Fast Neutron Irradiation Research Articles

Simultaneous co-axial multi-modal inspection using a laser driven x-ray and neutron source.

Laser-plasma interactions have been demonstrated to produce bright sources of energetic radiation including ions, electrons, photons across the electro-magnetic spectrum, and neutrons. Combinations of species can significantly increase information from non-destructive imaging. Here we demonstrate single-shot co-axial radiography with both x-ray and fast-neutron radiation from a laser-driven source using a pair of gated microchannel plate photomultiplier tube channels and a fast scintillator medium. The outlined system demonstrates recovery full-width-half-maximum of (18 ± 3) ns, which is sufficient to isolate x-rays from neutrons up to (72 ± 20) MeV and could be isolated only a short distance (2m) from the target.

Initiation of the Shape Memory Effect by Fast Neutron Irradiation

The band sample of austenitic steel 0.3C–13Cr–10Mn–3Si–1V was cold deformed to a shape of circular arc with a deflection of 3 mm and then irradiated by fast neutrons with a fluence of 6×1019 cm–2 in the vertical wet channel of the IVV-2M reactor at a temperature of 80 °C. This material belongs to the class of the stainless manganese austenitic steels with the shape memory effect (SME). The neutron irradiation was initially supposed to lower the SME upon the further heating in comparison with the reference sample. But instead, the SME appeared immediately under irradiation showing a decrease in the deflection of about 21 %. Check experiments confirmed that the lower limit of the SME in this material is 120 °C with its absence at 80 °C. This allows us to assert that the observed effect is the result of the neutron irradiation.

Synthesis, photoluminescence, Judd-Ofelt parameters, and high energy neutron/charged particle transmission efficiencies of Nd3+ ion-activated sodium-borate glasses

Sodium borate glasses doped with Nd3+ ions and having the molar formulations 75B2O3 – 15Na2O – 9.5x – 0.5Nd2O3, where x = Bi2O3; SrO and Li2O were prepared by employing the melt quenching technique. The glasses were coded as BiNd, SrNd, and LiNd for x = Bi2O3; SrO and Li2O, respectively. The prepared glasses were characterized for their physical and optical attributes. The influence of the glass composition on the photoluminescence and fast neutron (FN) and charged radiation (CR) transmission efficiencies were also investigated. The density of BiNd, SrNd, and LiNd is 3.32, 2.43, and 3.32 g/cm3, respectively. Optical constants of the glasses showed variations with glass composition. The FTIR study of the glass also revealed the structure of the glasses. The BiNd glass has the most intense PL of all the samples, followed by SrNd glass, while LiNd had the weakest PL emission. The value of for BiNd, SiNd, and LiNd is 0.1029 cm-1, 0.1009 cm-1, and 0.0987 cm-1, respectively. The projected ranges of electrons, protons, helium ions, and carbon ions were generally lower for denser XNd glass. The XNd glasses are potentially useful of optical, shielding and dosimetry applications.

Comparison of Mutations Induced by Different Doses of Fast-Neutron Irradiation in the M1 Generation of Sorghum (Sorghum bicolor).

Sorghum is an important C4 crop with various food and nonfood uses. Although improvements through hybridization and selection have been exploited, the introduction of genetic variation and the development of new genotypes in sorghum are still limited. Fast-neutron (FN) mutagenesis is a very effective method for gene functional studies and to create genetic variability. However, the full spectrum of FN-induced mutations in sorghum is poorly understood. To address this, we generated an FN-induced mutant population from the inbred line 'BTx623' and sequenced 40 M1 seedlings to evaluate the mutagenic effects of FNs on sorghum. The results show that each line had an average of 43.7 single-base substitutions (SBSs), 3.7 InDels and 35.15 structural variations (SVs). SBSs accounted for approximately 90.0% of the total number of small mutations. Among the eight treatment groups, FN irradiation at a dose of 19 Gy generated the highest number of mutations. The ratio of transition/transversion ranged from 1.77 to 2.21, and the G/C to A/T transition was the most common substitution in all mutant lines. The distributions of the identified SBSs and InDels were similar and uneven across the genome. An average of 3.63 genes were mutated in each mutant line, indicating that FN irradiation resulted in a suitable density of mutated genes, which can be advantageous for improving elite material for one specific or a few traits. These results provide a basis for the selection of the suitable dose of mutagen and new genetic resources for sorghum breeding.

