Radiation-induced Degradation Research Articles

Gamma radiation-induced degradation of Acid Violet 49 in the presence of hydrogen peroxide (H2O2) in an aqueous medium

Abstract The present study is about the effect of gamma radiations on the degradation of Acid Violet 49 (AV49) in the presence of H2O2 (γ/H2O2). The Cs-137 radiation source was calibrated to irradiate the aqueous solution of AV49 within the 1 kGy, 5 kGy & 10 kGy dose range. The results showed that 50–150 mg/L of AV49 was effectively degraded by γ radiation (85 %), however, the concentration of H2O2 in the range of 0.2–0.6 mL promoted degradation to 90 % and 98 %, respectively. It was observed that all absorption bands declined with rising irradiation dose and disappeared completely after 10 kGy applied dose. pH conditions (3, 5,7, and 9) were used in the radio-lytic degradation of AV49, the results showed that the best degradation efficiency has been found for pH 9. The optimum degradation rate is higher (98 %) with a 50 mg/L concentration of AV49, 0.6 mL H2O2, and pH 9 at a 10 kGy absorbed dose. In addition, the influence of various parameters on the rate of degradation such as the effect of irradiation dose, pH, H2O2, and dye (AV49) concentration was also studied. Furthermore, the removal of total organic carbon TOC was not as effective as that of the AV 49. Total nitrogen TN was not completely removed even at high dosage. Radio-lytic degradation of AV49 was analyzed by using Fourier transform infrared spectroscopy (FTIR) and liquid chromatography coupled to mass spectrometry (LC-MS) as an analytical technique. Results revealed that the proposed methodology for degradation of dyes is effective and probably could be applied for the removal of other toxic pollutants.

Probing elemental diffusion and radiation tolerance of perovskite solar cells via non-destructive Rutherford backscattering spectrometry

Mixed organic–inorganic halide perovskite-based solar cells have attracted interest in recent years due to their potential for both terrestrial and space applications. Analysis of interfaces is critical to predicting device behavior and optimizing device architectures. Most advanced tools to study buried interfaces are destructive in nature and can induce further degradation. Ion beam techniques, such as Rutherford backscattering spectrometry (RBS), is a useful non-destructive method to probe an elemental depth profile of multilayered perovskite solar cells (PSCs) as well as to study the inter-diffusion of various elemental species across interfaces. Additionally, PSCs are becoming viable candidates for space photovoltaic applications, and it is critical to investigate their radiation-induced degradation. RBS can be simultaneously utilized to analyze the radiation effects induced by He+ beam on the device, given their presence in space orbits. In the present work, a 2 MeV He+ beam was used to probe the evidence of elemental diffusion across PSC interfaces with architecture glass/ITO/SnO2/Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3/spiro-OMeTAD/MoO3/Au. During the analysis, the device active area was exposed to an irradiation equivalent of up to 1.62 × 1015 He+/cm2, and yet, no measurable evidence (with a depth resolution ∼1 nm) of beam-induced ion migration was observed, implying high radiation tolerance of PSCs. On the other hand, aged PSCs exhibited indications of the movement of diverse elemental species, such as Au, Pb, In, Sn, Br, and I, in the active area of the device, which was quantified with the help of RBS.

Islatravir Dimer: Crystal Form Dependence of a Radiation-Induced Degradation Product.

A rare example of crystal form-dependent, gamma radiation-induced degradation is presented. Islatravir is known to exist in several polymorphic forms, but only one of these forms shows the generation of a specific dimer degradation product under gamma irradiation. Extended gamma irradiation studies demonstrated that only one of the known crystalline forms shows an appreciable rate of dimer formation. Additionally, this dimer is not observed to form under other forced stress conditions. We present the structural elucidation of this dimer impurity and rationalize its form-dependent generation based on the analysis of the underlying crystal structure.

Study on damage of Gd2O3-CeO2 under electronic energy loss: comparison between bulk-like and nanostructure.

