High-performance Radiation Research Articles

Wide-angle low-scattering transmitarray antenna based on transmit-reflect selective metasurface

Abstract A high-gain transmitarray antenna with low radar cross section (RCS) properties is presented in this paper. Compared with conventional high-profile multilayer designs, we introduce a transmit-reflect selective metasurface integrated with high-gain transmission and random scattering functions, achieving a reduced thickness of 0.13 λ 0 (where λ 0 is the wavelength at the center frequency). For the meta-atom design, we combine geometric rotation and dimension optimization to realize 1-bit independent transmit and reflection phase modulation, respectively. Moreover, in metasurface coding strategy, we employ an initial phase optimization method and a simulated annealing algorithm to determine the optimal coding matrices. The experimental results demonstrate high-performance radiation characterized by the peak gain of 23.6 dB, maximum aperture efficiency of 28.5%, and 3 dB gain bandwidth of 18.4%. For x-polarization, measured 10 dB RCS reduction bandwidth under transverse magnetic (TM) 0°-45° and transverse electric (TE) 0°-20° incidence are 9.02–11.36 GHz. For y-polarization, 10 dB RCS reduction bandwidth under TM 0–60° and TE 0–30° incidence is 8.82–10.96 GHz.

Effects of colemanite, heavy aggregates and lead fibers on physical mechanics and radiation shielding properties of high-performance radiation shielding concrete

Radiation shielding concrete (RSC) is widely utilized as a construction material in specialized infrastructure of nuclear power plants and medical facilities. In this study, a high-performance-RSC (HPRSC) with excellent mechanical properties and radiation shielding properties was developed based on the modified Andreasen and Andersen model. HRPSC can effectively shield a broad spectrum of radiation rays due to the combination of neutron absorber (colemanite) and gamma scatterers (e.g., heavy aggregates of barite and magnetite, and lead fibers). The experiment results revealed that the compressive strength of HPRSC exceeds 70 MPa due to a scientific skeleton structure design, which contributes the formation of an exceptional interfacial transition zone between the heavy aggregate/lead fiber and the cementitious matrix. The type of heavy aggregates influenced the physical mechanics properties of HPRSC. The compressive strength of magnetite-based HPRSC was higher than that of barite-based counterparts under the same dosage of heavy aggregates. The incorporation of heavy aggregates and lead fibers enhanced the γ-ray shielding capacity of HPRSC. The μ index of designed HPRSC reached 0.1988 due to the synergistic complementary effects between the cementitious matrix and the radiation shielding additives. HPRSC shows a promising application prospect in high radiation environments.

Alpha particle detection based on low leakage and high-barrier vertical PtOx/β-Ga2O3 Schottky barrier diode

High-performance radiation detectors are essential in many sectors spanning medical diagnostics, nuclear control, and particle physics. Ultrawide bandgap semiconductor materials have become one of the most promising candidates due to their excellent performance. Here, based on β-Ga2O3, a Schottky diode-type alpha particle detector was demonstrated. In order to reduce the reverse leakage current of the large-area device, the metal-oxide electrode PtOx was introduced to form high-barrier contacts (1.83 eV) with Ga2O3. The device exhibits a low leakage current density of 63 pA/cm2 at −100 V and apparent energy spectra of 241Am generated alpha particles with an energy of 5.486 MeV at various reverse voltages from −40 to −120 V. The charge collection efficiency (CCE) and energy resolution of the device (at −120 V) are 31.7% and 15.3%, respectively. Meanwhile, the mechanism of interaction between alpha particles and β-Ga2O3 was analyzed, and a 45° oblique incidence was adopted to increase the deposited energy of alpha particles in the depletion region. Furthermore, the differences between actual CCE and theoretical CCE are investigated as guidance for further improving detector performance. This work reveals the great potential and good prospects of Ga2O3 as an economical, efficient, and radiation-resistant ionizing radiation detector.

