be determined, like Dynamic Light Scattering (DLS) that measures the size of particles in dispersed systems, which can range from sub-nanometers to several micrometers in diameter. Electrophoretic Light Scattering (ELS) analyzes the mobility and charge of particles, also known as the zeta potential. Static Light Scattering (SLS) determines the molecular weight of particles in a solution. The Zetasizer is part of the Zetasizer Advance range of benchtop systems available for laboratory use. The Zetasizer Ultra model offers unique measurement capabilities, such as Multi-angle Dynamic Light Scattering (MADLS) and particle concentration. These features offer a deeper understanding of samples, making the Zetasizer a vital instrument in numerous scientific and industrial applications. In this review, we have discussed Zetasizer’s principles for the determination of particle size, zeta potential, and molecular weight, along with its qualification and applications in different formulations.

THEORETICAL INVESTIGATION FOR YTTERBIUM EFFECT ON RADIATION SHIELDING CHARACTERISTICS OF 50Bi2O3-15Li2O-15PbO-(20-X)B2O3-Yb2O3 BORATE GLASSES

As the nuclear industry has developed and radiation technologies have become more widely used, the dose of radiation from both synthetically produced sources and radioisotopes has increased, as has the number of people being irradiated. It is of the utmost importance to utilise appropriate shielding materials in order to reduce the negative effects of radiation sources. Doped glasses are among the most significant candidate materials in the field of radiation shielding. To this end, it was aimed to investigate the charged particle, gamma-ray and neutron shielding characteristics of ytterbium doped glasses with composition of 50Bi2O3-15Li2O-15PbO-(20-x)B2O3-Yb2O3 (where x = 0.5, 1.0, 1.5, 2.0 and 2.5). In this regard, the radiation shielding parameters were estimated by using Phy-X/PSD, PAGEX, ESTAR, and SRIM codes. Furthermore, the results were compared comprehensively and comparatively. Charged particle (alpha, proton and electron), gamma ray and neutron shielding efficiencies were found to be proportional to ytterbium content. The glasses with the increasing amount of ytterbium exhibited higher shielding performances. It can be said that all the studied glasses and particularly Yb2.5 sample could be used as shielding materials in many radiation related applications.

Suppression effect of CO2 on ignition and combustion of AlH3-nanoparticles: A molecular dynamics study

AlH3 is a high-capacity hydrogen storage material but is prone to explosion. Thermodynamic and structural properties of AlH3-nanoparticles at different CO2 inerting systems from ignition to combustion are studied using ReaxFF-MD method. The influence of CO2 on AlH3-nanoparticles ignition and combustion is investigated by comparing the changes of surface O adsorption rates, particle charge, temperature rise rates and so on. Results indicate that an increase in CO2 is crucial for suppressing AlH3-nanoparticles ignition and combustion by impeding the formation of an Al-rich environment. In contrast to three stages of AlH3-nanoparticles combustion in pure O2 system: surface combustion, slow temperature rise, and self-sustaining combustion, the process of CO2 inerting system is different, with third stage is slow temperature rise at a constant rate. When CO2 concentration reaches to 90%, the dehydrogenation rate reduces by 70.0%, the temperature rise rate decreases by 78.6%, and the ignition delay time reaches 45 ps.

Design of dark-colored acrylic coatings for increased LiDAR detection in autonomous vehicles

Light Detection and Ranging (LiDAR) is the major sensor for autonomous vehicles. It emits near-infrared (NIR) pulsed light at 905 nm and detects the reflected portion of this light from the surrounding objects. Location and surface determination of the surrounding objects is performed using the time-of-flight (the elapsed time from launch of a pulsed beam to detection of the reflected returned beam). Solvent borne acrylic paints gained wide currency for the exterior automotive coatings over the years and topcoats with conventional dark-colored pigment dispersions exhibit low reflectivity in the NIR region. The formulation of innovative topcoats with high reflectivity in this region is an urgent task for leading paint manufacturers. In this study, pigment dispersions to be incorporated in LiDAR-detectable solvent borne acrylic automotive topcoats were designed considering the surface charges of individual pigment particles for dispersant selection. Stability of designed dispersions was demonstrated and color matching studies were realized. Three dark colors encoded RAL 9011 (Graphite black), RAL 5017 (Traffic blue), and RAL 5015 (Sky blue) from the RAL 841-GL color chart were formulated as acrylic topcoats with NIR reflective pigments. Based on the surface properties of the dry films, such as gloss, haze and distinctness of image, a significant increase in LiDAR detection was achieved for each color. The results affirmed the potential use of the developed formulations as end-product paints for coating the exterior surfaces of autonomous vehicles.

