Effect Of Heavy Ion Irradiation Research Articles

Effect of Heavy Ion Irradiation on Friction of GNSs: Implications for Aerospace Lubrication

Effect of Heavy Ion Irradiation on Friction of GNSs: Implications for Aerospace Lubrication

Change in Superparamagnetic State Induced by Swift Heavy Ion Irradiation in Nano-Maghemite

The effect of swift heavy ion irradiation on sol–gel-prepared maghemite nanoparticles was studied by 57Fe transmission Mössbauer spectroscopy and X-ray diffractometry (XRD). The room temperature Mössbauer spectra of the non-irradiated nano-maghemite showed poorly resolved magnetically split, typical relaxation spectra due to the superparamagnetic state of the nanoparticles. Significant changes in the line shape, indicating changes in the superparamagnetic state, were found in the Mössbauer spectra upon irradiation by 160 MeV and 155 MeV 132Xe26+ ions with fluences of 5 × 1013 ion cm−2 and 1 × 1014 ion cm−2. XRD of the irradiated maghemite nanoparticles showed a significant broadening of the corresponding lines, indicating a decrease in the crystallite size, compared to those of the non-irradiated ones. The results are discussed in terms of the defects induced by irradiation and the corresponding changes related to the change in particle size and consequently in the superparamagnetic state caused by irradiation.

An In Situ transmission electron microscopy study on the synergistic effects of Au-ion irradiation and high temperature on nuclear graphite microstructure

The combined effects of high-temperature and heavy-ion irradiation on Mrozowski cracks (MC) and nuclear graphite crystallographic dimensions have been studied using in situ heating and in situ ion-irradiation in the transmission electron microscope (TEM). Electron transparent lamella of nuclear graphite, IG-110, was irradiated using a 2.8 MeV Au beam at an ion flux of 3.991 ×1010 ion cm−2 s−1 for 70 min at 800 °C. Upon high-temperature irradiation, Mrozowski crack closure was studied quantitatively. The analysis showed linear, positive expansion of nuclear graphite which is significantly different from the dimensional changes previously reported for low-dose neutron irradiation of nuclear graphite in which the material undergoes negative to positive expansion via a turnaround radiation dose. The trend of the thermal expansion coefficient (CTE) of pristine IG-110 in this study is consistent with previous reports in the 100 °C–800 °C temperature region in which the dimensional change ranges from negative to positive values.

TCAD simulation study of heavy ion radiation effects on hetero junctionless tunnel field effect transistor

Semiconductor devices used in radiation environment are more prone to degradation in device performance. Junctionless Tunnel Field Effect Transistor (JLTFET) is one of the most potential candidates which overcomes the short channel effects and fabrication difficulties. In this work, 20 nm JLTFET is proposed with Silicon in the drain/channel region whereas source uses different materials, Silicon Germanium (SiGe), Gallium Nitride (GaN), Gallium Arsenide (GaAs), Indium Arsenide (InAs). The device performance is examined by subjecting it to heavy ion radiation at a lower and higher dose of linear energy transfer (LET) values. It can be seen that the most sensitive location is the source/channel (S/C) interface for SiGe, GaN and GaAs whereas the drain/channel (D/C) interface for InAs. Further analysis is carried out at these vulnerable regions by matching ION of all materials. The parameters, transient peak current (Ipeak), collected charge (QC), threshold voltage shift (ΔVth) and bipolar gain (β) are extracted using transient simulations. It is observed that for a lower dose of LET, Ipeak of SiGe is 27% lesser than InAs and for higher dose of LET, SiGe shows 56% lesser Ipeak than InAs. SiGe is less sensitive at lower and higher dose of LET due to reduced ΔVth, tunneling and electron density.

Effect of 710 MeV Bi+51 swift heavy ions irradiation on Se pre-implanted polycrystalline SiC