Radiation shielding parameterizations of FeSO4, CuSO4, NiSO4 and ZnSO4 Compounds: using (XRF) technique & Monte Carlo FLUKA approach

The mass attenuation coefficient (MAC) for different sulphate compounds can be estimated by using the Energy Dispersive X-ray Fluorescence (EDXRF), also known as X-ray Fluorescence (XRF) technique. The X-ray photons emitted have different energies depending on incident photon energy, atomic weight, and molecular structure of tested material. The excitation energy of the gamma rays source with 59.53 keV was obtained by using 241Am (40 µci). The (MAC) for sulphate compounds of a different element (Fe, Ni, Cu, Zn) have been calculated by measuring the intensity difference for kα in pure elements and their compounds. The determined results showed that the maximum value for (µm) was in FeSO4. These results are consistent with the theoretical value obtained by the XCOM software in addition to investigating the wide energy response of photon interaction with the introduced compounds using the FLUKA Monte Carlo simulation software. The mass attenuation coefficient (MAC) of these compounds is numerically evaluated in the energy range 0.015-15 MeV using the FLAIR code. The computed (µm) is used to generate significant radiation protection factors such as the linear attenuation coefficient (LAC), half-layer value (HVL), effective (Zeff), and equivalent (Zeq) atomic number. For studying the shielding effectiveness and efficiency, for fast and thermal neutron radiation, the removal cross-section ƩR was given.

Comparative Transcriptomics of Soybean Genotypes with Partial Resistance Toward Phytophthora sojae, Conrad, and M92-220 to Moderately Susceptible Fast Neutron Mutant Soybeans and Sloan.

The breeding of disease-resistant soybeans cultivars to manage Phytophthora root and stem rot caused by the pathogen Phytophthora sojae involves combining quantitative disease resistance (QDR) and Rps gene-mediated resistance. To identify and confirm potential mechanisms of QDR toward P. sojae, we conducted a time course study comparing changes in gene expression among Conrad and M92-220 with high QDR to susceptible genotypes, Sloan, and three mutants derived from fast neutron irradiation of M92-220. Differentially expressed genes from Conrad and M92-220 indicated several shared defense-related pathways at the transcriptomic level but also defense pathways unique to each cultivar, such as stilbenoid, diarylheptanoid, and gingerol biosynthesis and monobactam biosynthesis. Gene Ontology pathway analysis showed that the susceptible fast neutron mutants lacked enrichment of three terpenoid-related pathways and two cell wall-related pathways at either one or both time points, in contrast to M92-220. The susceptible mutants also lacked enrichment of potentially important Kyoto Encyclopedia of Genes and Genomes pathways at either one or both time points, including sesquiterpenoid and triterpenoid biosynthesis; thiamine metabolism; arachidonic acid; stilbenoid, diarylheptanoid, and gingerol biosynthesis; and monobactam biosynthesis. Additionally, 31 genes that were differentially expressed in M92-220 following P. sojae infection were not expressed in the mutants. These 31 genes have annotations related to unknown proteins; valine, leucine, and isoleucine biosynthesis; and protein and lipid metabolic processes. The results of this study confirm previously proposed mechanisms of QDR, provide evidence for potential novel QDR pathways in M92-220, and further our understanding of the complex network associated with QDR mechanisms in soybean toward P. sojae.

