60Co Gamma Radiation Research Articles

Effect of gamma-radiation on the transmission and return losses of FC/APC connectors

The Fibre Optics Current Sensor (FOCS) installed at ITER will use optical fibres to perform plasma current measurements based on the Faraday effect. A connection between the sensing fibre placed on the Vacuum Vessel and the fibre guiding the signal to the data-acquisition hardware will be required. Because of practical reasons, this link contains FC/APC connectors, which guarantee the low return loss required for normal operation of the FOCS. The connectors will be located in the port cell area and will be subject to high levels of nuclear radiation. Radiation may influence both transmission and return losses of the FC/APC connectors and, as a result, degrade the FOCS performance. To address the problem, several FC/APC connectors were exposed to Co60 gamma radiation up to a 550 kGy dose. Transmission through the connectors was monitored during irradiation. The return loss of mated FC/APC connectors was measured before and after irradiation. It was found that radiation-induced changes of both transmission and reflection parameters are acceptable for the FOCS at ITER.

Effects of athermal carrier injection on Co-60 gamma-ray damage in SiC merged-PiN Schottky diodes

Co-60 gamma irradiation of SiC merged-PiN Schottky (MPS) diodes up to fluences of 1 Mrad (Si) produces increases in both forward and reverse current, with less damage when the devices are biased during irradiation. Subsequent injection of minority carriers by forward biasing at 300 K can partially produce some damage recovery, but at high forward biases also can lead to further degradation of the devices, even in the absence of radiation damage. Recombination-enhanced annealing by carrier injection overall is not an effective technique for recovering gamma-induced damage in SiC MPS diodes, especially when compared to other near athermal methods like electron wind force annealing.

Behavior of uranium(VI) in the presence of a geomaterial: an aquifer sediment

Sediments from aquatic environments can be contaminated with uranium from natural and anthropogenic sources; the behavior of U(VI) was investigated in two natural (SPT and DS) and gamma-irradiated (SPT-I) aquifer sediments in batch systems. Sediments were characterized, and quartz, albite, and kaolinite were mainly found in both sediments by X-ray diffraction. The points of zero charge were 5.4, 5.3, and 5.5, and the organic matter percentages were 48.0, 46.0, and 4.7% for SPT, SPT-I, and DS, respectively. Uranyl nitrate solutions were put in contact with each sediment considering different parameters (pH, contact time, initial concentration of uranium, and temperature). DS sediment did not adsorb any quantity of uranium at different pH values; SPT and SPT-I, attained the highest q e values at pH 3.5–4. The results show chemisorption on homogenous materials and endothermic processes. Desorption behavior of U(VI)/SPT showed a hundred percent desorption with nitric acid and humic acid solutions; in the last case, it is due to the high stability constant of the complex of uranium with the humic acids. The results help to understand the contamination and decontamination processes of sediments with uranium, the bioavailability of uranium, the ecological risk of U-contaminated sediments, and remediation. Doses of 1 MGy of Co-60 gamma radiation did not affect the uranyl ions behavior in the aquifer sediment.

Impact of Co-60 γ-ray irradiation on the cross-linking and stability of fish collagen: Structural changes and digestibility

Irradiation can promote the cross-linking of collagen to enhance its biological properties, but the molecular changes in irradiated collagen have few been investigated. This study aimed to explore the impact of irradiation treatment on the molecular structure stabilization and cross-linking degree of skin collagen. The results showed that collagen in solution was more susceptible to Co-60 gamma irradiation than that in fish skin and in sponge forms. The solubility of collagen in solution decreased by more than 80% and the carbonyl content increased by more than 4 times compared with the control group after 12 kGy irradiation. Spectroscopic analysis and sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) showed that collagen in solution was cross-linked, especially at high irradiation doses. However, the triple helical structure of skin collagen and collagen sponge remained intact. Furthermore, irradiation also reduced the sensitivity of collagen to collagenase. Gastrointestinal digestion results showed that the antioxidant activity of collagen increased at 1–3 kGy doses and decreased at 9–12 kGy doses. Collagen irradiated at high doses (9–12 kGy) was more difficult to digest and had a larger average particle size. This study provides a potential new approach for the preparation of stable fishery-derived collagen with excellent antioxidant activity and resistance to digestion by irradiation treatment.

