Particle Radiation Research Articles

Experimental and numerical study on the combustion and infrared radiation characteristics of Mg/PTFE/Viton pyrotechnic compositions

The combustion process of Mg/PTFE/Viton-based pyrotechnics exhibits a complex multiphase flow phenomenon. However, the influence mechanism of metal particles undergoing dynamic diffusion combustion in the flow field on the infrared radiation output characteristics has not yet been elucidated. Systematic experiments and numerical simulations are performed with the combustion and infrared radiation behaviors of the pyrotechnic compositions. A small-scale sealed combustion experiment platform is specially manufactured to mimic the actual ambient pressure at different cruise altitudes. An infrared thermal imager and an infrared thermometer are adopted cooperatively to diagnose the burning process. The Euler-Langrangian method is applied to mathematically describe the gas–solid two-phase interaction in the combustion flow field, and the Eddy Dissipation Concept (EDC) combustion model is employed to simulate the coupling effect of turbulence and chemical reaction in the gas-phase reaction zone. The verified Source Six-Flux (SSF) method based in-house code solves the infrared radiative transfer equation integrating the emission, absorption and scattering effects of participating media. The comparisons with the experimental results demonstrate that the computational model involving heterogeneous reactions established in this paper better approximates the realistic situation. The results reveal that the infrared radiation output capability of dispersed combustion particles in the 2.0–5.5 μm band surpasses that of high-temperature gas molecules under different environmental pressures. The infrared radiation magnitude of both the gaseous phase and the particulate phase decrease significantly with decreasing pressure. The thermal radiation of combustion particles is mainly concentrated in the near- to mid-infrared band, while its emission in the far-infrared band is relatively weak. These scientific findings provide conducive insights for lucubrating the infrared radiation mechanism of pyrotechnics under negative pressure environments, and assist in further promoting the application of MTV pyrotechnics in the field of aerospace.

Reduced Critical Current Anisotropy and Improved Critical Current Performance in a Combined Pinning Landscape Created by Proton and Silver Irradiation

Particle irradiation using light ions and heavy ions is found to be an effective method to introduce flux-pinning centers into REBCO films and coated conductors. The degree of enhanced critical current at various conditions depends upon the size, morphology, and orientation of ion tracks. Proton irradiation to the optimised fluence results in greater isotropic enhancement at lower temperatures, the enhancement decreases as temperature increases. Silver ion irradiation on the other hand gives a greater enhancement at higher temperature but limited to particular angular ranges. We compare the results of these two types of irradiation and then produce a mixed pinning landscape with a combination of the two. We find a nearly isotropic enhancement in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I_c</i> at lower temperatures and an enhancement about the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</i> -axis direction, similar but broader than silver irradiation alone, at higher temperatures.

Effectiveness of radiation shields constructed from Martian regolith and different polymers for human habitat on Mars using MULASSIS/GEANT4 and OLTARIS

Mars exploration and the possibility of future Martian colonization have generated much interest in recent years. However, several problems make long-term permanence on Mars challenging, one of which is the radiation environment of the red planet. To ensure long-term durability on the Mars surface against the deleterious effects due to radiation, effective radiation shields are compulsory. This paper presents the effectiveness of radiation shields made of Martian regolith and light, hydrogenous polymers to protect astronauts on the Martian surface. Monte Carlo simulations were performed using a Geant4-based tool, Multi-layered shielding simulation software. The shielding properties were studied using low energy charged particle spectra from Mars Science Laboratory–Radiation Assessment Detector and particles (proton, alpha, and iron ions) with energies of 1 GeV/n. On-Line Tool for the Assessment of Radiation in Space (OLTARIS) is used for calculating the effective dose equivalent for the galactic cosmic ray spectra on the Mars surface. Martian regolith with Lithium Hydride (LiH) demonstrated greater efficiency in dose reduction. Based on the OLTARIS study, at 15 g/cm2 (10 g/cm2 Martian regolith with 5 g/cm2 chosen materials), these shields are even better than an aluminum shield of the same dimension.