Valorization of steel slag into sustainable high-performance radiation shielding concrete

The disposal of steel slag (SS) has become a serious ecological problem due to the waste of massive land resources. This study reveals the huge potential of recycling SS as heavy aggregates to develop radiation shielding concrete (RSC). The physical characteristics, radiation attenuation capabilities, microstructure, and environmental and ecological impacts of SS-based RSC are comprehensively evaluated and compared with those of normal concrete and the commonly used heavy concrete. The test results indicate that SS-based RSC is prospective to substitute the commonly used heavy concrete, emerging as a sustainable and efficient material for radiation shielding in nuclear energy engineering. Specifically, due to the reaction of cementitious active substances in the surface of SS, the developed SS-based RSC exhibits a fantastic interfacial transition zone (ITZ), and a compact pore structure, thereby showing excellent mechanical properties. The maximum compressive strength of developed SS-based RSC reaches 47.4 MPa. In terms of gamma ray attenuation property, due to the introduction of heavy nuclei and the increase in density, the gamma ray attenuation capacity of developed SS-based RSC is 17.2 % higher than that of normal concrete. The neutron attenuation property is also slightly enhanced due to the refinement effect of SS on pore structure of RSC. Life cycle assessment and unit cost evaluation results demonstrate that compared with barite based-RSC, SS-based RSC can save 97.6 % in cost, 52.0 % in energy consumption, and 70.4 % in carbon emission. The developed SS-based RSC exhibits excellent mechanical properties and radiation attenuation capacities, contributing to the further application of radiation shielding materials. Besides, this approach achieves the high-value recycling of SS, providing new insights for the utilization of high-density solid wastes.

Efficacy of Ni2+ on modification the structure, ultrasonic, optical, and radiation shielding behaviors of potassium lead borate glasses

This paper presents the method of preparing (60 − x) B2O3–20 K2O–20 PbO–x NiO, coded as (NiO x), and x = (0–10 mol%) glass systems fabricated through the melt-quench technique. The prepared glass was characterized through X-ray diffraction spectra (XRD); the mechanical behavior of the glass samples was investigated using the ultrasonic technique, Fourier transform infrared (FTIR) spectra, the optical reflectance R(λ), refractive index (n), optical conductivity (σopt), the dispersion parameters of the studied samples were deduced using Wemple and Di-Domenico models. The results obtained were reported in detail. One of the fundamental parameters used to evaluate the interaction of radiation with shielding material was the mass attenuation coefficient (μm), which was obtained using Phy/X software and PHITS code program. It was used to calculate radiation interaction parameters, e.g., linear (μL) attenuation coefficient, effective atomic number (Zeff), half value layer HVL, mean free path (MFP) and the average atomic cross section, σt. Comparing the shielding behavior of the glass samples revealed that (NiO 10) glass demonstrated the highest μm and μL compared to the other samples. The maximum μm values equal 48.13, 48.73, 49.42, 50.59, and 51.08 cm2/g for (NiO 0) to (NiO 10), recorded at 0.015 MeV, respectively. This study shows that increasing the amount of NiO in the preferred glass samples leads to achieving high-performance radiation shielding materials.Graphical abstract

A Reliable and high performance Radiation Hardened Schmitt Trigger 12T SRAM cell for space applications

In the vacuum of space, alpha particles and cosmic radiation can cause the node data to be altered, leading to data loss. When a radiation particle hits a vulnerable point of the typical 6T static random access memory (SRAM) cell, it results in the alteration of the stored data within the cell, leading to a single-event upset (SEU). Traditional 6T SRAM cannot withstand the extreme conditions present in space. Hence, it is imperative to develop an SRAM that can endure these challenging space conditions. To address the impact of SEUs, a Radiation Hardened Schmitt Trigger 12 transistor (RHST12T) SRAM cell is proposed in this paper. To gauge the comparative effectiveness of the proposed cell, it is compared with other radiation hardened SRAM cells, namely, QUCCE12T, WE-QUATRO, RHPD12T, and SRRD12T. Even if a radiation strike flips the node values, all of RHST12T sensitive nodes can recover their data. It shows up to 1.6×/45.32×/0.29 ×106× less read delay, write delay, and leakage power consumption, respectively as compared to other considered SRAM cells. It achieves up to 5.75×/3.09× better read and hold stability, respectively than the considered SRAM cells.

