Displacement Damage Research Articles

Proton irradiation effect mechanism of backside illuminated CMOS image sensors applied to FGS

A study of the mechanism of proton irradiation effects in the in-orbit operation of the backside illuminated CMOS image sensor (BSI CIS) used for imaging by the Fine Guidance Sensor (FGS) is presented in this paper. According to the proton irradiation environment of the Halo L2 orbit where FGS is located and the duration of in orbit operation, proton irradiation experiments were conducted on the BSI CIS, the core imaging device of FGS. Results show that proton irradiation is expected to cause a significant increase in the dark current of the BSI CIS of the FGS after four years of its in orbit, with the peak of the dark signal distribution shift to the right and an exponential trailing of the tail of the dark signal distribution when the proton fluence reached 6.71 × 1010p/cm2. This is the result of a combination of ionization defects and displacement damage defects. In addition, we also report about the device gain, which is of particular interest in space astronomical exploration. We performed a more detailed single pixel gain test of the device gain and found that the degradation of the gain appears to be correlated with the intensity of the ionization defects. The results of this study can provide theoretical basis for the radiation hardening by design of FGS to some extent.

Measuring the radiation hardness of terahertz devices for space applications

The application of terahertz technology in space is frontier for the development of 6G technologies. Terahertz transceiver devices based on gallium arsenide Schottky barrier diodes (GaAs SBDs) have the characteristics of small size, light weight and low power consumption, making them suitable for application on spacecraft. However, there is currently a lack of experimental assessments on their space adaptability. Here, we study the radiation hardness of terahertz devices to determine their adaptability in complex space environments. We exposed GaAs SBDs and terahertz multipliers as typical terahertz devices to gamma rays and protons. The experimental results showed that the terahertz devices exhibited good tolerance to protons, but prolonged exposure to gamma rays could significantly increase the leakage current of the GaAs SBDs and alter its C-V characteristics, leading to the failure of the terahertz multiplier. Nevertheless, the terahertz devices maintained a good level of radiation hardness, making them highly suitable for use in Low Earth Orbit (LEO) satellites. The comparison between the results of proton and gamma ray tests indicated that the terahertz devices exhibited high inherent radiation hardness against displacement damage but were more sensitive to ionization damage, requiring higher shielding requirements.

Gallium vacancy displacement damage induced by 1 MeV neutron irradiation in β-Ga2O3 solar-blind photodetector

Gallium vacancy displacement damage induced by 1 MeV neutron irradiation in β-Ga2O3 solar-blind photodetector

Experimental study on seismic damage of SRC-RC vertical hybrid structure

In order to analyze the seismic performance of the SRC-RC vertical hybrid structure, three substructure models were designed, and the key data of structural performance, such as hysteresis curve, skeleton curve, bearing capacity, energy dissipation of structure, residual deformation and damage degree were obtained by carrying out low cyclic loading tests. According to the tests, the plastic development at the column base was delayed because of the reinforcement of section steel, and the plastic development at beam end was much more sufficient, which benefited the beam hinge mechanism in the transition area, so that the transition area has better energy dissipation capacity and deformation capacity. Based on the more sufficient lateral displacement of beam hinge, the beams suffered bending deformation obviously, and interaction between the beams and the infilled wall was significant, which led to a more complex interface force transmission, so the bending cracks and the shearing cracks were densely distributed along the full length of the beam. Meanwhile, the reinforcement of section steel not only improved the deformation capacity of the models but also resulted in more significant damage difference in positive and negative loading. To quantitatively evaluate the damage level, a seismic damage index system was proposed, including displacement damage degree, bearing capacity damage degree and residual deformation index, which reflect the increment of deformation caused by structural damage, the deterioration of bearing capacity and the residual deformation, respectively. It is suggested that the structural failure should be defined respectively under different modes: For the strength degradation behavior mode and ductility behavior mode, structural failure should be confirmed if the load reduces to 0.90 and 0.85 times of the peak load, respectively; and for the brittle behavior mode, the frame is considered to fail when the load reaches the peak without considering the structural performance after the peak load.