Smart-Redundancy With In Memory ECC Checking: Low-Power SEE-Resistant FPGA Architectures

In harsh environments, such as space, radiation, and charged particles cause single-event effects (SEEs), faults occurring randomly on any electronic component. These must be mitigated to ensure device functionality. Modern mitigation methods, such as triple modular redundancy (TMR), are very effective against single-event transients (SETs) but incur a minimum of 3 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> cost in the area. Single-event upsets (SEUs) affect sequential elements and are regularly repaired using memory scrubbing. Scrubbing is a slow serial process going through every memory word, looking for errors to repair. Scrubbing involves a nonnegligible amount of time before an error is detected, during which other events can occur and compromise the system. Field-programmable gate arrays (FPGAs) rely heavily on sequential elements to store their configuration; thus, FPGA’s SEU detection time is critical to ensuring design sustainability in harsh conditions. In this article, we propose an alternative mitigation method based on sensor integration and FPGA architecture modification, called smart-redundancy with in-memory error correction code checking (SRIMECCC). The sensors allow asynchronous SEU detection, reducing the time to detect by 57 250 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> on average and enabling local reconfiguration. Our method includes built-in dual redundancy that reduces the power consumption by 87% on average, benefiting embedded systems. SRIMECCC is also an area-efficient technique that saves 28% of total effective area compared to TMRed designs implemented in FPGAs.

Impact of Particle Radiation and Temperature on the Retention Time of DDR4 SDRAM Cells

Impact of Particle Radiation and Temperature on the Retention Time of DDR4 SDRAM Cells

4H-SiC Schottky barrier diodes as radiation detectors: A role of Schottky contact area

Large-area SiC Schottky barrier diodes can significantly improve the sensitivity in radiation detection due to the increased interacting SiC volume. In this work, we tested a large SiC detector with an area of 1 × 1 cm2. Extensive electrical characterization was performed at temperatures ranging from 150 K to 390 K, demonstrating the impact of barrier inhomogeneities on the electrical performance of the diode. Forward current-voltage (I-V) measurements of the diodes revealed two distinct regions caused by Schottky barrier inhomogeneity present throughout the entire temperature range. The barrier heights in the low- and high-current forward voltage regions were extracted from Richardson plots corrected for the Gaussian distribution of barrier heights, yielding values of 1.52 eV and 1.79 eV, respectively. Deep-level transient spectroscopy (DLTS) revealed only one deep-level defect, Z1/2, with an activation energy for electron emission of 0.67 eV, which was assigned to the known carbon vacancy. The DLTS study showed no correlation between electrically active defects and barrier inhomogeneity. An excellent energy resolution of 3.2 % was measured using a large area 241Am radiation source, consistent with values for small area SiC detectors that exhibited no barrier height inhomogeneities. The impact of temperature on the alpha particle radiation response was determined within a temperature range of 200 K to 390 K.

Quality Assurance Plan on a Linear Accelerator (LINAC) Plane on Nasopharynx Cancer (NFC) by using Prowess Panther 5.10 at Radiotherapy Installation Ken Saras Hospital

Radiotherapy is the treatment of cancer by using electromagnetic and particle radiation. Nasopharyngeal Cancer (NPC) is one of the difficult case to be treated in radiotherapy because its anatomical location. Precision of radiation dose is part of Quality Assurance Program as the key factor in this treatment. Thus, it is very important to ensure that the output dose of Linear Accelerator (LINAC) matched with result of Treatment Planning System (TPS). This study used Siemens LINAC Type Primus MACH Series 5633 and a set of detectors for Nasopharynx Cancer analysis with 8 field. The total dose of 5,000 cGy divided into 25 fractions with 200 cGy dose per fraction. The 8 fields are irradiated with a target on a detector device. It is then accumulated with PTW-Verisoft software by plotting the results obtained from the detector tool with PTW (phantom) which we have CT Scanned first in PTW-Verisoft. From the total detectors exposed to the radiation, the detector corresponding to PTW is 372 detectors (100%) with unsuitable detector of 0 detectors (0.00%). It is proved that the planning is 100% match for NPC with 8 fields of radiation. Thus, this method is recomended to be implemented for NPC treatment

Nanocomposites for Space Applications

The drive to lower the cost of space launches has resulted in the use of polymer matrix composites with micro reinforcements such as carbon fibers. Further attempts to decrease the weight of spacecraft and to improve the performance have led to the addition of nano reinforcements to these composites. In this paper, the application of nanocomposites in spacecraft structures is reviewed. First, several nano reinforcements, such as graphene, fullerene, nanotubes, nanofibers, nanoclays and Polyhedral Oligomeric Silsesquioxane (POSS), are briefly reviewed. Then the stringent requirements of the space environment, in relation to material properties, are reviewed. The space environment poses several challenges such as ultraviolet radiation, temperature extremes, thermal cycling, charged particle radiation, impacts from micrometeoroids and orbital debris, and low earth orbital atomic oxygen. Next, the testing of candidate materials in actual space environment and at ground based testing facilities is reviewed. This is followed by specific applications of nanocomposites in space structures.