Synthesis of silver nanoparticles embedded on silica by gamma irradiation for utilization as antimicrobial agents

Silver nanoparticles deposited on silica (Ag nano/SiO2) have been prepared by Co-60 gamma irradiation of the mixture Ag+/SiO2/H2O/ethanol. The reduction of Ag+ in the suspension of SiO2 is brought by e-aq and H· generated during the radiolysis of water/ethanol solution. The presence of SiO2 prevents agglomeration of Ag clusters. The conversion dose (Ag+® Ag0) was determined by UV-Vis spectroscopy. Transmission electron microscopy (TEM) characterized the size of Ag nanoparticles. As a result, the particle sizes were determined to be in the range of 5-20 nm for an Ag+ concentration of 5 mM. The crystal structure of silver nanoparticles was also investigated by X-ray diffraction (XRD). In addition, the antifungal activity of Ag nano/SiO2 was tested against Aspergillus niger var Tieghn by plate count method. The results indicated that the antifungal efficiency of Ag nano/SiO2 was about 64, 71, 81, 82, and 96% at the concentrations of Ag nanoparticles of 30, 50, 70, 100, and 150 ppm, respectively.

Creating a novel genetic diversity of Trichoderma afroharzianum by γ-radiation for xylanase-cellulase production

Creating novel sources of a microbial strain using induced mutation can increase enzyme production for industrial use. According to this, we have developed a mutant strain of Trichoderma afroharzianum by Co60 gamma irradiation. Trichoderma mutants were isolated from an optimum dose of 250 Gy. The qualitative and quantitative screening were used for evaluating their enzyme production and the DNA barcoding method was used to identify the best Trichoderma mutant isolates. The highest cellulase (exo-glucanase, endoglucanase, β-glucosidase, and total cellulase) and xylanase activities were observed in superior mutant isolates of Trichoderma afroharzianum NAS107-M44 and Trichoderma afroharzianum NAS107-M82, which is approximately 1.6–2.5 times higher than its parent strain, respectively. The electrophoretic pattern of proteins showed that the exo-glucanase I, endo-glucanase III, and the xylanase I enzymes hydrolyzed the corn bran, synergistically. Overall, gamma irradiation-induced mutation could be an expedient technique to access such superior mutants for the bioconversion of corn bran wastes.

Co60 gamma irradiation reduces rooting ability in M1V1 Salvia uliginosa while inducing leaf variegation

Purpose Salvia uliginosa is a desirable ornamental shrub for the landscape with blue flowers and the ability to attract pollinators, but limited variation is commercially available in this species. Mutation breeding is a valuable tool to induce variation in ornamental species. However, many deleterious effects are associated with mutation breeding, including reduced rooting ability of vegetative cuttings. Materials and methods Cuttings of S. uliginosa were randomly assigned into groups of 10 and exposed to 0, 10, 20, 30, 40, or 50 Gy of gamma rays from a cobalt-60 source to determine an appropriate treatment rate. A follow-up experiment treated 25 S. uliginosa cuttings at 35 Gy to induce favorable mutations. Results and conclusions Root quality, survival, and plant height were reduced at higher levels of gamma radiation in the M1V1. However, rooting ability was not impacted in M1V2 selections. Additionally, one mutant was isolated from the 35 Gy treatment with variegated leaves for a mutation rate of 4%. Our research determined a treatment rate that induced a dominant mutation in S. uliginosa while minimizing the deleterious influence of gamma radiation.

Effect of Co-60 Gamma Irradiation on the Fluxgate Sensor’s Cores

Zayıf manyetik alan ölçümleri için kullanılan fluxgate sensörler uzay ortamındaki çevresel faktörlerden oldukça fazla etkileniyor olsa da uzay görevlerinde kanıtlanmış performansları ve güvenilirlikleri dolayısıyla oldukça yaygın tercih edilirler. Çevresel faktörler uzay araçlarının görevini kısmen ya da tamamen engelleyebilecek büyük sorunlara neden olacağından, bu çalışmada çevresel faktörlerden biri olan radyasyonun sadece sensör nüvesi üzerinde etkileri incelenmiştir. Üç farklı dozda Gama radyasyona maruz bırakılan nüvelerin karakterizasyon ölçümleri yapılmıştır. Hassasiyet ölçümlerinden elde edilen ölçek faktörlerinin çok az farkla birbirlerine yakın olduğu görülmüştür. Ayrıca yapılan gürültü analizlerinden artan radyasyon miktarıyla gürültü seviyesinin ise nT mertebesinde arttığı gözlenmiştir.

