Irradiation System Research Articles

Development of an automatic evaluation system for photooxidation and assessment of polyethylenes containing HALS and UVA

An automatic evaluation system for photooxidation has been developed by utilizing a chemiluminescence apparatus combined with a light irradiation system. The system is composed of a controller, a driving device, and irradiation equipment, which are integrated with the chemiluminescence measurement system. Various measurement conditions can be set independently, including irradiation time (fixed or variable), waiting time from irradiation to measurement, chemiluminescence measurement time, number of repetitions (up to 999 times), and measurement temperature. LLDPEs containing Hindered Amine Light Stabilizers (HALS) and Ultraviolet Absorbers (UVA) were evaluated using this system. The decay of chemiluminescence after UV irradiation was repeatedly measured at r.t. and 105℃, respectively, below the melting point of LLDPE, and the time-course of chemiluminescence was obtained by plotting time against I(t = 0) for each instance. I(t = 0) represent the rate of photooxidation under UV exposure, calculated using second-order analysis of the chemiluminescence decay. The chemiluminescence intensity increased significantly in the initial stage with irradiation time, maintained a stable intensity for a period, and then exhibited a substantial increase in the later stage. We termed the point at which this significant increase in chemiluminescence occurs as the induction time of photooxidation (photo-OIT). Using this system, the photo-OIT of LLDPE samples with HALS and UVA was measured, revealing the potential for assessing the synergistic effects of photooxidation stabilizers.

Low-cost, 3D printed irradiation system for invitro photodynamic therapy experiments.

The development of a suitable irradiation setup is essential for invitro experiments in photodynamic therapy (PDT). While various irradiation systems have been developed for PDT, only a few offer practical and high-quality setups for precise and reproducible results in cell culture experiments. This report introduces a cost-effective illumination setup designed for invitro photodynamic treatments. The setup consists of a commercially available light-emitting diode (LED) lamp, a cooling unit, and a specially designed 3D-printed enclosure to accommodate a multiwell plate insert. The LED lamp is versatile, supporting various irradiation wavelengths and adjustable illumination fields, ensuring consistent and reliable performance. The study evaluates the setup through various parameters, including photon flux density, illumination uniformity, photon distribution across the multiwell plate, and temperature changes during irradiation. In addition, the effectiveness of the LED-based illumination system is tested by treating mouse mammary breast carcinoma cells (4T1) with Rose Bengal and LED irradiation at around 525 nm. The resulting IC50 of 5.2 ± 0.9 μM and a minimum media temperature change of ca. 1.2°C indicate a highly promising LED-based setup that offers a cost-effective and technically feasible solution for achieving consistent, reproducible, and uniform irradiation, enhancing research capabilities and potential applications.

Performance Assessment and Analysis of a 1 MW Three-Phase Photovoltaic Power Station Connected to a Factory’s Electrical Grid in Morocco

In this study, a performance assessment and analysis of a 1 MW three-phase photovoltaic (PV) power station connected to the electrical grid of a factory in Morocco are presented. The main objective of this research is to assess the performance of the PV power station and analyze its efficiency, energy generation, and operational characteristics. To accomplish this, a combination of field measurements, data analysis, and simulation techniques are used. The study begins by providing an extensive overview of the PV power station, including a thorough description of its main elements such as solar panels, inverters, transformers, and grid interconnection infrastructure. Furthermore, field measurements are conducted to collect data on solar irradiance, ambient temperature, and PV system power, as well as electrical parameters such as voltage, current, and power factor. The findings of this study provide valuable insights into the performance and economic viability of the PV power station. These insights can serve as guidance for renewable energy stakeholders, investors, and policymakers, facilitating the development of sustainable solar energy projects and contributing to renewable energy targets.

The COX-2/PGE2 Response Pathway Upregulates Radioresistance in A549 Human Lung Cancer Cells through Radiation-Induced Bystander Signaling.

This study aimed to determine the mechanism underlying the modulation of radiosensitivity in cancer cells by the radiation-induced bystander effect (RIBE). We hypothesized that the RIBE mediates cyclooxygenase-2 (COX-2) and its metabolite prostaglandin E2 (PGE2) in elevating radioresistance in unirradiated cells. In this study, we used the SPICE-QST microbeam irradiation system to target 0.07-0.7% cells by 3.4-MeV proton microbeam in the cell culture sample, such that most cells in the dish became bystander cells. Twenty-four hours after irradiation, we observed COX-2 protein upregulation in microbeam-irradiated cells compared to that of controls. Additionally, 0.29% of the microbeam-irradiated cells exhibited increased cell survival and a reduced micronucleus rate against X-ray irradiation compared to that of non-microbeam irradiated cells. The radioresistance response was diminished in both cell groups with the hemichannel inhibitor and in COX-2-knockout cells under cell-to-cell contact and sparsely distributed conditions. The results indicate that the RIBE upregulates the cell radioresistance through COX-2/PGE2 intercellular responses, thereby contributing to issues, such as the risk of cancer recurrence.

