Analysis Of Charged Particles Research Articles

Intermittency analysis of charged particles generated in Xe-Xe~collisions at $\sqrt{s_{\rm{NN}}}$ = 5.44 TeV using the AMPT model

The multiplicity fluctuations are sensitive to QCD phase transition and to the presence of critical point in QCD phase diagram. At critical point a system undergoing phase transition is characterized by large fluctuations in the observables which is an important tool to understand the dynamics of particle production in heavy-ion interactions and phase changes. Multiplicity fluctuations of produced particles is an important observable to characterize the evolving system. Using scaling exponent obtained from the normalized factorial moments of the number of charged hadrons in the two dimensional (\eta,\phiη,ϕ) phase space, one can learn about the dynamics of system created in these collisions. Events generated using Xe-Xe collisions at $ = 5.44 $ TeV with string-melting (SM) version of the AMPT model are analyzed and the scaling exponent (\nu)(ν) for various p_TpT intervals is determined. It is observed that the calculated value of \nuν is larger than the universal value 1.304, as is obtained from Ginzburg-Landau theory for second order phase transition. Here we will also present the results of the dependence of the scaling exponent on the transverse momentum bin width.

Simulation Studies of Track-Based Analysis of Charged Particles in Symmetric Hadron–Hadron Collisions at 7 TeV

This manuscript presents a simulation study of a track-based analysis of the multiplicity distributions of the primary charged particle compared to experimental measurements in symmetric hadron–hadron collisions acquiring maximum energy for the new particle production. The data are compared to the simulations of EPOS, PYTHIA8, Sibyll, and QGSJET under the same conditions. The event generators in the current study are simple parton-based models that incorporate the Reggie–Gribov theory. The latter is a field theory based on the QCD that uses the mechanism of multiple parton interactions. It has been found that the PYTHIA8 model chases the data well in most of the distributions but depends on the momentum and the requirement of charged particles in a given track, due to its feature-like color reshuffling of quarks and gluons through the color re-connection modes and initial and final state radiations by incorporating the parton showers. The EPOS model could also reproduce some spectral regions and presents a good comparison after the PYTHIA8. All the other models could not produce most of the spectra except for the limited region, which also depends on the analysis’s cuts. Besides the model’s prediction, we used Tsallis–Pareto and Hagedorn functions to fit the aforementioned spectra of the charged particles. The fit is applied to the data and models, and their results are compared. We extract the temperature parameter T01 (effective temperature (Teff)) from the Tsallis–Pareto-kind function and T02 (kinetic freezeout temperature) from the Hagedorn function. The temperatures are affected by pT as well Nch cuts.

Dynamics of charged test particles around quantum-corrected Schwarzschild black holes

We investigate neutral and charged test particles’ motions around quantum-corrected Schwarzschild black holes immersed in an external magnetic field. Taking the innermost stable circular orbits of neutral timelike particles into account, we find that the black holes can mimic different ranges of the Kerr black hole’s spin |a/M| from 0.15 to 0.99. Our analysis of charged test particles’ motions suggests that the values of the angular momentum l and the energy E^{2} are slightly higher than Schwarzschild black holes. The allowed regions of the (l,E^{2}) demonstrate that the critical energy E^{2}_{c} divides the charged test particle’s bounded trajectory into three types. With the help of a Monte Carlo method, we study the charged particles’ probabilities of falling into the black holes and find that the probability density function against l depends on the signs of the particles’ charges. Finally, the epicyclic frequencies of the charged particles are considered with respect to the observed twin peak quasi-periodic oscillations frequencies. Our results might provide hints for distinguishing quantum-corrected Schwarzschild black holes from Schwarzschild ones by using the dynamics of charged test particles around the strong gravitational field.