A Review of the Effects of Fast-Neutron Irradiation on the Performance of 4H-SiC Schottky Barrier Detectors

A Review of the Effects of Fast-Neutron Irradiation on the Performance of 4H-SiC Schottky Barrier Detectors

Growth and characterization of 6LiI:Ag crystal scintillators for thermal and epithermal neutron detection on the lunar surface

This paper discusses crystal growth and characterization of 1.0-inch 6LiI:Ag scintillators for thermal and epithermal neutron detection on the lunar surface as part of the Lunar Vehicle Radiation Dosimeter project. Zone purification method was employed to purify the raw material of 6LiI, and the crystals were grown using the Bridgman method. X-ray luminescence spectrum was measured to confirm the presence of Ag+ in the crystal lattice of 6LiI. The feasibility of neutron detection under 252Cf fast neutron irradiation was investigated. A hydrogen-rich paraffin wax moderator was used to slow down fast neutrons to obtain thermal and epithermal neutrons. The charge comparison method was used to perform pulse shape discrimination. The maximum value of the Figure of Merit was obtained to be 1.3, which demonstrates the capability of using 6LiI:Ag crystal scintillators in high neutron and gamma mixed fields. The energy resolution of the thermal neutron peak varied with the thickness of scintillators, achieving 12.0 % for the 0.5 cm thick samples. The potential for further improvement of the scintillation performance of 6LiI:Ag crystal relies on reducing impurities and color centers.

Characterization of tracks from alpha-particles in PADC detectors for passive environmental monitoring of fast neutron radiation field

Fast neutron dosimetry is particularly crucial in the realm of radioprotection, as it significantly contributes to evaluating the radiation protection measures. This assessment aims to ensure and enhance the effectiveness of implemented safeguards and precautions, thereby minimizing the risks and potential harm associated with radiation exposure. Given the substantial biological damage that fast neutrons can inflict when interacting with living tissues, accurate dosimetry is indispensable for ensuring the safety of personnel in these environments and for optimizing radiation therapy treatments. Employing an indirect detector technique, this research focuses on characterizing the geometrical and optical properties of tracks produced by alpha particles resulting from boron-neutron reactions and distinguish them from the background made up of tracks generated from radon decay and impurities on the surface of the detector. This methodology holds potential utility particularly in situations where dosimeters are not adequately stored: while the idea of employing plastic or alternative materials to shield dosimeters from radon may appear straightforward, there are numerous factors complicating its effectiveness and universal applicability, for example when the radon proof encapsulations are not sealed perfectly. Through the development of a robust protocol for fast neutron dosimetry, we can not only differentiate between tracks produced by alpha particles of varying energy levels but also quantify the dose resulting from exposure to the neutron field. A solid-state nuclear track detector system (Politrack, Mi.am, Italy) was used to address the critical need for measuring exposure to fast neutrons, thermalized by polyethylene spheres. This advancement facilitates the implementation of more effective radioprotection strategies and contributes to the overall safety of radiation therapy procedures.

Mechanical and Architectural Changes in Animal Bone Following Fast Neutron Irradiation.

Damage to healthy bone following exposure to ionizing radiation has been well documented for at least seven decades. Among the reported effects are a transient increase in stiffness and a reduction in breaking strength. These changes have been linked to a decrease in osteoblast proliferation and differentiation, inducing cell cycle arrest, reducing collagen production, and increasing sensitivity to apoptotic agents. In this work, we analyzed some mechanical and structural changes in compact costal bovine bone (Hereford breed, n = 9) subjected to escalating doses of fast neutrons from a 7 Li(p,n) 7 Be reaction. The mean neutron energy was 233 keV with calculated absorbed doses ranging from 0 to 4.05 ± 10% Gy. Samples were subjected to Young's Modulus (YM) and breaking strength testing with a Universal Testing Machine (UTM). We found an increase in Young's Modulus and a decrease in breaking strength as functions of increasing dose equivalent. Optical coherence tomography (OCT) revealed trabecular displacement into compact bone in an irradiated sample (D = 4.05 ± 10% Gy), with breaching of the endosteal wall. OCT further revealed a "crack-like" structure across the irradiated sample, potentially consistent with damage from a proton track resulting from an elastic (n,p) reaction. No previous report has been found on mechanical changes in large mammalian bones following fast neutron doses, nor of the OCT imaging of such samples.

