Effects Of Ionizing Radiation Research Articles

Effect of low energy cesium ion irradiation on vanadium oxide: Structural and spectroscopic study

Vanadium di-oxide (VO2) and vanadium tetra oxide (V2O4) powders are exposed to cesium (Cs) ion irradiation using Pelletron accelerator. The energy of the Cs ions ranges from 0.2 keV to 5 keV. Mass spectroscopic data from the accelerator is plotted for various energy ranges. Un-irradiated samples and Cs ion irradiated samples are characterized by using x-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscopy and four-point probe method. XRD analysis showed improved VO2 crystallinity after ion irradiation. The V2O4 sample shows amorphous behavior after ion irradiation. Dislocation density and tolerance are calculated to explore structure distortion after ion irradiation. Raman spectroscopy reveals vibrational and rotational modes of bonding with oxygen and vanadium. SEM results explain the reduction in agglomeration after Cs ion irradiation. The resistivity of un-irradiated and irradiated (VO2 and V2O4) samples is calculated by four-point probe method. The resistivity of vanadium oxide is decreased after Cs ion irradiation to make it a potential candidate for optoelectrical applications.

Principal Component Analysis applied on MASCS/MESSENGER data for the spectral investigation of Mercury's surface

The surface of Mercury hosts several spectral units with variations in reflectance and spectral slope, mainly identified after the application of Principal Component Analysis (PCA) on MDIS data, the camera onboard the MESSENGER spacecraft. The major terrains identified on Mercury include the smooth plains such as High-reflectance Red Plains (HRP), Intermediate Plains (IP) and Low-reflectance Blue Plains (LBP), the spectrally Intermediate Terrains (IT) and Low-Reflectance Material (LRM). The minor terrains involve hollows, fresh ejecta, faculae and red material connected to impact craters.This work aims to examine the surface of Mercury by applying the PCA on photometrically corrected and quality-filtered spectra acquired by the MASCS-MESSENGER spectrometer.By combining PC1, PC2 and PC3 components in the red-green-blue image, major terrains (HRP, IP/IT, LBP, LRM) can be distinguished from each other; similarly, among the minor terrains, fresh ejecta and hollows are spectrally distinct from the faculae (connected to volcanism) and red material (related to impact craters). Furthermore, the composite image allows discrimination of the faculae with a spectrally distinct deposit from those with a faint spectral contrast. Examination of PC1 and PC2 separates the surface of Mercury into three sections, characterized by a progressive reddening of the Visible (VIS) spectral slope. Section A includes “spectrally blue” units (LRM, LBP, hollows and fresh ejecta) with lower VIS slope values, whereas Section B involves the “spectrally red” units (RM, HRP, faculae and IT) with higher VIS slope values and with an origin connected to volcanism. The variation in VIS slope could be ascribed to differences in composition or space weathering alterations. Section C, with intermediate PC2 and VIS Slope values, includes terrains with variations in reflectance and spectral slopes. Furthermore, Section C brings to the attention areas distributed around the cold poles longitudes and high latitudes in the southern hemisphere with the maximum surface temperature spanning from 450 K to 650 K. Finally, localized regions corresponding to the walls of craters and explosive vents are also revealed from the Section C, suggesting possible exposure of material slightly altered by solar ion irradiation and/or thermal effects.

PO-2221 The effect of Ultra-High Dose-Rate Carbon ion irradiation to cell invasion on breast tumor cells.

PO-2221 The effect of Ultra-High Dose-Rate Carbon ion irradiation to cell invasion on breast tumor cells.

Modeling of Ionizing Radiation Effects for Negative Capacitance Field-Effect Transistors

A theoretical model for simulating ionizing radiation effects on negative capacitance field-effect transistors (NCFETs) with a metal–ferroelectric–insulator–semiconductor (MFIS) structure was established. Based on the model, the effects of total ionizing dose (TID) and dose rate on the surface potential, ferroelectric capacitance, voltage amplification factor, and transfer characteristics of NCFETs were investigated. The simulation results demonstrated that, with the increase in total dose, the curves of surface potential versus gate voltage and driving current versus gate voltage shift left significantly, resulting in the point of voltage amplification shifting left. Meanwhile, with the increase in dose rate, the amplitude of both the surface potential and driving current decreases slightly. Meanwhile, the derived result indicated that relatively thin ferroelectric thickness can effectively reduce the effect of TID. It is expected that this model can be helpful for analyzing the radiation effects of NCFETs.