In this study, the effect of swift heavy ions (SHIs) irradiation in the recrystallization of polycrystalline SiC pre-implanted with selenium (Se) ions and migration of Se was investigated. The main objective of this study is to investigate the role of SHIs with the maximum electronic energy loss greater than 20 keV/nm on structural evolution of initially amorphized pre-implanted SiC and the migration of pre-implanted fission products (FPs). The pristine SiC samples were first implanted with 200 keV Se ions to a fluence of 1 × 1016 cm−2 at room temperature (RT) and at 350 °C. Some of the pre-implanted samples were then irradiated with bismuth (Bi) ions of 710 MeV to a fluence of 1 × 1013 cm−2 at RT. The characterization of both the implanted and implanted then irradiated SiC was conducted using techniques such as transmission electron microscopy (TEM), Raman spectroscopy, scanning electron microscopy (SEM), and Rutherford backscattering spectrometry (RBS). At RT, Se ions implantation caused the amorphization of SiC to a depth of about 187 nm beneath the surface. In contrast, when implanted at 350 °C, the SiC retained its crystalline structure with some defects (i.e., point defects, point defect clusters and some dislocation loops). The SHIs irradiation of the RT implanted SiC resulted in the reduction of the amorphous layer thickness from 187 nm to around 178 nm and led to the formation of nanocrystalline SiC in the amorphous layer. Irradiation of the SiC implanted at 350 °C induced some crystallization of defects. Notably, no evidence of Se ions migration was observed in both the irradiated RT-implanted and the hot-implanted SiC.

Analysis of drought resistance of Malus hupehensis plants irradiated with 12C6+ heavy ion

Heavy ion radiation is widely used in radiation mutation breeding because it usually leads to a high mutation rate of irradiated materials. However, there is a scarcity of reports on heavy ion radiation's effects on apples. In this study, the seeds of Malus hupehensis irradiated by 12C6+ heavy ions were used as materials. Subsequently, the germinated plants underwent two brief drought treatments. The results revealed enhanced drought resistance in the irradiated plants, leading to the selection of four mutants (DR-1, DR-2, DR-3, and DR-27). Under prolonged drought treatment, these four mutant lines exhibited significantly lower stomatal density and higher POD activity than the control. Consequently, they suffered less damage while maintaining consistent growth and development, showcasing substantial drought resistance. Transcriptome analysis indicated higher expression levels of stress-responsive genes and pathways in DR-1 and DR-27 plants under prolonged drought stress compared to the control. Notably, within the starch and sucrose metabolic pathway, mutant plants displayed elevated sucrose synthase expression and significantly higher sucrose content than the control, indicating enhanced osmoregulation of mutants. Therefore, these results demonstrate that, under prolonged drought stress, mutant plants sustain growth and development by reducing stomatal density and boosting antioxidant enzyme activity and osmoregulation. We found that 12C6+ heavy ion radiation could enhance the drought resistance of Malus hupehensis plants, and the drought resistant plants which had been verified by long-term drought were selected from the irradiated plants, which provided a new theoretical and technical basis for 12C6+ heavy ion radiation breeding and was of great significance to the development of apple industry in arid areas.

Heavy-ion irradiation effects of high-entropy A2Ti2O7 pyrochlore with multi-elements at a site

In this work, the irradiation response of A2Ti2O7 (A represents rare earth elements of Gd, Dy, Ho, Er, Yb and Nd) series ceramics were systematically studied under 3 MeV Au2+ ions. The structural changes pre- and post-irradiation were characterized using X-ray diffraction (XRD), grazing incidence X-ray diffraction (GIXRD) and Raman spectroscopy. After heavy ion irradiation, all the samples undergo structural transformations from ordered pyrochlore to disordered fluorite and then to amorphous phase. The sample surface became fully amorphous when exposed to the maximum irradiation dose. The 5RETO high-entropy pyrochlore exhibits the lowest rate of amorphization during the process of structural transformation. The cation radius ratio and mixed entropy are the primary factors influencing amorphization rate. The cation radius ratio shows a strong positive correlation with the amorphization rate, while the mixed entropy demonstrates a weak negative correlation with the amorphization rate. The cation radius ratio can thus serve as a reliable indicator for predicting the radiation resistance of high-entropy pyrochlore ceramics.

Effect of heavy ion irradiation on the electrochemical behavior of 321 stainless steel

Aiming to the environment for 321 stainless steel (SS) in primary circuit of pressurized water reactor (PWR), the effect of heavy ion irradiation to simulate neutron irradiation on the electrochemical behavior of alloy is unclear. The purpose of this work is to evaluate the corrosion resistance of 321 SS at different doses and the contribution of heavy ion irradiation in it. This work reveals that the corrosion resistance decreases in the order of 2 dpa > 0 dpa > 10 dpa > 60 dpa at room temperature, consistent with the sequence of δ-phase content near the surface. The effect of irradiation dose on the corrosion resistance of 321 SS is inversely proportional at higher dose and optimal performance of the SS irradiated to 2 dpa is attributed to the highest content of Cr-rich δ-phase. The pits occur in C enrichment zone, accompanied by increase of O content, while no pit occurs in Ti enrichment area. The results provide a reference for the irradiated SS with heavy ion to acquire optimal pitting resistence.

