Effects Of Proton Irradiation Research Articles

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.

Corrosion of 316L Stainless Steel in High Temperature Water and Steam: Effects of Simultaneous Proton Irradiation

Corrosion of 316L Stainless Steel in High Temperature Water and Steam: Effects of Simultaneous Proton Irradiation

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.

Synergistic effect of proton irradiation and electrical stress on high-speed 850 nm vertical-cavity surface-emitting lasers

The synergistic effect significantly impact VCSEL's reliability for potential applications in spatial data communication. The synergistic effect of 3 MeV proton irradiation and electrical stress on 850 nm high-speed VCSELs is investigated. The degradation of VCSEL slow down under the influence of bias current. However, device degradation is more pronounced during irradiation under high bias current density. Low frequency noise (LFN) analysis results indicate that defects induced by proton irradiation are the primary cause of the optical-electrical parameter degradation in the device. The bias current density significantly influences the final defect yield, leading to variations in the degree of degradation after irradiation at different bias currents. At a bias current density of 6.03 × 105 A/m2, the degradation of the modulation bandwidth is reduced in comparison to the unbiased state. A mechanism investigation into the synergistic effect of proton irradiation and electrical stress on VCSELs lends support for accurately evaluating the radiation hardness of optical communication system composed of VCSELs in harsh radiation environments.

Synergistic effect of electrical bias and proton irradiation on the electrical performance of β-Ga2O3 p–n diode

The synergistic impact of reverse bias stress and 3 MeV proton irradiation on the β-Ga2O3 p–n diode has been studied from the perspective of the defect in this work. The forward current density (JF) is significantly decreased with the increase in proton irradiation fluence. According to the deep-level transient spectroscopy results, the increase in the acceptor-like trap with an energy level of EC-0.75 eV within the β-Ga2O3 drift layer, which is most likely to be Ga vacancy-related defects, can be the key origin of the device degradation. The increase in these acceptor-like traps results in the carrier concentration reduction, which in turn leads to a decrease in JF. Furthermore, compared with the case of proton irradiation with no bias, the introduction of −100 V electrical stress induced a nearly double decrease in JF. Based on the capacitance–voltage (C–V) measurement, with the support of the electric field, the carrier removal rate increased from 335 to 600 cm−1. Similar to the above-mentioned phenomenon, the trap concentration also increased significantly. We propose a hypothesis elucidating the synergistic effect of electrical stress and proton irradiation through the behavior of recoil nuclei under the electric field.

Comparison of Proton and Gamma Irradiation on Single-Photon Avalanche Diodes

In this paper, the effects of proton and gamma irradiation on reach-through single-photon avalanche diodes (SPADs) are investigated. The I–V characteristics, gain and spectral response of SPAD devices under proton and gamma irradiation were measured at different proton energies and irradiation bias conditions. Comparison experiments of proton and gamma irradiation were performed in the radiation environment of geosynchronous transfer orbit (GTO) with two different radiation shielding designs at the same total ionizing dose (TID). The results show that after 30 MeV and 60 MeV proton irradiation, the leakage current and gain increase, while the spectral response decreases slightly. The leakage current degradation is more severe under the “ON”-bias condition compared to the “OFF”-bias condition, and it is more sensitive to the displacement radiation damage caused by protons compared to gamma rays under the same TID. Further analysis reveals that the non-elastic and elastic cross-section of protons in silicon is 1.05 × 105 times greater than that of gamma rays. This results in SPAD devices being more sensitive to displacement radiation damage than ionizing radiation damage. Under the designed shielding conditions, the leakage current, gain and spectral response parameters of SPADs do not show significant performance degradation in the orbit.

Early effects of different brain radiotherapy modalities on circulating leucocyte subpopulations in rodents

