Radiation Physics and Chemistry最新文献

英文中文

Optimizing minibeam collimator design for enhancing normal tissue sparing in ocular tumour proton therapy

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-03-03 DOI: 10.1016/j.radphyschem.2025.112674

Tsz-Yui Chan , Chien-Yu Lin , Shen-Hao Lee , Jiunn-Woei Liaw , Tsi-Chian Chao , I-Chun Cho

Uveal melanoma, the most common primary intraocular tumour in adults, presents significant therapeutic challenges due to its aggressive nature and the potential for severe treatment-related complications, including vision loss. Achieving effective tumour control while minimizing damage to surrounding healthy tissues remains a critical goal in radiotherapy. Proton minibeam radiotherapy (pMBRT), an advanced form of spatially fractionated radiotherapy (SFRT), has emerged as a promising approach to address these challenges.

pMBRT employs a mechanical collimator to spatially fractionate a broad proton beam into multiple narrow beamlets, creating a dose distribution with high-dose peaks and low-dose valleys in shallow regions. As the beamlets travel deeper into tissue, multiple Coulomb scattering facilitates their convergence, resulting in a uniform dose at the tumour target.

This study systematically optimized the collimator design by evaluating various geometries and materials, specifically brass and polylactic acid (PLA). Simulations of dose distributions were performed using the Tool for Particle Simulation (TOPAS) and validated through experimental measurements with Gafchromic films. Results indicated that brass collimators, with their high atomic number, produced sharper dose profiles and higher peak-to-valley dose ratios (PVDR), demonstrating superior spatial dose modulation. Conversely, PLA collimators yielded smoother dose profiles and lower secondary dose contributions, showcasing their potential for reducing collateral tissue damage.

The optimized collimator design, featuring a 0.8 mm slit width and a 1 mm spacing, achieved an ideal balance between maximizing PVDR and ensuring uniform beam recombination at the target depth. These findings underscore the potential of tailored collimator designs to enhance the therapeutic precision of pMBRT, offering improved tumour control with minimized impact on healthy tissues. This study provides a foundation for further advancements in collimator technology and its clinical applications in treating uveal melanoma and other challenging tumour sites.

{"title":"Optimizing minibeam collimator design for enhancing normal tissue sparing in ocular tumour proton therapy","authors":"Tsz-Yui Chan , Chien-Yu Lin , Shen-Hao Lee , Jiunn-Woei Liaw , Tsi-Chian Chao , I-Chun Cho","doi":"10.1016/j.radphyschem.2025.112674","DOIUrl":"10.1016/j.radphyschem.2025.112674","url":null,"abstract":"<div><div>Uveal melanoma, the most common primary intraocular tumour in adults, presents significant therapeutic challenges due to its aggressive nature and the potential for severe treatment-related complications, including vision loss. Achieving effective tumour control while minimizing damage to surrounding healthy tissues remains a critical goal in radiotherapy. Proton minibeam radiotherapy (pMBRT), an advanced form of spatially fractionated radiotherapy (SFRT), has emerged as a promising approach to address these challenges.</div><div>pMBRT employs a mechanical collimator to spatially fractionate a broad proton beam into multiple narrow beamlets, creating a dose distribution with high-dose peaks and low-dose valleys in shallow regions. As the beamlets travel deeper into tissue, multiple Coulomb scattering facilitates their convergence, resulting in a uniform dose at the tumour target.</div><div>This study systematically optimized the collimator design by evaluating various geometries and materials, specifically brass and polylactic acid (PLA). Simulations of dose distributions were performed using the Tool for Particle Simulation (TOPAS) and validated through experimental measurements with Gafchromic films. Results indicated that brass collimators, with their high atomic number, produced sharper dose profiles and higher peak-to-valley dose ratios (PVDR), demonstrating superior spatial dose modulation. Conversely, PLA collimators yielded smoother dose profiles and lower secondary dose contributions, showcasing their potential for reducing collateral tissue damage.</div><div>The optimized collimator design, featuring a 0.8 mm slit width and a 1 mm spacing, achieved an ideal balance between maximizing PVDR and ensuring uniform beam recombination at the target depth. These findings underscore the potential of tailored collimator designs to enhance the therapeutic precision of pMBRT, offering improved tumour control with minimized impact on healthy tissues. This study provides a foundation for further advancements in collimator technology and its clinical applications in treating uveal melanoma and other challenging tumour sites.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112674"},"PeriodicalIF":2.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploration of the gamma-ray shielding capabilities of tungsten oxide and chromium-infused silicone rubber composites

