Heavy Ion Research Articles

Effects of swift heavy ions on metal nanoparticles embedded in silica: Using linearly polarized light to monitor the elongation kinetics.

The elongation of metallic nanoparticles (NPs) embedded in a dielectric matrix after irradiation with swift heavy ions is a phenomenon that has been known for several years. However, the precise mechanism behind this deformation process is still not fully understood, primarily due to the dearth of information during intermediate stages of deformation. In this study, we report the continuation of our previous work [Peña-Rodríguez et al., Sci. Rep. 7(1), 922 (2017)], exploiting the strong dependence of the localized surface plasmon resonance on the aspect ratio of elongated metal NPs to study the elongation kinetics in situ. In situ optical absorption spectra were measured using a polarizing beam splitter to separate the longitudinal and transverse plasmon modes of the anisotropic NPs. Then, the detailed geometrical and compositional parameters were determined from a fit of these spectra. The use of linearly polarized light allowed for a more accurate analysis of the elongation kinetics, particularly useful in the first stages, where longitudinal and transverse modes overlap.

Delayed fragmentation of isolated nucleobases induced by MeV ions.

We evaluated the dissociation of isolated gas-phase nucleobase molecules induced by mega electron volt (MeV)-energy ions to gain fundamental insights into the reactions of nucleobases upon fast ion irradiation. We studied five nucleobase molecules-adenine, guanine, cytosine, thymine, and uracil-as gas-phase targets. We compared the fragmentation patterns obtained from carbon ion impacts with those obtained from proton impacts to clarify the effect of heavy ion irradiation. We also compared the results with electron impact and photoionization results. In addition, we identified several delayed fragmentation pathways by analyzing the correlation between fragment pairs generated from singly and doubly charged intermediate ions. To determine the lifetimes of delayed fragmentation from singly charged intermediate ions, we evaluated the detection efficiencies of the microchannel plate detector for the neutral fragment HCN as a function of kinetic energy using a new methodology. As the first demonstration of this method, we estimated the lifetimes of C5H5N5+ generated by 1.2-MeV C+ and 0.5-MeV H+ collisions to be 0.87 ± 0.43 and 0.67 ± 0.09 µs, respectively. These lifetimes were approximately one order of magnitude longer than those of the doubly charged intermediate ion C5H5N52+.

Magnetically Controllable Paper-Based Soft Robots for Colorimetric Detection of Heavy Metal Ions.

Magnetically controllable soft robots are of great interest because they have unique properties compared with conventional rigid counterparts and can be used in diverse applications such as intelligent electronics, bionics, personalized medicine, and cargo grasping. However, the fabrication of such multifunctional soft robots has been challenging because of the integration of dissimilar materials into the robot body. Herein, we designed and fabricated a soft robotic multifunctional system using conventional papers and elastomeric polymers for the colorimetric detection of heavy metal ions (Hg2+ and Fe3+) in water samples. The magnetic actuation of the platforms was shown to correlate with the type of underlying paper and magnetic particle content in the mixtures. Moreover, it was observed that actuation can also be manipulated by controlling the magnetic field strength. A proof-of-concept robotic paper-based Hg2+, Zn2+, and Fe3+ ion detection was demonstrated by combining colorimetric paper sensors and magneto-papers. Our study highlights the significant potential of paper as a material for the fabrication of effective and multifunctional untethered soft robots.

A Green and Energy‐Supply‒Free Artificial Plant for Efficient and Non‐Selective Enrichment of Heavy Metal Ions Out of Soil

AbstractRemoving heavy metal (loid) s (HMs) from contaminated soil in a nonselective, highly efficient, and energy‐free manner is a major global challenge. Herein, this work synthesizes and assembles a biomimetic materials system (BMS) consisting of an artificial plant, a hemispherical glass cover, and a reflective plate, capable of non‐selective and highly efficient remediation of soil contaminated by various HM ions under sunlight. Specifically, a water cycle is driven to establish between the soil, artificial plant, and atmosphere by solar energy in the BMS, which induced water‐soluble HM ions to enrich and precipitate at the top edge of the artificial plant. The formed HM precipitate is easily removed, contributing to the extremely strong recyclability of BMS. This system has significant advantages in terms of soil properties, contamination characteristics, energy consumption, processing time, and removal amount over other representative remediation methods, demonstrating its great potential for practical application in the remediation of various HM‐contaminated soils.

