Irradiated Glasses Research Articles

Precipitation of Silver Nanoparticles in Borate Glasses by 1064 nm Nd:YAG Nanosecond Laser Pulses: Characterization and Dielectric Studies

This work aims to present a modern process to synthesis nanoparticles in a glassy matrix. Borate glasses doped by silver nitrate (AgNO3) via the melt annealing technique were irradiated by a (1064 nm wavelength) Nd:YAG (Neodymium–doped Yttrium Aluminum Garnet) laser to yeild precipitation of silver nanoparticles (AgNPs) in borate glasses. The characterization of the irradiated glasses was investigated using ultraviolet/visible (UV/Vis.), x-ray diffraction (XRD), high resolution-transmission electron microscopy (HR-TEM), field emission-scanning electron microscopy (FE-SEM), and dielectric properties. XRD patterns depict the presence of sharp diffraction peaks at 111 and 200 planes that can be attributed to the precipitated AgNPs in the borate glass sample after laser irradiation. A significant change in color was observed within the borate glass after laser irradiation, which was attributed to the appearance of surface plasmon resonance and confirmed the presence of AgNPs in the borate glass. The morphological properties and the distribution of the observed AgNPs inside the sample were performed via HR-TEM and FE-SEM. The behavior of dielectric constant and dielectric loss progressively decreased as the frequency increased. The values of AC conductivity increased as the temperature of the borate glass matrix increased.

Structural and optical properties of γ-ray irradiated BaF2– Bi2O3–SiO2Glasses

The influence of γ-ray irradiation on the optical and structural properties of BaF2– Bi2O3–SiO2 glasses has been studied. The absorption spectra of respective glasses are found to shift to higher wavenumber side as dosage rate of gamma irradiation increases. This is because of the formation of non-bridging oxygen hole centers (NBOHC) and electrons due to ionizing power of BaF2. The optical band gap value decreases from 3.07 to 2.61eV with an increase in dosage rate as well as alkaline content. The Urbach energy of glasses increases due to gamma irradiation may be attributed to formation of non-bridging oxygen in the system. The electron paramagnetic resonance (EPR) spectra exhibit resonance signals at g = 4.17 and g = 2.17 due to triplet hole pairs localized on apical oxygens. There were no significant variations in Raman spectra and this may be due to high content of Bismuth that is known for shielding of gamma irradiation. Photoluminescence (PL) studies reveal that both pure and irradiated barium silicate glasses exhibit white light where red region is predominant than blue in irradiated glasses.

Studying the Interaction of Hot Magnetospheric Plasma With the Protective Coating of the Spacecraft Solar Array

This paper presents the results of the simultaneous electron–proton irradiation of glass samples used as the protective coating of solar cells of high-altitude spacecraft. Combined irradiation with 20-keV electrons and protons was carried out in a vacuum chamber at a pressure of $10^{-4}$ Pa; charged particles fluxes were varied in the range of $10^{14}$ – $10^{15}\,\,\text{m}^{-2}\cdot \text {s}^{-1}$ . Structural changes of irradiated glass surfaces were studied by atomic force microscopy, and the reduction in glass transmittance due to the irradiation was measured in the wavelength range of 200–2500 nm. These changes in the surface structure and electrostatic discharge development under the combined irradiation are compared with the data obtained for separate exposure of the same glasses to electron or proton beams.

Thermoluminescence characteristics and dose response of electron beam and gamma rays irradiated alumino-phosphate glasses doped with Gd2O3 and Tb2O3

Phosphate glass samples doped with Gd2O3 and Tb2O3 oxides were synthesized and studied towards potential application in high dose radiation measurements. Glass/polytetrafluoroethylene composite detectors were prepared and used to study dosimetric signal dependencies, and thermoluminescence dosimetry (TLD) technique was used as a main investigation tool to study detectors response. Influence of dopants and polymer on TL signal were investigated. The dosimetric properties, like dose response, linearity and signal stability of the composite dosimeters were investigated. Incorporation of lanthanide oxides into glass matrix changes substantially the thermoluminescent behavior of phosphate glass. The highest luminescence yield exhibits glass doped with terbium oxide. Negligible influence of polytetrafluoroethylene agglutinator on dosimetric signal was observed. Dependence of the integrated thermoluminescent signals for all samples vs. absorbed dose can be considered as linear. The new phosphate glass-polytetrafluoroethylene composites show good material and thermoluminescent properties for the high gamma and electron beam dose measurement applications.