Pair correlations and freezing transitions in a two-dimensional system of tilted axially symmetric quadrupoles

We study the pair structure and the transition from the liquid to the solid state in a system of axially symmetric charged particles confined to a two-dimensional plane and characterised by only one non-zero component of the electric quadrupole moment, which we assume to be inclined with respect to the perpendicular to the confining plane. The particles interact via anisotropic repulsive quadrupole–quadrupole interactions. The pair correlation functions (PCF) were calculated by solving the hypernetted chain integral equation (HNC) theory in the range of the tilt angle 75.0 ∘ ≤ 90 ∘ − ϕ ≤ 90 ∘ . NVT Monte Carlo (MC) simulations were also performed to test the accuracy of the PCFs. We find that the PCFs calculated with the HNC theory agree well with those of the MC simulation at smaller tilt angles and show anomalous behaviour with respect to the in-plane angular variation. The PCFs obtained with the HNC theory were used in the Ramakrishnan-Yussouff (RY) density functional theory (DFT) to investigate the transition between liquid and solid freezing. It was found that the RY DFT stabilises the triangular solid only for tilt angles ≥ 80 ∘ . When the tilt angle is decreased compared to the normal orientation of the quadrupoles, the transition density increases.

Simultaneous removal of cyanobacteria and algal organic matter (AOM) by CaCO3 precipitation combined with Polyaluminum chloride (PACl) flocculation

Simultaneous removal of cyanobacteria and algal organic matter (AOM) is still a difficult task for drinking water treatment plants (DWTPs) during cyanobacteria blooms. CaCO3 precipitation, an environment-friendly drinking water treatment technique, has been recommended to removal cyanobacteria or AOM from drinking water. However, knowledge of simultaneous removal performance by CaCO3 precipitation is limited. Here, the simultaneous removal performance to cells and AOM of CaCO3 precipitation, combined with polyaluminum chloride (PACl) flocculation, was investigated, as well as the underlying mechanisms. The results showed that CaCO3 precipitation strategy significantly improved the simultaneous removal performance of PACl, with removal efficiency up to 98 % for cells and 48 % for AOM. CaCO3 precipitation exhibited reliable simultaneous removal effects at various initial cells densities and AOM concentrations. Scanning electron microscope (SEM), transmission electron microscope (TEM) and zeta potential results suggested that mutual flocculation between positively charged CaCO3 crystalline particles and negatively charged cells is the main responsible mechanism for cells removal. Despite that the adsorption of AOM on CaCO3 nuclei surface delays its precipitation, co-precipitation removal mechanism of AOM is realized during CaCO3 nucleation. Moreover, further AOM removal can be obtained by CaCO3 crystalline particles via chemisorption between organic molecules and the particles surface.

Revolutionizing treatment for topical fungal infections: evaluating penetration-enhancer-containing vesicles as a fluconazole delivery system: Ex-vivo and in-vivo dermal testing