Reactive oxygen species may be involved in the distinctive biological effects of different doses of 12C6+ ion beams on Arabidopsis.

Heavy ion beam is a novel approach for crop mutagenesis with the advantage of high energy transfer line density and low repair effect after injury, however, little investigation on the biological effect on plant was performed. 50 Gy irradiation significantly stimulated the growth of Arabidopsis seedlings, as indicated by an increase in root and biomass, while 200 Gy irradiation significantly inhibited the growth of seedlings, causing a visible decrease in plant growth. The Arabidopsis seeds were irradiated by 12C6+. Monte Carlo simulations were used to calculate the damage to seeds and particle trajectories by ion implantation. The seed epidermis received SEM detection and changes in its organic composition were detected using FTIR. Evidence of ROS and antioxidant systems were analyzed. RNA-seq and qPCR were used to detect changes in seedling transcript levels. Monte Carlo simulations revealed that high-dose irradiation causes various damage. Evidence of ROS and antioxidant systems implies that the emergence of phenotypes in plant cells may be associated with oxidative stress. Transcriptomic analysis of the seedlings demonstrated that 170 DEGs were present in the 50 Gy and 200 Gy groups and GO enrichment indicated that they were mainly associated with stress resistance and cell wall homeostasis. Further GO enrichment of DEGs unique to 50 Gy and 200 Gy revealed 58 50Gy-exclusive DEGs were enriched in response to oxidative stress and jasmonic acid entries, while 435 200 Gy-exclusive DEGs were enriched in relation to oxidative stress, organic cyclic compounds, and salicylic acid. This investigation advances our insight into the biological effects of heavy ion irradiation and the underlying mechanisms.

Impact of heavy ions on a-Si:H/PolySi bilayer thin film transistors with Schottky barrier source and drain based on Nickel Silicide

This study investigates the influence of heavy ion irradiation on thin film transistors (TFTs) based on an a-Si:H/PolySi active layer and Schottky barrier-based source and drain. Through the use of Technology Computer-Aided Design (TCAD) simulations, we analyze the impact on device performance. We examine the ambipolar device characteristics by varying the thickness of the active layer (Poly-Si) and studying the corresponding physics. Our results reveal that reducing the active layer thickness from 140 to 80 nm decreases the magnitude of the threshold voltage (|VT|) for both nMOS and pMOS operating voltages. Additionally, the subthreshold slope is reduced for both nMOS and pMOS as the active layer thickness is decreased from 140 to 80 nm.Further, we investigated the transient response of the drain current to heavy ion irradiation in the sensitive regions across the Schottky barrier-based source and drain. We specifically analyze the phenomenon of bipolar amplification for various Linear Energy Transfer (LET) values, ranging from 0.1 MeV cm2/mg to 100 MeV cm2/mg. Our findings indicate that increasing the LET values from 0.1 MeV cm2/mg to 100 MeV cm2/mg results in amplified bipolar behavior and a drain current overshoot of over 10 % for both pMOS and nMOS operating voltages. To summarize, this work highlights the effects of heavy ion irradiation on TFTs with an a-Si:H/PolySi active layer and Schottky barrier-based source and drain. The study explores the influence of active layer thickness on device characteristics and demonstrates the transient response of drain current under different LET values. These findings contribute to a better understanding of the behavior and performance of TFTs subjected to heavy ion irradiation.

Analysis of Plasmon Loss Peaks of Oxides and Semiconductors with the Energy Loss Function.

This paper highlights the use and applications of the energy loss function (ELF) for materials analysis by using electron energy loss spectroscopy (EELS). The basic Drude-Lindhart theory of the ELF is briefly presented along with reference to reflection electron energy loss (REELS) data for several dielectric materials such as insulating high-k binary oxides and semiconductors. Those data and their use are critically discussed. A comparison is made to the available ab initio calculations of the ELF for these materials. Experimental, high-resolution TEM-EELS data on Si, SiC, and CeO2 obtained using a high-resolution, double-Cs-corrected transmission electron microscope are confronted to calculated spectra on the basis of the ELF theory. Values of plasmon energies of these three dielectric materials are quantitatively analyzed on the basis of the simple Drude's free electron theory. The effects of heavy ion irradiation on the TEM-EELS spectra of Si and SiC are addressed. In particular, the downward shifts of plasmon peaks induced by radiation damage and the subsequent amorphization of Si and SiC are discussed. TEM-EELS data of CeO2 are also analyzed with respect to the ELF data and with comparison to isostructural ZrO2 and PuO2 by using the same background and with reference to ab initio calculations.