Monte Carlo simulation of the corrosion of irradiated simplified nuclear waste glasses

Ballistic effects due to recoil nuclei will be the predominant mode of long-term radiation damage of nuclear waste glass in disposal facilities. While these ballistic effects are known to modify the glass structure in ways that have been quantified using molecular dynamics (MD) simulations, the effect of irradiation-induced structural changes on glass corrosion is not understood. Monte Carlo (MC) simulations were therefore performed to quantify the effects of structural changes determined from MD simulations on the corrosion of simplified nuclear waste glasses, namely sodium borosilicate and sodium alumino-borosilicate glasses. MC simulations were first performed to determine separately the effects of irradiation-induced changes in boron coordination, the number and nature of Qn species, and the angular distribution of SiOSi linkages, that is, changes to the short-range order of the glass. Generally, the MC simulations showed the resulting effects on the kinetics (B release rate) and extent (B leached thickness) of corrosion were correlated to the extent of depolymerization of the glass network introduced by these local structural changes. The combined effects of these structural changes, as parameterized using the results of MD simulations, were then determined using a glass composition for which relevant experimental data were available for comparison. Here, the combined effect of local changes was lower than the increase in alteration depth observed upon irradiation. This insight from the MC simulations highlighted the need to consider changes in the medium-range order to completely account for experimental observations.

The Effect of Heavy Ion Irradiation on the Forward Dissolution Rate of Borosilicate Glasses Studied in Situ and Real Time by Fluid-Cell Raman Spectroscopy.

Borosilicate glasses are the favored material for immobilization of high-level nuclear waste (HLW) from the reprocessing of spent fuel used in nuclear power plants. To assess the long-term stability of nuclear waste glasses, it is crucial to understand how self-irradiation affects the structural state of the glass and influences its dissolution behavior. In this study, we focus on the effect of heavy ion irradiation on the forward dissolution rate of a non-radioactive ternary borosilicate glass. To create extended radiation defects, the glass was subjected to heavy ion irradiation using 197Au ions that penetrated ~50 µm deep into the glass. The structural damage was characterized by Raman spectroscopy, revealing a significant depolymerization of the silicate and borate network in the irradiated glass and a reduction of the average boron coordination number. Real time, in situ fluid-cell Raman spectroscopic corrosion experiments were performed with the irradiated glass in a silica-undersaturated, 0.5 M NaHCO3 solution at temperatures between 80 and 85 °C (initial pH = 7.1). The time- and space-resolved in situ Raman data revealed a 3.7 ± 0.5 times increased forward dissolution rate for the irradiated glass compared to the non-irradiated glass, demonstrating a significant impact of irradiation-induced structural damage on the dissolution kinetics.

Commercial kitchenware glass as a potential thermoluminescent media for retrospective dosimetry

Study has been made of the thermoluminescence (TL) yield of various glass-based commercial kitchenware (Reko-China, Skoja-France, Godis-China, Glass Tum-Malaysia, Lodrat-France). Interest focuses on their potential for retrospective dosimetry. Use was made of a60Co gamma-ray irradiator, delivering doses in the range 2–10 Gy. Results for the various media show all the glassware brands to yield linearity of response against dose, with a lower limit of detection of ∼0.06 and ∼0.08 Gy for loose and compact powdered samples. Among all of the brands under study, the Lodrat glassware provides the greatest sensitivity, at 6.0 E+02 nC g−1 Gy−1 and 1.5E+03 nC g−1 Gy−1 for compact- and loose-powdered forms respectively. This is sufficiently sensitive to allow its use as a TL material for accident dosimetry (2 Gy being the threshold dose for the onset of a number of deterministic biological effects, including skin erythema and sterility). Energy Dispersive X-ray (EDX) analyses have been conducted, showing the presence of a number of impurities (including C, O, Na, Mg, Al, Si, Ca and Br). Fading of the irradiated glasses show the amount of better than 3% and 5% of the stored energy for both loose and compact powdered samples within 9 days post irradiation. As such, commercial kitchenware glass has the potential to act as relatively good TL material for gamma radiation dosimetry at accident levels. This is the first endeavour reporting the TL properties of low cost commercial kitchenware glasses for gamma-ray doses in the few Gy range, literature existing for doses from 8 Gy to 200 Gy.