Stimulating the amorphous structure of Fe56Co24Nb4B13Si2Cu1 ferromagnetic alloy by thermal annealing, laser and electron beam irradiation: A Mӧssbauer spectroscopy investigation

This study presents a Mӧssbauer spectroscopy investigation of the Fe56Co24Nb4B13Si2Cu1 amorphous ferromagnetic alloy in the as-quenched state and after thermal annealing, laser and electron beam irradiation. Thermal treatment at temperatures of 450–750° C caused nano, partial and complete crystallization of the alloy system. Crystalline phases such as α-(FeCo), (FeCo)2(BSi) and (FeCo)3(BSi) were identified in the thermally annealed specimens. By analyzing the hyperfine magnetic field distributions, it was shown that continuous wave (cw) CO2 laser irradiation of fresh samples determined a more pronounced in-plane orientation of magnetic moment directions and caused changes in the chemical short-range order in the system with non-zero magnetostriction. For direct comparison, atomic rearrangements were not observed in the Fe68.5Co5Nb3Cu1Si15.5B7 ferromagnetic alloy having a zero magnetostriction constant. Unlike the case of laser annealing, irradiation with 11 GeV electrons of the Fe56Co24Nb4B13Si2Cu1 alloy determined a pronounced out-of-plane magnetic anisotropy and supported the formation of stress centers in the irradiated system. Both laser and electron beam irradiation were found to essentially preserve the amorphous phase of the processed alloy.

Development of proton beam irradiation system for the NA65/DsTau experiment

Tau neutrino is the least studied lepton of the Standard Model (SM). The NA65/DsTau experiment targets to investigate Ds , the parent particle of the ντ , using the nuclear emulsion-based detector and to decrease the systematic uncertainty of ντ flux prediction from over 50 % to 10 % for future beam dump experiments. In the experiment, the emulsion detectors are exposed to the CERN SPS 400 GeV proton beam. To provide optimal conditions for the reconstruction of interactions, the protons are required to be uniformly distributed over the detector's surface with an average density of 105 cm-2 and the fluctuation of less than 10%. To address this issue, we developed a new proton irradiation system called the target mover. The new target mover provided irradiation with a proton density of 1.01 × 105 cm-2 and the density fluctuation of 1.9 ± 0.3% in the DsTau 2021 run.

Surface Activated Si-Si Wafer Bonding Using Different Ion Species

Surface activated bonding on wafer level is enabled by an advanced direct wafer bonding system for irradiation with different ion species. In this process, the native oxide of 200 mm Si wafers is sputter-removed and an amorphous layer is generated. After ion treatment, the wafers are bonded in ultra-high vacuum at room temperature. The impact of Ar, Kr and Xe ion irradiation on the amorphous layer thickness was investigated with the goal of optimizing the bonding process for establishing interfaces with electronic functionality. This was i.a. motivated by the fact, that the presence of an amorphous layer reduces the electrical conductivity across the wafer interface.

Simulation of ranges and sputtering of low energy Helium and Argon ions irradiation on Tungsten surface

The interactions of low energy He and Ar ions with pure W target were simulated by a new Monte-Carlo (MC) based computer code which was designed to insure maximum accuracy. For these irradiation systems, incident ions projected ranges in the target material, sputtering yield, and the percentage of backscattered ions at various incident energies were studied. furthermore, the effect of the angle of incidence on sputtering yield and the percentage of backscattered ions were also simulated. Our simulation results were compared with experimental data and those calculated by the TRIM simulation program. Our code is based on an algorithm that uses detailed numerical solutions for the classical scattering integral for evaluating the binary collision process. This approach has provided sputtering yield data with a higher level of accuracy compared to TRIM's simulation results. Also, a new approach of using a reduced atomic displacement threshold in the top surface monolayer enhances the simulation results in the near sputtering threshold energy range and eliminates its dependence on the selected value of the displacement energy threshold Ed. Nonetheless, both simulation programs produced less contrasting results in terms of incident ions mean projected ranges. Furthermore, fundamental discrepancies in the percentage of backscattered ions between the results of both simulation programs were found.