High radiation performance and multi-band acoustically driven piezoelectric antenna based on energy trapping theory

The paper introduces a novel design method for an acoustically driven piezoelectric antenna with high radiation performance and broadband characteristics based on energy trapping theory. The reasonableness of the design method is demonstrated by analytically deriving the radiated magnetic field, radiated efficiency and resonant frequency, which are further validated by simulation analysis. Furthermore, a prototype is fabricated and measured, and the results indicate remarkable improvements compared to the non-energy trapping mode, the bandwidth is widened by 10%, the radiation efficiency is increased by 28%, the radiation magnetic field is increased by three times, the transmission distance is increased by 2.75 times. The radiation enhancement and multi-band capability of the proposed antenna has been successfully demonstrated. Additionally, we have successfully implemented amplitude modulation signals transmission using proposed antenna. These results highlight the significant potential of the proposed antenna for portable, miniaturized, and high-performance wireless communication devices.

Value-added recycling of cathode ray tube funnel glass into high-performance radiation shielding concrete

This study proposed a novel method for recycling cathode ray tube (CRT) glass as heavy aggregates to prepare radiation shielding concrete (RSC). Microstructure, physical properties, radiation shielding characteristics, as well as economic and environmental benefits of CRT glass-based RSC were evaluated. Compared to conventional RSC, the CRT glass-based RSC showed a 13.8 % higher gamma ray shielding capacity. Although the mechanical properties of CRT glass-based RSC slightly decreased by 25.7 % due to the weak interfacial transition zone, the 28-day compressive strength of CRT glass-based RSC still fulfilled the requirement of criteria (> 30 MPa). Based on the cost-benefit assessment, there was 166.7 $/m3 profit in CRT glass-based RSC. Furthermore, CRT glass-based RSC demonstrated 47.7 % and 37.0 % reduction in fossil fuel depletion and carbon emissions compared with barite-based RSC.

The impact of strontium composition on thallium-doped cesium iodide scintillators

Investigating new scintillators with more alternative methods has been an attractive topic for a long time. This work aims to study the impact of strontium composition on thallium-doped cesium iodide scintillators. There are three different composition ratios of cesium iodide and strontium iodide precursors of 99:1, 95:5, and 90:10 with the same thallium doping of 0.28 mol%. The EDS measurements analyzed the soluble Sr-compositions in these grown crystals as 0%(undetectable), 0.43%, and 2.31%, respectively. With slightly increased strontium composition, the crystallite size was slightly smaller from 59.17, 45.51, to 33.23 nm, respectively. Moreover, the crystals have a somewhat more compressive strain and a slightly higher single crystallinity when the composition of strontium iodide increases. By analyzing the crystals' optical properties, the luminescent properties were trivially enhanced with a bit higher scintillation light yielding up to 29,859 photon/MeV of the crystal with a Sr-composition of 2.31%. Photoluminescence measurements exhibit the enhanced 520 nm scintillation and the lower 410 nm emission at higher Sr contents. These crystals’ emission decay times were obtained as τ1 = 500 ns (fast component) and τ2 = 700 ns (slow component) and slightly slower times with a higher Sr content. Lastly, radiation detection efficiency has been investigated at various energy levels of gamma rays from Am-241, Co-57, Ba-133, and Cs-137 sources. We found that the crystal with a higher Sr composition of 2.31% has better energy resolutions down to the best one of 7.9% at 662-keV measurement. In summary, higher strontium codoping with thallium in cesium iodide scintillators can enhance the crystal structure and optical properties. This would be one candidate of the promising scintillators for developing alternative high-performance radiation detectors for high-speed imaging applications.