To understand the physical phenomena responsible for radiation damage of the materials used in nuclear reactors, and thus study their operation life and/or efficiency, it is required to simulate the conditions by exposing the materials to energetic ions. Ceria (CeO2) has been proposed as one of the inert matrices for the transmutation of minor actinides in the futuristic inert matrix fuel (IMF) concept. The inert matrix should also contain burnable poison to compensate for the initial reactivity of fuel. In this context, gadolinium (Gd) is an excellent burnable poison with a high neutron absorption cross-section. In view of this, Gd2O3-CeO2 nano-powders were synthesized and sintered at 800 °C and 1300 °C to obtain different grain sizes and morphologies. FESEM and TEM were carried out to study the grain size of pristine pellets. The sintered pellets were irradiated with 80-MeV Ag ions (electronic energy loss (Se) regime) at room temperature to emulate the effect of fission fragments. For analysis of the effect of grain size on the irradiation-induced structural degradation at different fluences, GIXRD and Raman spectroscopy were performed. Significantly large damage has been observed for the smaller grain-sized samples (sintered at 800 °C) as compared to the large grain-sized sample (sintered at 1300 °C). Neither of the samples amorphized under the present experimental conditions as indicated by the presence of the Raman-active T2g mode (centred at 462 cm-1) and all the XRD peaks of fluorite cubic structure up to the highest fluence employed (1 × 1014 ions cm-2). X-ray photoelectron spectroscopy results demonstrate that Ce4+ to Ce3+ and vacancy-related isolated clusters are the main defects produced in the systems. The radiation tolerance behaviour of the samples is understood with the help of thermal spike simulation, which indicates higher transient lattice temperatures with longer duration in the smaller grain-sized sample upon irradiation. Gd-doped ceria thus possesses good radiation stability in the Se regime, indicating its potential for application in IMFs.

Bias and Temperature Dependence of Radiation-induced Degradation for SiC MOSFETs

Bias and Temperature Dependence of Radiation-induced Degradation for SiC MOSFETs

Irradiation-induced age-related degradation mechanisms effect on integrity of baffle former bolts

For long-term operation of nuclear power plants, integrity of structures, systems and components should be ensured rigorously. In particular, since the complicated reactor vessel internals (RVIs) have been exposed to high temperature and neutron irradiation environment, materials reliability programs on the RVIs to resolve anticipated issues were conducted by several research institutes. The objectives of this research are to examine evaluation procedures derived from the previous works and to apply them for RVIs in two operating reactors with baffle former assembly from different electricity powers. Finite element (FE) analyses were performed employing five user-subroutines developed by the authors for reflection of multiple age-related degradation mechanisms (ARDMs) as well as pre- and post-processing. Temperature distributions due to gamma heatings, fuel cycles, typical normal operating temperature and pressure histories were considered with relevantly varying material properties. As results, effects of irradiation were quantified in terms of stresses, strains and irradiation assisted crack sensitivity parameters. Further assessment was carried out through not only investigating contribution of each ARDM but also comparing the present FE analysis results with those obtained from a different reactor type in detail.

Electron Irradiation-Induced Degradation of TiN Thin Films on Quartz and Sapphire Substrates.

In this contribution, we investigated the properties of magnetron-sputtered TiN thin films on sapphire and quartz substrates before and after 5 MeV electron irradiation with a fluence of 7 × 1013 e/cm2. Structural, morphological, optical, and electrical properties were analyzed to observe the impact of electron irradiation on the TiN thin films. The results showed improved electrical properties of the TiN thin films due to high-energy electron irradiation, resulting in increased specific conductivity compared to the as-deposited thin films on both sapphire and quartz substrates. The structural features of the TiN thin films on the sapphire substrate transformed from polycrystalline to amorphous, while the TiN thin films deposited on the quartz substrate remained unchanged. Chemical state analysis indicated changes in the metallic bonding between Ti and N in the deposited TiN on the sapphire substrate, while TiN deposited on the quartz substrate retained its Ti-N bonding. This study provides insights into the effects of electron irradiation on TiN thin films, emphasizing the importance of investigating radiation resistance for the reliable operation of optoelectronic devices and photovoltaic systems in extreme ionizing radiation environments.

