Pub Date : 2024-08-05DOI: 10.3389/fphy.2024.1435767
Razvan G. Romanescu
Compartmental models of disease spread have been well studied on networks built according to the Configuration Model, i.e., where the degree distribution of individual nodes is specified, but where connections are made randomly. Dynamics of spread on such “first order” networks were shown to be profoundly different compared to epidemics under the traditional mass action assumption. Assortativity, i.e., the preferential mixing of nodes according to degree, is a second order property that is thought to impact epidemic trajectory. We first show how assortative mixing can come about from individual preferences to connect with others of lower or higher degree, and propose an algorithm for constructing such a network. We then investigate via simulation how this network structure favors or inhibits diffusion processes, such as the spread of an infectious disease.
{"title":"Building a network with assortative mixing starting from preference functions, with application to the spread of epidemics","authors":"Razvan G. Romanescu","doi":"10.3389/fphy.2024.1435767","DOIUrl":"https://doi.org/10.3389/fphy.2024.1435767","url":null,"abstract":"Compartmental models of disease spread have been well studied on networks built according to the Configuration Model, i.e., where the degree distribution of individual nodes is specified, but where connections are made randomly. Dynamics of spread on such “first order” networks were shown to be profoundly different compared to epidemics under the traditional mass action assumption. Assortativity, i.e., the preferential mixing of nodes according to degree, is a second order property that is thought to impact epidemic trajectory. We first show how assortative mixing can come about from individual preferences to connect with others of lower or higher degree, and propose an algorithm for constructing such a network. We then investigate via simulation how this network structure favors or inhibits diffusion processes, such as the spread of an infectious disease.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945749","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}
Pub Date : 2024-08-05DOI: 10.3389/fphy.2024.1405435
Esmat Ghorbanpour, Fabio Belloni
We have revisited recent results on the ideal ignition of H11B fuel, in the light of the latest available reactivity, an alternative self-consistent calculation of the electron temperature, an increased extent of the suprathermal effects and the impact of plasma density. At high density, we find that the ideal ignition temperature is appreciably relaxed (e.g., Ti≃150 keV for ni∼1026cm−3 and an optimal 11B/H concentration ε=0.15) and burn becomes substantial. We have then investigated central hot-spot ignition in both isobaric and isochoric inertial confinement configurations. Although implosion-driven ignition appears to be unfeasible, the isochoric self-heating conditions foster favourable preliminary conclusions on the utilization of proton fast ignition. In the isochoric case, we find a broad minimum in the ignition energy at ρR≃8.5g/cm2 and 220≲Ti≲340 keV (80 ≲Te≲95 keV), for ε=0.15.
{"title":"On the ignition of H11B fusion fuel","authors":"Esmat Ghorbanpour, Fabio Belloni","doi":"10.3389/fphy.2024.1405435","DOIUrl":"https://doi.org/10.3389/fphy.2024.1405435","url":null,"abstract":"We have revisited recent results on the ideal ignition of H<jats:sup>11</jats:sup>B fuel, in the light of the latest available reactivity, an alternative self-consistent calculation of the electron temperature, an increased extent of the suprathermal effects and the impact of plasma density. At high density, we find that the ideal ignition temperature is appreciably relaxed (e.g., <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:msub><mml:mi>T</mml:mi><mml:mi>i</mml:mi></mml:msub><mml:mo>≃</mml:mo><mml:mn>150</mml:mn><mml:mtext> keV</mml:mtext></mml:mrow></mml:math></jats:inline-formula> for <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:msub><mml:mi>n</mml:mi><mml:mi>i</mml:mi></mml:msub><mml:mo>∼</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mn>26</mml:mn></mml:msup><mml:mtext> </mml:mtext><mml:msup><mml:mtext>cm</mml:mtext><mml:mrow><mml:mo>−</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math></jats:inline-formula> and an optimal <jats:sup>11</jats:sup>B/H concentration <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:mi>ε</mml:mi><mml:mo>=</mml:mo><mml:mn>0.15</mml:mn></mml:mrow></mml:math></jats:inline-formula>) and burn becomes substantial. We have then investigated central hot-spot ignition in both isobaric and isochoric inertial confinement configurations. Although implosion-driven ignition appears to be unfeasible, the isochoric self-heating conditions foster favourable preliminary conclusions on the utilization of proton fast ignition. In the isochoric case, we find a broad minimum in the ignition energy at <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:mi>ρ</mml:mi><mml:mi>R</mml:mi><mml:mo>≃</mml:mo><mml:mn>8.5</mml:mn><mml:mtext> </mml:mtext><mml:mi