First-principles study on the effects of fast neutron irradiation and fast neutron irradiation under the external electric field on carbon-based material AB bilayer graphene

The irradiation damage mechanism of fast neutron irradiation and the fast neutron irradiation under the practical application of an additional electric field on carbon-based material AB bilayer graphene is not yet clear. This paper systematically investigates the impact of fast neutron irradiation and fast neutron irradiation under the practical application of the additional electric field (−0.2 V/Å) on carbon-based material AB bilayer graphene through density functional theory and molecular dynamics simulations. The research results indicate that the changes in the configuration of AB bilayer graphene and the appearance of surface ripples induced by fast neutron irradiation are the two main reasons for the alterations in the system's microstructure, band structure, Young's modulus, and optical properties, which may lead to performance degradation and damage of carbon-based devices. The further variation in the average interlayer spacing of the system under external electric field irradiation leads to the diversity of the system configuration, which ultimately leads to the diversity of the band structure of the system. The uncertainty in the type and width of the bandgap in AB bilayer graphene under fast neutron irradiation with an external electric field may be one of the reasons for the performance degradation and permanent damage of carbon based devices in practical applications. In the fast neutron irradiation environment, the precise control of the bandgap of AB bilayer graphene by an applied electric field will fail.

Germination, Physiochemical, and Morphology Changes of TR10 Rice Seeds Irradiated to Filtered and Unfiltered Neutron

In 2020, Sabah’s rice production was 117, 846 metric tonnes with a planted area of 40, 446 ha is relatively low compared to other states such as Selangor, which has 36,004 ha less planted area but can produce up to 159,535 metric tonnes more than Sabah. Low rice production in Sabah has contributed to the shortage of supply. Thus, new varieties could be needed that sufficiently produce yields that comparable to the efforts and cost of rice planting. One of the methods is producing new varieties that probably produce high yields using physical mutagen. From the literature available, gamma and neutrons were found to be the most common agents to increase rice production per unit planting area but used they were used separately. Theoretically, using fast neutron irradiation was found to produce a superior mutant. Thus, this paper aims to study the effect of rice seeds irradiated to both gamma and neutron simultaneous, and compare with neutron alone on the germination rates and physiochemical of rice seeds after the irradiations at different dosages. TR10 rice seeds were irradiated simultaneously to gamma and neutrons in the nuclear reactor core using Pneumatic Transfer System–PTS facility, while irradiation to neutrons alone was performed in a neutron chamber using Beam ports–BP facility at Nuclear Malaysia. The germination study shows a linear decrease as the irradiation doses increase in BP and fail to germinate in PTS. Yet, seeds irradiated in PTS showed no hazardous compounds and a remarkable increase in mineral content in seeds, particularly potassium and magnesium at 14 Gy. Similarly, to the shape of the starch granules in both facilities, the starch structure changes after being exposed to 14 Gy in PTS and 35 Gy in BP. As a result, seeds exposed to neutron alone induced considerably more inclusive effects and may raise growth performance and improve rice quality with optimal neutron dosage range from 7 to 14 Gy.

Waste to shield: Tailoring cordierite/mullite/zircon composites for radiation protection through controlled sintering and Y2O3 addition

In this study, investment casting shell waste successfully utilized to produce cordierite/mullite/zircon composites. Green pellets, consisting of investment casting shell waste, alumina, and magnesia, were prepared and sintered at temperatures between 1250 and 1350 °C. The influence of the sintering temperature on the crystalline phase composition, densification behavior, flexural strength, microstructure, and radiation shielding properties of the cordierite/mullite/zircon composites is investigated. Phase analysis showed that characteristic cordierite peaks appear at 1250 °C, but the complete conversation of silica from investment casting shell waste into cordierite requires a sintering temperature of at least 1300 °C. Notably, the cordierite/mullite/zircon composite sintered at 1350 °C exhibited a sixfold increase in flexural strength compared to the ceramic composite directly fabricated from investment casting shell waste at the same sintering temperature. Furthermore, the effect of Y2O3 addition on composites' radiation shielding properties is investigated. The results show that the Y2O3 addition improves densification behavior, enhancing the shielding capabilities of the composites against fast neutron and gamma radiation. Our findings suggest that the developed ceramic composites show significant potential for gamma-ray and neutron shielding applications.