Data driven surrogate modeling of horn antennas for optimal determination of radiation pattern and size using deep learning

AbstractHorn antenna designs are favored in many applications where ultra‐wide‐band operation range alongside of a high‐performance radiation pattern characteristics are requested. Scattering‐parameter characteristics of antennas is an important design metric, where inefficiency in the input would drastically lower the realized gain. However, satisfying the requirement for scattering parameters are not enough for having an antenna with high‐performance results, where the radiation characteristic of the design can be changed independently than the scattering parameters behavior. A design might have a high‐efficiency performance, but the radiation characteristics might not be acceptable. Furthermore, there are other design considerations such as size and volume of the design alongside of these conflicting characteristics, which directly affect the manufacturing cost and limits the possible applications. In this work, by using data‐driven surrogate modeling, it is aimed to achieve a computationally efficient design optimization process for horn antennas with high radiation performance alongside of being small in or within the limits of the desired application limits. Here, the geometrical design variables, operation frequency, and radiation direction of the design will be taken as the input, while the realized gain of the design is taken as the output of the surrogate model. Series of powerful and commonly used artificial intelligence algorithms, including Deep Learning had been used to create a data‐driven surrogate model representation for the handled problem, and 80% computational cost reduction had been obtained via proposed approach. As for the verification of the studied optimization problem, an optimally designed antenna is prototyped via the use of three‐dimensional printer and the experimental results ware compared with the results of surrogate model.

Boriding of tungsten by the powder-pack process: Phase formation, growth kinetics and enhanced neutron shielding

In this study, tungsten boride coating was grown on pure tungsten substrate by pack boriding method for improved neutron shielding ability. The microstructure, growth kinetics and radiation shielding performance were systematically studied. It is found that the boronized layer shows a dual-phase structure under the boriding temperature of 950–1050 °C. The main layer closes to coating surface is identified to be the WB phase, while the inner layer adjacent to the substrate is W2B. Thermodynamics calculation proves the W2B is more favored to nucleate and grow adhering to W than α-WB. Once the W2B layer was formed, further increasing boron concentration enables to introduce the formation of WB at the interface. On the basis of the calculated WB phase diagram, two separated diffusion models were developed to elucidate the growth of WB with composition gradient and W2B with constant composition. The diffusion coefficients of boron in boride phases as well as the activation energy for boron diffusion were estimated. Finally, the large improvement of neutron attenuation ability for tungsten specimen upon boriding treatment was demonstrated. Our findings could provide new directions for developing high performance radiation shielding materials.

Radiation shielding, physical, and elastic properties of BaO-B2O3-Bi2O3 glass system

In this research, the radiation shielding, structural, mechanical, and acoustic features of the 20BaO-(80-x) Bi2O2 -x B2O3 (where x = 70, 60, 50, 40, 30, 20 mol%) glasses are investigated and the obtained results are reported in detail. One of the fundamental parameters in the evaluation of the interaction of radiation with shielding material was the mass attenuation coefficient (MAC) that was obtained using the Phy-X/PSD program in the energy range from 0 to 10 MeV and the calculated results are presented in this paper. Increasing the Bi2O3 concentration changes the composition and density of glass samples and affects the mechanical properties. As a result, the values of elastic moduli such as Young’s, Bulk, Shear, and Longitudinal moduli experience a slight reduction. In addition, the Poisson’s ratio decreases from 0.27 to 0.17 but the quantity of fractal Bond Connectivity (FBC) increases between 2.26 and 3.59 from BaBiB1to BaBiB6 glass samples which hints that present glasses have chain structure (3D). Furthermore, the micro-hardness (H) increases from 6.67 to 9.88 GPa with the increase in Bi2O3 concentration. The reported acoustic impedance (Zi) increases between 15.16 * and 19.00 * The result of this study shows that increasing the amount of Bi2O3 in the preferred glass samples leads to the achievement of high performance radiation shielding materials. Finally, from this research, we can exploit valuable information about the structure of the glass samples.