Comparison of Monte Carlo Tools for Displacement Calculations for Protons and Heavy Ions Irradiation on Iron and EUROFER97

Abstract Ion irradiation of structural materials for the current and future generation nuclear reactors is a widespread technique used to simulate neutron irradiation in the context of material science research. During the designing phase of irradiation experiments Monte Carlo transport codes are often employed to quantify the radiation exposure, by estimating the displacements per atom (dpa) quantity. From the available displacement calculation codes, four popular choices were selected: cern-fluka, mcnp, phits, and srim. These codes will be used to simulate the irradiation effects of proton and Fe ions on pure iron (G379) and EUROFER97 alloy (a common material in fusion applications) targets. Results coming from the different software are presented in the form of damage profiles and of number of displacements as a function of the primary beam energy. This study identifies discrepancies between the codes' outputs and provides optimized simulation setup parameters.

Chromium adsorption efficiency by functional polymeric nanocomposite membrane: A case study for environmental sustainability

AbstractWe have designed and developed nonwoven fabric supported electrospun polymeric nanofibrous‐based membrane for robust filtration system for ecological sustainability of clean water. The fabricated nanocomposites filters were tested for the removal of chromium (VI) toxic heavy metal ions from contaminated feedstock water. The interpenetrating network like morphological structure obtained from pure and composite nanofibers‐based membranes have been thoroughly investigated to understand the structure–properties of highly entangled system. It has been found that incorporating functional moieties onto nanocomposite membranes significantly impacts the absorption efficiency of toxic metals. The pore sizes of the hierarchical geometries have been varied to insight into its impact on flow rate and efficiency of filtration. The strategy of interfacing the multifunctional composite polyethylene terephthalate nanofiber membrane supported on nonwoven fabric to generate heterostructures has found to provide mechanically stable platform for efficient metal ion removal. It has been found by BET surface area analysis that the nanofibers reinforced with functional nanomaterials has controlled pore geometry compared to pristine PET electrospun nanofibers which lead to higher absorption of metal ions. We have highlighted the importance of mechanically stable electrospun polymeric nanofibers membrane‐based mitigation strategies to meet the huge demand of potable water for long‐term environmental sustainability.Highlights Mechanically toughened freestanding nanofibers mat supported on nonwoven fabric. Functionally upgrade nanofibers by incorporation of carbon based nanofillers. Controlled porosity by morphological optimization for removal of contaminates.

P-Morpholinomethylcalix[4]arene incorporated polyacrylonitrile nanofibers as selective adsorbent for removal of Cu+2 from aqueous environment

ABSTRACT In this study, p-morpholinomethylcalix[4]arene (p-MC4) was synthesized using Mannich reaction and utilized for the fabrication of polyacrylonitrile nanofibers impregnated with p-morpholinomethylcalix[4]arene (PAN/p-MC4) using electrospinning. The nanofibers were prepared by blending 12% solution of PAN with 20% solution of p-MC4. The PAN/p-MC4 NFs were thoroughly evaluated for their removal efficiency of Cu2+ from the aqueous media. The selectivity of PAN/-p-MC4 nanofibers was also examined by adsorbing a set of metal ions with same charge and similar ionic radius. The results of distribution ratio showed that PAN/p-MC4 nanofibers have superior selectivity for Cu2+ as compared to other heavy metal ions. The relative selectivity coefficients of PAN/p-MC4 nanofibers were found to be 25.2, 14.1, 8.9, and 4.03 for Cu2+/Ni2+, Cu2+/Co2+, Cu2+/Cd2+ and Cu2+/Pb2+, respectively. This indicates that PAN/p-MC4 nanofibers have a higher selectivity for Cu2+ ions. Numerous parameters such as pH, time, adsorbent dosage and analyte concentration were optimized to evaluate the maximum adsorption capacity of nanofibers for Cu2+. Adsorption isotherm models showed that the adsorption is promising and follows Langmuir adsorption isotherm. Whereas, PAN/p-MC4 nanofibers followed pseudo- second order kinetics during adsorption experiments. The PAN/p-MC4 nanofibers showed excellent adsorption capacity (q o ) of 65.35 mg/g for Cu2+ at pH 5 in 60 min under shaking speed of 120 rpm. Moreover, PAN/p-MC4 nanofibers had been used to remove Cu2+ from real surface water samples. According to the results, PAN/p-MC4 nanofibers are more effective adsorbent for removing Cu2+ from contaminated water.