Development of a low energy ion irradiation system for erosion test of first mirror in fusion devices

A low energy ion irradiation system based on the deuterium arc ion source with a high perveance of 1 μP for a single extraction aperture has been successfully developed for the investigation of ion irradiation on plasma-facing components including the first mirror of plasma optical diagnostics system. Under the optimum operating condition for mirror testing, the ion source has a beam energy of 200 eV and a current density of 3.7 mA/cm2. The ion source comprises a magnetic cusp-type plasma source, an extraction system, a target system with a Faraday cup, and a power supply control system to ensure stable long time operation. Operation parameters of plasma source such as pressure, filament current, and arc power with D2 discharge gas were optimized for beam extraction by measuring plasma parameters with a Langmuir probe. The diode electrode extraction system was designed by IGUN simulation to optimize for 1 μP perveance. It was successfully demonstrated that the ion beam current of ∼4 mA can be extracted through the 10 mm aperture from the developed ion source. The target system with the Faraday cup is also developed to measure the beam current. With the assistance of the power control system, ion beams are extracted while maintaining a consistent arc power for more than 10 min of continuous operation.

Research on the shielding performance of concrete in a 60Co irradiation environment

The 60Co irradiation system used in this study created a γ environmental space. A type of cylindrical concrete shielding container with a cavity was used. The ratio of γ radiation that penetrated the shielding concrete was examined and compared to the results from the straight-line penetration tests. The outcomes demonstrated that barite concrete improved the linear attenuation coefficient by 13–18% compared to normal concrete regardless of whether the environmental method or linear 60Co irradiation method was used. The environmental method was used to determine the shielding ability of concrete in three dimensions, while the linear method was used to obtain the shielding rate from γ radiation in a single direction. The environmental 60Co radiation shielding method was more consistent with the γ diffusion model of an actual nuclear engineering design. This research is beneficial to the control of γ diffusion in nuclear engineering.

New developments for theranostic radioisotope production with solid targets at the Bern medical cyclotron

The concept of theranostics in nuclear medicine is based on the use of a pair of radioisotopes to label radiopharmaceuticals for both diagnosis and therapy and is essential for nuclear medicine developments. The production of novel medical radioisotopes using solid target stations is challenging and new instruments and methods are needed. A research program is ongoing at the 18 MeV Bern medical cyclotron, equipped with a Solid Target Station and a 6.5 m Beam Transfer Line ending in a separate bunker. To irradiate isotope-enriched materials in form of compressed powder pellets, a novel target coin was conceived and realized together with methods to assess the beam energy and the production cross sections. To optimize the irradiation procedure, a novel ultra-compact active irradiation system based on a specific magnetic lens and a two-dimensional beam detector was conceived, constructed and tested. The system allows to control on-line the size and position of the beam and to correct its characteristics by steering and focusing it in order to keep it on target. The first results on the production of several radionuclides (43Sc, 44Sc, 47Sc, 61Cu, 64Cu, 67Cu, 68Ga, 165Er, 165Tm, 167Tm and 155Tb) are presented.

Reducing airborne transmission of SARS-CoV-2 by an upper-room ultraviolet germicidal irradiation system in a hospital isolation environment

Upper-room ultraviolet germicidal irradiation (UVGI) technology can potentially inhibit the transmission of airborne disease pathogens. There is a lack of quantitative evaluation of the performance of the upper-room UVGI for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) airborne transmission under the combined effects of ventilation and UV irradiation. Therefore, this study aimed to explore the performance of the upper-room UVGI system for reducing SARS-CoV-2 virus transmission in a hospital isolation environment. Computational fluid dynamics and virological data on SARS-CoV-2 were integrated to obtain virus aerosol exposure in the hospital isolation environment containing buffer rooms, wards and bathrooms. The UV inactivation model was applied to investigate the effects of ventilation rate, irradiation flux and irradiation height on the upper-room UVGI performance. The results showed that increasing ventilation rate from 8 to 16 air changes per hour (ACH) without UVGI obtained 54.32% and 45.63% virus reduction in the wards and bathrooms, respectively. However, the upper-room UVGI could achieve 90.43% and 99.09% virus disinfection, respectively, with the ventilation rate of 8 ACH and the irradiation flux of 10 μW cm−2. Higher percentage of virus could be inactivated by the upper-room UVGI at a lower ventilation rate; the rate of improvement of UVGI elimination effect slowed down with the increase of irradiation flux. Increase irradiation height at lower ventilation rate was more effective in improving the UVGI performance than the increase in irradiation flux at smaller irradiation height. These results could provide theoretical support for the practical application of UVGI in hospital isolation environments.