Rate theory model of irradiation effects in UO2: Influence of electronic energy losses

To investigate the effect of electronic energy losses on nuclear damage in UO2, we use a simple Rate Theory (RT) model, based on the time evolution of single point defects, governed by their absorption at the surface of TEM lamellae, and by interstitial-type dislocation loops nucleation, solely characterized by their number and average size. We first parametrize the model by fitting six different experimental datasets at various temperatures, ion type and energy (0.39 MeV Xe and 4 MeV Au ion irradiations at 93, 298 and 873 K) where defect evolution in UO2 is dominated by displacement damage caused by nuclear energy losses. The model suggests that dislocation evolution kinetics is driven by monomers diffusion at 873 K. At lower temperature (93 and 298 K) monomer diffusion has little impact and the evolution is governed by the nucleation of loops within the collision cascade. Analysis of four additional experimental datasets at 93 and 298 K where electronic energy losses are strong (single 6 MeV Si and dual simultaneous Xe & Si ion irradiations) required modification of monomer's diffusion coefficients. In the case of single Si ion irradiation, evolution is temperature independent and the enhanced diffusion due to electronic excitations and ionizations are best captured by adding athermal component to the monomer diffusion coefficients. In case of the dual Xe & Si ions irradiation, electronic excitation caused by Si ions impacts the defects pre-generated by Xe ions and enhances defect diffusion by at local heating induced by the thermal spike of Si ions. This effect is best captured by artificially raising the irradiation temperature.

Molecular Dynamic Simulation of Primary Damage with Electronic Stopping in Indium Phosphide.

Indium phosphide (InP) is an excellent material used in space electronic devices due to its direct band gap, high electron mobility, and high radiation resistance. Displacement damage in InP, such as vacancies, interstitials, and clusters, induced by cosmic particles can lead to the serious degradation of InP devices. In this work, the analytical bond order potential of InP is modified with the short-range repulsive potential, and the hybrid potential is verified for its reliability to simulate the atomic cascade collisions. By using molecular dynamics simulations with the modified potential, the primary damage defects evolution of InP caused by 1-10 keV primary knock-on atoms (PKAs) are studied. The effects of electronic energy loss are also considered in our research. The results show that the addition of electronic stopping loss reduces the number of point defects and weakens the damage regions. The reduction rates of point defects caused by electronic energy loss at the stable state are 32.2% and 27.4% for 10 keV In-PKA and P-PKA, respectively. In addition, the effects of electronic energy loss can lead to an extreme decline in the number of medium clusters, cause large clusters to vanish, and make the small clusters dominant damage products in InP. These findings are helpful to explain the radiation-induced damage mechanism of InP and expand the application of InP devices.

Influence of suppressed blistering by heavy ion pre-damage on deuterium retention in tungsten

Surface damage and fuel retention are one of the major threats to the performance of plasma-facing materials (PFMs) in ITER and future fusion reactors. This work aims to investigate the influence of suppressed blistering by heavy ion pre-damage on deuterium (D) retention in tungsten (W). Recrystallized W samples were irradiated with 3.5 MeV iron (Fe13+) ions at room temperature to create displacement damage with a peak damage level of 0.1 dpa. Afterwards, a series of low-energy (38 eV) D plasma exposures were performed at 500 K. Three exposure fluences below and above the blistering threshold (5 × 1024 ∼ 3 × 1025 D m−2) of the pre-damaged W are selected to decouple and couple the damage-induced defects and blistering-induced defects, respectively. Surface observations show that no blisters are formed in un-damaged W after low-fluence D exposure (5 × 1024 D m−2), whereas severe blistering (surface coverage ratio: 34.2 %) occurs in the high-fluence case (3 × 1025 D m−2). In contrast, only a small number of blisters (4.2 %) are formed in Fe-damaged W when D fluence reaches 3 × 1025 D m−2. Moreover, Fe pre-damage increases D retention by a factor of 3.33 and 1.20 at the low-fluence (5 × 1024 D m−2) and medium-fluence (1 × 1025 D m−2) D exposure, respectively. While in the high-fluence case (3 × 1025 D m−2), the enhancement effect of D retention in Fe-damaged W is significantly weakened, such that retention is lower for damaged W, probably due to the significant suppression effect on surface blistering and its accompanying defect formation. This work highlights the suppressed blistering-induced D retention by pre-existing damage in W.