Electromagnetic fields in low-energy heavy-ion collisions with baryon stopping

Electromagnetic fields in low-energy heavy-ion collisions with baryon stopping

Petroleum coke-derived carbon nanotubes decorated by gold nanoparticles towards highly selective Pb2+ electrochemical sensing

The utilization of petroleum coke with a simple and eco-friendly way is still a challenging task. In this study, an in-situ texturing strategy has been proposed for the preparation of the N-doped carbon nanotubes (N-CNTs), which employs cheap petroleum coke as carbon source and graphitic carbon nitride (g-C3N4) as template and nitrogen source. The synergistic effect between N-CNTs with multilayer adsorption and Au nanoparticles (AuNPs) with remarkable electrocatalytic properties is conducive to constructing a promising N-CNTs/AuNPs nanocomposite as sensing flatform for monitoring the trace amount of heavy metal ions. The sensitivity of N-CNTs/AuNPs-modified glassy carbon electrode (GCE) for lead (II) ion (Pb2+) detection is as high as 26.1 μA·μM−1, which has 42.5 and 3.0-times enhancement compared to bare GCE (0.6 μA·μM−1), and N-CNTs-modified GCE (6.5 μA·μM−1), respectively. Additionally, the corresponding limit of detection of N-CNTs/AuNPs-modified GCE has achieved as low as 0.011 μM (S/N = 3). Encouragingly, the interference of co-existing ions could be negligible, which allows the accurate detection of Pb2+ in real water samples for further practical applications with a satisfactory recovery between 95.7 % and 106.6 %. The exceptional anti-interference performance can be ascribed to the robust chemical interaction between Pb2+ and N-CNTs/AuNPs nanocomposite, which has been proved by the X-ray photoelectron spectroscopy analyses. This work not only opens up a new avenue for the high added-value and efficient utilization of petroleum coke, but also provides valuable insights into harnessing synergistic catalysis of noble metal nanoparticles to improve the electrochemical activity of electrode materials in the electrochemical analysis field.

Study on the preparation of Nano-Fe3O4 by steel pickling waste liquor and its effective removal of Cr (VI) from wastewater

In order to comprehensively treat and utilize steel pickling waste liquor (SPWL), this study used SPWL as raw material to prepare two different crystalline forms of Nano-Fe3O4 by co-precipitation and precipitation-oxidation methods, and investigated their removal effect on Cr(VI) in wastewater. The two kinds of Nano-Fe3O4 were characterized using SEM, XRD, and VSM, and the results showed that the Nano-Fe3O4 synthesized by the co-precipitation method has better properties. The two kinds of Nano-Fe3O4 were used to remove Cr(VI) in wastewater, the adsorption capacity could reach 38.38 mg/g and 15.83 mg/g, respectively. Five adsorption kinetic models and five isothermal adsorption models were used to study the adsorption mechanism of Fe3O4 on Cr(VI). The adsorption process of Cr(VI) by Nano-Fe3O4 was explained well using the pseudo-second-order and Freundlich isotherm model, and the results showed that the adsorption process mainly involved physical and chemical adsorption. Through the characterization analysis before and after the reaction, the removal mechanism of Cr(VI) by Nano-Fe3O4 prepared from SPWL is mainly attributed to electrostatic adsorption and reduction reaction. According to the market survey and analysis, the production cost is reduced by at least 58.33 % compared to that of Nano-Fe3O4 prepared using analytical purity in the market. Therefore, the preparation of Nano-Fe3O4 by steel pickling waste liquor provides an economical and effective way to remove heavy metal ions in wastewater.

A 14-Bit Digital to Analog Converter for a Topmetal-CEE Pixel Readout Chip

The Lanzhou Heavy Ion Research Facility (LIRF) is the largest heavy ion research facility in China, providing a substantial volume of experimental data for fundamental research in nuclear physics. The Topmetal-CEE is a pixel readout chip specifically designed for tracking detectors. Within the Topmetal-CEE framework, the front-end amplifier and comparator necessitate precisely adjustable bias voltages. Hence, in this paper, a 14-bit resolution DAC with an R-2R resistor network structure is designed, along with an amplifier featuring high driving capabilities as the DAC driver, thus preventing potential impedance issues when driving large pixel arrays. Test results demonstrate that the DAC module, operating under a 3.3 V supply voltage, can consistently output voltages ranging from 0 to 1.8 V. Furthermore, the differential non-linearity error is less than 1.07 LSB, and the integral non-linearity error is less than 1.57 LSB.