Effects of 7.5 MeV electron beam irradiation on optical properties of Eu3+-doped zinc sodium bismuth borate glasses

The present study aims to examine the effects of beaming 7.5 MeV electron on europium-doped zinc sodium bismuth borate glasses (prepared through melt quench technique) and the resulting changes in structural and optical properties. The study also examines the structural depolymerization of irradiated glasses, analyzed using recorded Fourier transform infrared spectra. Absorbance spectra along with Tauc’s plot were used to find the optical band gap of pristine and irradiated glasses. The study observes changes in photoluminescence spectra of irradiated Eu3+-doped glasses, monitored by exciting the samples at 394 nm. The study notes a decrease in emission intensity of Eu3+ ions observed from the emission spectra of electron beam treated glass samples. The thermally stimulated luminescence (TL) measurements of irradiated glasses resulted in intense glow peaks with increasing electron beam doses [4–50 kGy]. The TL glow curve exhibited two dissimilar peaks at distinct temperatures of 490 K and 610 K respectively. The obtained trap-depth (0.93 eV) using Chen’s relation and intensity variation of first glow peak at 490 K as a function electron beam doses facilitates ZNBBE-4 glass for dosimetry applications.

Femtosecond laser induced two-photon absorption in Au-ion embedded glasses

AbstractTwo-photon absorption (TPA) of Au-ion irradiated glasses in the femtosecond regime has been analyzed by an open-aperture Z scan technique. Three types of glasses, namely GIL49, BK7, and Glass B were irradiated by using 1700 keV Au+ ion beams. Samples were post-annealed at 600°C for 5 h. Penetration depth and distribution of Au+ ions having 1700 keV energy within glass substrates were estimated by transport of ions in matter (TRIM) simulations. Detailed calculations with full-damage cascades were performed for each sample, taking into account the chemical composition of glass substrates. TRIM results reveal that there is no significant change in ion range, straggling, and ion distribution with the change in the substrate composition. However, Z scan results showed a difference in TPA coefficients for all three glasses. Extent of crosslinking within each of irradiated sample, owing to its chemical composition, may have affected their TPA coefficients.

EPR dosimetric properties of different window glasses

To better estimate the individual dose and assess the levels of radiation accidents, this paper exhaustively explored the electron paramagnetic resonance (EPR) dosimetric properties of window glasses. Three types of commercial window glasses were ground into five different sizes and washed with various solutions to explore the influence of grinding and washing. An in-depthanalysisof the thermal stability of the radio-induced EPR signal was conducted at 40–200 °C for a varying length of time. The postirradiation signal stability with different storage conditions was also studied. For the dose response, irradiated samples (4–30 Gy) were used to build calibration curves. The results were as follows. Irradiated window glasses exhibit a paramagnetic center with an EPR signal at g = 2.0038 ± 0.0016. Different filling factors of the cavity make a difference in the signal. A glass size of 1–2 mm is optimal for the experiments. Alcohol and distilled water do not affect the EPR signals. A quick thermal treatment at 200 °C for 20 min can clear the radio-induced signals. Sunlight can accelerate the decline of the radio-induced signals, whereas low-temperature storage slows down that decline. The background signals and radiation responses are different for the same type of glass from different manufacturers. Finally, transparent window glasses show characteristics more suitable for dosimetry and triage applications than glasses of other types. In summary, window glasses are promising for applications in accidental retrospective dosimetry and have great potential for improvement in future work.

DOSE RECONSTRUCTION FROM ESR SIGNAL OF GAMMA-IRRADIATED SODA-LIME GLASS FOR TRIAGE APPLICATION.

In this work, we report some preliminary results regarding the analysis of electron spin resonance (ESR) response of soda-lime samples used for retrospective dosimetry. Six different soda-lime glass batches were evaluated after irradiation. We compared several dose reconstruction techniques: saturation method, subtraction method and g-effective, geff, approach. The differences were observed and discussed. ESR signal responses of soda-lime glass samples to different radiation doses for the triage application were investigated. Results confirmed that geff approach has potential for the identification and dosimetry of irradiated soda-lime glass samples using either additive dose method or only calibration curve.