A unified modeling approach for concrete masonry shear walls: Conception, validation and insights

Distinct modeling strategies have been developed to simulate concrete masonry shear walls; however, each is validated with a limited number of specimens tested under identical laboratory conditions and only covers specific detailing scenarios. This research seeks a unified finite element-based modeling approach integrating macro-modeling concepts for grouted masonry (GM) regions and simplified micro-modeling for ungrouted masonry (UGM) regions. The objective is to facilitate accurate simulation of the in-plane behavior of diverse typologies of concrete masonry shear walls: unreinforced masonry (URM), fully grouted reinforced masonry (FGRM), and partially grouted reinforced masonry (PGRM). A smeared crack approach is used to capture the crushing and cracking of grouted masonry (GM) and ungrouted masonry (UGM), and interface elements are incorporated into UGM regions to model the mortar joints, resulting in a combined smeared-discrete model. The validation process comprises two levels. The first-level evaluation focuses on URM and FGRM walls, emphasizing the analysis and comparison of lateral force–displacement curves. Second-level validation is done through simulation of PGRM walls by evaluating lateral force–displacement curves, damage patterns, and reinforcement strains. The implemented modeling approach generally simulates the response of the different experimental masonry shear walls evaluated with good accuracy. A sensitivity analysis was also performed to reveal the influence of some parameters on the numerical results, providing additional perceptions into the reliability of the modeling approach. Relevant insights into the modeling approach were obtained, allowing complex phenomena in the tested walls to be simulated, thus contributing to advances in the simulation of in-plane loaded concrete masonry walls.

Comparison of displacement damage effects on the dark signal in CMOS image sensors induced by CSNS back-n and XAPR neutrons

Comparison of displacement damage effects on the dark signal in CMOS image sensors induced by CSNS back-n and XAPR neutrons

Accelerated formation of M2C carbides by proton irradiation inhibits molten salt corrosion in Ni-based alloy

The effect of displacement damage on the corrosion behavior in a molten FLiBe salt environment was investigated. The element distribution and microstructure around the grain boundaries (GBs) after corrosion were characterized. The results show a decrease in corrosion thickness with increasing irradiation dose and the presence of intergranular corrosion. Nanoscales M2C carbides were observed to be distributed, with a denser and thicker distribution in samples with higher irradiation doses. Their distribution depth is related to the Cr depletion region, inhibiting Cr diffusion toward the GBs and surface. Furthermore, the nucleation mechanism of M2C carbides along the GBs and in irradiated regions was revealed, attributed to the combined effects of thermal influences, element preferential dissolution due to corrosion, and irradiation-induced segregation.

Dopant, coating, and grating effects in silica optical fibers under extreme neutron irradiation

Radiation effects on fiber Bragg gratings (FBGs) have been studied but data gaps related to the effects of displacement damage resulting from high fast neutron fluence remain. In this work, Type-I and Type-II FBGs inscribed in optical fibers with various core dopants (Ge and F) and fiber coatings (acrylate, polyimide) were monitored in situ during 75 days of neutron irradiation to a peak fast (>0.1 MeV) neutron fluence of 3×1021 nfast/cm2. The reflected intensity of the Type-I FBGs inscribed in a Ge-doped core fiber decreased by >30 dB within 7 h of irradiation (1019 nfast/cm2), whereas Type-II FBGs inscribed in a pure silica core fiber eventually approached >40 dB attenuation after accumulating a fast neutron fluence on the order of 1020 nfast/cm2. Type-II FBGs inscribed in F-doped core fiber improved stability: the attenuation approached an equilibrium value in the range of 10 to 20 dB.