Fungal infections pose a significant challenge in numerous developing nations and worldwide, necessitating urgent solutions. Oral administration of antifungal medications often leads to severe adverse reactions. Hence, employing topical delivery systems is preferred to ensure efficient dermal delivery of antifungal agents while minimizing side effects. Furthermore, the incorporation of penetration enhancers into nanocarriers loaded with antifungal agents has demonstrated enhanced efficacy in combating mycotic infections. Consequently, ultra-deformable penetration enhancer-containing vesicles (PEVs) were developed to explore this promising approach. In this study, Labrasol® and Transcutol® were used as penetration enhancers in formulating ultra-deformable PEVs containing the antifungal agent Fluconazole (FCZ). The PEVs underwent comprehensive characterization, including measurements of particle size (PS), charge, and entrapment efficiency (EE%). The results revealed that the size of tested PEVs ranged from 100 to 762 nm. All particles exhibited a negative charge, with a minimum zeta potential (ZP) of −38.26 mV, and an intermediate entrapment efficiency (EE%) that reached approximately 40%w/w. Ex-vivo studies demonstrated the ability of PEVs to deliver FCZ to the dermis while minimizing transdermal delivery. The selected formula was tested in-vivo using candidiasis-induced rat model and showed a superiority in its antifungal effect against Candida Albicans compared to the drug control. Stability studies were executed for the selected formula, and revealed good stability shown by the insignificant change in the PS, ZP& EE% over a six-month period.

Band structure for relativistic charged particles immersed in a structurally chiral electromagnetic field

In this paper, we determine the band structure of an electromagnetic space-time crystal. We construct a coordinate transformation in which the matrix elements of the Dirac equation are constant. Consequently, their corresponding band structure is recovered analytically. The band structure is fragmented into three different energy regions. In the center, there is a region prohibited for all particles (universal band gap), which is symmetrically enveloped by two energy regions of the same width. These regions allow the passage of particles with a specific spin (discriminatory band gaps). Furthermore, we demonstrate that, through the appropriate combination of the refractive index, the length of the electromagnetic wave, and the amplitude of the electric field, it is possible to shorten the bandwidth of the universal gap and replace it with a discriminatory band gap. In that sense, the proposed system constitutes an alternative procedure to observe the Schwinger mechanism experimentally.

Remote sensing of high energy charged particle current (HEC) for megavoltage therapeutic electron beams

Objective. We demonstrate detection of high energy particle current (HEC) for MeV therapeutic electron beams. Detection of HEC comprises of remote sensing or acquiring information about HEC inside radiation transport medium from a distance outside of the medium. Approach. HEC is self-propelled motion of charged particles through a radiation transport medium. Remote sensing of HEC is embodied in an experimental setup, which includes homogeneous and heterogeneous phantoms irradiated with 4–15 MeV electron beams and two large area parallel-plane electrodes extraneous to the phantoms providing two-parameter detection. We also introduce a new type of scanning method (depth-scan) for probing object properties along the beamline axis. Main Results. Deterministic radiation transport simulations and measurements agree, considering differences in simulation vs experimental geometry and experimental uncertainties. Significance. This method may be suitable for range detection of charged particle beams, or for probing of radiation opaque objects in non-destructive testing.

Multiplicity and transverse momentum dependence of charge-balance functions in pPb and PbPb collisions at LHC energies

Abstract Measurements of the charge-dependent two-particle angular correlation function in proton-lead (pPb) collisions at a nucleon-nucleon center-of-mass energy of $$ \sqrt{s_{\textrm{NN}}} $$ s NN = 8.16 TeV and lead-lead (PbPb) collisions at $$ \sqrt{s_{\textrm{NN}}} $$ s NN = 5.02 TeV are reported. The pPb and PbPb data sets correspond to integrated luminosities of 186 nb−1 and 0.607 nb−1, respectively, and were collected using the CMS detector at the CERN LHC. The charge-dependent correlations are characterized by balance functions of same- and opposite-sign particle pairs. The balance functions, which contain information about the creation time of charged particle pairs and the development of collectivity, are studied as functions of relative pseudorapidity (∆η) and relative azimuthal angle (∆ϕ), for various multiplicity and transverse momentum (pT) intervals. A multiplicity dependence of the balance function is observed in ∆η and ∆ϕ for both systems. The width of the balance functions decreases towards high-multiplicity collisions in the momentum region < 2 GeV, for pPb and PbPb results. Integrals of the balance functions are presented in both systems, and a mild dependence of the charge-balancing fractions on multiplicity is observed. No multiplicity dependence is observed at higher transverse momentum. The data are compared with hydjet, hijing, and ampt generator predictions, none of which capture completely the multiplicity dependence seen in the data. The comparison of results with different center-of-mass energies suggests that the balance functions become narrower at higher energies, which is consistent with the idea of delayed hadronization and the effect of radial flow.