Comparative analysis of different charged particles emerging from a broad beam ion source

In this research, the ion-source is modified to produce differently charged particles; that could be successfully used in a variety of applications. The different parameters affecting the particles; neutral charge, electron, and positive ion emerging from a broad beam cold cathode ion source are studied using argon and nitrogen gases. The neutral and the electron current are measured using a simple technique. It is found that the neutral particles and the electrons depend on the positive ion current, gas pressure, and gas type. Also, the ratio of the neutral to the positive charge is increased by increasing the gas pressure and its reach to 1.2 at pressure 4 × 10-4 mbar in case of argon and reach to 1.45 at pressure 5 × 10-4mbar in case of nitrogen gas. Also; it is found that the ratio of the electron to the positive charge is inversely proportional to the gas pressure in the case of argon gas. But in the case of the nitrogen gas it is found that this ratio is directly proportional and reaches 2.1 at pressure 5 × 10-4mbar.

Projection-type electron spectroscopy collimator analyzer for charged particles and x-ray detections.

We developed a compact sized device for angular and energy analysis of charged particles in a wide acceptance cone angle of nearly 1π steradian. This device is configured from an electrostatic lens comprising an axisymmetric aspherical mesh, which has a concave shape viewed from the point source, a set of axisymmetric electrodes, planar grids, microchannel plates, and a fluorescent screen positioned coaxially. The potentials of electrodes are adjusted so that the trajectories of the electrons with arbitrarily set kinetic energy are substantially parallelized by the electrostatic lens and enter the planar grid perpendicularly. Instead of the planar grid, a collimator plate with parallel holes can be used as an energy band-pass filter. The angular distribution of electrons with the selected kinetic energy is projected directly onto the fluorescent screen without converging and passing through a pinhole. This is a simple but significant electron-optical design to obtain wide-range angular distribution with high angular resolution, and the analyzer can be suitably used for the two-dimensional angular distribution measurements of electrons and ions emitted from surfaces.

Maximal kinetic energy and angular distribution analysis of spatial map imaging: Application to photoelectrons from a single quantum state of H2O.

Dynamical or spatial properties of charged species can be obtained using electrostatic lenses by velocity map imaging (VMI) or spatial map imaging (SMI), respectively. Here, we report an approach for extracting dynamical and spatial information from patterns in SMI images that map the initial coordinates, velocity vectors, and angular distributions of charged particles onto the detector, using the same apparatus as in VMI. Deciphering these patterns required analysis and modeling, involving both their predictions from convolved spatial and velocity distributions and fitting observed images to kinetic energies (KEs) and anisotropy parameters (βs). As the first demonstration of this capability of SMI, the ensuing photoelectrons resulting from (2 + 1) resonant ionization of water in a selected rotational state were chosen to provide a rigorous basis for comparison to VMI. Operation with low acceleration voltages led to a measured SMI pattern with a unique vertical intensity profile that could be least-squares fitted to yield KE and β, in good agreement with VMI measurement. Due to the potential for improved resolution and the extended KE range achievable by this new technique, we expect that it might augment VMI in applications that require the analysis of charged particles and particularly in processes with high KE release.

A mathematical model of the electric field perturbation about an array of conductive wires and its impact on the passing charged particle distribution

An analytic model of the electric field perturbation about an array of wires, such as a grid or a mesh, is presented to assess the impact of using such arrays in charged particle analyzers. The analysis begins with an exact solution for the electric field about a grid of flat wires. The result is connected to the Fourier analysis of a grid with high transparency, which is extended to give a solution for the field perturbation about a mesh of wires. The Fourier decomposition of the electric field profile is utilized to calculate the effective barrier that a grid or a mesh provides to charged particles and to calculate the diffusion of the particle energies that pass through such arrays of wires. The results are applied to the measurements of the temperature of a Maxwellian particle distribution by these arrays and by a collector placed downstream.

The integrated diagnostic suite of the C-2W experimental field-reversed configuration device and its applications.