Effects of tumour heterogeneous properties on modelling the transport of radiative particles.

Dose calculation plays a critical role in radiotherapy (RT) treatment planning, and there is a growing need to develop accurate dose deposition models that incorporate heterogeneous tumour properties. Deterministic models have demonstrated their capability in this regard, making them the focus of recent treatment planning studies as they serve as a basis for simplified models in RT treatment planning. In this study, we present a simplified deterministic model for photon transport based on the Boltzmann transport equation (BTE) as a proof-of-concept to illustrate the impact of heterogeneous tumour properties on RT treatment planning. We employ the finite element method (FEM) to simulate the photon flux and dose deposition in real cases of diffuse intrinsic pontine glioma (DIPG) and neuroblastoma (NB) tumours. Importantly, in light of the availability of pipelines capable of extracting tumour properties from magnetic resonance imaging (MRI) data, we highlight the significance of such data. Specifically, we utilise cellularity data extracted from DIPG and NB MRI images to demonstrate the importance of heterogeneity in dose calculation. Our model simplifies the process of simulating a RT treatment system and can serve as a useful starting point for further research. To simulate a full RT treatment system, one would need a comprehensive model that couples the transport of electrons and photons.

Early stages of X-ray induced molecular unit modifications in poly(lactic acid)

Exposure of polymers to ionizing radiation and high-energy particle beams is involved in many processes – from food sterilization to radiotherapy protocols. The resulting effects, at the final stages, determine the functional, structural, and morphological alteration of the material. However, the processes responsible for cumulative chain scission, crosslinking, and reactions with the environment are often difficult to disentangle as a sequence of elementary events. Here we report a spectroscopic study – by attenuated-total reflection Fourier transform infrared spectroscopy and powder x-ray diffraction measurements, together with differential scanning calorimetry and thermogravimetric analyses – that sheds light on the very initial stages of the mechanisms involved in radiation-induced modifications of poly(lactic acid) (PLA). The results, collected on samples from biobased processes and exposed to low x-ray doses in the range of 100–103Gy after different thermal treatments, show spectroscopic evidence of the emergence of molecular unit perturbations – mainly related to methyl and carbonyl groups with the formation of C=C double bonds – with a clear-cut dependence on the polymer conformation. Understanding the mechanisms involved and the role of crystallinity provides information potentially useful for the development of PLA with a suitable radiation hardness for applications in radiotherapy.

Larmor Temperature, Casimir Dynamics, and Planck’s Law

Classical radiation from a single relativistically accelerating electron is investigated where the temperature characterizing the system highlights the dependence on acceleration. In the context of the dynamic Casimir effect with Planck-distributed photons and thermal black hole evaporation, we demonstrate analytic consistency between the ideas of constant acceleration and equilibrium thermal radiation. For ultra-relativistic speeds, we demonstrate a long-lasting constant peel acceleration and constant power emission, which is consistent with the idea of balanced equilibrium of Planck-distributed particle radiation.

Single-Particle Irradiation Effect and Anti-Irradiation Optimization of a JLTFET with Lightly Doped Source.

In this article, the particle irradiation effect of a lightly doped Gaussian source heterostructure junctionless tunnel field-effect transistor (DMG-GDS-HJLTFET) is discussed. In the irradiation phenomenon, heavy ion produces a series of electron-hole pairs along the incident track, and then the generated transient current can overturn the logical state of the device when the number of electron-hole pairs is large enough. In the single-particle effect of DMG-GDS-HJLTFET, the carried energy is usually represented by linear energy transfer value (LET). In simulation, the effects of incident ion energy, incident angle, incident completion time, incident position and drain bias voltage on the single-particle effect of DMG-GDS-HJLTFET are investigated. On this basis, we optimize the auxiliary gate dielectric, tunneling gate length for reliability. Simulation results show HfO2 with a large dielectric constant should be selected as the auxiliary gate dielectric in the anti-irradiation design. Larger tunneling gate leads to larger peak transient drain current and smaller tunneling gate means larger pulse width; from the point of anti-irradiation, the tunneling gate length should be selected at about 10 nm.

Results from the Radiation Assessment Detector on the International Space Station: Part 3, combined results from the CPD and FND

The energetic particle radiation environment on the International Space Station (ISS) includes both charged and neutral particles. Here, we make use of the unique capabilities of the Radiation Assessment Detector (ISS-RAD) to measure both of these components simultaneously. The Charged Particle Detector (CPD) is, despite its name, capable of measuring neutrons in the energy range from about 4 MeV to a few hundred MeV. Combined with data from the Fast Neutron Detector (FND) in the 0.2 to 8 MeV range, we present the first broad-spectrum measurements of the neutron environments in various locations within the ISS since an early Bonner-Ball experiment that was conducted before the Station was fully constructed. The data presented here span the time period from February 2016 to February 2022. In addition to presenting broad-spectrum neutron fluence measurements, we show correlations of the measured neutron dose equivalent with charged-particle dose rates. The ratio of charged-particle dose to neutron dose equivalent is found to be relatively stable within the ISS.