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-03-01 DOI: 10.1016/j.radphyschem.2025.112661

B.P. Srilakshmi , A. Jagannatha Reddy , M.R. Ambika , Sherry Shajan Kuttukaran , Yeshwanth H. Reddy , N. Nagaiah , D.N. Deepika , Kalappa Prashantha

Gamma rays are highly energetic type of ionizing radiation important in medical diagnostics, which requires effective protective measures. Polymers reinforced with appropriate fillers can offer excellent radiation shielding properties comparable to conventional materials. This study investigates the gamma radiation shielding efficiency of silicone rubber reinforced with tungsten oxide (WO₃) and chromium (Cr). Composites with fixed 30 phr WO₃ and varying Cr concentrations (10–70 phr) were fabricated and characterized. Field Emission Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy (FESEM/EDX) confirmed uniform filler dispersion, while FTIR showed no significant chemical changes. X-ray diffraction (XRD) analysis revealed average crystallite sizes of 11–32 nm (Scherrer's formula) and 16–39 nm (Williamson-Hall plot). The mechanical properties were explored using a Universal Testing Machine (UTM), revealing that an increase in filler content correlated with enhanced tensile strength and hardness. Gamma attenuation studies (using Cs-137 and Ba-133 sources) revealed the excellent efficiency of the composite with 30 phr WO₃ and 50 phr Cr (3WO5C) with Mass Attenuation Coefficients (MAC) increasing from 1.45, 0.202, and 0.103 cm²/g to 1.57, 0.258, and 0.129 cm²/g, and half-value layer (HVL) thickness decreasing from 0.356, 2.551, and 6.722 cm to 0.269, 1.642, and 5.366 cm, for gamma energies 80, 356 and 662 keV respectively. Critically, these composites are significantly lighter than lead, offering improved shielding performance at a reduced weight.

{"title":"Exploration of the gamma-ray shielding capabilities of tungsten oxide and chromium-infused silicone rubber composites","authors":"B.P. Srilakshmi , A. Jagannatha Reddy , M.R. Ambika , Sherry Shajan Kuttukaran , Yeshwanth H. Reddy , N. Nagaiah , D.N. Deepika , Kalappa Prashantha","doi":"10.1016/j.radphyschem.2025.112661","DOIUrl":"10.1016/j.radphyschem.2025.112661","url":null,"abstract":"<div><div>Gamma rays are highly energetic type of ionizing radiation important in medical diagnostics, which requires effective protective measures. Polymers reinforced with appropriate fillers can offer excellent radiation shielding properties comparable to conventional materials. This study investigates the gamma radiation shielding efficiency of silicone rubber reinforced with tungsten oxide (WO<sub>3</sub>) and chromium (Cr). Composites with fixed 30 phr WO<sub>3</sub> and varying Cr concentrations (10–70 phr) were fabricated and characterized. Field Emission Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy (FESEM/EDX) confirmed uniform filler dispersion, while FTIR showed no significant chemical changes. X-ray diffraction (XRD) analysis revealed average crystallite sizes of 11–32 nm (Scherrer's formula) and 16–39 nm (Williamson-Hall plot). The mechanical properties were explored using a Universal Testing Machine (UTM), revealing that an increase in filler content correlated with enhanced tensile strength and hardness. Gamma attenuation studies (using Cs-137 and Ba-133 sources) revealed the excellent efficiency of the composite with 30 phr WO<sub>3</sub> and 50 phr Cr (3WO5C) with Mass Attenuation Coefficients (MAC) increasing from 1.45, 0.202, and 0.103 cm<sup>2</sup>/g to 1.57, 0.258, and 0.129 cm<sup>2</sup>/g, and half-value layer (HVL) thickness decreasing from 0.356, 2.551, and 6.722 cm to 0.269, 1.642, and 5.366 cm, for gamma energies 80, 356 and 662 keV respectively. Critically, these composites are significantly lighter than lead, offering improved shielding performance at a reduced weight.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112661"},"PeriodicalIF":2.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comprehensive characterization of proton pencil beam profiles using a novel couch-mounted 2D strip detector system