In the current experimental device of TAE Technologies, C-2W (also called "Norman"), record breaking advanced beam-driven field-reversed configuration (FRC) plasmas are produced and sustained in steady state utilizing variable energy neutral beams (15-40 keV, total power up to 20MW), advanced divertors, bias electrodes, and an active plasma control system. This fully operational experiment is coupled with a fully operational suite of advanced diagnostic systems. The suite consists of 60+ individual systems spanning 20 categories, including magnetic sensors, Thomson scattering, interferometry/polarimetry, spectroscopy, fast imaging, bolometry, reflectometry, charged and neutral particle analysis, fusion product detection, and electric probes. Recently, measurements of main ion temperatures via a diagnostic neutral beam, axial profiles of energy flux from an array of bolometers, and divertor and edge plasma parameters via an extensive set of electric probes, interferometers, and spectrometers have all been made available. All the diagnostics work together to provide a complete picture of the FRC, fast-ion inventory, and edge plasma details enabling tomographic reconstruction of plasma parameter profiles and real-time plasma control.

Drift Current Analysis of Charged Particles in a Barrier Rib-Type Electronic Paper Display

The drift current flowing in an electronic paper due to charged particles is analyzed. Sample panels having barrier ribs are fabricated using a photolithographic process: the cells have a rib height of 53.57 μm, a size of 220 μm × 220 μm, and a total capacitive area of 6.22 cm2. The upper and lower electrodes are fabricated with indium tin oxide and biased between − 2 and + 2 V. The electronic ink is loaded into the samples with different particle concentrations in an electrically neutralized fluid with mixing ratios of 1:0.2, 1:1, and 1:5 as a weight ratio. In the amplitudes of the current peaks, we see that the charged particles of the sample having mixing ratio of 1:0.2 have the most rapid slope with current value of 3.58 μΑ, without any interference from other neighboring particles. Particles of the sample having mixing ratio of 1:5 show the least saturation current than those of other samples. We ascertained that the point where the reflectivity change starts is not the point to which the input pulse is applied, but the maximum value of the current because of displacement current and delay time.

Analysis of charged acrylic particles by on-line comprehensive two-dimensional liquid chromatography and automated data-processing

A thorough understanding of particle formation and polymer growth during emulsion polymerization is indispensable for the development of particles and products with very specific properties. This has created a demand for the detailed characterization of various properties and property distributions – and the relation between these. A method is described that enables comprehensive, simultaneous determination of the size distribution of nanoparticles and the molecular-weight distribution of the constituting polymers as a function of the particle size. The result is a complete two-dimensional distribution that details the interdependence of the two parameters. The approach comprehensively combines hydrodynamic chromatography with size-exclusion chromatography. An automated band-broadening filter has been developed to improve the accuracy of the measured distributions. The algorithm utilizes automated curve-fitting approaches to describe detected particle distributions for each horizontal slice of the 2D-LC chromatogram, and filters band broadening using calibration curves. The method has been applied to samples of complex nanoparticles comprising hydrophobic, hydrophilic and charged moieties, viz. stabilized dispersions of poly[(methyl methacrylate)-co-(butyl acrylate)-co-(methacrylic acid)]-nanoparticles in water. We consistently found that, within a single population of particles, the weight-average molecular weight increases with particle size.

Effects of key factors of rotary triboelectrostatic separator on efficiency of fly ash decarbonization

On the basis of understanding the principle of rotary triboelectrostatic separation, dynamic analysis of charged fly ash particles aimed at determining the key factors and separation experiments to improve decarbonization efficiency had been carried out. Variables of electrode plate voltage and corrected wind speed are the key factors which affect the decarbonization efficiency on the separation of fly ash. The results of separation experiments show that: (1) With the plate voltage increasing, the efficiency of decarbonization continuously rises and in its selected range, the optimal voltage level is 45kV; (2) The corrected wind speed can impact the efficiency of decarbonization significantly: with the speed increasing, the efficiency of decarbonization shows a trend of first decline, then increase and decrease again, and in its selected range, the optimal speed is 2.0m/s. This study is of significance for the improvement of rotary triboelectrostatic separation performance and its decarbonization separation efficiency.