Purposes Lymphopenia is extensively studied, but not circulating leucocyte subpopulations, which however have distinct roles in tumor tolerance. Proton therapy has been shown to have a lesser impact on the immune system than conventional X-ray radiotherapy through lower dose exposure to healthy tissues. We explored the differential effects of brain X-ray and proton irradiation on circulating leucocyte subpopulations. Materials and methods Leucocyte subpopulation counts from tumor-free mice were obtained 12 hours after 4 fractions of 2.5 Gy. The relationships between irradiation type (X-rays or protons), irradiated volume (whole-brain/hemi-brain) and dose rate (1 or 2 Gy/min) with circulating leucocyte subpopulations (T-CD4+, T-CD8+, B, and NK-cells, neutrophils, and monocytes) were investigated using linear regression and tree-based modeling approaches. Relationships between dose maps (brain, vessels, lymph nodes (LNs)) and leucocyte subpopulations were analyzed and applied to construct the blood dose model, assessing the hypothesis of a direct lymphocyte-killing effect in radiation-induced lymphopenia. Results Radiation-induced lymphopenia occurred after X-ray but not proton brain irradiation in lymphoid subpopulations (T-CD4+, T-CD8+, B, and NK-cells). There was an increase in neutrophil counts following protons but not X-rays. Monocytes remained unchanged under both X-rays and protons. Besides irradiation type, irradiated volume and dose rate had a significant impact on NK-cell, neutrophil and monocyte levels but not T-CD4+, T-CD8+, and B-cells. The dose to the blood had a heterogeneous impact on leucocyte subpopulations: neutrophil counts remained stable with increasing dose to the blood, while lymphocyte counts decreased with increasing dose (T-CD8+-cells > T-CD4+-cells > B-cells > NK-cells). Direct cell-killing effect of the dose to the blood mildly contributed to radiation-induced lymphopenia. LN exposure significantly contributed to lymphopenia and partially explained the distinct impact of irradiation type on circulating lymphocytes. Conclusions Leucocyte subpopulations reacted differently to X-ray or proton brain irradiation. This difference could be partly explained by LN exposure to radiation dose. Further researches and analyses on other biological processes and interactions between leucocyte subpopulations are ongoing. The various mechanisms underlying leucocyte subpopulation changes under different irradiation modalities may have implications for the choice of radiotherapy modalities and their combination with immunotherapy in brain cancer treatment.

Effect of proton radiation on gallium nitride light emitting diodes

The compound semiconductor gallium nitride offers enormous potential for facilitating economic expansion in the silicon-based semiconductor industry, which is currently seeing decreasing performance returns compared to investment costs. Its high electron mobility and electric field strength at the material level have already demonstrated enormous potential for photonics and high-frequency communications applications. However, its application in devices used in the radiation-prone environment is hindered by degradation and failure caused by the radiation. In this paper, the effect of proton radiation on the electrical properties of InGaN light emitting diodes (LEDs) for the fluence range of 1×1014 cm-2 to 3×1014 cm-2 is performed. On comparing the results before and after radiation, it is found that radiation mainly affected the reverse IV characteristics of the device with little or no effect on forward IV or CV characteristics. Apart from the electric properties, the optical properties of the LEDs show improvement after radiation as the light intensity increases post-irradiation.

Effect of Proton Irradiation on the Optical Properties and Defect Formation in Gd3AlxGa5 – xO12 (x = 2, 3) Crystals

Effect of Proton Irradiation on the Optical Properties and Defect Formation in Gd3AlxGa5 – xO12 (x = 2, 3) Crystals

СРАВНИТЕЛЬНАЯ ОЦЕНКА ВЛИЯНИЯ ЛОКАЛЬНОГО ПРОТОННОГО ИЗЛУЧЕНИЯ В ДОЗЕ 30 ГР НА МЫШЕЙ ЛИНИЙ BALB/с И С57BL/6

Purpose: To evaluate the effect of local proton irradiation at a dose of 30 Gy on Balb/c and C57BL/6 mice in terms of the degree and dynamics of radiation-induced skin damage formation, changes in body weight and peripheral blood elements count. Material and methods: Experiments were performed on non-depilated male mice aged 7‒8 weeks from two strains: Balb/c and C57BL/6 (n=15). Local irradiation of the skin was carried out on the dorsal side of the animals using a scanning proton beam at an extended Bragg peak in the proton therapy complex «Prometheus» of the LPI Physico-technical Centre (Protvino) at a dose of 30 Gy with a proton energy of 87.8 MeV. During the irradiation session, animals were subjected to intraperitoneal anesthesia using a combination of Zoletil 100 (Virbac, France) and Xyla (Interchemie, Netherlands) in a previously determined ratio 1:3 (20‒40 mg/kg). Photographic documentation of radiation-induced skin damage was performed weekly for 70 days. Animals were examined daily for clinical manifestations of radiation-induced skin damage formation according to the RTOG international scale for 21 days following irradiation. The body weight dynamics of mice were evaluated one day before irradiation and then weekly for 70 days. Blood samples were collected from the tail vein by cutting the tip of the tail and analyzed using a DH36 Vet hematology analyzer (Dymind, China) one day before irradiation, one day and three days after irradiation, and weekly thereafter for 70 days. Experimental data were presented as mean ± standard deviation (M ± SD). Results: In this study, the impact of a single local exposure to proton radiation at a dose of 30 Gy on the degree and dynamics of radiation-induced skin damage formation was evaluated. It was demonstrated that Balb/c mice exhibited a higher frequency and degree of radiation-induced skin damage formation compared to the C57BL/6 mice. Analysis of body weight in mice after radiation exposure revealed no significant decrease in either mouse strain. A comparative analysis of the number of platelets, erythrocytes and hemoglobin concentration in both mouse strains did not reveal any changes, while a tendency towards a decrease in the number of leukocytes, lymphocytes, and granulocytes was observed in the irradiated Balb/c mice group compared to the control group. Conversely, in irradiated C57BL/6 mice, the number of lymphocytes was higher compared to control animals. Conclusion: In this study, Balb/c mice exhibited higher radiosensitivity compared to C57BL mice in response to a single local proton irradiation at a dose of 30 Gy.