Effects of radiation exposure and storage on the energy metabolome of platelets in whole blood.

Exposure to radiation through battlefield use of nuclear weapons, terrorist attacks or accidents at nuclear power plants is a current concern for the military. Beyond the risk of exposure to personnel is the intentional or accidental irradiation of our blood banking supply system. It is unknown how large doses of ionizing radiation affect storage of blood and blood products, including platelets. The major function of platelets is clot formation which includes aggregation, shape change, vesicle release, and fibrinogen attachment; these tasks require a significant amount of energy. Here, we determine whether the ionizing radiation effects the energy metabolome of platelets in storage. Fresh whole blood from healthy volunteers was subjected to 0, 25, or 75Gy of X-irradiation, and stored at 4°C. Platelets were isolated from stored WB at 0, 1, 7, 14, and 21 days of storage. Krebs cycle intermediates, nicotinamide adenine dinucleotides, and the tri-, di, and mono- phosphorylated versions of adenosine and guanosine were extracted and measured by tandem mass spectroscopy. Irradiation at either 25Gy or 75Gy had no significant effect on the amount of any metabolite measured compared to control (0Gy). However, there was a significant fall over time in storage for most of the metabolites measured. These data show that irradiation at high doses has no effect on the concentration of the energy metabolome of platelets derived from whole blood stored in 4°C for up to 21 days and suggests that platelets can maintain their metabolome even after radiation exposure.

Molecular dynamics study of the tensile properties of gold nanocrystalline films irradiated by gallium Ions

Understanding the effects of heavy ion irradiation on the tensile properties of metals at the nanoscale is important for the development of nanomechanical and other nanodevices using focused ion beam fabrication. This is both in terms of achieving the expected performance of designed devices and in potentially exploiting changes in mechanical properties to develop novel device concepts. We report investigation of the tensile properties of gold nanocrystalline films bombarded by high-energy Ga ions using molecular dynamics calculations. Ga ion irradiation leads to multiple grains with the redistribution of the grain boundaries (GBs). Importantly, Ga ion irradiation causes the film to become less ductile and more prone to fracture. The main reason is not surface damage caused by the sputtering effect of high-energy particles, but the convergence of GBs to the surface crater. On the other hand, for porous films with micropores in the GBs, irradiation results in the hardening of film and the ultimate tensile strength is larger than that of unirradiated counterpart.

Dielectric study of CoFe2O4/MWCNT/epoxy nanocomposites: Effect of temperature, concentration and irradiation

AbstractIn this work, dielectric behavior of CoFe2O4/MWCNT/epoxy nanocomposites affected by concentration, temperature and Au ion irradiation is reported. The CoFe2O4 nanoparticles are synthesized via co‐precipitation technique. The samples of CoFe2O4/MWCNT/epoxy nanocomposites are prepared by varying ferrite contents (upto 50 phr). After that, the dielectric behavior is evaluated using LCR meter. The results exhibited that the dielectric constant of CoFe2O4/MWCNT/epoxy nanocomposites increases with increased ferrite content. The effect of temperature on dielectric of CoFe2O4/MWCNT/epoxy nanocomposites is observed at 27–100°C. The dielectric constant of prepared nanocomposites is gradually enhanced with elevation in temperature up to a certain value then decreased due to accumulation of charges at interfaces. Furthermore, reduced dielectric behavior of prepared nanocomposites can be seen on the account of ion irradiation effect.