Ionization Radiation-Induced Reliability Degradation of SiC Power MOSFET

Ionization Radiation-Induced Reliability Degradation of SiC Power MOSFET

Radiation-Induced Degradation of PVA 26 by UV Radiation in the Presence of Zno Nanocatalyst

This research work evaluates the degradation of PVA-26 by UV radiation dose between different time intervals from 15-60 minutes under a UV chamber with the intensity of 144W by nanocatalyst ZnO, in the presence of H2O2. We investigated the effect of radiation, acidic medium, sample initial and final concentration, H2O2 concentration, and catalyst dose on the degradation process under these conditions. Different solutions of PVA-26, i.e., 50 ppm, 100 ppm, 150 ppm, and 200 ppm irradiated by the UV lamp at a wavelength of 290 nm. The efficiency of degradation of PVA-26 was checked using different parameters such as (UV/H2O2, UV/ H2O2 + ZnO, UV/ H2O2 + ZnO acidic medium, UV/ZnO H2O2/ZnO, and H2O2/ZnO + acidic medium). The experimental results showed that the rate of degradation increased by increasing radiation time, the concentration of H2O2, and the catalyst. The maximum degradation was observed up to 82 % under optimum conditions (60 minutes radiation time, 0.3 ml H2O2, and 0.1 g/L ZnO in HNO3) after that degradation rate decreased dramatically due to coagulation of HOo radicals. The characterization of the maximum degraded product was analyzed and examined by UV-spectrophotometer and FTIR.

On the Mechanism of the Ionizing Radiation-Induced Degradation and Recycling of Cellulose.

The use of ionizing radiation offers a boundless range of applications for polymer scientists, from inducing crosslinking and/or degradation to grafting a wide variety of monomers onto polymeric chains. This review in particular aims to introduce the field of ionizing radiation as it relates to the degradation and recycling of cellulose and its derivatives. The review discusses the main mechanisms of the radiolytic sessions of the cellulose molecules in the presence and absence of water. During the radiolysis of cellulose, in the absence of water, the primary and secondary electrons from the electron beam, and the photoelectric, Compton effect electrons from gamma radiolysis attack the glycosidic bonds (C-O-C) on the backbone of the cellulose chains. This radiation-induced session results in the formation of alkoxyl radicals and C-centered radicals. In the presence of water, the radiolytically produced hydroxyl radicals (●OH) will abstract hydrogen atoms, leading to the formation of C-centered radicals, which undergo various reactions leading to the backbone session of the cellulose. Based on the structures of the radiolytically produced free radicals in presence and absence of water, covalent grafting of vinyl monomers on the cellulose backbone is inconceivable.

Radiation-induced thermal conductivity degradation modeling of zirconium

This study presents a radiation-induced thermal conductivity degradation (TCD) model of zirconium as compared to the conventional UO2 TCD model. We derived the governing factors of the radiation-induced TCD model, such as maximum TCD value and temperature range of TCD. The maximum TCD value was derived by two methods, in which 1) experimental result of 32 % TCD was directly utilized as the maximum TCD value and 2) a theoretical approach based on dislocation was applied to derive the maximum TCD value. Further, the temperature range of TCD was determined to be 437–837 K by 1) experimental results of post-annealing of irradiation hardening as compared to 2) the rate theory and thermal equilibrium. Consequently, the radiation-induced TCD model of zirconium was derived to be fr=1−0.321+exp⁡{(T−637)/45} . Because the thermal conductivity of zirconium is one of the factors determining the storage and transport system, this newly proposed model could improve the safety analysis of spent fuel storage systems.

Gold-coated porous silicon as a SERS substrate for near-infrared excitation: Off- and on-resonant conditions

Porous silicon, being one of the most popular SERS-active substrates, was in this work utilized for near-infrared 1064 nm excitation which minimizes the radiation-induced degradation of molecules. The production of porous silicon photonic crystals and deposition of gold nanoparticles, as the two possible methods for quenching the crystal silicon band-gap photoluminescence, were thoroughly discussed. For the off-resonant laser excitation conditions, gold nanoparticles were grown on porous silicon by the immersion plating procedure. For the on-resonant conditions, gold nanorods with the appropriate aspect ratio were synthesized by a seed-mediated protocol and deposited on the porous silicon surface. The capability of these metal-dielectric substrates toward SERS enhancement was evaluated using crystal violet dye and the advantages and drawbacks of both methods were addressed in detail. The obtained detection limits for the crystal violet dye were in the range between 10−7 and 10−8 M. So far, gold-coated porous silicon SERS-active substrates for near-infrared 1064 nm excitation have not been reported, both for the off- and on-resonant regimes.

Radiation-resistant cerium co-doped erbium-doped fibers for C- and L-band amplifiers in a high-dose gamma-radiation environment.