Imaging systems for the liquid Argon target of SAND at the DUNE Near Detector Complex

The Deep Underground Neutrino Experiment (DUNE) has among its primary goals the determination of the neutrino mass ordering and the possible CP-violating phase in the neutrino mixing matrix. The System for On-Axis Neutrino Detection (SAND) is one of the three components of the DUNE Near Detector complex, permanently located on-axis to monitor the neutrino beam stability and measure its flux. SAND includes a novel liquid Argon detector - GRAIN - designed to image neutrino interactions using scintillation light produced in Ar by charged particles, eliminating the dependence on slow charge collection of LAr TPCs. Two optical systems are currently being developed for GRAIN, both based on Silicon Photomultiplier (SiPM) matrices, coupled either to UV cryogenic lenses or Coded Aperture masks. This contribution will present the design of GRAIN optical systems and their spatial resolution performance in preliminary simulation studies.

On the reconstruction of LEIS spectra after distortion by an electrostatic energy analyzer

The study attempts to reveal the influence of the transmission function of electrostatic deflector analyzers with linear voltage scan on the shape of the LEIS energy spectra and the arising error in surface elemental composition and film thickness analysis. The practical applicability of several analytical and numerical approaches for reconstructing true energy distributions of particles is studied using examples of simulated LEIS spectra. The presented methodology can be extended to a wider range of applications involving electrostatic or magnetic analyzers of charged particles. The study proposesa freely available and ready-to-use tool for simulating distortions of spectra caused by the transmission function of spectrometers and for reconstructing true distributions of arbitrary spectra.

Design of electrostatic lenses through genetic algorithm and particle swarm optimisation methods integrated with differential algebra

Genetic algorithm (GA) and particle swarm optimisation (PSO) techniques have been integrated with the differential algebra (DA) method in charged particle optics to optimise an Einzel lens. The DA method is a robust and efficient tool for the calculation of aberration coefficients of electrostatic lenses, which makes use of nonstandard analysis for ray tracing a particle as it is subjected to the field generated by a lens. In this study, initial populations of lenses with random geometrical configurations are generated. These initial populations are then subjected to GA and PSO algorithms to alter the geometry of each lens for a set number of iterations. The lens performance is evaluated by calculating the spot size using the aberrations coefficients up to third-order generated by the DA method. Moreover, a focusing column comprising two lenses and a Wien filter was optimised using GA method.

Characteristics of 2N4416 Si JFETs for radiation spectrometer charge sensitive preamplifiers

The input transistors (JFETs) of feedback resistor-less charge sensitive preamplifiers (CSPs), for photon and charged particle counting radiation spectrometers, that use semiconductors as their detectors, are operated in an unusual forward biased mode; consequently, manufacturer datasheets cannot necessarily be relied upon, as they do not specify the characteristics of the JFETs when they are operated with the gate-to-source junction forward biased. This experimental study, in which 165 2N4416 and 2N4416A NJ26 silicon junction field effect transistors (JFETs) were electrically characterised at ambient laboratory temperature, focused on the JFETs’ performances in the context of their use as input transistors of feedback resistor-less charge sensitive preamplifiers (CSPs). The experimental study found evidence which supports much of the common practice of the skilled CSP designer but which had not been documented with results in the open literature until now. This includes, inter alia, that: the 2N4416 performs better than the 2N4416A; not all transistors even of the same type have comparable performance when operated in forward bias mode; only a small proportion of 2N4416 and 2N4416A transistors are of desirable performance characteristics for CSPs; and, individual screening of each candidate JFET is required if an optimally performing CSP is to be produced – even when using JFETs of the same type from the same batch. The methodology and analysis documented here will also be useful to researchers developing new wide bandgap semiconductor JFETs for high temperature tolerant and radiation-hard CSPs.