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-02-28 DOI: 10.1016/j.radphyschem.2025.112663

Hsiao-Chieh Huang , Hsien-Hsin Chen , Chih-Hsun Lin , Fu-Xiong Chang , Wei-Heng Kao , Po-Jui Chen , Tsi-Chian Chao

Proton therapy has gained prominence in recent years, with over 300,000 patients treated worldwide using advanced techniques like pencil beam scanning (PBS). Accurate measurement of proton beam characteristics is crucial for optimizing treatment plans and ensuring patient safety. This study introduces a novel two-dimensional strip detector system, CROSS, integrated with a programmable couch mount, designed to evaluate proton beam properties across various gantry angles. The CROSS detector's performance was validated through comparisons with a pinpoint chamber, Gafchromic EBT3 film, and the XRV-124 detector. Spot size measurements showed a slight increase compared to the pinpoint chamber, with average deviations of 11.3% in the Y-direction and 6.3% in the X-direction. Spot position accuracy tests demonstrated excellent agreement with EBT3 film, with an average positional deviation of 0.11 ± 0.06 mm, and all deviations remaining within 0.2 mm. The beam characteristics across different gantry angles showed maximum spot size variations of 0.17 mm in the Y-axis and 0.11 mm in the X-axis. Proton isocenter measurements with CROSS were largely consistent with XRV-124, with deviations under 0.2 mm in most cases, except for gantry angles of 90° and 315°, where deviations of 0.25 mm and 0.33 mm were observed. These findings highlight the CROSS detector's precision and versatility, making it a valuable tool for quality assurance in proton therapy.

{"title":"Comprehensive characterization of proton pencil beam profiles using a novel couch-mounted 2D strip detector system","authors":"Hsiao-Chieh Huang , Hsien-Hsin Chen , Chih-Hsun Lin , Fu-Xiong Chang , Wei-Heng Kao , Po-Jui Chen , Tsi-Chian Chao","doi":"10.1016/j.radphyschem.2025.112663","DOIUrl":"10.1016/j.radphyschem.2025.112663","url":null,"abstract":"<div><div>Proton therapy has gained prominence in recent years, with over 300,000 patients treated worldwide using advanced techniques like pencil beam scanning (PBS). Accurate measurement of proton beam characteristics is crucial for optimizing treatment plans and ensuring patient safety. This study introduces a novel two-dimensional strip detector system, CROSS, integrated with a programmable couch mount, designed to evaluate proton beam properties across various gantry angles. The CROSS detector's performance was validated through comparisons with a pinpoint chamber, Gafchromic EBT3 film, and the XRV-124 detector. Spot size measurements showed a slight increase compared to the pinpoint chamber, with average deviations of 11.3% in the Y-direction and 6.3% in the X-direction. Spot position accuracy tests demonstrated excellent agreement with EBT3 film, with an average positional deviation of 0.11 ± 0.06 mm, and all deviations remaining within 0.2 mm. The beam characteristics across different gantry angles showed maximum spot size variations of 0.17 mm in the Y-axis and 0.11 mm in the X-axis. Proton isocenter measurements with CROSS were largely consistent with XRV-124, with deviations under 0.2 mm in most cases, except for gantry angles of 90° and 315°, where deviations of 0.25 mm and 0.33 mm were observed. These findings highlight the CROSS detector's precision and versatility, making it a valuable tool for quality assurance in proton therapy.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112663"},"PeriodicalIF":2.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of electron beam irradiation on properties of EVA/HDPE blends with intumescent flame retardants