Near-space radiation environment analysis and protective measures

As a matter of fact, near space radiation environment analysis plays a crucial role in near space physics. With this in mind, this study introduces the types of radiation damage in the near-space radiation environment as well as corresponding protective measures. To be specific, the protective strategy for Total Ionizing Dose (TID) and for Displacement Damage (DD) are similar, focusing on material shielding to mitigate the effects. According to the analysis, the guiding principle for the protection strategy against Single Event Effects (SEE) is risk management, aiming to minimize the probability of catastrophic SEE and to detect and mitigate the impact of non-destructive SEE. Based on the analysis, some measures are proposed accordingly. In fact, current strategies for future radiation protection may involve the use of biological membranes to absorb radiation or the application of quantum mechanics principles to eliminate the effects brought about by radiation. These results shed light on guiding further exploration if near space radiation.

Patterning damage mechanisms for two-dimensional crystalline polymers and evaluation for a conjugated imine-based polymer

High-quality patterning determines the properties of patterned emerging two-dimensional (2D) conjugated polymers and is essential for potential applications in future electronic nanodevices. However, the most suitable patterning method for 2D polymers has yet to be determined because we still do not have a comprehensive understanding of their damage mechanisms by visualizing the structural modification that occurs during the patterning process. Here, the damage mechanisms during patterning of 2D polymers, induced by various patterning methods, are unveiled based on a systematic study of structural damage and edge morphology in an imine-based 2D polymer (polyimine). Patterning using a focused electron beam, focused ion beam (FIB) and mechanical carving is evaluated. The focused electron beam successively introduces a sputtering effect, knock-on displacement damage and massive radiolysis with increasing electron dose from9.46×107electrons nm-2to1.14×1010electrons nm-2. Successful patterning is enabled by knock-on damage but impeded by carbon contamination beyond a critical sample thickness. A FIB creates current-dependent edge morphologies and extensive damage from ion implantation caused by the tail of the unfocused beam. A precisely controlled tip can tear the polyimine film through grain boundaries and hence create a patterning edge with suitable edge roughness for certain application scenarios when beam damage is avoided. Taking structural damage and the resulting quantitative edge roughness into consideration, this study provides a detailed instruction on the proper patterning techniques for 2D crystalline polymers and paves the way for tailored intrinsic properties and device fabrication using these novel materials.

Impact of proton radiation and annealing of CMOS image sensors on star sensor performance

Star sensors play a crucial role as high-precision optical attitude navigation devices in satellite attitude control systems. The CMOS image sensor is an important component of the imaging system of the star sensor and experiences performance degradation due to the total ionizing dose effect and displacement damage effect in the radiation environment of its long-term operational workspace. As a result, the detection capability and attitude positioning accuracy of the star sensor gradually deteriorate. The performance of CMOS image sensors can be partially restored after annealing but the impact on the performance of star sensors is unclear. This study conducted 100 MeV proton irradiation experiments with different fluences on CMOS image sensors and performed room temperature and high temperature annealing treatments. By testing and analyzing the performance of star sensors equipped with irradiated and different annealing treatments on CMOS image sensors, the impact mechanism of CMOS image sensor radiation damage and annealing recovery on the performance variation of star sensors was obtained. This study provides theoretical support for reliability of long-term in-orbit star sensors.

Transverse seismic analysis method of underground interchange prefabricated utility tunnel

The rapid development of underground utility tunnels has led to the formation of a large number of interchange utility tunnels. Due to significant differences in the lateral resisting stiffness in orthogonal directions, coupled with the close relationship between soil deformation and the depth of the utility tunnel, the seismic response mechanism of the interchange utility tunnel is complex. This paper proposes a method for transverse seismic analysis of the underground interchange utility tunnel based on the response displacement method. A load-structure analysis model of a certain underground cross-type interchange utility tunnel is first established. Then, the different conditions corresponding to maximum relative deformation between layers of the interchange node are discussed, and the proposed method is validated via the time-history analysis method. Based on the proposed analysis method in this paper, seismic response analysis is performed on the interchange utility tunnel considering the condition of vertical incidence of three different input seismic waves. Discussions are conducted in terms of internal forces, inter-story displacement angles, and damage responses under seismic excitations in different principal axis directions. The results show that under major earthquakes, the maximum inter-story displacement angle of the interchange node exceeds the standard limit by up to approximately 184 %, while the tensile damage can reach up to 0.985, significantly surpassing the tensile damage limit. Accordingly, the interchange node is the weakest part of the interchange utility tunnel. There exists deformation inconsistency between the interchange node and standard segments due to significant stiffness differences, with the influence range of the interchange node on internal forces, inter-story displacement angles, joint deformations and damage of the utility tunnel is approximately 7, 6, 8, and 6 prefabricated standard segments, respectively. Since the maximum relative deformation between layers of the interchange node does not occur simultaneously, for double-layered and multi-layered interchange utility tunnels, it is necessary to comprehensively consider the maximum inter-story displacement angle between each layer to determine their most unfavorable condition. The analytical method and related research conclusions presented in this paper can provide references for the transverse seismic design of interchange utility tunnels.