Scalable and High-Performance Radiative Cooling Fabrics through an Electrospinning Method.

Reduction in human body temperature under hot conditions is a subject of extensive research. Radiative cooling fabrics have attracted considerable attention because the material reduces body temperature without any energy input, saving both energy and the environment. Researchers have been exploring effective and scalable preparation methods for radiative cooling fabrics. Herein, we employed the electrospinning method to prepare a radiative cooling fabric comprising the poly(vinylidene fluoride-co-hexafluoropropene) nanofiber and SiO2 nanoparticles. The fabric had a reflectivity exceeding 0.97 in the solar band and an emissivity of over 0.94 within the atmospheric window. The material achieved a radiative cooling effect of 15.9 °C under direct sunlight using a testing device built in-house. The method is simple and scalable and uses abundant and inexpensive raw materials; the technique can help promote the widespread adoption of radiative cooling fabrics.

Eight-Element Antenna Array with Improved Radiation Performances for 5G Hand-Portable Devices

This study aims to introduce a new phased array design with improved radiation properties for future cellular networks. The procedure of the array design is simple and has been accomplished on a low-cost substrate material while offering several interesting features with high performance. Its schematic involves eight air-filled slot-loop metal-ring elements with a 1 × 8 linear arrangement at the top edge of the 5G smartphone mainboard. Considering the entire board area, the proposed antenna elements occupy an extremely small area. The antenna elements cover the range of 21–23.5 GHz sub-mm-wave 5G bands. Due to the air-filled function in the configurations of the elements, low-loss and high-performance radiation properties are observed. In addition, the fundamental characteristics of the introduced array are insensitive to various types of substrates. Moreover, its radiation properties have been compared with conventional arrays and better results have been observed. The proposed array appears with a simple design, a low complexity profile, and its attractive broad impedance bandwidth, end-fire radiation mode, wide beam steering, high radiation coverage, and stable characteristics meet the needs of 5G applications in future cellular communications. Additionally, the smartphone array design offers sufficient efficiency when it comes to the appearance and integration of the user’s components. Thus, it could be used in 5G hand-portable devices.

Construction of MAPbBr3/EP composites with blocking path for high-performance gamma-rays shielding

As deep space exploration is getting further and further away, it is necessary to develop novel packaging shielding material with lightweight and high performance to improve the service life of spacecraft integrated circuits in space radiation environment. However, up to now, constructing a lightweight perovskite/epoxy composite packaging shielding material for spacecraft integrated circuits has not been reported. Hence, in this work, a novel MAPbBr3/epoxy (CH3NH3PbBr3/EP) composite is firstly reported, which shows excellent gamma-rays shielding performance with high linear attenuation coefficient (3.082 cm−1) and high mass attenuation coefficient (2.047 cm2/g). Radiation shielding mechanism indicates that gamma-rays mainly interact with MAPbBr3 dispersed in epoxy. In other words, MAPbBr3 forms a radiation blocking path in epoxy, which significantly attenuates the intensity of incident gamma-rays. In addition, MA+ in MAPbBr3 crystal structure effectively blocks the penetrating behavior of secondary electrons. This work provides a novel strategy for the design and synthesis of high-performance radiation shielding packaging materials.

Multilayer ceramic varistors with high thermal radiation performance for superior reliability against surges

Multilayer ceramic varistors with high thermal radiation performance for superior reliability against surges

Wide-Angle Impedance Matching Layer-Enhanced Dual-Polarization sub-6 GHz Wide-Scan Array for Next-Generation Base Stations

A new sub-6 GHz antenna array that supports slant ±45° dual-polarization multiple-input multiple-output (MIMO) communications with high interport isolation and stable radiation performance over wide scan angles and bandwidths is designed. An architecturally inexpensive solution, which combines a standard truncated waveguide array and a single-layer patterned metasurface superstrate with wave manipulation capabilities, is proposed. A task-oriented formulation is adopted to mathematically formulate the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">EM</i> associated multiscale design problem, then solved with an innovative instance of the system-by-design (SbD) paradigm where the fast and reliable modeling of the device is yielded by an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ad hoc</i> artificial intelligence-based surrogate. The final layout of the antenna array is validated with industry-standard full-wave numerical simulators.