We experimentally demonstrate a comparative study on the radiation-resistant cerium (Ce) co-doped erbium-doped fiber amplifiers (EDFAs) exposed to a high-dose gamma-radiation environment of 1.8 kGy/h dose rate in the C and L bands. Our results show that Ce is an effective co-dopant in the aluminosilicate EDFs for suppressing radiation-induced attenuation (RIA) of more than an order of magnitude lower than the Ce-free EDF. After exposure to a high-dose gamma-radiation of up to 10 kGy, the Ce co-doped EDF still exhibits good radiation tolerance, providing 41.6 ± 2.9 dB gain and 5 ± 0.8 dB NF from 1535-1560 nm for a -25 dBm input signal. In the L-band, we report, for the first time, the radiation-resistant EDFA with the radiation-induced gain degradation (RIGD) of 3.7 dB under 2.5 kGy irradiation and 4.4 dB under 10 kGy irradiation at 1600 nm. Also, the radiation-dependent gain coefficient and gain saturation were studied in the C and L bands. A comparison of different Ce co-doped EDFs exposed to different total gamma doses reveals the radiation impact on the amplifier performance, indicating the feasibility of using Ce co-doped EDFs for space-based optical communications, requiring robust radiation stability.

Review of qualification and modeling for radiation-induced polymer degradation

Polymeric materials have multiple potential applications in nuclear power reactors including advanced and small modulus reactors, in addition to their extensive usage in safety electronic cables in the existing light water reactors. Through the qualification programs, knowledge accumulates about the polymer degradation kinetics under gamma-irradiation environment to facilitate the development of service-life predictive models. This paper aims to promote mechanistic-based predictability as a new approach to the qualification of polymeric components. Reviewed in this article are the current qualification standards and procedures, the current understandings of the degradation mechanisms, and kinetic models applicable to accelerated experiments for qualification.

Effects of 63 MeV proton irradiation on the performance of MWIR InGaAs/InAsSb nBn photodetectors

An investigation into the effects of 63 MeV proton irradiation on high-sensitivity mid-wave infrared InGaAs/InAsSb nBn devices is performed. Three different structures with various absorber region doping profiles are irradiated and characterized to assess their impact on performance degradation. Minority carrier lifetime is measured using time-resolved photoluminescence and lifetime damage factors are assessed. The majority carrier concentration is determined via capacitance–voltage measurements and dopant introduction rates are calculated. An analysis of dark current density is performed using these material parameters, revealing a reduction in mobility with proton fluence and the emergence of a proton-induced trap energy level. Quantum efficiency is calculated at each proton fluence, and quantum efficiency damage factors show that the graded doping structure exhibits the least reduction of quantum efficiency with dose, attributed to its effective mobility enhancement. Conclusively, detector sensitivity, assessed via shot-noise limited noise-equivalent irradiance, shows that the graded doping structure is the least susceptible to high energy proton irradiation-induced performance degradation.

Electron beam irradiation-induced co-grafting and degradation of cotton cellulose with ionic liquid

We developed a cellulose upgrading method based on electron beam processing technology by using a carbon-carbon double bond-containing ionic liquid as an auxiliary reagent. The irradiation of cellulose was implemented by a 10 MeV high-energy electron accelerator or a 200 keV low-energy electron accelerator. The established method enabled grafting of the ionic liquid onto cellulose while triggering an irradiation degradation of cotton cellulose. By employing irradiation co-grafting degradation with a high-energy electron accelerator in the dose range of 30–40 kGy, highly uniform cotton cellulose with a high degree of polymerization (DP) of 500 and low degree of polymerization deviation (DPD) was obtained. By using a low-energy accelerator in the dose range of 4–6 kGy, cotton cellulose with a high DP of 1000 and low DPD was prepared. This method to upgrade cellulose has advantages of simple operation, short reaction time, and minimal amount of chemical reagents. It opened an avenue to access high quality of cellulose that cannot be attained with other method.

Influence of neutron and gamma irradiation on the electrocaloric properties of Mn-doped 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 ceramics

The influence of neutron and gamma irradiation on the low- and high-field dielectric and electrocaloric (EC) properties of Mn-doped 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 (PMN–10PT) ceramic is studied. Upon exposure to neutron fluences of up to 1017 cm−2 and gamma-ray doses of up to 1200 kGy the Mn-doped PMN–10PT exhibits a lower saturated polarization, increased internal bias field and reduced EC temperature change. In comparison, the respective properties of the undoped PMN–10PT remain almost unchanged upon exposure to neutrons and gamma rays. In Mn-doped PMN–10PT, the acceptor-oxygen vacancy defect complexes, introduced via doping, contribute to the lowering of the threshold radiation dose that the material survives without noticeable changes in properties. Radiation-induced degradation of the EC response of Mn-doped PMN–10PT can be partially healed by annealing at 450 °C. The study provides guidance for designing EC ceramic materials for solid-state cooling applications in environments of high ionizing radiation, such as the medical field or space technologies.