Mechanical Properties of Borosilicate Glass with Different Irradiation of Heavy Ions

To understand the evolutions in mechanical properties of borosilicate glass under irradiation is significant for evaluating its performance after long-term interaction with irradiation environment. In this study, borosilicate glass samples were irradiated with 0.3 MeV P-ions, 4 MeV Kr-ions, 5 MeV Xe-ions and 8 MeV Au-ions, respectively. Modification of the samples' mechanical properties before and after radiation was investigated with nano-indentation measurement. With increase of irradiation dose, both hardness and modulus of samples irradiated with P, Kr, Xe and Au ions drop and then saturate at 0.1 dpa. The trends of hardness variations for the sample irradiated with four kinds of ions at different energies are similar, and the change of modulus also follows the same rule. The maximum variation of NBS2 sample' hardness and modulus are about 35% and 18%, respectively. The grazing incident X-ray diffraction (GIXRD) was employed to analyze the phase structure. The results indicate that borosilicate glass still remains amorphous after irradiation. The microstructure evolutions of irradiated borosilicate glasses were characterized by Raman spectroscopy. The decrease of network polymerization and the increase of structural disorder are suggested by Raman spectra. In addition, the results also suggest that the main factor for the evolutions of the hardness and modulus of the borosilicate glass under ion irradiation is the change of the deformation of glass network, which was caused by nuclear energy deposition in samples.

Mechanical property modifications of microsphere glass induced by Ar ion irradiation

In order to study the mechanical properties of ion irradiated hollow glass microspheres, the glass sample with the same composition of the hollow glass microspheres was irradiated by Ar ions. Combining with the annealing treatment, the mechanical properties of microsphere glass were studied by means of nanoindentation. The results show that the hardness and modulus of the microsphere glass are decreased after ion irradiation, and the recovery resistance is obviously increased. After annealing, the hardness and modulus of unirradiated samples showed an upward trend, and the recovery resistance did not change within the error range; the hardness of the irradiated microsphere glass is increased, while the modulus and the recovery resistance are significantly decreased. After annealing at around 300 ℃, the recovery resistance of the irradiated sample is the same as the unirradiated sample within the error range.

Optical properties of electron and gamma ray irradiated glass samples

Soda-lime cam orneklerin optik gecirgenlik ve sogurma spektrumlari 8 MeV elektron ve γ-isini demetlerine maruz birakilmasi sonrasinda calisildi. Elektron demeti uretimi icin modifiye klinik LINAC kullanilirken buna karsilik γ-isini kaynagi olarak Co-60 kullanildi. Cam numunelerin optik ozellikleri, farkli dozlar ve radyasyon turleri icin analiz edildi. Her iki durumda da cam orneklerinde radyasyonun sebep oldugu renk merkezleri gozlendi. Dahasi da, isinlama kaynagi kapatildiktan sonra zamana bagli optik ozellikler de elde edilerek bu renk merkezlerinin oda sicakliginda bile yavasca kayboldugu gozlendi. 8 MeV elektron ve γ- isini demetlerine maruz birakilan orneklerin optik gecirgenlik spektrumu, gorunur bolgede siradisi sopurma bandi gostermektedir. Ote yandan, isinlanmis numuneler 100 °C' nin uzerinde kisa bir sure firinlaninca bu sogurma bantlari neredeyse kaybolmaktadir.

Design and fabrication of 1D and 2D optical scanner for electron beams using color centre generation

The present paper focuses on the design and fabrication of 1D and 2D optical scanners to characterize the spatial profile of electron beams. The basis of the two systems is the generation of color centers in glass plates by irradiation, followed by the scanning of the plates, illuminated by a fixed power source (LED) with a maximum power of 3 W in the spectral range of 520–560 nm, with a TCS3200 sensor. In both systems, 6 mm thick glass blades (SiO2:76%) are used instead of expensive dosimetric films. The experimental results section first focuses on the validation and calibration accuracy of the effective absorbance of the irradiated glass in the LED spectral range with a radiation dose of up to 20 kGy. Then, it describes how the 1D optical scanner was used to scan the spatial profile obtained under the scanning horn of a Rhodotron accelerator with a maximum radiation dose of 7.8 kGy. The experimental results obtained from this method are entirely consistent with the results of other research studies, while this method is more cost-efficient and accurate compared to the previously reported methods. The 2D optical scanner was also used to accurately measure the spatial profile of the Rhodotron electron beam in static mode by scanning the color centers generated by irradiation.