A novel approach to enhance the ionic conductivity of silver nanoparticles incorporated PVA:NaBr polymer electrolyte films via fast neutron irradiation

This study investigates the unprecedented impact of fast neutron irradiation on the structural, electrical, and morphological properties of solid polymer electrolytes (SPEs). The SPE, a poly (vinylalcohol) (PVA)-sodium bromide (NaBr) based matrix with the incorporation of silver nanoparticles (AgNPs), was prepared via a solution casting method and subjected to various time intervals of fast neutron irradiation. X-ray diffraction (XRD) analysis revealed a distinct trend in the polymer electrolyte sample's amorphous phase, with decreased levels at lower neutron fluence and augmented levels at higher fluences. Fourier transform infrared (FTIR) spectroscopy highlighted plausible interactions leading to chain scission and cross-linking. Optical investgations below 300 nm exhibited increased absorbance and a shifted position of the surface plasmon resonance peak correlated with AgNPs. Validation of structural changes in the Ag-incorporated PVA-NaBr system was supported by reduced bandgap and elevation in Urbach energy, corroborating FTIR findings. Enhanced thermal stability was confirmed using thermogravimetric (TGA) analysis. Morphological modification upon irradiation were evident via Field emission scanning electron microscope (FESEM). Transport properties evaluated by Nyquist plot fitting showcased escalating room temperature conductivity with neutron fluence, and the highest conductivity obtained was 4.38 × 10−3 S/cm, an order higher than the pristine sample. Transference number measurements (TNM) indicated that the primary charge carriers are ions rather than electrons. This novel approach confirms that neutron irradiation can be used as a potential way to obtain highly conductive polymer electrolyte films.

Initiation of the Shape Memory Effect by Fast Neutron Irradiation

Initiation of the Shape Memory Effect by Fast Neutron Irradiation

Influence of a neutron beam on the electrical properties of nanosized Y2O3 crystals

In the presented work, high purity yttrium oxide (99.99%), nanosized crystal density 0.069 g/cm3, specific surface area 100-150 m2/g, average crystal size 8-10 nm and difrent intensities (4.0×10 12 n/cm2, 1.3×10 13 n/cm² and 4.0×10 14 n/cm²) in the temperature range of 300-700 K, the electrical properties were investigated after irradiation with fast neutrons. It has been established that the electrical properties of Y 2 O 3 nanocrystals in a wide temperature range show an increase in the electrical conductivity according to a linear law after irradiation of various intensities. The increase in conductivity depending on the intensity of fast neutron radiation is due to the predominance of yttrium vacancies in the conductivity.

Dielectric, conductivity properties, elastic moduli, and gamma-ray attenuation abilities: A wide-ranging investigation into Molybdenum added ferrite nanoparticles