Effect of Ion Irradiation on the Resource Characteristics of the V95 Alloy (Al–Zn–Mg–Cu)

Effect of Ion Irradiation on the Resource Characteristics of the V95 Alloy (Al–Zn–Mg–Cu)

Effects of Ion Irradiation on Modifying Surface Characteristics and Dielectric Properties of PVA Polymeric Materials

In this work, PVA polymeric sheets were irradiated utilizing a homemade ion beam cold cathode source for use in optoelectronics applications. The PVA films were exposed to hydrogen beams with fluence range 8 × 1017 to 24 × 1017 ions.cm−2. The structural and functional group characteristics of pure and treated PVA films were investigated using XRD and FTIR methods, which confirmed the success fabrication of the PVA films. In frequency of 102 to 5 × 106 Hz, the conductivity, electrical impedance, and dielectric modulus of untreated and treated samples were determined. The dielectric characteristics of PVA films exhibit a significant modification when subjected to a hydrogen beam. Additionally, after being exposed to 16 × 1017 ions, the dielectric constant ε′ improved from 0.0078 for un-irradiated PVA to 0.0395, and conductivity changed from 8.87 × 10−11 S cm−1 to 3.32 × 10−10 S cm−1. Moreover, the relaxation time for PVA is reduced from 28.4 × 10−5 s to 8.98 × 10−5 s for 8 × 1017 ions.cm−2 and to 3.5 × 10−5 s for 24 × 1017 ions.cm−2. The present study extends the potential use of the treated PVA films to a broader range of fields, including microelectronics.

Analysis of Single Event Transients in Arbitrary Waveforms Using Statistical Window Analysis

Window or taper functions are commonly used in data processing to detect transient events or for time-averaging of frequency spectra. A generalized window function is demonstrated using the Ionizing Radiation Effects Spectroscopy (IRES) technique to enhance the measurement of transient anomalies within arbitrary waveforms. The IRES filter is used to convolve time data with a sliding window consisting of a moment-generating function. The resulting time-dependent statistical moments can be used to eliminate any steady-state signatures, including noise, and extract transient behaviors. The IRES filter is used to analyze data from heavy-ion exposures of commercial off-the-shelf (COTS) operational amplifiers, laser-induced transients in CMOS phase-locked loops, and simulated transients in digital and analog circuits. The performance of the IRES filter in noisy environments shows that transients can be measured with higher fidelity than standard amplitude thresholding. This statistical window analysis technique may remove the need for complex triggering mechanisms on instrumentation and does not require <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a-priori</i> knowledge of transient characteristics. Potential applications of IRES include real-time measurement, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in-situ</i> data analysis, and machine learning.

Effects of proton and oxygen ion irradiation on cardiovascular function and structure in a rabbit model

PurposeAstronauts on missions beyond low Earth orbit will be exposed to galactic cosmic radiation, and there is concern about potential adverse cardiovascular effects. Most of the research to identify cardiovascular risk of space radiation has been performed in rodent models. To aid in the translation of research results to humans, the current study identified long-term effects of high-energy charged particle irradiation on cardiovascular function and structure in a larger non-rodent animal model. Materials and methodsAt the age of 12 months, male New Zealand white rabbits were exposed to whole-body protons (250 MeV) or oxygen ions (16O, 600 MeV/n) at a dose of 0 or 0.5 Gy and were followed for 12 months after irradiation. Ultrasonography was used to measure in vivo cardiac function and blood flow parameters at 10- and 12-months post-irradiation. At 12 months after irradiation, blood cell counts and blood chemistry values were assessed, and cardiac tissue and aorta were collected for histological as well as molecular and biochemical analyses. Plasma was used for metabolomic analysis and to quantify common markers of cardiac injury. ResultsA small but significant decrease in the percentage of circulating lymphocytes and an increase in neutrophil percentage was seen 12 months after 0.5 Gy protons, while 16O exposure resulted in an increase in monocyte percentage. Markers of cardiac injury, cardiac troponin I (cTnI) and N-Terminal pro-B-type Natriuretic Peptide were modestly increased in the proton group, and cTnI was also increased after 16O. On the other hand, metabolomics on plasma at 12 months revealed no changes. Both types of irradiation demonstrated alterations in cardiac mitochondrial morphology and an increase in left ventricular protein levels of inflammatory cell marker CD68. However, changes in cardiac function were only mild. ConclusionLow dose charged particle irradiation caused mild long-term changes in inflammatory markers, cardiac function, and structure in the rabbit heart, in line with previous studies in mouse and rat models.