Estimation of different calculation models for evaluating heavy ion-induced damage in plasma facing materials

In a fusion reactor, plasma-facing materials are bombarded by various energetic particles (such as neutrons) from fusion reactions, leading to inevitable irradiation damages. These damages can significantly affect the material servicing life time and threaten the safety of fusion reactors. Accurate and consistent evaluation of irradiation damage is quite important to investigate the evolution mechanism of irradiation defect. In this study, the irradiation damage of tungsten caused by high-energy particles were evaluated using the SRIM code and molecular dynamics simulations. The accuracy of three atomic displacements calculation models, i.e., VAC model, NRT model, and arc-dpa model, under two computational modes of SRIM (the K-P mode and F-C mode) were discussed. It was found that with the increase of the incident particle atomic number, the peak depth of displacement moved to the shallow layer and increased in peak height, while the trend was opposite with the increase of the incident particle energy. As to the different calculation modes, the F-C and K-P modes produced a ratio of vacancies of about 1.8 times in the VAC model. What's more, the VAC model and NRT model predicted results consistent with molecular dynamics simulation results at lower energy ranges (approximately <100 eV), but deviated from them as the energy increased. In contrast, the arc-dpa model exhibited good consistency with the molecular dynamics simulations and had higher accuracy. Therefore, it is recommended to use the arc-dpa model under the K-P mode for the calculation of atomic displacement. This model can accurately and quickly calculate the irradiation damage level caused by high-energy particle irradiation in fusion reactors.

Attenuation range of particle radiations (alpha and beta) in human skin by Monte Carlo simulation

Particle radiations such as alpha and beta particles are more hazardous to humans than photons because of their higher linear energy transfer (LET). It is important to analyze the profile of particle radiations when interact with human skin. It is generally said that α particles can be stopped by a piece of paper while β rays can be stopped by an aluminum plate. A Monte Carlo simulation (PHITS code) is used for determining the attenuation and range of commonly available alpha (Po-210, Po-214, Am-241) and beta sources (Y-90) in human skin. These particle radiations were set at the surface of several materials such as skin, paper, water, aluminium and air to see their distribution within the materials. The PHITS code outputs were verified by comparing it with other literature for its range in air. Results showed that alpha particles barely pass through the outer layer of dead human skin and definitely can be stopped by a piece of paper. From the particle trajectory output, fluence of α particles from Po-210, Po-214, and Am-241 are completely stopped at 0.005 cm, 0.009 cm, and 0.012 cm in a paper, respectively, with no secondary particles are generated. On the other hand, beta particles would easily penetrate human skin and its range in human skin is ~0.8 cm for Y-90, while it would stop at ~0.3 cm in aluminium. In conclusion, based on these simulations, it was found that this study had justified the common sense on the shielding for the particle by using paper for alpha and aluminium for beta particle as a function of particle energy. Calculation with PHITS can be used for range calculation of various radiation types, including neutron and proton particles.

Low energy electronic recoils and single electron detection with a liquid Xenon proportional scintillation counter

Liquid xenon (LXe) is a well-studied detector medium to search for rare events in dark matter and neutrino physics. Two-phase xenon time projection chambers (TPCs) can detect electronic and nuclear recoils with energy down to kilo-electron volts (keV). In this paper, we characterize the response of a single-phase liquid xenon proportional scintillation counter (LXePSC), which produces electroluminescence directly in the liquid, to detect electronic recoils at low energies. Our design uses a thin (10–25 μm diameter), central anode wire in a cylindrical LXe target where ionization electrons, created from radiation particles, drift radially towards the anode, and electroluminescence is produced. Both the primary scintillation (S1) and electroluminescence (S2) are detected by photomultiplier tubes (PMTs) surrounding the LXe target. Up to 17 photons are produced per electron, obtained with a 10 μm diameter anode wire, allowing for the highly efficient detection of electronic recoils from beta decays of a tritium source down to ∼ 1 keV. Single electrons, from photoemission of the cathode wires, are observed at a gain of 1.8 photoelectrons (PE) per electron. The delayed signals following the S2 signals are dominated by single-photon-like hits, without evidence for electron signals observed in the two-phase xenon TPCs. We discuss the potential application of such a LXePSC for reactor neutrino detection via Coherent Elastic Neutrino Nucleus Scattering (CEνNS).