The auto combustion technique was employed to synthesis magnesium nano ferrite (MgMoxFe2-xO4). The impact of Mo-doped on the crystal’s structural, morphological, and elastic properties were inspected by applying x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy techniques. Pursuant to the XRD analysis, all samples have a cubic structure with single-phase. The average crystallite size was identified to be in the nanometer range confirmed by SEM and TEM investigations. FTIR data was implemented to assign the force constants of the octahedral and tetrahedral sites. Elastic moduli including the Poisson ratio, Young’s modulus, bulk modulus, and rigidity modulus have been estimated. The division of elastic moduli for all synthesized concentrations was interpreted using binding forces between ions of the cubic lattice spinel. Over and above, the AC conductivity (σ AC) and dielectric properties and their frequency dependence were investigated for the nano ferrites samples as a function of dopant Mo content and temperature. Finally, the radiation shielding capacities of the proposed samples against gamma and fast neutron radiation have been assessed. The findings reveal that the higher the Mo content, the lower the value of the mass attenuation coefficient. There is no significant diversity between the obtained mass attenuation coefficients for the nano and the micro. Among the samples investigated in this study, the highest Mo concentration sample had the largest fast neutron removal cross-section.

Особенности изменения мощности излучения светодиодов на основе соединений AlGaInP под воздействием быстрых нейтронов

The results of the study on the degradation of AlGaInP red (630 nm) light-emitting diode parameters under fast neutron irradiation are presented. The study showed that in the region of LEDs, an uneven drop in radiation power is characterized, for high currents, a smaller decrease in power and a constant angle of inclination of the curve are characteristic, while in the region of low currents, with an increase in neutron fluence, the angle of inclination of the curve describing this process increases. A feature of the studied LEDs for short-circuit and breakage modes is the restoration of radiation power at the first stage of irradiation, which is explained by the relaxation of mechanical stresses during partial annealing of structural defects under the influence of low fluences.

Screening of Fast-Neutron Mutant Population to Identify Candidate Rice Blast Defense Response Genes

Rice is the most widely consumed staple food in the world, feeding over half of global population. Thailand has long been an important rice producer and exporter, ranked 6th in the world regarding total milled rice yield. Unfortunately, the major problem of rice production worldwide is rice blast disease which caused by the fungus Magnaporthe oryzae. The most effective method for managing rice blast disease is using resistant rice varieties. One of Thai rice variety that show highly resistance against various rice blast fungus isolates is Jao Hom Nin (JHN) rice, containing broad-spectrum resistance gene, Pi7. However, the identification of resistance genes other than the R gene will confer long-lasting and sustainable resistance to the plant, which lead to identification of genes involved in the plant’s defense against the rice blast fungus in this study. JHN were previously mutagenized with fast-neutron radiation. 2,200 JHN M4 lines were inoculated with mixture of five Thai rice blast fungus isolates. Five susceptible lines lost their resistance due to mutations in the Pi7 gene, while one susceptible line with an intact Pi7 gene could not be characterized as it failed to produce an F1 population. Two moderate resistance lines with intact Pi7 gene were sent for whole-genome resequencing along with JHN wildtype. The sequence comparison between JHN and two mutant lines revealed 491,759 Indel variants. The Indel variants, whose nucleotide sequences differed by less than 10 bp between JHN and mutants, were filtered out. Consequently 33 candidate rice blast defense response genes were predicted to contain high-impact effect Indels, with only 15 of them having predicted functions. Eleven genes were identified as transposons or retrotransposons. Four genes with predicted functions stand out as interesting candidates for future characterization.

Utilization of investment casting shell waste in the production of cordierite-mullite-zircon composites for radiation shielding: The influence of La2O3 additive

Cordierite-mullite-zircon ceramic composites were produced via reaction sintering of investment casting shell waste, Al2O3, and MgO at 1350 °C. The influence of La2O3 addition on the crystalline phase composition, microstructure, densification behavior, mechanical strength, and radiation shielding capabilities of the cordierite-mullite-zircon composites has been investigated. The X-ray diffraction (XRD) analysis confirmed the successful synthesis of cordierite-mullite-zircon composites with up to 5 wt% La2O3 additive content. However, a higher La2O3 content, exceeding 7 wt% resulted in cordierite decomposition. Furthermore, the addition of La2O3 significantly enhanced the densification behavior and microstructural development, leading to improved flexural strength and enhanced shielding against fast neutron and gamma radiation. This research suggests the potential of the fabricated ceramic composites derived from investment casting shell waste for applications in radiation shielding.