Applications of emulation and Bayesian methods in heavy-ion physics

Applications of emulation and Bayesian methods in heavy-ion physics

An organic visible-photocatalytic-adsorbence mechanism to high-efficient removal of heavy metal antimony ions

Purification of emerging heavy metal antimony contaminated water based on advanced ingenious strategies. An activated modified coconut shell charcoal (CSC) was synthesized and evaluated as a substrate-supported loaded organic photovoltaic material, PM6:PYIT:PM6-b-PYIT, to prepare a surprisingly highly efficient, stable, environmentally friendly, and recyclable organic photocatalyst (CSC-N-P.P.P), which showed excellent effects on the simultaneous removal of Sb(III) and Sb(V). The removal efficiency of CSC-N-P.P.P on Sb(Ⅲ) and Sb(V) reached an amazing 99.9% in quite a short duration of 15 min. At the same time, under ppb level and indoor visible light (∼1 W m-2), it can be treated to meet the drinking water standards set by the European Union and the U.S. National Environmental Protection Agency in 5 min, and even after 25 cycles of recycling, the efficiency is still maintained at about 80%, in addition to the removal of As (III), Cd (II), Cr (VI), and Pb (II) can also be realized. The catalyst not only solves the problems of low reuse rate, difficult structure adjustment and high energy consumption of traditional photocatalysts but also has strong applicability and practical significance. The pioneering approach provides a much-needed solution strategy for removing highly toxic heavy metal antimony pollution from the environment.

In-beam performance of a Resistive Plate Chamber operated with eco-friendly gas mixtures

ALICE (A Large Ion Collider Experiment) studies the Quark-Gluon Plasma (QGP): a deconfined state of nuclear matter obtained in ultra-relativistic heavy-ion collisions. One of the key probes for QGP characterization is the study of quarkonia and open heavy flavour production, of which ALICE exploits the muonic decay. In particular, a set of Resistive Plate Chambers (RPCs), placed in the forward rapidity region of the ALICE detector, is used for muon identification purposes.The correct operation of these detectors is ensured by the choice of the proper gas mixture. Currently they are operated with a mixture of C2H2F4, i-C4H10 and SF6 but, starting from 2017, new EU regulations have enforced a progressive phase-out of C2H2F4 because of its large Global Warming Potential (GWP), which is making it difficult and costly to purchase. Moreover, CERN asked LHC experiments to reduce greenhouse gases emissions, to which RPC operation contributes significantly.A possible candidate for C2H2F4 replacement is the C3H2F4 (diluted with other gases, such as CO2), which has been extensively tested using cosmic muons. Promising gas mixtures have been devised; the next crucial steps are the detailed in-beam characterization of such mixtures as well as the study of their performance under increasing irradiation levels.This contribution will describe the methodology and results of beam tests carried out at the CERN Gamma Irradiation Facility (equipped with a high activity 137Cs source and muon beam) with an ALICE-like RPC prototype, operated with several mixtures with varying proportions of CO2, C3H2F4, i-C4H10 and SF6 . Absorbed currents, efficiencies, prompt charges, cluster sizes, time resolutions and rate capabilities will be presented, both from digitized (for detailed shape and charge analysis) and discriminated (using the same front-end electronics as employed in ALICE) signals.

Design a Combined Function Curved DCT Superconducting Magnet for the Compact Heavy ION Therapy

Design a Combined Function Curved DCT Superconducting Magnet for the Compact Heavy ION Therapy

Validation of the synthetic model for the imaging heavy ion beam probe at the ASDEX Upgrade tokamak (invited).

Recent experiments at the ASDEX Upgrade tokamak have provided the first ever measurements from the imaging heavy-ion beam probe. In this work, we show that the developed simulation framework can reproduce qualitatively the measurement's observed shape and position. Quantitatively, we demonstrate that the model reproduces, within the experimental uncertainties, the observed signal levels. A detailed explanation of the synthetic model is presented, along with the calibration of the optical setup that reproduces the measurements.