Radiation crosslinking and grafting of chitosan: Conversion of biowaste to an efficient adsorbent for removal of cationic dyes

By the mutual radiation grafting technique using Co60 gamma radiation, a novel anionic adsorbent “CRChitosan-g-SSS” was developed where in p-Sodium Styrene Sulphonate was covalently grafted onto crosslinked chitosan backbone. The synthesized radiation-grafted adsorbent was tested for the adsorptive removal of cationic dyes: methylene blue, malachite green and Congo red from aqueous solutions. The adsorbed amount of the respective dyes was 89.12, 73.13, and 29.14 (mg/g) respectively, which could be better described with Langmuir isotherm and pseudo-second-order reaction according to the correlation coefficient values, indicating favorable and feasible adsorption. Various factors influencing the adsorption capacity of“CRChitosan-g-SSS” like initial dye concentration, contact time, solution pH, and temperature were also studied. Different thermodynamic parameters such as standard free energy, standard enthalpy, and standard entropy were calculated which revealed the adsorption process to be exothermic and spontaneous. The radiation-grafted anionic adsorbent showed promising properties for the removal of toxic cationic dyes (i.e. Methylene blue, Malachite green, and Congo red).

Radioadapted Response Early Effects and Late Effects on Survival of White Blood Cells in Mice (Mus musculus L) Post C0-60 Gamma Radiation

Aims: Determine the radioadapted response to the early and late effects of white blood cells in mice after Co-60 gamma radiation. Furthermore, the effect of the radioadapted early and late effects of the radioresponse with the interval dose adaptation (DA) with the challenge dose (DC) to the white blood cells of mice, as well as the survival rate of mice white blood cells after gamma Co-60 radiation through the radio-adapted response of the early effect and the late effect.
 Place and Duration of Study: The Radioteraphy Installation in Prof. I.G.N.G. NGOERAH Hospital, between from August to October 2022.
 Methodology: This research used a low-dose method (adapted-DA dose) and at certain time intervals was continued with a larger dose (dose challenge-DC) in mice with six treatments and one as a control. From each treatment, mice's white blood cells were taken to determine the number of leukocytes and their components. Through the number of leukocytes, it is possible to analyze the radio-adaptated response to the early effect and the late effect, so that thesurvival rate of whiteblood cells inmice after gamma Co-60 radiation can be determined.
 Results: The results of research on the survival of leukocyte cells, neutrophils, and lymphocyte cell components show early-responding tissue and late-responding tissue. As for cell survival, other componentssuch asmonocytes, eosinophils, andbasophils did not respond in the same way after gamma Co-60 radiation. In general, giving a time delay to the challenge dose for all radiation dose treatments gives a fast response (early effect) to cell survival within a few days after radiation, then with time the full response that occurs is a slow (late effect). The longer the delay in giving the challenge dose, the slower the response will fully occur in the tissue after gamma Co-60 radiation. The cell survival curve also shows that the α/β ratio for the early effect is 3 and for the late effect is 10, which is an illustration of the early effect on radiation, with a linear shape of the cell death curve indicating that tissue is more sensitive to changes in radiation dose and has a greater α/β ratio. When compared to the tissue with a late effect on radiation, the tissue has a smaller α/β ratio indicating that the tissue is less sensitive to changes in the timing of the challenge dose.
 Conclusion: Radioadapted response to the survival of leukocytes, neutrophils cell components, and lymphocytes have shown early responding tissue and late responding tissue after gamma Co-60 radiation. By giving a time lag for the challenge dose, an early response to cell survival occurs for only a few days, then with time, fully the response that occurs is late responding.

Extreme γ-Ray Radiation Tolerance of Spectrometer-Grade CsPbBr3 Perovskite Detectors.

The perovskite compound CsPbBr3 has recently been discovered as a promising room-temperature semiconductor radiation detector, offering an inexpensive and easy-to-manufacture alternative to the current benchmark material Cd1-x Znx Te (CZT). The performance of CsPbBr3 sensors is evaluated under harsh conditions, such as high radiation doses often found in industrial settings and extreme radiation in space. Results show minimal degradation in detector performance after exposure to 1Mrad of Co-60 gamma radiation, with no significant change to energy resolution or hole mobility and lifetime. Additionally, many of the devices are still functional after being exposed to a 10Mrad dose over 3 days, and those that do not survive can still be refabricated into working detectors. These results suggest that the failure mode in these devices is likely related to the interface between the electrode and material and their reaction, or the electrode itself and not the material itself. Overall, the study suggests that CsPbBr3 has high potential as a reliable and efficient radiation detector in various applications, including those involving extreme fluxes and energies of gamma-ray radiation.

Should the ISO slab phantom be used for calibrations in terms of the new ICRU 95 operational quantity personal dose?