Research on heavy ion irradiation effects on SOI SRAM

SRAM based on SOI devices has been widely used in aerospace storage devices due to its good electrical characteristics and radiation resistance. However, with the development of semiconductor technology, the feature size of devices continues to shrink, and the irradiation effects of high-energy ions have become increasingly serious. Single event effect has become the biggest threat to the failure of the spacecraft. A mixed-simulation method was used to research the heavy ion irradiation effects on SOI SRAM. SRAM consists of two coupled inverters. Firstly, the voltage changes of the inverter and SRAM output nodes under heavy ion irradiation were compared and analyzed, then the influence of the device itself and heavy ion parameters on the single particle flipping effect of the SRAM is investigated, and finally the necessary conditions for the flipping of the stored information in the SRAM are discussed and derived. The results show that heavy ion incidence does not permanently change the final state of the inverter; devices in the off state in the SRAM will undergo information flipping only when they are irradiated by heavy ions, and the threshold voltage of the N-type MOSFET is lower than that of the P-type MOSFET; an increase in the penetration depth will accelerate the flipping speed of the SRAM, but when the LET is high, the influence of the penetration depth on the flipping speed decreases; the change of the stored information in the SRAM is the result of the combined effect of pulse width and pulse height.

Swift heavy ion irradiation effect on structural, morphological and mechanical properties of Zr70Ni30 metallic glass

Metallic glass films are considered for coating applications in the nuclear field owing to their advantageous performances. However, the response to irradiation remains to be more thoroughly characterized. Zr70Ni30 metallic glass films were irradiated by 0.71MeV/u129Xe23+ ions in the fluence range from 5 × 1012 to 8 × 1013 ions cm−2. The structural, morphological, and mechanical properties were determined using grazing incidence X-ray diffraction (GI-XRD), atomic force microscopy (AFM), and nanoindentation for the as-deposited and irradiated samples. The Xe ion induced surface smoothening, thereby increasing the corrosion resistance. One-dimensional power spectral density of the AFM data of irradiated film demonstrated that the irradiation-induced evolution of the surface morphology could be attributed to a transition between viscous flow and the evaporation-condensation mechanism. The amorphous structure was unaffected after irradiation up to a fluence of 8 × 1013 ions cm−2. Nanoindentation revealed first a softening as the fluence increases up to 4 × 1013 ions cm−2, reflecting the creation of free volume defects. Then the hardness and Young’s modulus slightly increase when reaching 8 × 1013 ions cm−2. Moreover, at a critical dose of 0.008 dpa, the hardness is found to increase. Moreover, the calculation of the inelastic thermal spike model reveals the formation of the track with a radius of 7 nm.

Surface modifications of TiO2 nanostructured materials induced by 120 MeV Ag ions

The effect of swift heavy ion irradiation on structural, optical, and microstructural properties of TiO2 has been studied. Pellets prepared from TiO2 nanoparticles have been irradiated by 120 MeV Ag ions at different fluences ranging from 5 × 1011 to 1 × 1013 ions cm−2. X‐ray diffraction (XRD), Raman, UV–visible, and photoluminescence (PL) studies indicated anatase phase both in as‐prepared and irradiated pellets. XRD study revealed the crystallite size of the particles as ~16 nm, which is close to the upper limit of the particle size where anatase phase is most stable. Our study thus established the importance of the initial microstructure on the irradiation response of the nanoparticles. Though irradiation did not affect the crystal structure and the polycrystalline nature of the anatase TiO2, it suppressed the crystalline volume fraction. Poisson fitting of the suppression of XRD peak area with irradiation fluence revealed radius of the track of each 120 MeV Ag ion in TiO2 nanoparticles as ~2.1 nm. Irradiation, in addition to creating disorder, darkened the surface of the pellets because of the creation of oxygen vacancies in the TiO6 octahedra. Reorganization of these defects led to suppression of the band gap of TiO2 nanoparticles from 3.19 eV of the pristine sample to 3 eV for samples irradiated beyond a critical fluences 3 × 1012 ions cm−2. The size of the nanoparticles and their agglomeration remained unaffected by irradiation as indicated by field emission scanning electron micrographs.

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.