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-02-28 DOI: 10.1016/j.radphyschem.2025.112664

Sangwon Park , Hyun-Rae Kim , Sang-Yun Kang , Seung-Tae Jung , Young-Chang Nho , Jong-Seok Park , Byoung-Min Lee , Jae-Hak Choi

Conventional thermoplastics are widely used as insulating materials in various industrial fields, but various research efforts are being conducted to improve their thermal stability and flame retardancy. In this study, poly(ethylene-co-vinyl acetate) (EVA)/high-density polyethylene (HDPE)/intumescent flame retardants (IFRs) blends were prepared, and changes in properties were investigated according to the IFRs contents and electron beam irradiation conditions. As the content of IFRs increased, the flame retardancy of the blends improved significantly, but mechanical properties deteriorated. Mechanical properties, thermal stability, and flame retardancy were enhanced by electron beam irradiation, attributed to the formation of crosslinked network structures. UL-94 vertical tests results revealed that blends containing more than 50 g of IFRs and irradiated at 100 kGy exhibited a UL-94 V-0 rating. Therefore, the EVA/HDPE/IFRs blends prepared in this study can be applied as insulating materials with excellent thermal stability, mechanical properties, and flame retardancy.

{"title":"Effect of electron beam irradiation on properties of EVA/HDPE blends with intumescent flame retardants","authors":"Sangwon Park , Hyun-Rae Kim , Sang-Yun Kang , Seung-Tae Jung , Young-Chang Nho , Jong-Seok Park , Byoung-Min Lee , Jae-Hak Choi","doi":"10.1016/j.radphyschem.2025.112664","DOIUrl":"10.1016/j.radphyschem.2025.112664","url":null,"abstract":"<div><div>Conventional thermoplastics are widely used as insulating materials in various industrial fields, but various research efforts are being conducted to improve their thermal stability and flame retardancy. In this study, poly(ethylene-co-vinyl acetate) (EVA)/high-density polyethylene (HDPE)/intumescent flame retardants (IFRs) blends were prepared, and changes in properties were investigated according to the IFRs contents and electron beam irradiation conditions. As the content of IFRs increased, the flame retardancy of the blends improved significantly, but mechanical properties deteriorated. Mechanical properties, thermal stability, and flame retardancy were enhanced by electron beam irradiation, attributed to the formation of crosslinked network structures. UL-94 vertical tests results revealed that blends containing more than 50 g of IFRs and irradiated at 100 kGy exhibited a UL-94 V-0 rating. Therefore, the EVA/HDPE/IFRs blends prepared in this study can be applied as insulating materials with excellent thermal stability, mechanical properties, and flame retardancy.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112664"},"PeriodicalIF":2.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Positron driven molecular processes for H2CO, NO2 and HCN

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-02-28 DOI: 10.1016/j.radphyschem.2025.112643

Neha Barad, Smruti Parikh, Chetan Limbachiya

In this work, we report results of comprehensive study of positron driven molecular chemistry for planetary compounds, H₂CO, NO₂ and HCN. All these molecules are highly polar in nature making the positron-molecule interaction more sensitive to polarization potential at lower energies. We have employed a novel approach to construct the polarization potential that takes Positron Correlation Polarization (PCP) to determine the energy independent cut-off thereby properly accounting for the short range effects. We have quantified various molecular processes initiated due to positron interaction by evaluating elastic (

Q_{e l}

), inelastic (

Q_{i n e l}

), direct ionization (

Q_{D - i o n}

), positronium formation (

Q_{P s}

), total ionization (

Q_{i o n}

) and total cross-sections (

Q_{t o t}

) for the wide energy span from circa 1 eV–5000 eV using modified Spherical Complex Optical Potential (SCOP) method. Positron driven ionization is investigated using Complex Scattering Potential – ionization contribution (CSP-ic) method. In this work, positronim formation and direct ionization channels are reported for the first time, except for H₂CO. This study aims to find probabilities for different positron assisted processes for these molecules using the quantum chemical treatment that can contribute to improve various models of atmospheric chemistry.