Effect of gravity number on soil contamination during dynamic adsorption of heavy metal ions: A lattice Boltzmann study

Contamination of soils and aquifers as a result of heavy metal ions adsorption is an extremely negative environmental phenomenon associated with natural or industrial disasters. This paper presents the first systematic study of the dynamic adsorption of heavy metal ions in soils during water-air immiscible displacement induced by pressure drop and gravitational force. This study addresses three objectives. The first purpose is to determine a representative elementary volume to estimate the adsorbed amount of heavy metal ions during two-phase flow with density contrast. The second objective is to study the effect of different balances between viscous and gravitational forces, described by the gravity number, on the adsorbed amount at drainage and imbibition regimes. And the final task is to identify the effect of the pore space heterogeneity on the adsorbed amount for various gravity numbers and wetting conditions. As samples of study, we examine two-dimensional granular digital images characteristic of soils. The lattice Boltzmann method, verified on the problem of capillary-gravitational equilibrium of a meniscus, was used as a research tool. It has been established that the scale of 4–5 mm is sufficient to be representative for estimating the adsorbed amount of heavy metal ions. An increase in gravity number promotes the destabilization of the interfacial front both in the drainage and imbibition regimes and results in suppression of the adsorbed amount. The effect of gravity number on the adsorbed amount is stronger in the drainage mode compared to the imbibition regime. It has been found that pore space heterogeneity is a factor negatively affecting the adsorbed amount of heavy metal ions. The strength of the heterogeneity effect is independent of wetting conditions and gravity numbers.

Flavor-independent yield of high- pT hadrons from nuclear collisions

Data on high-pT hadron production in heavy ion collisions at Feynman xF=0 indicate at universality of the observed nuclear suppression. Our analysis of the production mechanisms demonstrates important role of the color transparency effects which make the survival probability of a quark-antiquark dipole independent of the quark flavor, provided that the hadron wave function is formed outside the medium. The latter condition imposes restrictions on the range of pT, which should be sufficiently high to make the nuclear suppression universal. We also found that the in-medium broadening rate q^ (frequently called transport coefficient) significantly depends on the quark flavor, diminishing for heavy quarks. Published by the American Physical Society 2024

Diffusion model approach to simulating electron-proton scattering events

Generative artificial intelligence is a fast-growing area of research offering various avenues for exploration in high-energy nuclear physics. In this work, we explore the use of generative models for simulating electron-proton collisions relevant to experiments like the Continuous Electron Beam Accelerator Facility and the future Electron-Ion Collider (EIC). These experiments play a critical role in advancing our understanding of nucleons and nuclei in terms of quark and gluon degrees of freedom. The use of generative models for simulating collider events faces several challenges such as the sparsity of the data, the presence of global or eventwide constraints, and steeply falling particle distributions. In this work, we focus on the implementation of diffusion models for the simulation of electron-proton scattering events at EIC energies. Our results demonstrate that diffusion models can reproduce relevant observables such as momentum distributions and correlations of particles, momentum sum rules, and the leading electron kinematics, all of which are of particular interest in electron-proton collisions. Although the sampling process is relatively slow compared to other machine-learning architectures, we find diffusion models can generate high-quality samples. We foresee various applications of our work including inference for nuclear structure, interpretable generative machine learning, and searches of physics beyond the Standard Model. Published by the American Physical Society 2024

GREEN SYNTHESIS OF MAGNETIC REDUCED GRAPHENE OXIDE HYBRID NANOCOMPOSITE USING NOVEL CLERODENDRUM PANICULATUM FOR THE REMOVAL OF MB DYE AND Cd (II) FROM AQUEOUS SOLUTION VIA MAGNETIC SEPARATION

The utmost dangerous and significant source of environmental contamination is constituted by ionic dyes and heavy metals. Graphene oxide (GO) can eradicate heavy metal ions and dyes from effluent, but the major difficulty associated with GO is the inconvenience during separation. In this study, magnetic reduced GO (rGO-Fe3O[Formula: see text] hybrid nanocomposite is synthesized by using the novel green reducing agent and is used as an adsorbent for the removal of methylene blue (MB) dye and Cd (II) ions. The prepared samples are characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and FTIR spectroscopy. adsorption study of rGO-Fe3O4 is carried out using UV visible spectrophotometry and it is obtained that the maximum adsorption capacity in the mono component system using double distilled water for MB dye and Cd (II) ions is 64.52 and 93.49[Formula: see text]mg/g, respectively. Moreover, the effect of different parameters such as temperature, adsorbent dosage, contact time, pH and initial adsorbate concentration on the adsorption of heavy metal and dye is investigated.