Effects Of Proton Irradiation 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.

Effects of Cold Rolling–Induced Defects on Proton Irradiation Response in Nb-1Zr-0.1C Alloy

This work highlights the effect of proton irradiation in the presence of preexisting defects in the Nb-1Zr-0.1C alloy. To introduce the initial defects, the Nb-1Zr-0.1C alloy was subjected to cold rolling (10% and 20%) prior to irradiation. Characterization of the irradiated material was performed using detailed X-ray diffraction line profile analyses. The results, in terms of various microstructural parameters, revealed that the preexisting defects in these materials act as effective sinks for irradiation-induced defects during the initial irradiation. Electron backscattered diffraction analyses suggested that the fraction of low-angle grain boundaries plays a crucial role during irradiation and determines the outcome of the competing process between defect annihilation and defect production. Transmission electron microscopy analyses revealed that the black dots were coexisting with carbide precipitate in the cold-rolled Nb alloy after irradiation. Mechanical properties were also assessed by measuring microhardness to correlate with the changes in microstructure after irradiation. The change in yield strength calculated from the change in the microhardness value as a function of dose indicated that the 20% cold-rolled Nb alloy was more radiation resistant than the 10% cold-rolled Nb alloy at ambient temperature and a low-dose regime. To see the effect of alloying elements, similar studies were also carried out on pure Nb, and the results were compared with that of the Nb-1Zr-0.1C alloy. All these findings help to develop a better understanding of the behavior of the proton-irradiated Nb-1Zr-0.1C alloy in the presence of preexisting defects introduced by means of cold rolling prior to irradiation.

Binary proton therapy of Ehrlich carcinoma using targeted gold nanoparticles

Proton therapy can treat tumors located in radiation-sensitive tissues. This article demonstrates the possibility of enhancing the proton therapy with targeted gold nanoparticles that selectively recognize tumor cells. Au-PEG nanoparticles at concentrations above 25 mg/L and 4 Gy proton dose caused complete death of EMT6/P cells in vitro. Binary proton therapy using targeted Au-PEG-FA nanoparticles caused an 80% tumor growth inhibition effect in vivo. The use of targeted gold nanoparticles is promising for enhancing the proton irradiation effect on tumor cells and requires further research to increase the therapeutic index of the approach.

Proton Irradiation Effects on Dual Delta-Doped AlGaAs/InGaAs/AlGaAs Pseudomorphic High-Electron-Mobility Transistors

Proton Irradiation Effects on Dual Delta-Doped AlGaAs/InGaAs/AlGaAs Pseudomorphic High-Electron-Mobility Transistors

3174: Effects of whole brain conventional or FLASH proton irradiation in Sprague Dawley rats

3174: Effects of whole brain conventional or FLASH proton irradiation in Sprague Dawley rats

Proton-Irradiation Effects and Reliability on GaN-Based MIS-HEMTs.

A comprehensive study of proton irradiation reliability on a bilayer dielectrics SiNx/Al2O3 MIS-HEMT, the common Schottky gate HEMT, and a single dielectric layer MIS-HEMT with SiNx and with Al2O3 for comparison is conducted in this paper. Combining the higher displacement threshold energy of Al2O3 with the better surface passivation of the SiNx layer, the bilayer dielectrics MIS-HEMT presents much smaller degradation of structural materials and of device electrical performance after proton irradiation. Firstly, the least of the defects caused by irradiation suggesting the smallest structural material degradation is observed in the bilayer dielectrics MIS-HEMT through simulations. Then, DC and RF electrical performance of four kinds of devices before and after proton irradiation are studied through simulation and experiments. The smallest threshold voltage degradation rate, the smallest maximum on-current degradation and Gm degradation, the largest cut-off frequency, and the lowest cut-off frequency degradation are found in the bilayer dielectrics MIS-HEMT among four kinds of devices. The degradation results of both structural materials and electrical performance reveal that the bilayer dielectrics MIS-HEMT performs best after irradiation and had better radiation resilience.