{"title":"Positron driven molecular processes for H2CO, NO2 and HCN","authors":"Neha Barad, Smruti Parikh, Chetan Limbachiya","doi":"10.1016/j.radphyschem.2025.112643","DOIUrl":"10.1016/j.radphyschem.2025.112643","url":null,"abstract":"<div><div>In this work, we report results of comprehensive study of positron driven molecular chemistry for planetary compounds, H<sub>2</sub>CO, NO<sub>2</sub> and HCN. All these molecules are highly polar in nature making the positron-molecule interaction more sensitive to polarization potential at lower energies. We have employed a novel approach to construct the polarization potential that takes Positron Correlation Polarization (PCP) to determine the energy independent cut-off thereby properly accounting for the short range effects. We have quantified various molecular processes initiated due to positron interaction by evaluating elastic (<span><math><mrow><msub><mi>Q</mi><mrow><mi>e</mi><mi>l</mi></mrow></msub></mrow></math></span>), inelastic (<span><math><mrow><msub><mi>Q</mi><mrow><mi>i</mi><mi>n</mi><mi>e</mi><mi>l</mi></mrow></msub></mrow></math></span>), direct ionization (<span><math><mrow><msub><mi>Q</mi><mrow><mi>D</mi><mo>−</mo><mi>i</mi><mi>o</mi><mi>n</mi></mrow></msub></mrow></math></span>), positronium formation (<span><math><mrow><msub><mi>Q</mi><mrow><mi>P</mi><mi>s</mi></mrow></msub></mrow></math></span>), total ionization (<span><math><mrow><msub><mi>Q</mi><mrow><mi>i</mi><mi>o</mi><mi>n</mi></mrow></msub></mrow></math></span>) and total cross-sections (<span><math><mrow><msub><mi>Q</mi><mrow><mi>t</mi><mi>o</mi><mi>t</mi></mrow></msub></mrow></math></span>) for the wide energy span from circa 1 eV–5000 eV using modified Spherical Complex Optical Potential (SCOP) method. Positron driven ionization is investigated using Complex Scattering Potential – ionization contribution (CSP-ic) method. In this work, positronim formation and direct ionization channels are reported for the first time, except for H<sub>2</sub>CO. This study aims to find probabilities for different positron assisted processes for these molecules using the quantum chemical treatment that can contribute to improve various models of atmospheric chemistry.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112643"},"PeriodicalIF":2.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis, structural, linear/nonlinear optical properties, and radiation shielding potential of iron silicate (Fe2SiO4) nanoparticles for multi-functional applications

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-02-27 DOI: 10.1016/j.radphyschem.2025.112619

Ahmed M. Hassan , B.M. Alotaibi , Ahmed S. Ali , Shams A. M. Issa , Hesham M.H. Zakaly

In this study, Fe-doped SiO₂ nanoparticles (Fe–SiO₂ NPs) were synthesized using the sol-gel method to investigate their structural, and linear/nonlinear optical attributes as well as radiation shielding properties. The doping levels of Fe ranged from 0% to 12%. The X-ray diffraction (XRD) analysis confirmed the hexagonal structure of the SiO₂ matrix with the incorporation of a iron silicate cubic phase (Fe₂SiO₄) and minor peaks of monoclinic Fe₂O₃. With increasing Fe concentrations, the crystallite size increased from 39 nm to 48 nm, while lattice strain and dislocation density decreased. The optical measurements revealed a red shift in the absorption spectra with Fe doping, and the bandgap decreased from 5.65 eV for undoped SiO₂ to 5.26 eV for SOF-12. Nonlinear optical properties were significantly enhanced with Fe doping, as evidenced by the third-order nonlinear susceptibility (χ³) increased by more than double as Fe concentrations increased. Additionally, the nonlinear refractive index (n₂) exhibited a sharp increase with Fe content, indicating potential for nonlinear photonic applications. Radiation shielding assessments revealed a mass attenuation coefficient of 10.987 cm²/g at 0.015 MeV and a half-value layer of 3.36 cm at 1 MeV for the 12% Fe-doped sample (SOF-12), demonstrating superior lightweight shielding efficiency compared to conventional materials. These results demonstrate that Fe-doped SiO₂ NPs possess favorable structural and optical characteristics, making them promising candidates for applications in optoelectronics, radiation shielding, and photonic devices.