Bifurcation Analysis of Charged Particles Moving on a Rough Surface Under Different Damping Effects

This paper deals with two types of bifurcation behaviors of charged particles moving on rough surface under different damping effects. Based on the derived models, the stability of the particle system is judged by eigenvalue analysis and then the eigenvalue movement of the Jacobian matrix is analyzed to reveal the underlying mechanism of the dynamical evolution. It is shown that in the particle system with constant damping force, the system loses stability via Neimark–Sacker bifurcation, whereas in the system with time-dependent damping force, the stability is lost by way of period-doubling bifurcation. In addition, a powerful tool called manifold is employed to meticulously characterize the phase space so as to clearly describe the process of energy evolution, which leads to the inherent understanding of the complex behaviors and particularly the global dynamical properties in the particle system. Finally, some bifurcation diagrams are obtained to give a more evident explanation of complex behaviors. These results are very useful for the entire transport knowledge of charged particle system.

The proton and electron radiation belts at geosynchronous orbit: Statistics and behavior during high‐speed stream‐driven storms

AbstractThe outer proton radiation belt (OPRB) and outer electron radiation belt (OERB) at geosynchronous orbit are investigated using a reanalysis of the LANL CPA (Charged Particle Analyzer) 8‐satellite 2‐solar cycle energetic particle data set from 1976 to 1995. Statistics of the OPRB and the OERB are calculated, including local time and solar cycle trends. The number density of the OPRB is about 10 times higher than the OERB, but the 1 MeV proton flux is about 1000 times less than the 1 MeV electron flux because the proton energy spectrum is softer than the electron spectrum. Using a collection of 94 high‐speed stream‐driven storms in 1976–1995, the storm time evolutions of the OPRB and OERB are studied via superposed epoch analysis. The evolution of the OERB shows the familiar sequence (1) prestorm decay of density and flux, (2) early‐storm dropout of density and flux, (3) sudden recovery of density, and (4) steady storm time heating to high fluxes. The evolution of the OPRB shows a sudden enhancement of density and flux early in the storm. The absence of a proton dropout when there is an electron dropout is noted. The sudden recovery of the density of the OERB and the sudden density enhancement of the OPRB are both associated with the occurrence of a substorm during the early stage of the storm when the superdense plasma sheet produces a “strong stretching phase” of the storm. These storm time substorms are seen to inject electrons to 1 MeV and protons to beyond 1 MeV into geosynchronous orbit, directly producing a suddenly enhanced radiation belt population.

Investigation of partial discharge between moving charged metal particles and electrodes in insulating oil under flow state and AC condition

Theoretical analysis and experimental study were conducted to clear the partial discharge (PD) between moving charged metal particles and electrodes in insulation oil under flow state and AC condition. The rise time of the PD pulse current is tens of nanoseconds, which is not affected by velocity and voltage. The dominant frequency component of the ultra-high-frequency (UHF) signal due to charged metal particle movement is near 0.39 GHz, which is independent from velocity and voltage. The magnitudes of PD UHF signals are discontinuous and the time of occurrence of PD depends on the trajectories of charged metal particles. PD &-U-N maps clearly indicate that the phase information of the PD UHF signal on the maps is similar regardless of flow velocity and AC condition, but the voltage intensifies the PD and the flow velocity weakens the PD. The trajectories of charged metal particles in the horizontal transformer oil tract were investigated through stress analysis of charged metal particles under flow state and AC voltage. When charged metal particles move along the oil tract under the oil flow, reciprocating oscillation simultaneously occurs in the vertical direction.

Electrostatic-Potential Analysis of Charged Particles by Split-Illumination Electron Holography

Electrostatic-Potential Analysis of Charged Particles by Split-Illumination Electron Holography

Formation Mechanism Analysis and Detection of Charged Particles in an Aero-engine Gas Path

The components of an aero-engine gas path cannot be monitored in a timely way due to a lack of real-time monitoring technologies. As an attempt to address this problem, we have conducted research on a condition monitoring technology based on the charging characteristics of particles in an aero-engine gas path, and emphatically analyze the formation of particles in an aero-engine gas path, the charging mechanism of carbon particles and the factors that influence the charge quantity and polarity. The verification experiments are performed on the simulated experiment platform and a turbo-shaft engine test bench. The results show the carbon particles' carry charge, and an obvious change in the total electrostatic charge level in the aero-engine gas path due to the increased carbon particles produced by burning or abnormal metal particles; the charge number is related to the size of particles, and the bigger carbon particles carry a negative charge and metal particles carry a positive charge; the change in engine power can lead to an obvious change in the level of electrostatic charge in the gas path, and the change in electrostatic charge results from the extra carbon particles formed in the rich-oil burning process. The research provides a reference for establishing the baseline of electrostatic charge while the engine runs on different power. The study also demonstrates the validity of the electrostatic monitoring technology and establishes a base for developing the application of electrostatic monitoring technology in aero-engines.