Dependence of the Silicon Carbide Radiation Resistance on the Irradiation Temperature

The effect of high-temperature electron and proton irradiation on SiC-based device characteristics is being investigated. Industrial integrated 4H-SiC Schottky diodes, each with an n-type base and a blocking voltage of either 600 V, 1200 V, or 1700 V, manufactured by Wolfspeed, are being studied. 0.9 MeV electron and 15 MeV proton irradiation were applied. It has been found that the irradiation resistance of silicon carbide Schottky diodes at high temperatures significantly exceeds their resistance at room temperature. This effect is attributed to the annealing of compensating defects induced by high-temperature irradiation. The parameters of radiation-induced defects are determined using the method of deep level transient spectroscopy (DLTS). Under high-temperature ("hot") irradiation, the spectrum of radiation-induced defects introduced into SiC appears to differ significantly from the spectrum of defects introduced at room temperature. It is suggested that approximately half of the compensation is due to radiation-induced defects formed in the bottom part of the bandgap.

Enhancement of the Cytotoxic Effect of Proton Irradiation by Gold Nanoparticles

Enhancement of the Cytotoxic Effect of Proton Irradiation by Gold Nanoparticles

Displacement damage effect of proton irradiation on vertical β-Ga2O3 and SiC Schottky barrier diodes (SBDs)

In this study, we fabricated vertical Schottky barrier diodes (SBDs) based on wide bandgap semiconductor beta-phase gallium oxide (β-Ga2O3) and silicon carbide (SiC), respectively, and conducted proton irradiation experiments to analyze the radiation hardness of the SBDs comparatively. The effects of proton radiation on the performance of SBDs were assessed through measurements of forward current, capacitance, and breakdown characteristics. Both devices exhibited degradation in current and capacitance characteristics following proton irradiation, attributed to displacement damage (DD). Notably, the β-Ga2O3-based SBD demonstrated more pronounced deterioration compared to the SiC-based device despite similar vacancy distributions as confirmed by SRIM simulation. Moreover, a decrease in contact radius correlated with exacerbated degradation in the current characteristics of the β-Ga2O3-based SBD. Following proton irradiation, breakdown voltages of both devices increased due to elevated resistance induced by displacement damage. While both β-Ga2O3 and SiC-based SBDs experienced displacement damage under high fluence proton irradiation, the extent of performance degradation varied depending on the dimensions and quality of epitaxial and substrate layers.

Corrosion of 316L stainless steel in high temperature water and steam: effects of simultaneous proton irradiation

316L stainless steel was exposed to 320 °C hydrogenated water and 480 °C hydrogenated steam for 24 h and 72 h while simultaneously irradiated with 5.4 MeV protons to yield a damage rate of 7 × 10–7 dpa/s. Oxide films characterized in cross-section STEM revealed chemical and morphological differences. High levels of radiolysis in water resulted in significantly reduced corrosion rates while inducing dissolution of the inner oxide layer, whereas in steam the effects of radiolysis are insignificant. Conversely, displacement damage effects are negligible in water but significantly increase the corrosion rate in the steam condition through the growth of inner oxide porosity.

Accelerated corrosion of FeCrAlTi coating by in situ proton irradiation in molten lead-bismuth eutectic

The synergistic effect of simultaneous proton irradiation and LBE corrosion on FeCrAlTi coating is investigated, and the surface morphology, elementary composition, microstructure and crystal structure of the formed oxide scale are systematically analyzed. The results reveal the accelerated LBE corrosion behavior of proton irradiated FeCrAlTi coating, which can be attributed to irradiation produced defects leading to enhanced diffusion, irradiation induced more porous oxide scale resulting in promoted short-circuit diffusion, and irradiation enhanced adsorption energy of O, Pb and Bi on coating surface contributing to intensive interface interaction.

Investigation of Proton Radiation Effect on Indium Gallium Nitride Light Emitting Diodes

This paper investigates the effects of proton radiation on the electrical and optical properties of InGaN light-emitting diodes (LEDs). InGaN LEDs are known for their high brightness and efficiency, making them useful in various applications. However, they are vulnerable to radiation damage, which can degrade their performance over time. In this study, InGaN LEDs were exposed to proton radiation with the fluences of 1 × 1013 cm-2, 3 × 1013 cm-2 and 3 × 1014 cm-2 and their electrical and optical properties were measured before and after irradiation. Results show that proton radiation causes asignificant increase in the reverse leakage current. The light intensity also increases due to radiation. These changes are attributed to radiation-induced defects created in the LED material. The findings of this study provide important insights into the reliability and durability of InGaN LEDs in space and other radiation environments.