The applicability of the ISO slab phantom as calibration phantom for the new ICRU report 95 quantity personal dose should be legitimated by simulations and measurements of backscatter factors on the ISO slab phantom and, comparatively, on a human-like Alderson Rando phantom. An ionization chamber was used to determine backscatter factors for standardized X-ray spectra in the energy range of 16-250keV and for gamma radiation of 137Cs (662keV) and 60Co (1250keV). For the validation of measurement results on the ISO slab, the results were compared with those obtained by means of Monte Carlo simulations using MCNP 6.2. Since the deviations of the backscatter factors on the ISO slab from those on the Alderson Rando were within ±5%, it could be concluded that it is not necessary to develop a new calibration phantom for the assessment of personal dose.

Improvement in the aged silicon solar cells parameters by thermal annealing

In this paper, to simulate and accelerate the effects of aging, solar cells were exposed to the different doses of co60 gamma radiation. The current–voltage (I–V) characteristics of mono-crystalline solar cells under AM1.5 illumination condition were studied before and after the gamma irradiation. Experimental results showed that the solar cell parameters such as open circuit voltage (Voc), short circuit current (Isc) and efficiency (η) decrease with the increase of the gamma radiation doses. The effect of subsequent thermal annealing on solar cells degraded by gamma irradiation is investigated. A significant improvement in the electric parameters of by low doses gamma irradiated silicon solar cells is observed after the thermal annealing.

Effects of Co-60 gamma radiation on the characteristics of red, green, and blue LEDs

Red, Green and Blue LEDs are irradiated by Co-60 gamma radiation at the doses ranging from 1.8 kGy to 172.8 kGy. Effects of these radiation doses on the I-V and Intensity-Power characteristics of RGB LEDs are examined. I-V characteristics shows only marginal variations, however, significant reduction in output intensity is observed at the maximum dose level of 172.8 kGy. We attribute this optical intensity degradation to radiation induced decrease in the minority carrier lifetime, displacement damage and radiation induced defects

A gamma radiation scene image clarification method based on spatiotemporal combination

For the problems of complex noise and color cast in the images captured by complementary metal oxide semiconductor image sensors in the gamma radiation environment, this paper proposed a joint temporal correlation denoising and color cast correction approach for the gamma radiation scene image clarification. Concretely, we first adaptively stretch the difference between noise and background to improve the salience of weak noise, making noise detection results more accurate. Secondly, the temporal transient characteristics of gamma radiation noise are utilized for noise detection, and these noisy pixels are repaired by exploiting the temporal correlation characteristics of background pixels. Lastly, the Bayer-Guided auto white balance method is proposed to solve the problem of dysregulated color in the gamma radiation scene image, and the color level remapping approach is applied to eliminate the problem of insufficient dynamic range. Extensive experiments are carried out on the images captured from the Co60 gamma radiation scene. Compared with the source images, our method improves the peak signal to noise ratio by 6.3(dB) and structural similarity by 0.34. Experimental results demonstrate that the proposed method enjoys state-of-the-art performance in improving the clarity of gamma radiation scene images.

A Study on Shield Design Aspects of a Semi-Industrial Co-60 Gamma Irradiation Facility at Gamma Source Division of Institute of Food and Radiation Biology of the Bangladesh Atomic Energy Commission

The aim of this work is to investigate the existing shield design aspects of a semi-industrial Cobalt- 60 Gamma Irradiation Facility for 100 kCi, designed for irradiation of pharmaceutical products and daily foodstuffs as well as for research and development purposes at the Institute of Food and Radiation Biology (IFRB) of the Bangladesh Atomic Energy Commission. Earlier, the initial activity of this facility was 65 kCi and stone based reinforced concrete (SBRC) of density 2.60 g/cc and specific thicknesses were used to shield the facility for safety to operational personnel and outside public. Due to a large demand for irradiation of pharmaceutical products as well as of daily foodstuffs, IFRB has decided to increase the initial activity up to 100 kCi for this facility. For this reason, the shielding design aspects of this facility were needed to be recalculated and checked for safety. This analysis was done using the Point-kernel Shielding Code Micro-Shield 5.05 and public domain Point-kernel Shielding code QAD-CGGP2 respectively considering the radiation worker dose limit of 10 μSv/hr of the International Commission on Radiological Protection, ICRP-60, 1990. The corresponding dose limit for public at large is 0.5 μSv/hr. The calculated dose rates at different locations around the facility are far below 10 μSv/hr except in one area. This location is inside the source room. No one is allowed to enter the room when the facility is in the ON mode. However, except one location, positions outside the facility have dose rates about 3 time higher than 0.5 μSv/hr, the dose limit for public at large. Therefore, this analysis shows that the existing shield design aspects of IFRB’s Co-60 gamma source room is safe for a 100 kCi source from the viewpoint of radiation safety to operating personnel but not for public at large within proximity of the facility.
 Bangladesh Journal of Medical Physics Vol.15 No.1 2022 P 1-7