Machine Learning–Based Prediction of Irradiation-Induced Swelling from Synergistic Effects of Helium and Hydrogen

Understanding irradiation-induced degradation processes of nuclear structural materials is essential for creating methodologies and procedures for nuclear reactor safety. Due to the time- and resource-intensive property of both experiments and multiscale simulations of irradiation damage, the trial-and-error approach is completely inefficient. Recently, machine learning techniques have been employed to predict the properties of reduced activation ferritic martensitic (RAFM) steels, such as yield strength and elongation, as well as irradiation embrittlement in steel pressure vessels, with encouraging progress. In this work, void swelling is predicted using a machine learning method for the first time, taking into account the synergistic effects of displacement damage, helium, and hydrogen. Assisted by the analysis of feature engineering, seven machine learning models are trained and compared by multicriteria evaluation methods. Finally, the parameter-optimized gradient-boosting model is selected as the mapping function with the highest accuracy and universality to predict void swelling. In particular, the dependence of the void swelling and the injection amount of helium and hydrogen in the continuous parameter variation range is predicted beyond the existing experimental data. This work demonstrates the feasibility of machine learning to predict material irradiation damage by synergistic effects and has practical significance in nuclear material optimization and reactor safety.

A novel radiation-dependence model of InP HBTs including gamma radiation effects

In order to predict the lifetime of InP Heterojunction Bipolar Transistor (HBT) devices and related circuits in the space radiation environment, a novel model including gamma radiation effects is proposed in this paper. Based on the analysis of radiation-induced device degradation effects including both DC and AC characteristics, a set of empirical expressions describing the device degradation trend are presented and incorporated into the Keysight model. To validate the effective of the proposed model, a series of radiation experiments are performed. The correctness of the novel model is validated by comparing experimental and simulated results before and after radiation.

Degradation of polyacrylamide (PAM) in aqueous solution by electron beam technology: Efficiency, viscosity reduction and correlation with microstructure of polymer molecules

In this paper, we present a systematic evaluation about degradation of partially hydrolyzed polyacrylamide (HPAM) in aqueous solution by ionizing radiation to find relationship between HPAM decomposition, viscosity reduction and microstructure of polymer molecules. The viscosity of the two HPAM solution declined rapidly from 5.2 to 3.0 mPa s to 1.4–1.2 mPa s with the adsorbed dose of 0.1 kGy, and then reached the level of pure water at 0.5 kGy. The molecular weight declined remarkably from 1.6 × 107 Da to 1.4 × 105 Da (HPAM1) and from 1.2 × 107 Da to 1.1 × 106 Da (HPAM2) at 0.1 kGy. The HPAM solution changed from pseudoplastic fluid behavior to Newtonian fluid after irradiation. Following ionizing radiation, the presence of anion Na+, Ca2+, Mg2+, anions HCO3- and SO42-(1000–5000 mg/L) and surfactant sodium dodecyl sulfate (SDS) (50–100 mg/L) respectively has slight effect on the rate and extent of viscosity reduction, while CO32- and surfactant petroleum sulfonate exhibit a great negative effect on reducing HPAM viscosity. Ionizing radiation is able to destroy the molecular structure and spatial structure of HPAM. Both the C-C backbones and pendant are attacked. It is proposed that the degradation products include ammonium, aliphatic hydrocarbon, small molecular acids and compounds with double-bond. With the absorbed dose of 0.1 kGy, the micelles-like aggregates are broken into small particles by direct microscope observation, while the stretched and coiled molecular strands shrink and curl to form an irregular network from AFM and SEM observation. The chains break into fragment scattered randomly as increasing dose to 1.0 kGy. Both the diameter size and dispersity of HPAM molecules decreased remarkably after irradiation.·OH is the major active species responsible for HPAM degradation and viscosity reduction. This study contributes to a multiscale understanding the mechanism of ionizing radiation-induced degradation of HPAM in aqueous solution.