Effect of proton irradiation on superconducting fluctuations of SmBCO-coated conductor tapes

Effect of proton irradiation on superconducting fluctuations of SmBCO-coated conductor tapes

Effect of Proton Irradiation on Complementary Metal Oxide Semiconductor (CMOS) Single-Photon Avalanche Diodes

The effects of proton irradiation on CMOS Single-Photon Avalanche Diodes (SPADs) are investigated in this article. The I–V characteristics, dark count rate (DCR), and photon detection probability (PDP) of the CMOS SPADs were measured under 30 MeV and 52 MeV proton irradiations. Two types of SPAD, with and without shallow trench isolation (STI), were designed. According to the experimental results, the leakage current, breakdown voltage, and PDP did not change after irradiation at a DDD of 2.82 × 108 MeV/g, but the DCR increased significantly at five different higher voltages. The DCR increased by 506 cps at an excess voltage of 2 V and 10,846 cps at 10 V after 30 MeV proton irradiation. A γ irradiation was conducted with a TID of 10 krad (Si). The DCR after the γ irradiation increased from 256 cps to 336 cps at an excess voltage of 10 V. The comparison of the DCR after proton and γ-ray irradiation with two structures of SPAD indicates that the major increase in the DCR was due to the depletion region defects caused by proton displacement damage rather than the Si-SiO2 interface trap generated by ionization.

Experiment and Analysis of Damage Effect of Proton Irradiation on Transmission Transistor of CMOS Image Sensor

Experiment and Analysis of Damage Effect of Proton Irradiation on Transmission Transistor of CMOS Image Sensor

Effect of proton irradiation on the cathodoluminescence of gallium nitride films

In this work, we studied the effect of 350 keV proton irradiation with two different fluences of 1013 cm−2 and 1015 cm−2 on the cathodoluminescence (CL) spectrum of GaN. Three lines were observed in the CL spectra of virgin and proton pre-irradiated samples - band edge line (3.4 eV), blue line (2.8 eV) and yellow line (2.15 eV). A strong decrease in the CL intensity for samples pre-irradiated by protons, especially at high proton fluence of 1015 cm−2, is shown. The evolution of the cathodoluminescence spectra during electron irradiation demonstrates a further decrease in all line intensities. It was shown that virgin and proton pre-irradiated GaN samples were not charged under electron irradiation. The cathodoluminescence signal drop can be caused by a decrease in the concentration of initial luminescence centers associated with intrinsic and impurity defects due to their transformation under proton bombardment and electron-stimulated diffusion implanted H+ ions.

Study of Single-Event Effects Influenced by Displacement Damage Effects under Proton Irradiation in Static Random-Access Memory

Static random-access memory (SRAM), a pivotal component in integrated circuits, finds extensive applications and remains a focal point in the global research on single-event effects (SEEs). Prolonged exposure to irradiation, particularly the displacement damage effect (DD) induced by high-energy protons, poses a substantial threat to the performance of electronic devices. Additionally, the impact of proton displacement damage effects on the performance of a six-transistor SRAM with an asymmetric structure is not well understood. In this paper, we conducted an analysis of the impact and regularities of DD on the upset cross-sections of SRAM and simulated the single-event upset (SEU) characteristics of SRAM using the Monte Carlo method. The research findings reveal an overall increasing trend in upset cross-sections with the augmentation of proton energy. Notably, the effect of proton irradiation on the SEU cross-section is related to the storage state of SRAM. Due to the asymmetry in the distribution of sensitive regions during the storage of “0” and “1”, the impact of DD in the two initial states is not uniform. These findings can be used to identify the causes of SEU in memory devices.

The influence of proton radiation on the friction and wear of Ti:WS2/P201 composite lubricating materials for space application

The effects of proton radiation (PR) irradiation on the components, friction and wear of Ti:WS2/P201 composite lubricating system were mainly investigated. PR irradiation has a great effect on the physicochemical properties of P201 oil, which can not only decompose oil into small molecular but also make it cross-linking and polymerization. More seriously, oil layer with good wettability transfers to a solid-like organic film on sample surfaces after PR irradiation. In addition, PR irradiation has a slight effect on the microstructure of Ti:WS2 film due to coverage of oil layer. Meanwhile, Ti:WS2/P201 system obviously increases the friction coefficient and wear rate, especially extremely shortened life at high irradiation dose. It attributes to P201 oil occurred degradation when suffers from high PR energy, forming polymer with higher molecular weight. The polymer has poor replenishment on sliding contact interface, so destroying endurance of transfer film, which deteriorates the component and property of the system. At the high irradiation dose, the oil nearly loss fluidity, causing severe abrasive wear and tribo-oxidation, further accelerating the failure of the solid-oil materials.