The derivation of Jacobian matrices for the propagation of track parameter uncertainties in the presence of magnetic fields and detector material

In high-energy physics experiments, the trajectories of charged particles are reconstructed using track reconstruction algorithms. Such algorithms need to both identify the set of measurements from a single charged particle and to fit the parameters by propagating tracks along the measurements. The propagation of the track parameter uncertainties is an important component in the track fitting to get the optimal precision in the fitted parameters. The error propagation is performed at intersections between the track and local coordinate frames defined on detector components by calculating a Jacobian matrix corresponding to the local-to-local frame transport. This paper derives the Jacobian matrix in a general manner to harmonize with numerical integration methods developed for inhomogeneous magnetic fields and materials. The Jacobian and transported covariance matrices are validated by simulating the propagation of charged particles between two frames and comparing with the results of numerical methods.

Computer modeling of a new type galactic cosmic rays simulator

A new type of a galactic cosmic rays (GCR) simulator, provided at the JINR Laboratory of Radiation Biology, is potentially capable of generating a complex radiation field with inclusions of a variety of ions with a wide energy range and with required abundance at the charged particle accelerators. This complex multicomponent radiation field simulates radiation environment inside a spacecraft during an interplanetary flight, for example, to Mars. The article provides an analytical description of the GCR simulator as well as a description of a specially developed software that enables selection of necessary parameters of a simulator model for creating relevant mixed radiation conditions. The software implements processing of data obtained with Monte Carlo-based FLUKA and PHITS programs, fitting and optimization of model parameters as well as data visualization tools.

Smart pixel sensors: towards on-sensor filtering of pixel clusters with deep learning

Abstract Highly granular pixel detectors allow for increasingly precise measurements of charged particle tracks. Next-generation detectors require that pixel sizes will be further reduced, leading to unprecedented data rates exceeding those foreseen at the High- Luminosity Large Hadron Collider. Signal processing that handles data incoming at a rate of O (40 MHz) and intelligently reduces the data within the pixelated region of the detector at rate will enhance physics performance at high luminosity and enable physics analyses that are not currently possible. Using the shape of charge clusters deposited in an array of small pixels, the physical properties of the traversing particle can be extracted with locally customized neural networks. In this first demonstration, we present a neural network that can be embedded into the on-sensor readout and filter out hits from low momentum tracks, reducing the detector’s data volume by 57.1%–75.7%. The network is designed and simulated as a custom readout integrated circuit with 28 nm CMOS technology and is expected to operate at less than 300 μ W with an area of less than 0.2 mm2. The temporal development of charge clusters is investigated to demonstrate possible future performance gains, and there is also a discussion of future algorithmic and technological improvements that could enhance efficiency, data reduction, and power per area.

Evolution of self-assembled amphiphilic colloidal particles in strong-flavor Chinese baijiu

This study proposed the evolution of self-assembled amphiphilic colloidal particles in Strong-Flavor (SF) Baijiu based on Ostwald ripening for the first time. The evolution process occurs in two stages: disordered amphiphilic molecules self-assemble into small colloidal particles and subsequently undergo Oswald ripening to form larger hydrophobic particles. Microscopic observations revealed the average size of oil-like spherical colloidal particles in Baijiu increased from 1.86 μm to 2.96 μm while the number of particles decreased by 39.50% during the 16-year cellaring process of SF Baijiu, consistent with the particle size trend observed via laser scattering. During fusion process, the charge-to-mass ratio of positively charged colloidal particles decreased, leading ζ-potential decreased from 23.7 mV to 4.66 mV within 16 years of storage. The electrochemical impedance spectroscopy approach tracked the unidirectional variation in the dielectric constant during evolution of SF Baijiu, reflecting the gradual expansion of colloidal particles, which aligns with the evolution trend observed in molecular dynamics simulations. By integrating direct microscopic observations of amphiphilic colloidal particles with electrochemical techniques, the evolution of Baijiu samples is capable to be evaluated in-situ, laying the foundation for intelligent Baijiu aging monitoring technology.