CFD modeling of room airflow effects on inactivation of aerosol SARS-CoV-2 by an upper-room ultraviolet germicidal irradiation (UVGI) system

Ultraviolet germicidal irradiation (UVGI) systems inactivate microorganisms indoors. Upper-room UVGI systems use wall- or ceiling-mounted fixtures to create an air disinfection zone above the occupied zone. The performance of upper-room UVGI systems varies with indoor airflow patterns induced by mechanical ventilation and thermal plumes from indoor heat sources. Little information is available on the effects of ventilation strategies on upper-room UVGI system performance for the control of viral aerosols in occupied spaces. This study simulated the effects of ventilation system characteristics in an office space on the ability of an upper-room UVGI system to inactivate viral aerosols with UV-C susceptibility representative of coronaviruses. UVGI reduced viral aerosol concentration by two orders of magnitude relative to the concentration without UVGI. Air change rates and air distribution strategy (mixing vs. displacement) had notable effects on the effectiveness of the UVGI system. For mixing ventilation, as the recirculation airflow rate increased from 0 to 5.3 h−1 for a room volume of 108 m3 with a fixed outdoor air change rate of 0.7 h−1, UVGI inactivation increased by 96.7%. Mixing ventilation with 100% outdoor air of 0.7 h−1 yielded airborne virus inactivation that was double that of displacement ventilation, due to enhanced air mixing.

Experimental and theoretical study on the photocatalytic degradation of brilliant green dye by N-doped Zn2GeO4

In this study, experimental and theoretical insights on the photocatalytic degradation of BG in an N-doped Zn2GeO4/UV irradiation system were explored. Kinetic experiments, degradation mechanisms analysis, and toxicity evaluation of intermediates were involved. The catalytic performance of N-doped Zn2GeO4 was optimum when the molar ratio of CO(NH2)2 and GeO2 is 1: 1. BG was almost 100% degraded within 10 min. Catalyst dosage and initial concentration had effects on the photodegradation of BG. Materials Studio calculations indicated that the nitrogen atoms are interstitially doped into Zn2GeO4 in the form of Zn–N–Ge. The N 2 s orbital contributes more than the N 2p orbital to the PDOS of N-doped Zn2GeO4, suggesting the difficult recombination of e- and h+. According to mass spectrometry analysis, de-ethylation, hydroxylation, condensation, carboxylation, and ring-opening were the main photocatalytic degradation pathways of BG. ∙OHs and O2∙-s played important roles in the Hg lamp/N-doped Zn2GeO4 reaction system, while h+ was existed in this system using quenching experiments. The 2FED2HOMO and (FED2HOMO + FED2LUMO) values implied the locations vulnerable to attack by free radicals of BG, which validated the reasonableness of the LC-MS/MS analysis result. Toxicity evaluations by the ECOSAR program suggested that photocatalytic degradation can exacerbate the aquatic toxicity of BG in the initial stage.

Retracted: Wireless Control Industrial Robot Processing Irradiation System Based on Artificial Intelligence Technology

Retracted: Wireless Control Industrial Robot Processing Irradiation System Based on Artificial Intelligence Technology

Effect of ventilation strategy on performance of upper-room ultraviolet germicidal irradiation (UVGI) system in a learning environment

Upper-room ultraviolet germicidal irradiation (UVGI) system is recently in the limelight as a potentially effective method to mitigate the risk of airborne virus infection in indoor environments. However, few studies quantitatively evaluated the relationship between ventilation effectiveness and virus disinfection performance of a UVGI system. The objective of this study is to investigate the effects of ventilation strategy on detailed airflow distributions and UVGI disinfection performance in an occupied classroom. Three-dimensional computational fluid dynamics (CFD) simulations were performed for representative cooling, heating, and ventilation scenarios. The results show that when the ventilation rate is 1.1 h−1 (the minimum ventilation rate based on ASHRAE 62.1), enhancing indoor air circulation with the mixing fan notably improves the UVGI disinfection performance, especially for cooling with displacement ventilation and all-air-heating conditions. However, increasing indoor air mixing yields negligible effect on the disinfection performance for forced-convection cooling condition. The results also reveal that regardless of indoor thermal condition, disinfection effectiveness of a UVGI system increases as ventilation effectiveness is close to unity. Moreover, when the room average air speed is >0.1 m/s, upper-room UVGI system could yield about 90% disinfection effect for the aerosol size of 1 μm–10 μm. The findings of this study imply that upper-room UVGI systems in indoor environments (i.e., classrooms, hospitals) should be designed considering ventilation strategy and occupancy conditions, especially for occupied buildings with insufficient air mixing throughout the space.