Large-Area Photonic Bound State in the Continuum for Ultraviolet and Deep-Blue Emission for Organic, Inorganic, and Perovskite Scintillators

Optimizing the emission properties of materials in ultraviolet and deep blue (UV-DB) is interesting in development of new scintillator devices for the detection of X-ray, γ-ray and radiation particles as those materials can be strong candidates for high light yield and fast scintillators. While their intrinsic material properties are already well studied, photonic enhancement generated through optical confinement could significantly improve their emission characteristics, however one needs to overcome the problem of relatively low refractive indices contrast resulting in poor confinement of UV-DB light. This motivates the search for resonator structures built from readily accessible materials that can boast strong confinement in this spectral regime. Here, we present such a structure, leveraging bound states in the continuum (BICs) to realize large-area confinement of UV-DB light with ultra-high quality factors up to <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> ~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> . These ultra-high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> -factors in turn result in strong enhancements in light emission via the Purcell effect. We demonstrate the operation of such a design by simulating the mode shape, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> -factor and emission behaviour in organic, hybrid perovskite and III-V scintillating materials. By tailoring the structure geometry, it can be robustly tuned to match the emission characteristics of chosen materials. We start with considering ideal infinite structure supporting perfect BIC and we extend our model on finite sized structures and we discuss the limitations associated with the self-absorption and thickness of the structure. Our findings pave the way to cost-effective and efficient designs for scintillators in the UV-DB regime.

Utilizing GOES-16 instruments to forecast geomagnetic storm during Solar Cycle 25

This paper focuses on the study of active region AR12891 in conjunction with geostorm from space weather data. A flare of magnitude M1.7 occurred in this active region, resulting in a geomagnetic storm of magnitude 3. By observing solar activity, x-ray flux, and radiation particle monitoring, GOES-16 instruments were used to forecast these events. A python program was used to analyze data collected from the online database of solar monitor and space weather live provided by the NOAA. Solar flare events can be studied and monitored through GOES-16 instruments to forecast geomagnetic storms. This allows less impacts towards satellite navigations and power sources if geomagnetic storm was detected early.

A 3D simulation model of thermal runaway in Li-ion batteries coupled particles ejection and jet flow

A coupled simulation model of the 18650 lithium-ion batteries (LIB) thermal runaway (TR) is presented in this study, which includes TR decomposition reaction, gas generation and combustion processes, solid particles ejection and particles heat transfer process. The model considers a combination of solid heat conduction, gas convection, flame and particles radiation, which is validated to accurately capture the temperature evolution and two typical jet processes during TR. Model validation conducts with experimental measurements for the temperature of the battery surface. The simulation results show that the “ignition” time of the flammable gas mixture is delayed and the rate of flame temperature increase is slowed down when the effect of solid particles is considered. The radiation heat transfer rate and convection heat transfer rate on the adjacent battery surfaces are 80.3W and 12.76W, and are approximately 4.29 times and 1.76 times larger than the results calculated by the model without solid particles, respectively. The difference between these two can be further magnified in confined space. The model developed in this study combines the effect of the solid particles’ radiation into the TR simulation innovatively. It can provide a more accurate calculation method for the prediction of TR propagation.

Nuclear Technology in Horticulture: Boosting Productivity, Controlling Pests, Conserving Water

Horticulture faces significant challenges due to the destruction of crops by pests and diseases, both before and after harvesting, resulting in a significant reduction in crop production. Nuclear technology has emerged as a valuable tool for enhancing agricultural productivity. Despite the common association of nuclear technology with energy and weaponry, its use in Horticulture is diverse and multifaceted. Physical mutagens such as nuclear radiation, including gamma rays, X-rays, and UV light, as well as particle radiation, can be employed to induce chromosomal breakages, cross-linking of DNA strands, nucleotide deletion, and substitution. UV rays can be used to irradiate cell suspensions and pollen grains in the early or late uninucleate phases. Through the application of nuclear technology, agricultural productivity can be improved by increasing crop yields, controlling pests and diseases, and enhancing water quality. Food preservation can also be achieved through food irradiation, where ionizing radiation is applied to target pathogens to break their DNA bonds. Nuclear technology can also be utilized to induce beneficial mutations in crops through genetic modification, sterilization-based pest control, and water usage management. In conclusion, nuclear technology presents an innovative and effective solution for addressing challenges in Horticulture, thus contributing significantly to global food security.