Effects of He ion and electron beam irradiation on a CdTe solar cell dosimeter in a substrate configuration

In this work, the effects of He ion and electron beam irradiation on substrate-type CdTe solar cells that are suitable for the detection of alpha and beta radiation are investigated. He ion irradiation revealed that the induced current proportionally increased with the increase of He ion current and that it is possible to detect alpha radiation using a substrate-type CdTe solar cell dosimeter. Next, the electron irradiation effects were investigated. The induced current proportional to the electron flux was also observed, and the sensitivity depended on the electron energy. In addition, the degradation of a substrate-type CdTe solar cell dosimeter by electron beam irradiation was investigated. No significant degradation in short-circuit current was observed at the electron irradiation of 3 × 1016 cm−2 at 200 keV and 1 × 1016 cm−2 at 400 keV. This result suggests that the substrate-type CdTe solar cell dosimeter is sufficiently resistant to electron irradiation.

Ion-Induced Lateral Damage in the Focused Ion Beam Patterning of Topological Insulator Bi2Se3 Thin Films

Focused Ion Beam patterning has become a widely applied technique in the last few decades in the micro- and nanofabrication of quantum materials, representing an important advantage in terms of resolution and versatility. However, ion irradiation can trigger undesired effects on the target material, most of them related to the damage created by the impinging ions that can severely affect the crystallinity of the sample, compromising the application of Focused Ion Beam to the fabrication of micro- and nanosized systems. We focus here on the case of Bi2Se3, a topological material whose unique properties rely on its crystallinity. In order to study the effects of ion irradiation on the structure of Bi2Se3, we irradiated with Ga+ ions the full width of Hall-bar devices made from thin films of this material, with the purpose of inducing changes in the electrical resistance and characterizing the damage created during the process. The results indicate that a relatively high ion dose is necessary to introduce significant changes in the conduction. This ion dose creates medium-range lateral damage in the structure, manifested through the formation of an amorphous region that can extend laterally up to few hundreds of nanometers beyond the irradiated area. This amorphous material is no longer expected to behave as intrinsic Bi2Se3, indicating a spatial limitation for the devices fabricated through this technique.

Fe ion irradiation effects on the precipitates of P92 steel after thermomechanical treatment

Although thermomechanical treatment (TMT) can significantly improve the high temperature strength of high Cr F/M steels being material candidates for Generation-IV reactors, the change of precipitates in TMT-strengthened steels under irradiation remains unknown. To understand this, high Cr F/M steel P92 was subjected to an optimized TMT process, and which was irradiated with 3.5 MeV Fe13+ ions at 700 °C to 0.37 and 0.75 dpa, while precipitates in the unirradiated and irradiated steels were observed and analyzed using transmission electron microscopy. After irradiation, overall, precipitates number reduced, large precipitates increased but nano-sized precipitates uniformly distributed throughout the matrix, and precipitates distribution changed from densely networked to isolated dispersion distribution. The change of precipitate composition after irradiation varied with precipitate phase type, mainly, the composition of M23C6 precipitates was unchanged; Cr decreased, and V increased in Cr-rich M2X precipitates, along with a significant decrease in Cr/V ratio; Nb increased, and V decreased in Nb-rich MX-I precipitates, along with an obvious increase in Nb/V ratio; Nb increased, Cr significantly decreased in Nb-rich MX-II precipitates, along with a striking increase in Nb/Cr ratio. During irradiation, the obvious coarsening of Cr-rich M23C6 and M2X precipitates occurred mainly due to the irradiation assisted diffusion, and densely networked Cr-rich M2X precipitates partially dissolved, leading to a decrease in precipitates number. The compositional changes of the precipitates during irradiation were also discussed.