The effects of heavy-ion irradiation on electrical properties and hydrogen isotope permeation behavior of ceramic coatings

Tritium permeation through structural materials in fusion reactor blanket systems is a crucial problem in terms of fuel efficiency and radiological safety. A tritium permeation barrier has been developed using ceramic coatings for several decades to mitigate tritium leakage. Recent studies are focused on irradiation effects on microstructure and hydrogen isotope permeation behavior of the coatings. However, most of the analytical methods used in these studies were destructive and time-consuming, which is undesirable to apply to the actual reactor components. Here, we report the influence of irradiation damage on electrical properties and deuterium permeation behaviors of ion-irradiated zirconium oxide coatings fabricated by metal organic decomposition to develop a convenient approach for coating characterization. The undamaged and irradiated coatings decreased the deuterium permeation flux by a factor of more than 1000 in comparison with an uncoated substrate at 300 °C. The irradiated coatings had lower permeation flux than the undamaged coatings, suggesting that irradiation-induced grain growth reduced deuterium permeation. While the undamaged coating degraded in the measurement at around 450 °C, the irradiated coatings kept high permeation reduction performance after the measurement at 600 °C. The total electrical conductivities of the irradiated coatings were up to two orders of magnitude higher than those of the undamaged one below 400 °C and then increase linearly with inverse temperature. The dominant influence on the electrical conductivity was irradiation defects at low temperatures and the inherent conduction performance of the coating at high temperatures. Our results show that electrochemical impedance measurements are useful even for submicron-thick ceramic thin coatings and confirm the irradiation effects on electrical conductivity, especially in the low-temperature range.

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.

Effects of heavy-ion irradiation on the structure and anti-wear properties of polycrystalline diamond compacts for nuclear applications

The structural transitions and resultant changes in the tribological properties of HT/HP-sintered polycrystalline diamond compacts (PDCs) irradiated by 3.25 MeV Xe15+ ions with ion fluence of 4.3 × 1014−4.3 × 1015 ions/cm2 have been examined using various characterization techniques. A significant destruction of sp3 bonds was observed when the damage increased to 0.5 dpa. Thereafter, with a further increase in the irradiation damage, the samples stepped into a quasi-saturation amorphous state at a threshold value of damage, critically depending on the size of diamond grains. Thereafter, no other difference could be found between the samples composed of diamond grains in different sizes, especially in terms of the chemical structure and lubrication performance in an ambient air atmosphere. Thanks to the irradiation-induced transitions of the morphology and chemical structures, the anti-wear property of the PDCs degraded significantly in a damage range of 0–3.5 dpa, and then kept stable in a quasi-saturation state. But overall, owing to the formation of lubricious tribofilms with a rich presence of multilayer graphene on sliding interfaces, the wear rates of all the quasi-saturation samples were below the value of 3.0 × 10−7 mm3/N‧m, which suggests that the PDCs can be applied as one of the potential materials for solid lubrication in nuclear applications.

Damage Effects of Heavy Ion Irradiation on MOST/C Multilayer Films

In this study, the nano-multilayer film was prepared by alternating deposition of MoS2/Ti composite layer and amorphous C layer, and the irradiation damage effect was studied by the heavy ion bombardment experiment of 2 MeV Au2+. The results show that the irradiation region of the film is about 500 nm deep. The MoS2 crystal inside the MoS2/Ti composite layer in the irradiation-affected area is destroyed by incident Au2+ ions and turns into a disordered state. With the increase of irradiation dose, the hardness of the film increases from 1.58 to 3.28 GPa, and the wear life of the film decreases sharply from 3 × 104 to 5 × 103 r due to the destruction of the internal crystal and the embrittlement of the structure. In addition, with the increase of irradiation dose, the interlayer interface is gradually blurred and the interlayer diffusion is gradually aggravated.

Investigation of heavy ion irradiation effects on a charge trapping memory capacitor by C–V measurement

Heavy ion irradiation effects on charge trapping memory (CTM) capacitors with TiN/Al2O3/HfO2/Al2O3/HfO2/SiO2/p-Si structure have been investigated. The ion-induced interface charges and oxide trap charges were calculated and analyzed by capacitance–voltage (C–V) characteristics. The C–V curves shift towards the negative direction after swift heavy ion irradiation, due to the net positive charges accumulating in the trapping layer. The memory window decreases with the increase of ion fluence at high voltage, which results from heavy ion-induced structural damage in the blocking layer. The mechanism of heavy ion irradiation effects on CTM capacitors is discussed in detail with energy band diagrams. The results may help to better understand the physical mechanism of heavy ion-induced degradation of CTM capacitors.