Creation of glass-characteristic point defects in crystalline SiO2 by 2.5 MeV electrons and by fast neutrons

Point defects in crystalline SiO2, created by 2.5 MeV electron irradiation at dose below the amorphization threshold or by fast neutrons, were compared by luminescence spectroscopy. Oxygen dangling bonds (“non-bridging oxygen hole centers”, NBOHCs), peculiar to amorphous state of SiO2, were detected for the first time in electron-irradiated non-amorphized α-quartz crystal. Their presence may signal the formation of nucleation centers in crystal structure as the first step to radiation-induced amorphization. Compared to crystal, irradiated by 1019 cm−2 fast neutrons, their concentration was over 100 times lower, and their inhomogeneous broadening was at least 2.5 times smaller. Divalent silicons (“silicon oxygen deficiency centers”, SiODC(II)), inherent to oxygen-deficient or irradiated SiO2 glass, were detected in neutron-irradiated (1019 n/cm2) α-quartz but were not found after the electron irradiation. Radiation-induced interstitial O2 molecules, characteristic to irradiated glassy SiO2 and other oxide glasses, are found in α-quartz only after neutron irradiation. The oxygen atoms, displaced by the 2.5 MeV e− irradiation of α-quartz for fluences up to 1019 e−/cm2 evidently stays entirely in the peroxy linkage (Si-O-O-Si bond) form.

Molecular dynamics simulation of ballistic effects in simplified nuclear waste glasses

Ballistic effects in simple sodium borosilicate (Na2OB2O3=1) and sodium alumino-borosilicate glasses (Na2O−Al2O3B2O3=1) were investigated using molecular dynamics simulations. Specifically, the glasses were irradiated with heavy projectiles that caused atomic displacements by elastic collisions (displacement cascades) and progressively damaged the bulk glass. The accumulated pressure and internal energy inside the glass were found to saturate with deposited energy. Furthermore, structural analysis of the irradiated glasses revealed several important ballistic effects including a decrease in glass density, depolymerization of the borosilicate network, and increase in chemical mixing, short range and intermediate disorder. The magnitude of radiation damage was found to depend on the glass composition and, in general, alumino-borosilicate glasses were found to be slightly less damaged, after irradiation, as compared to borosilicate glasses.

The microstructure and mechanical properties of He+ ion irradiated Zr55Cu30Al10Ni5 bulk metallic glass

The hardness and plasticity of Zr55Cu30Al10Ni5 metallic glass (MG) is investigated under He+ ion irradiation. After ion irradiation, the softening of Zr55Cu30Al10Ni5 MG is observed, which is attributed to the spatial homogeneity of free volume and the destruction of the structural backbone induced by ion irradiation. As increase of ion influence, the formation of helium bubbles and the reduction of free volume may be result in the hardening of Zr55Cu30Al10Ni5 MG. Moreover, the plasticity of Zr55Cu30Al10Ni5 MG is modified after ion irradiation, which is attributed to the formation of multiple shear bands, propagation of shear bands and spatial distribution of free volume at different ion influence.

Xenon solubility and formation of supercritical xenon precipitates in glasses under non-equilibrium conditions

Estimates of noble gas solubility in glasses and minerals are important to understand the origin of these gases, particularly xenon, in the atmosphere. However, technical difficulties and ambiguities in quantifying the dissolved gases introduce large uncertainties in the solubility estimates. We present here the use of transmission electron microscopy (TEM) with in-situ noble gas ion implantation as a non-equilibrium approach for noble gas solubility estimates. Using a suitable Xe equation of state and Monte-Carlo simulations of TEM images, a clear distinction between Xe filled precipitates and empty voids is made. Furthermore, implantation-induced changes in the solubility are estimated using molecular dynamics simulations. These studies allow us to evaluate the xenon solubility of irradiated and pristine silica glasses and monitor in-situ the diffusion-mediated dynamics between the precipitates and voids — otherwise impossible to capture. On exceeding the solubility limit, supercritical xenon precipitates, stable at least up to 1155 K, are formed. The results highlight the high capacity of silicates to store xenon and, predict higher solubility of radiogenic xenon due to the accompanying radiation damage.

In situ TEM study on electron irradiation effects in SiO2–Na2O–B2O3 glasses

AbstractIn situ transmission electron microscopy (TEM) was used to study the electron irradiation effects of SiO2–Na2O–B2O3 (SNB) glasses. Three kinds of SNB glasses were designed and fabricated with constant K (K = [SiO2]/[B2O3] molar ratio) and varying R (R = [Na2O]/[B2O3] molar ratio). The electron irradiation effects were found to be significantly dependent on the value of R. Gas bubbles and small particles were observed in the bright field (BF) images of irradiated SNB glasses with sufficient Na2O content. The bubbles are believed to be composed of molecular oxygen O2 which was formed in the recombination processes of broken non‐bridging oxygen (NBO) structures. Irradiation‐produced small particles are suggested to be Si‐enriched phases which were formed via deconstruction of reedmergnerite groups. The different responses of these three kinds of SNB glasses agree well with their initial structural groups that are theoretically derived from the Bray's model.