The multimodal effect of Photothermal/Photodynamic/Chemo therapies mediated by Au-CoFe2O4 @Spiky nanostructure adjacent to mitoxantrone on breast cancer cells.

Conventional cancer treatments are associated with a number of limitations, including non-selectivity, toxicity and multidrug resistance, so new nanotechnologies are being developed forcancer diagnosis and therapy. Phototherapy approach based on nanotechnology is a hopeful strategy to overcome these problems. Photothermal (PTT) and photodynamic therapies (PDT), in addition to having non-invasive properties, are known as promising methods for treatment of tumors. In this study, CoFe2O4 theranostic magnetic nanoparticles coated with spiky gold nanoparticles were designed and synthesized and its photothermal effects were evaluated in combination with the photodynamic and chemotherapeutic effects of mitoxantrone (MTX) under in vitro conditions. At first, CoFe2O4 @Spiky Au nanostructure was synthesized and after its characterization, cytotoxicity of MTX, CoFe2O4 @ Spiky Au (MGNS) and CoFe2O4 @ Au were determined on MDA-MB-231 cell line. Then, the concentrations required for inducing 50% cell death (IC50) and appropriate concentration for this study was obtained. Cells were irradiated by an 808nm laser and a non-synchronous light source at 670nm at the separate groups. The viability of treated cells was determined via MTT test 48h after treatment. In the groups receiving energy density (5-40) J/cm2, at the lower laser dose an increase in cell survival was observed (P<0.05) and then cell survival was decreased (P<0.05). In the groups receiving non-coherent light (2-18J/cm2) from the beginning, a decreasing trend in cell survival is observed. The overlap of the emission spectrum of the light source and the absorption spectrum of the nanostructure amplified the cell death. Similar to the Hormesis model reported for ionizing radiation effects, at low light doses with the bio-phasic response dose model, increased cell survival and proliferation can be expected.

Ion Irradiation Effects on Two-Dimensional MXene Ti2C for Applications in Extreme Conditions: Combined Ab Initio and Monte Carlo Simulations

As an emerging category of two-dimensional (2D) materials, transition metal carbides and/or nitrides (MXenes) have attracted considerable interest for various disciplines. They exhibit unique properties typical of both metals and ceramics, rendering significant potential for harsh conditions such as in outer space and nuclear systems. In this work, using Ti2C as a prototype probe, we investigate the ion irradiation effects by combining ab initio and Monte Carlo simulations. We first consider the structures and energetics of various atomic vacancies in Ti2C. Based on binary collision approximation, a Monte Carlo approach is developed to explore the defects induced by ion bombardment. Systematic Monte Carlo (MC) simulations of different incident ions (i.e., H, He, Li, Be, B, C, N, O, F, and Ne) and selected isotopes reveal that defects are formed via primary collision and in-plane recoils, and the number of displaced atoms decreases with incident energy and increases with the atomic number of incident ions. Interestingly, Ti atoms are much easier to be knocked out than C atoms, beneficial for selective etching for nanoelectronics. We show that Ti2C remains metallic with vacancies of large size, indicating the high irradiation tolerance of electrical conductivity. This work not only provides fundamental insights into the irradiation response of MXenes but also paves the way for future exploration and implementation of 2D nanostructures in extreme conditions, e.g., as coatings or structural materials for nuclear reactors.

Genome-wide analysis of mutations induced by carbon ion beam irradiation in cotton.