{"title":"Synthesis, structural, linear/nonlinear optical properties, and radiation shielding potential of iron silicate (Fe2SiO4) nanoparticles for multi-functional applications","authors":"Ahmed M. Hassan , B.M. Alotaibi , Ahmed S. Ali , Shams A. M. Issa , Hesham M.H. Zakaly","doi":"10.1016/j.radphyschem.2025.112619","DOIUrl":"10.1016/j.radphyschem.2025.112619","url":null,"abstract":"<div><div>In this study, Fe-doped SiO<sub>2</sub> nanoparticles (Fe–SiO<sub>2</sub> NPs) were synthesized using the sol-gel method to investigate their structural, and linear/nonlinear optical attributes as well as radiation shielding properties. The doping levels of Fe ranged from 0% to 12%. The X-ray diffraction (XRD) analysis confirmed the hexagonal structure of the SiO<sub>2</sub> matrix with the incorporation of a iron silicate cubic phase (Fe<sub>2</sub>SiO<sub>4</sub>) and minor peaks of monoclinic Fe<sub>2</sub>O<sub>3</sub>. With increasing Fe concentrations, the crystallite size increased from 39 nm to 48 nm, while lattice strain and dislocation density decreased. The optical measurements revealed a red shift in the absorption spectra with Fe doping, and the bandgap decreased from 5.65 eV for undoped SiO<sub>2</sub> to 5.26 eV for SOF-12. Nonlinear optical properties were significantly enhanced with Fe doping, as evidenced by the third-order nonlinear susceptibility (χ<sup>3</sup>) increased by more than double as Fe concentrations increased. Additionally, the nonlinear refractive index (n<sub>2</sub>) exhibited a sharp increase with Fe content, indicating potential for nonlinear photonic applications. Radiation shielding assessments revealed a mass attenuation coefficient of 10.987 cm<sup>2</sup>/g at 0.015 MeV and a half-value layer of 3.36 cm at 1 MeV for the 12% Fe-doped sample (SOF-12), demonstrating superior lightweight shielding efficiency compared to conventional materials. These results demonstrate that Fe-doped SiO<sub>2</sub> NPs possess favorable structural and optical characteristics, making them promising candidates for applications in optoelectronics, radiation shielding, and photonic devices.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112619"},"PeriodicalIF":2.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of γ-irradiation on surface morphology, microstructure and diffuse reflectance of polytetrafluoroethylene

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-02-27 DOI: 10.1016/j.radphyschem.2025.112650

A.S. Smolyanskii , M.I. Ikim , S.M. Ryndya , D.P. Kiryukhin , L.I. Trakhtenberg

The effect of γ-irradiation on the structural, morphological and optical properties of polytetrafluoroethylene was studied at an absorbed dose of 0.1 kGy. It has been shown that such a dose leads to an increase in the diffuse reflectance coefficient by 28% in the spectral range of 220–850 nm. The maximum effect is observed in the wavelength range from 300 to 400 nm. A correlation between radiation-induced changes in the surface microstructure and the enhancement of light reflection from γ-irradiated PTFE was established.