High throughput on-chip analysis of high-energy charged particle tracks using lensfree imaging

We demonstrate a high-throughput charged particle analysis platform, which is based on lensfree on-chip microscopy for rapid ion track analysis using allyl diglycol carbonate, i.e., CR-39 plastic polymer as the sensing medium. By adopting a wide-area opto-electronic image sensor together with a source-shifting based pixel super-resolution technique, a large CR-39 sample volume (i.e., 4 cm × 4 cm × 0.1 cm) can be imaged in less than 1 min using a compact lensfree on-chip microscope, which detects partially coherent in-line holograms of the ion tracks recorded within the CR-39 detector. After the image capture, using highly parallelized reconstruction and ion track analysis algorithms running on graphics processing units, we reconstruct and analyze the entire volume of a CR-39 detector within ∼1.5 min. This significant reduction in the entire imaging and ion track analysis time not only increases our throughput but also allows us to perform time-resolved analysis of the etching process to monitor and optimize the growth of ion tracks during etching. This computational lensfree imaging platform can provide a much higher throughput and more cost-effective alternative to traditional lens-based scanning optical microscopes for ion track analysis using CR-39 and other passive high energy particle detectors.

A multi-stage image charge detector made from printed circuit boards

We present the first reported instance of an image-charge detector for charged particles in which detection elements are patterned onto printed circuit boards. In contrast to conventional techniques involving separately machined and positioned segments of metal tubing, this technique is much simpler to assemble, align, and connect to electrical wiring, with no loss in sensitivity. The performance of single-stage and 5-stage charge detectors is demonstrated using electrospray-charged, micrometer-size polystyrene spheres. Both velocity and charge of each particle are measured. Multiple detection stages--which require no extra effort to pattern or setup compared with a single stage--result in an ensemble averaging effect, improving the detection limit over what can be achieved with a single-stage detector. A comparison is made between the printed circuit board detector and a conventional tubular charge detector and found to be statistically equivalent. These results demonstrate and illustrate that devices for detection, analysis, and/or manipulation of charged particles and ions can be made using printed circuit boards rather than using separately fabricated metal electrodes.

Geometric analysis of phase bunching in the central region of cyclotron

An optimum condition for realizing phase bunching in the central region of a cyclotron was quantitatively clarified by a simplified geometric trajectory analysis of charged particles from the first to the second acceleration gap. The phase bunching performance was evaluated for a general case of a cyclotron. The phase difference of incident particles at the second acceleration gap depends on the combination of four parameters: the acceleration harmonic number h, the span angle θD of the dee electrode, the span angle θF from the first to the second acceleration gap, the ratio RV of the peak acceleration voltage between the cyclotron and ion source. Optimum values of θF for phase bunching were limited by the relationship between h and θD, which is 90°/h+θD/2≤θF≤180°/h+θD/2, and sinθF>0. The phase difference with respect to the reference particle at the second acceleration gap is minimized for voltage-ratios between two and four for an initial phase difference within 40 RF degrees. Although the slope of the first acceleration gap contributes to the RF phase at which the particles reach the second acceleration gap, phase bunching was not affected. An orbit simulation of the AVF cyclotron at the Japan Atomic Energy Agency verifies the evaluation based on geometric analysis.

The combined energy analyzer composed of electrostatic mirror fields

A model of an electrostatic spectrometer for the energy analysis of charged particles has been calculated. The instrument is based on a combination of hyperbolic and cylindrical mirrors. The scheme for an energy- and angle-resolved spectrometer which provides angular second-order focusing, high luminosity and exit angle 90° from the source has been theoretically substantiated.