DETECTION OF IRRADIATED BLACK SEED AND POPPY SAMPLES BY OSL TECHNIQUE

Bu çalışmada, farklı markalara ait ışınlanmış çörek otu ve haşhaş örneklerinin hızlı, kolay ve ucuz tespiti için OSL (Optik Uyarmalı Lüminesans) okuyucunun kullanım potansiyeli mavi ışık uyarımı altında araştırıldı. Yerel marketlerden her bir gıda için üç farklı marka seçildi ve her marka gıda 1 kGy, 3 kGy, 5 kGy ve 7 kGy dozlarında Co-60 gama radyasyonu ile ışınlandı. Her bir doz için OSL sinyal şiddetleri hem ışınlamadan hemen sonra hem de ışınlamadan bir yıl sonra ölçüldü. Işınlanmayan örneklerin hiçbirinde OSL sinyali gözlenmezken, ışınlamadan sonra tüm örneklerin OSL sinyal şiddetlerinde önemli bir artış gözlendi. Ayrıca bazı haşhaş ve çörek otu markalarından elde edilen OSL sinyal şiddetlerinin, ışınlamadan bir yıl sonra dahi ışınlamanın belirlenmesine imkân verecek kadar yüksek olduğu belirlendi.

Effects of ionizing radiation decontamination on botanical collections in herbaria

Herbaria collections are very sensitive to attacks from microorganisms and insects. Therefore, preservation strategies and appropriate treatments are essential to manage these artifacts. Decontamination by ionizing radiation has become an effective strategy to preserve cultural heritage objects and archived materials, achieving excellent results. Therefore, this work aimed to study the effects of Co-60 gamma radiation on botanical collections. To accomplish this, samples of exsiccates, including botanical pressed and dehydrated specimens from Asteraceae and Solanaceae families, collected on diferentes dates were selected from the Dom Bento José Pickel Herbarium (SPSF), located in São Paulo (Brazil). Irradiation was performed at the Multipurpose Gamma Irradiation Facility at IPEN, applying absorbed doses of 1 kGy, 6 kGy and 10 kGy. Gamma radiation effect was analyzed using colorimetry with CIELAB color space scale, scanning electron microscopy (SEM) and attenuated total reflectance with Fourier transform infrared (ATR-FTIR) spectroscopy. Results showed no significant colorimetric changes, or changes in the morphological properties of samples, indicating that this decontamination method can be used as an alternative treatment to eliminate insects and micro-fungi of botanical collections without the use of toxic substances.

Co-60 gamma irradiation induced ovalbumin-glucose glycation and allergenicity reduction revealed by high-resolution mass spectrometry and ELISA assay

Ovalbumin (OVA)-glucose mixture was treated with Co-60 irradiation at 0–25 kGy, and effects of irradiation on the glycation and allergenicity of OVA were investigated. Irradiation induced glycation between OVA and glucose, reflected in the significant increase of glycation sites from 3 to 14. Interestingly, OVA irradiated at 25 kGy had three new glycated peptides (568.782+, 739.382+ and 509.752+). The degree of substitution per peptide molecule (DSP) of glycated peptides exhibited different trends with increasing irradiation dose. Particularly, glycated peptides 17–26, 55–60, 263–267 and 368–375 showed markedly decreased DSP values after irradiation at 20 and 25 kGy, which could be caused by the generation of Maillard reaction products (MRPs). MS/MS spectra suggested that neutral loss occurred in glycated arginine, whose structure was similar to MRPs. The IgG- and IgE-binding abilities of OVA significantly decreased with increasing irradiation dose, indicating that the protein allergenicity was reduced.

Graphite ionization chamber as an ionometric standard of absorbed dose to water for Co-60 gamma radiation

In the paper GUM-Dw3 graphite-walled cylindrical cavity ionization chamber (of design and volume typical for the chambers for radiation therapy dosimetry) was presented as a realization of an ionometric standard for absorbed dose to water. A state-of-the-art uncertainty budget and results of comparison to GUMs standards has been presented. Good agreement of absorbed dose to water with reference standard, with relative deviation of 0.28%, and standard uncertainty (k=2) of 0.48% indicates good quality of the GUM-Dw3 as a primary standard. This paper describes the step-by-step procedure to calculate a perturbation factor, that is a crucial issue for ionometric measurement of absorbed dose to water. Capabilities of FLUKA code for this factor determination have been also investigated.