A simulation study of irradiation effect on InAs/GaAsSb type II quantum dot structures

Particles in space cause irradiation damage to the solar cells (SCs), resulting in the degradation of their performance. Quantum dot solar cells (QDSCs) have higher theoretical efficiency and better irradiation resistance than the conventional GaAs SCs, which makes them highly promising for application in space. In this paper, we study the proton irradiation effect on InAs/GaAs0.8Sb0.2 QDSCs by SRIM program. The simulation result shows that the InAs/GaAs0.8Sb0.2 QDSCs have fewer vacancies than GaAs SCs when irradiated with low-energy proton, which indicates that the InAs/GaAs0.8Sb0.2 QDSCs have better anti-irradiation characteristics. The study about displacements per atom and proton concentration in two SCs shows that protons with low energy and high irradiation fluences will cause more serious damage in InAs/GaAs0.8Sb0.2 QDSCs. In addition, the proton incident angle affects the vacancy distribution, while the number of QD layers has little effect on it.

Multi-scale wear mechanism of material surface and hinge interface based on TC4 alloy in space environment

PurposeThe purpose of this paper is to clarify the influence of low earth orbit space environment on the wear mechanism of TC4 alloy material and crank rocker mechanism.Design/methodology/approachIn this study, friction experiments were carried out on TC4 alloy friction discs and crank rocker mechanisms, both before and after exposure to atomic oxygen and proton irradiation. Nanoindentation, grazing incidence X-ray diffraction (GIXRD), and X-ray photoelectron spectroscopy were employed to systematically characterize alterations in mechanical properties, surface phase, and chemical composition.FindingsThe results show that the wear mechanism of TC4 alloy friction disc is mainly adhesive wear in vacuum environment, while the wear mechanism of crank rocker mechanism includes not only adhesive wear but also abrasive wear. Atomic oxygen exposure leads to the formation of more oxides on the surface of TC4 alloy, which form abrasive particles during the friction process. Proton irradiation will lead to a decrease in fatigue performance and an increase in hardness on the surface of TC4 alloy, thus causing fatigue wear on the surface of TC4 alloy, and more furrows appear on the crank rocker mechanism after proton irradiation. In the three environments, the characteristics of abrasive wear of the crank rocker mechanism are more obvious than those of the TC4 alloy friction disc.Originality/valueThese results highlight the importance of understanding the subtle effects of atomic oxygen and proton irradiation on the wear behavior of TC4 alloy and provide some insights for optimizing its performance in space applications.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2024-0051/

Defect-Driven MoS2 Nanosheets toward Enhanced Sensing Sensitivity.

In this study, S-deficient MoS2 was prepared using proton irradiation and then applied as sensing materials for the detection of NO2 gas. First, bulk MoS2 was treated by ultrasonics to produce 2D nanosheets of MoS2, which were subsequently bombarded by a flux of high-energy protons, resulting in the appearance of structural defects throughout MoS2. The proton fluxes were adjusted to different densities of 1 × 1011, 1 × 1012, 1 × 1013, and 1 × 1014 ions/cm2. The effects of proton irradiation on the defects, also referred to as atomic vacancies, were systematically investigated using Raman measurements to locate the E1 2g and A1g modes and X-ray photoelectron spectroscopy to determine the binding energy of Mo 3d and S 2p orbitals. It was revealed that the density of proton irradiation greatly affects the degree of S atom vacancies in irradiated MoS2, while also enhancing the n-type semiconducting behaviors of MoS2. The vacancy-rich MoS2 was then demonstrated to exhibit a higher response to NO2 gas compared to that of nonirradiated MoS2, showing a 4-fold increase in response within a concentration range from 1 to 20 ppm. These results could pave the way for new approaches to fabricating sensing materials.

STUDYING THE INFLUENCE OF PROTON IRRADIATION ON THE DISTRIBUTION PROFILE OF Pt AND Cr IN SURFACE LAYERS n-Si˂Pt˃, n-Si˂Сr˃ USING ELLIPSOMETRIC SPECTROSCOPY

In this work, the effect of high-temperature doping and proton irradiation on the depth profile and the creation of layers on the surface of single-crystal silicon was studied. The study used singlecrystal n-type silicon samples doped with phosphorus during growth. These samples were first doped with platinum and chromium and after polishing they were irradiated with protons with an energy of 2 MeV, a dose of 5.1 × 1014 cm–2 at the EG-5 accelerator. Studies of the optical properties of the sample surface were carried out using an ELLIPS-1991 spectroscopic ellipsometer at room temperature