引用次数: 0

Anisotropic stressed radiation induced synthesis of N-Isopropylacrylamide gel: Effect on swelling extent and types of waters

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-02-27 DOI: 10.1016/j.radphyschem.2025.112647

Khushboo Varshney , K.V. Vivekananda , B.N. Kaul , R.K. Mondal , K.A. Dubey , Y.K. Bhardwaj

Thermosensitive poly (N-Isopropylacrylamide) gels were prepared by simultaneous polymerization and crosslinking of monomer using high energy gamma radiation at room temperature and at temperatures well below the LCST of N-Isopropylacrylamide. It was observed that at very low temperature (−78°C) only there is significant effect on equilibrium water uptake that too at significantly high dose. The mechanical properties of the gels also depend on the dose and synthesis temperature. But the temperature effect gets nullified as the absorbed dose increases.

引用次数: 0

Occupational radiation dose assessment of professionals working in a nuclear medicine and PET/CT centre

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-02-27 DOI: 10.1016/j.radphyschem.2025.112648

Essam M. Alkhybari , Jafar M. Faqeeh , Abdulrahman A. Albatly , Salman Altimyat , Turki Alruwaili , Khaled Soliman , Hanaa Alsheikh , Saeed Mueed Al-Qahtani , Asim Abualnaja , Waleed Suliman Alrakaf , Wadha Alyami , Faisal Alahmari , Abdelmoneim Sulieman , David A. Bradley

Nuclear medicine (NM) and positron emission tomography/computed tomography (PET/CT) personnel are daily exposed to radiation dose, their protection being crucial. This study of occupational doses within the NM and PET/CT department of a large Riyadh tertiary covers the period 2019 to 2022. Calibrated optically stimulated luminescence dosimeters (OSLD) were utilized to determine personal dose equivalent Hp(10). Both departments perform a wide range of adult and paediatric examinations, involving 18 technologists, 4 NM physicians, 2 nurses and 2 medical physicists; quoted in mSv. The average annual whole-body occupational radiation exposure for technologists, nurses, medical physicists and NM physicians over 4 years was 0.72, 0.94, 0.51 and 0.16 mSv, respectively. The reported annual occupational whole-body exposure for NM staff groups were in the acceptable range of published peer-reviewed data in the literature. However, a careful evaluation of working conditions for the nurse group is recommended to further minimise the radiation doses attributed to the recent increase in the number of single photon emission computed tomography (SPECT) and PET diagnostic workload examinations. However, annual staff doses were found to be below the value recommended by the International Commission on Radiological Protection (ICRP).

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引用次数: 0

Analytical and Monte Carlo approaches for photon and neutron Kerma coefficient determination in gel-like polymer dosimeters

IF 2.8 3区物理与天体物理 Q3 CHEMISTRY, PHYSICAL

Radiation Physics and Chemistry

Pub Date : 2025-02-26 DOI: 10.1016/j.radphyschem.2025.112651

Rahim Khabaz , Harith Mohamed Al-Azri

Dosimetry in radiation therapy and nuclear applications relies on accurate determination of Kerma coefficients for photons and neutrons. This study investigates photon and neutron Kerma coefficients for 15 gel-like polymer dosimeters using analytical and Monte Carlo methods. Analytical calculations involve 36 photon energies (1 keV–20 MeV) and 39 neutron energies (2.53 × 10⁻⁸ MeV–25 MeV), while Monte Carlo simulations were executed using MCNPX-2.6 code. Results show a good agreement between methods. Photon Kerma coefficients exhibit nuanced energy dependence, with a minimum around 60 keV, followed by sharp increase due to Compton scattering and pairs production processes. Neutron Kerma coefficients display distinct responses across energy regimes, with discrepancies at lower energies attributed to significant Kerma contribution from neutron capture in nitrogen component. Relative concentrations of nitrogen and hydrogen influence tissue equivalence of gel dosimeters, achieving effectiveness for intermediate and fast neutron energies. This research enhances understanding of photon and neutron interactions within gel dosimeters, crucial for precise dosimetry in biological contexts. Future studies could explore additional dosimeter compositions and energy ranges, further advancing knowledge of radiation interactions in gel dosimeters. Overall, these findings contribute to the dosimetry field, particularly in conformal radiotherapy and 3D dose distribution verification.

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引用次数: 0

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