Dynamic response of spherical tanks subjected to the explosion of hydrogen-blended natural gas

Hydrogen is a renewable and clean energy and obtains increasing attention all around the world. Blending hydrogen into natural gas can promote hydrogen development and storage tank farms play an essential role in the storage of hydrogen-blended natural gas (HBNG). However, upon leakage from the tank, HBNG accumulates to create a vapor cloud and may explode, resulting in more severe consequences than natural gas. Furthermore, the explosion has the potential to trigger the domino effect in the spherical tank storage area, leading to multiple explosions. But little attention has been paid on this research issue. This article analyzes the dynamic response of the spherical tank exposed to HBNG explosions. The fluid–structure interaction theory is adopted to establish the whole finite element model. Meanwhile, the advanced Arbitrary Lagrangian-Eulerian (ALE) method can reduce mesh distortion and enhance computational accuracy, and the process of explosion is analyzed through the coupling of the Lagrangian mesh for the structure and the Eulerian mesh for the vapor cloud. Then, the algorithm is employed that couples shell elements with solid elements by utilizing a penalty function. Besides, the dynamic response of the spherical tank and pillar surfaces is analyzed in the trends of effective stress, displacement, velocity, and structural damage under various parameters, evaluating the energy absorbed by the spherical tank and pillar. Accordingly, the equipment damage caused by HBNG explosions considering possible damage caused by secondary explosions can be obtained. Then, the effects of the HBNG explosion chain on equipment are analyzed in tank areas. The dynamic response of structures in the explosion is closely related to the different hydrogen blended ratios, distances, and structural thickness, which significantly impact the effective stress of the spherical tank and pillar. Moreover, the damage caused by the HBNG explosion is more serious for pillars than the spherical tank, making the role of pillars crucial in supporting the spherical tank. The results obtained in this study can be used to support the design and safety operation of HBNG storage areas.

Seismic performance assessment of a base-isolated hospital building subjected to February 6, 2023, Kahramanmaraş, Türkiye earthquakes (Mw 7.7 Pazarcık and Mw 7.6 Elbistan) and seismic fragility analysis considering different construction stages

The construction period of large structures such as hospitals can be prolonged due to complex construction processes. The behavior of frictional pendulum systems (FPSs) is strongly influenced by the seismic weight of the superstructure and the corresponding coefficient of friction. Therefore, the effects of the isolator behavior, which varies throughout the construction stages (CSs), on structural responses should be evaluated. Existing literature lacks adequate investigation into the behavior of isolated structures subjected to earthquakes during CSs. To address this gap, this paper investigates the structural performance of a base-isolated hospital building equipped with FPSs that experienced residual displacements during the February 6, 2023, Kahramanmaraş, Türkiye earthquakes (Mw 7.7 Pazarcık and Mw 7.6 Elbistan). At the time of the earthquakes, the building was still under construction (65–70 % complete). In addition to the hospital building under consideration, there were three more hospital buildings equipped with FPSs under construction during the 2023 Kahramanmaraş-Türkiye earthquakes in Türkiye. The seismic behavior and residual displacements of the structure during this CS were evaluated and numeric results were validated with real data measured in the field. Moreover, fragility analyses were performed for different CSs of the hospital building to reveal the probabilities of damage for base-isolated buildings exposed to earthquakes at various CSs. For fragility assessment, damage states (slight, moderate, extensive, collapse) were defined and four damage measures were chosen. Thus, the extent to which construction stages affected which types of damage was determined. A total of 1296 nonlinear time-history analysis were conducted to obtain fragility curves for all CSs and damage measures considering lower bound, nominal, and upper bound values of isolators. Selected isolated hospital building showed vulnerability in maximum top floor acceleration (MTFA) and maximum isolator displacement (MID) damage measures, but resilience in maximum roof drift ratio (MRDR) and maximum inter-story drift ratio (MIDR) damage measures. For the design basis earthquake (DBE) level, the probability of reaching the extensive damage state was 5.25 % for the MID, 11.39 % for MTFA, and 0 % for MIDR and MRDR. Similarly, for the maximum considered earthquake (MCE) level, these values were determined as 34.09 % for MID, 43.42 % for MTFA, and 0 % for MIDR and MRDR. The analysis revealed that while the probability of damage to the base isolation system was not related to CSs, residual displacements increased as construction progressed. Collapse thresholds for MIDR and MRDR demand exceptionally severe seismic events. As construction progresses, probabilities of exceeding damage states increase for MIDR and MRDR, indicating heightened vulnerability.