Implementing the single/multiport tunable terahertz circularly polarized dielectric resonator antenna

A tunable terahertz circularly-polarized dielectric resonator antenna is implemented and numerically studied. An aperture coupled terahertz rectangular dielectric resonator antenna operating with the fundamental magnetic dipole is designed. The modal field distribution is perturbed using the material-perturbation technique and the electric field vectors are aligned in the horizontal plane with their orthogonal components having quadrature phase difference between them. Consequently, the circular polarization is obtained in the operating passband. The proposed antenna provides the 10-dB impedance bandwidth of 12.94% (4.27–4.86 THz) and 3 dB axial ratio bandwidth of 3.77% (4.43–4.60 THz). Moreover, tunability is achieved by modulation in the chemical potential of graphene layer coated at the top of the dielectric resonator by applying an electrostatic bias voltage. In addition, antenna provides the gain of 6.45 dBic along with 98% radiation efficiency. The proposed antenna can also be used for the implementation of multi-port wireless THz communication systems with the advantage of tunable CP response with impeccably high radiation performance parameters. A two-port multi input, multi output (MIMO) antenna is implemented with the usage of the proposed metal strip coated DR. This antenna provides high isolation between both the ports along with polarization response and pattern diversity with the acceptable value of MIMO performance parameters like envelop correlation coefficient and diversity gain.

Improved radiation resistance of an Er-doped silica fiber by a preform pretreatment method.

We report a novel pretreatment method to improve the radiation resistance of Er-doped fiber (EDF). The processing object of this method is EDF preform, and the pretreatment processing involves three steps: deuterium loading, pre-irradiation, and thermal annealing. The effects of pretreatment conditions on the optical loss, gain performance, and radiation resistance of EDF were systematically studied. The relevant mechanisms were revealed using Fourier transform infrared (FTIR), radiation-induced absorption (RIA), and electron paramagnetic resonance (EPR) spectroscopies. The results show that the pretreatment can not only greatly reduce the hydroxyl content of the EDF core, but it can also effectively improve the radiation resistance of EDF. The online test results show that the gain of the commercial, pristine, and pretreated EDFs were reduced by 19.0, 4.2, and 1.3 dB, respectively, corresponding to a decrease of 68.1, 16.2, and 4.7% after 98 krad X-rays irradiation. The high vacuum experiments show that the pretreatment method can maintain long-term stable high radiation resistance. This work provides a reference for the development of high-performance radiation resistant EDFs for use in the lower, middle, and geosynchronous earth orbit.

Microstrip patch antenna design, simulation and fabrication for 5G applications

This study provides a deeper knowledge of the usage of finite integration techniques (FIT) and the finite element method (FEM) for analyzing various microstrip antenna shapes such as rectangular, circular and triangular patches. These patch shapes are fabricated practically and the efficiency of both mentioned methods have been identified through the evaluation of the microstrip antenna parameters such as, gain, bandwidth, VSWR, return loss S11, directivity and ration pattern operating at 28 GHz. Comparison between measured and simulated results with both techniques reveals that the FIT better for all types of microstrip antennas patch shapes whereas FEM is only reliable for rectangular microstrip antennas shape due to its regularity in its configuration. In addition, a good agreement between the results of the proposed antenna parameters with previously research works operating at the same frequency are also identified. Beside of this, our proposed antenna has the advantage of small size of the order of (5.2 mm3) which is compact and suitable for the 5 G wireless communication system applications. Furthermore, with this small profile configuration, the antennas still provide high radiation performance with a bandwidth of the order of (900 MHz), gain of (6 dB) and directivity of the order of (7 dB).