Carbon ion beam (CIB) irradiation is a powerful way to create mutations in animals, plants, and microbes. Research on the mutagenic effects and molecular mechanisms of radiation is an important and multidisciplinary issue. However, the effect of carbon ion radiation on cotton is uncertain. In this study, five different upland cotton varieties and five CIB doses were used to identify the suitable irradiation dose for cotton. Three mutagenized progeny cotton lines from the wild-type Ji172 were re-sequenced. The effect of half-lethal dose on mutation induction indicated that 200 Gy with LETmax of 226.9 KeV/μm was the most effective heavy-ion dose for upland cotton and a total of 2,959-4,049 single-base substitutions (SBSs) and 610-947 insertion-deletion polymorphisms (InDels) were identified among the three mutants by resequencing. The ratio of transition to transversion in the three mutants ranged from 2.16 to 2.24. Among transversion events, G:C>C:G was significantly less common than three other types of mutations (A:T>C:G, A:T>T:A, and G:C>T:A). The proportions of six types of mutations were very similar in each mutant. The distributions of identified SBSs and InDels were similar with unevenly distributed across the genome and chromosomes. Some chromosomes had significantly more SBSs than others, and there were "hotspot" mutation regions at the ends of chromosomes. Overall, our study revealed a profile of cotton mutations caused by CIB irradiation, and these data could provide valuable information for cotton mutation breeding.

Microstructure and defect evolution of nuclear graphite under temperature-dependent ion irradiation

Nuclear graphite plays a vital role in GEN-IV reactors and is expected to function in the harsh environments such as high temperature and high-dose irradiation. The ion irradiation behaviour of ET-10 nuclear graphite in comparison with highly orientated pyrolytic graphite (HOPG) was reported in this work, to explore the combined effects of ion irradiation and temperature. Ion irradiation experiments were carried out using 190 keV H+ and 1.8 MeV Ar+ at different doses. SRIM simulation, scanning electron microscopy (SEM) and Raman spectroscopy were employed to characterize the microstructural changes and defect evolution of graphite specimens under different irradiation conditions. The vein structure in HOPG graphite and the vertical scale-like structure in ET-10 graphite caused by ion irradiation were observed. The effects of temperature on ion irradiation could be divided into two stages of recovering and saturation according to mutual analysis of SEM and Raman. It was also found that the recovery degree of the half-width at half maximum (HWHM) for the G band was greater than that of ID/IG, probably because the deformed or ruptured graphite layers were difficult to recover at rising temperatures and/or could even be enhanced. HWHM(G), ID/IG, and La was comprehensively discussed, giving an overall perspective of defect evolution and crystallite size changes under temperature-dependant ion irradiation.

Simulation of heavy ion irradiation effect on 3D MOSFET

Single event upset effect is an important factor that causes performance degradation and functional failure of aerospace equipment components in space radiation environment. When high-energy particles incident on semiconductor devices in working state, they will induce functional errors of devices and even cause permanent damage. Based on the finite element method, the three-dimensional simulation of Metal-oxide-semiconductor field-effect transistor (MOSFET) is carried out. The single event upset effect of MOSFET under heavy ion irradiation and the influence of heavy ion irradiation on transient drain current are investigated. The results show that the transient drain current of MOSFET devices will increase rapidly when heavy ions are incident, and then the logic state of the devices will change. With the increase in linear energy transfer density, the peak value of the transient drain current pulse increases and the pulse width decreases. With the increase in the incident angle, the peak value of the pulse first increases and then decreases. The maximum value is obtained when the incident angle is vertical, the pulse width first decreases and then increases, and the minimum value is obtained when the incident angle is vertical. With the increase in MOSFET size, the difference of transient drain current formed by symmetrical heavy ion incidence is becoming smaller and smaller. When the incident track is completely in the drain region, the simulation results are the same.

Unsupervised machine learning application to identify single-event transients (SETs) from noise events in MOSFET transistor ionizing radiation effects

This article presents a novel application of the k-means unsupervised machine learning algorithm to the problem of identifying single event transient (SET) events from noise during heavy-ion irradiation experiments of an electronic device. We explore the performance of the k-means algorithm by analyzing experimental datasets of SET events produced by several heavy-ions irradiations of a MOSFET transistor. Data anomalies and effectiveness of the chosen features (mean, standard deviation, skewness, and kurtosis) were investigated using the Isolation Forest and Random Forest algorithms, respectively. The results show a high capability of the K-means algorithm to identify SET events from noise using the first four statistical moments as features, allowing in the future the use of this method for in situ event detection and diagnosis without previous algorithm training or pre-analysis of the experimental data.