Photoelectric property degradation of graded barrier InAs/GaSb type II superlattice long-wave infrared detectors under 1 MeV electron irradiation.

Amid rapid advancements in aerospace science and technology, studying the effects of space radiation on an infrared detector is crucial for enhancing their reliability in radiation environments, particularly against electrons-one of the most damaging charged particles. Barrier structures significantly reduce dark current without any substantial degradation in the optical performance of the devices. Consequently, they are being investigated for use in extreme environments. This paper presents a study on the performance degradation of InAs/GaSb type II superlattice (T2SLs) long-wave infrared (LWIR) detectors with a graded barrier structure under 1 MeV electron irradiation and analyzes potential damage mechanisms. The findings indicate that 1 MeV electron irradiation causes both ionization and displacement damage to the graded barrier InAs/GaSb T2SL LWIR detectors. After irradiation with a fluence of 2 × 1015 e/cm2, the device's dark current density has increased by approximately two orders of magnitude, while the quantum efficiency has decreased by approximately one order of magnitude. As the device mesa shrinks, the sensitivity of dark current to radiation exposure increases. Electron irradiation notably exacerbates surface leakage and bulk dark current, with a pronounced increase in surface leakage current. The study also reveals that electron irradiation primarily enhances the dark current by introducing defect states, thereby leading to device performance degradation.

Synchrotron-based x-ray diffraction analysis of energetic ion-induced strain in GaAs and 4H-SiC

Strain engineering using ion beams is a current topic of research interest in semiconductor materials. Synchrotron-based high-resolution x-ray diffraction has been utilized for strain-depth analysis in GaAs irradiated with 300 keV Ar and 4H-SiC and GaAs irradiated with 100 MeV Ag ions. The direct displacement-related defect formation, anticipated from the elastic energy loss of Ar ions, can well explain the irradiation-induced strain depth profiles. The maximum strain in GaAs is evaluated to be 0.88% after Ar irradiation. The unique energy loss depth profile of 100 MeV Ag (swift heavy ions; SHIs) and resistance of pristine 4H-SiC and GaAs to form amorphous/highly disordered ion tracks by ionization energy loss of monatomic ions allow us to examine strain buildup due to the concentrated displacement damage by the elastic energy loss near the end of ion range (∼12 μm). Interestingly, for the case of SHIs, the strain-depth evolution requires consideration of recovery by ionization energy loss component in addition to the elastic displacement damage. For GaAs, strain builds up throughout the ion range, and the maximum strain increases and then saturates at 0.37% above an ion fluence of 3×1013 Ag/cm2. For 4H-SiC, the maximum strain reaches 4.6% and then starts to recover for fluences above 1×1013 Ag/cm2. Finally, the contribution of irradiation defects and the purely mechanical contribution to the total strain have been considered to understand the response of different compounds to ion irradiation.

Displacement Damage, Total Ionizing Dose, and Transient Ionization Effects in Gate-All-Around Field Effect Transistors

Displacement Damage, Total Ionizing Dose, and Transient Ionization Effects in Gate-All-Around Field Effect Transistors