15.5 MeV proton irradiation treatment of liquid phase exfoliated graphene

Exceptional Physical properties, including lightweight nature of graphene make it a highly promising material for space applications. However, the impact of proton irradiation, a common phenomenon in space environments, on the structural integrity and functional properties of graphene remains a critical area of research. This study aims to fill this gap by investigating the effects of proton irradiation on liquid-phase exfoliated graphene. We focus specifically on the alterations in infrared spectra and structural characteristics of graphene induced by irradiation with 15.5 MeV protons. Our analysis reveals that organic molecules and functional groups adsorbed on graphene during exfoliation elevate the Fermi level, suppressing graphene's infrared absorption through the Pauli blocking effect. We demonstrate that proton irradiation, at fluences up to 1 × 1015 proton/cm2, effectively removes adsorbed molecules and functional groups, thereby eliminating Pauli blocking effect. These findings contribute to a better understanding of the behavior of graphene under proton irradiation, essential for its utilization in space-centric applications such as thermal coatings, electronics, and optical devices.

Binary Proton Therapy of Ehrlich Carcinoma Using Targeted Gold Nanoparticles.

Proton therapy can treat tumors located in radiation-sensitive tissues. This article demonstrates the possibility of enhancing the proton therapy with targeted gold nanoparticles that selectively recognize tumor cells. Au-PEG nanoparticles at concentrations above 25 mg/L and 4 Gy proton dose caused complete death of EMT6/P cells in vitro. Binary proton therapy using targeted Au-PEG-FA nanoparticles caused an 80% tumor growth inhibition effect in vivo. The use of targeted gold nanoparticles is promising for enhancing the proton irradiation effect on tumor cells and requires further research to increase the therapeutic index of the approach.

Evaluation of specific RBE in different cells of hippocampus under high-dose proton irradiation in rats.

The study aimed to determine the specific relative biological effectiveness (RBE) of various cells in the hippocampus following proton irradiation. Sixty Sprague-Dawley rats were randomly allocated to 5 groups receiving 20 or 30Gy of proton or photon irradiation. Pathomorphological neuronal damage in the hippocampus was assessed using Hematoxylin-eosin (HE) staining. The expression level of NeuN, Nestin, Caspase-3, Olig2, CD68 and CD45 were determined by immunohistochemistry (IHC). The RBE range established by comparing the effects of proton and photon irradiation at equivalent biological outcomes. Proton20Gy induced more severe damage to neurons than photon20Gy, but showed no difference compared to photon30Gy. The RBE of neuron was determined to be 1.65. Similarly, both proton20Gy and proton30Gy resulted in more inhibition of oligodendrocytes and activation of microglia in the hippocampal regions than photon20Gy and photon30Gy. However, the expression of Olig2 was higher and CD68 was lower in the proton20Gy group than in the photon30Gy group. The RBE of oligodendrocyte and microglia was estimated to be between 1.1 to 1.65. For neural stem cells (NSCs) and immune cells, there were no significant difference in the expression of Nestin and CD45 between proton and photon irradiation (both 20 and 30Gy). Therefore, the RBE for NSCs and immune cell was determined to be 1.1. These findings highlight the varying RBE values of different cells in the hippocampus in vivo. Moreover, the actual RBE of the hippocampus may be higher than 1.1, suggesting that using as RBE value of 1.1 in clinical practice may underestimate the toxicities induced by proton radiation.

Effect of proton irradiation on the sensitivity of CO2 sensors based on SnO2 and SnO–SnO2 heterojunctions

Gas sensors are integral to space exploration and development projects. However, few studies have examined the effects of proton irradiation on the performance of semiconductor gas sensors. This study fills this gap by investigating the effect of proton irradiation on the sensitivity of CO2 semiconducting sensors, specifically SnO2 and SnO–SnO2 heterojunction types. In SnO2-based sensors, sensitivity was indicated to remain stable at low fluence and increase at higher fluences owing to proton-induced oxygen vacancy formations, mainly. Meanwhile, in SnO–SnO2 heterojunction sensors, it was found to decrease at low fluences and increase significantly at higher fluences owing to changes in the electrical properties of SnO. These findings suggest that proton irradiation can enhance sensor sensitivity, enabling potential applications in radiation-prone environments, such as outer space. This study contributes to the understanding of the effects of proton irradiation on semiconductor gas sensors and paves the way for their development.