低エネルギーX線によるタマネギおよびジャガイモ発芽防止のための効果的照射方法

The sprout inhibition of onion and potato by low energy X-rays was investigated using a 160 kV X-ray irradiation system to determine optimal irradiation conditions. The sprouting of onion was effectively suppressed by irradiating 20 Gy at a depth of 3.2 mm from root side for small onion and at 8.0 mm depth for large onion, respectively. For potato, double-sided irradiation was necessary to irradiate the entire potato because the buds were distributed throughout the entire potato. Irradiation on double-sided at a depth of 8.0 mm with 50 Gy (60 Gy at 5.4 mm) effectively inhibited the sprouting. The throughput calculated to be 80.9 kg/h for large onion, 34.1 kg/h for small onion, and 9.9 kg/h for potato at a distance of 350 mm from the focal point of source. Dose uniformity (Dmax at surface/Dmin at 8.0 mm depth) of potato in case of double-sided irradiation was improved from 3.6 (182 Gy/50 Gy) to 1.2 (58 Gy/50 Gy) by using an aluminum 1.0 mm filter (F1) to cut off low energy X-rays, whereas the throughput capacity decreased from 9.9 kg/h to 7.4 kg/h.

Optimizing Neutronic and Photonic Performance in Irradiation Systems of Symmetric TRIGA Cores

The BAEC TRIGA MARK-II Research Reactor (BTRR) in Bangladesh has been used for a wide range of purposes, including basic and applied nuclear research and human resource development. Therefore, its core management should be flexible to meet various objectives with different priorities and to deliver the best possible outcome. In this study, neutron and gamma photon flux variation was studied at different radial and axial irradiation systems of the current core (C-0) as well as six symmetric reconfigurations (C-1, C-2, C-3, C-4, C-5, and C-6) of the existing BTRR using the universal MCNP code. While keeping the exact core component and material density, the symmetric reconfigured cores were modeled based on core criticality calculation and excess reactivity in the critical state. Finally, it was observed that the reconfigured core C-1 has the best neutronic and photonic performance at the irradiation systems compared to other reconfigured cores, against the reference core C-0.

A new 124Xe irradiation system for 123I production

Since 2001, Nuclear and Energy Research Institute IPEN-CNEN has produced weekly ultrapure iodine-123, using a manual irradiation system, fully developed in IPEN. Iodine-123 radiopharmaceuticals have been produced and distributed to hospitals and clinics of nuclear medicine, where several diagnostic imaging procedures for thyroid, brain and cardiovascular functions are performed. Due to the short half-life and emission of low-energy photons, this radioisotope becomes suitable for diagnosis in children. In the present work, the technical and constructive aspects of a new fully automated irradiation system, dedicated to 123I routine production, employing enriched xenon-124 gas as the target material is presented. This new system consists of a target, a water and helium cooling system, a cryogenic system, an electric power system, and a control and process monitoring unit, composed of supervisory software, connected to a programmable logic controller via personal computer. In this new concept, there is no need for human intervention during radioisotope production, reducing the possibility of eventual failures or incidents involving radioactive material. By using this new system, a specific yield of 2.70 mCi/μAh per irradiation was achieved in validation runs, and after three years of routine production of iodine-123, the system showed reliability and resilience.

BASIC PRINCIPLES OF CONSTRUCTION OF MODULAR HARDWARE COMPLEXES FOR LED THERAPY

The industrial production of powerful light-emitting diodes has led to the appearance of devices for therapeutic purposes, where such diodes are used as sources of electromagnetic radiation in the optical range. The development and production of such devices was established in the city of Kharkiv with the participation of scientists and specialists of Kharkiv National University named after V.M. Karazin and National Technical University "Kharkiv Polytechnic Institute". Methods of using devices and hardware complexes in medical practice were created at the Kharkiv Medical Academy of Postgraduate Education. The article analyzes the main principles of building modular hardware complexes for LED therapy, defines structures and options for connecting modules. As a result of the work performed, it was established that the modular implementation of hardware complexes for LED therapy has five main options, which differ in the number and types of emitters connected to the control unit, in the connection scheme of photon emitters, and in their functionality. It was also noted that the modular principle of building hardware complexes for LED therapy makes it quite easy to carry out their modernization and form the necessary configuration of the irradiating system, that is, to significantly expand the functional capabilities of the complex for carrying out phototherapy treatment procedures with the greatest efficiency. The expediency of using microprocessor technology for the implementation of the information part of the control unit of the complex is shown. This makes it possible to ensure the operation of photon emitters in continuous, pulsed and scanning modes, as well as separate operation of the emitters of the irradiation system of the complex and irradiation of the patient in biosynchronization mode.