mathvariant=\"normal\">g</mml:mi><mml:mo>/</mml:mo><mml:msup><mml:mtext>cm</mml:mtext><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math></jats:inline-formula> and <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:mn>220</mml:mn><mml:mo>≲</mml:mo><mml:msub><mml:mi>T</mml:mi><mml:mi>i</mml:mi></mml:msub><mml:mo>≲</mml:mo><mml:mn>340</mml:mn><mml:mtext> keV</mml:mtext></mml:mrow></mml:math></jats:inline-formula> (80 <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:mo>≲</mml:mo></mml:mrow></mml:math></jats:inline-formula><jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:msub><mml:mi>T</mml:mi><mml:mi>e</mml:mi></mml:msub><mml:mo>≲</mml:mo><mml:mn>95</mml:mn><mml:mtext> keV</mml:mtext></mml:mrow></mml:math></jats:inline-formula>), for <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:mi>ε</mml:mi><mml:mo>=</mml:mo><mml:mn>0.15</mml:mn></mml:mrow></mml:math></jats:inline-formula>.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"15 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945750","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}
Pub Date : 2024-08-02DOI: 10.3389/fphy.2024.1432783
Ning Zhao, Yongyi Fang, Siying Wang, Qian Li, Xiaonan Wang, Chi Feng
Identifying cable insulation defects is crucial for preventing system failures and ensuring the reliability of electrical infrastructure. This paper introduces a novel method leveraging the Markov transition field (MTF) and Transformer network to improve the precision of cable insulation defect identification and enhance the algorithm's noise resistance. Firstly, the algorithm performs modal transformation on the time series data acquired by the ultrasonic probe through MTF, generating corresponding images. Following this, the image data are input into a pre-trained Transformer network to achieve automated feature extraction. Subsequently, a multi-head attention mechanism is introduced, which assigns weights to the features extracted by the Transformer network, thereby emphasizing the most critical information for the identification task. Finally, more accurate defect identification is achieved based on the weighted features. The results demonstrate that this method achieves higher accuracy and stronger noise resistance compared to traditional image processing and recognition methods, making it a robust solution for cable insulation defect identification.
{"title":"Research on the identification method of cable insulation defects based on Markov transition fields and transformer networks","authors":"Ning Zhao, Yongyi Fang, Siying Wang, Qian Li, Xiaonan Wang, Chi Feng","doi":"10.3389/fphy.2024.1432783","DOIUrl":"https://doi.org/10.3389/fphy.2024.1432783","url":null,"abstract":"Identifying cable insulation defects is crucial for preventing system failures and ensuring the reliability of electrical infrastructure. This paper introduces a novel method leveraging the Markov transition field (MTF) and Transformer network to improve the precision of cable insulation defect identification and enhance the algorithm's noise resistance. Firstly, the algorithm performs modal transformation on the time series data acquired by the ultrasonic probe through MTF, generating corresponding images. Following this, the image data are input into a pre-trained Transformer network to achieve automated feature extraction. Subsequently, a multi-head attention mechanism is introduced, which assigns weights to the features extracted by the Transformer network, thereby emphasizing the most critical information for the identification task. Finally, more accurate defect identification is achieved based on the weighted features. The results demonstrate that this method achieves higher accuracy and stronger noise resistance compared to traditional image processing and recognition methods, making it a robust solution for cable insulation defect identification.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"4 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883630","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}
Pub Date : 2024-08-02DOI: 10.3389/fphy.2024.1433208
Wolfgang Lechner, Barbara Knäusl, Jacob Brunner, Dietmar Georg, Peter Kuess
This work aimed to characterize a dedicated phantom for assessing the dose near metal implants for radiotherapy with photons and protons. A dosimetry audit phantom was redesigned to position a Gafchromic EBT-3 film within a bisected titanium pedicle screw (6.5 mm diameter). The mass density and the water equivalent thickness (WET) of the phantom material were determined. The phantom was irradiated using a photon arc and a horizontal proton beam in combination with a couch rotation of 20°, with three repeated measurements each. Treatment plans utilizing a single field covering the screw and the EBT-3 film were optimized to deliver a physical dose of 2 Gy using a collapsed cone and Monte Carlo dose engine for photons and protons, respectively. The mass density and the WET of the phantom were determined as (1.033 ± 0.010) gcm−3 and (1.022 ± 0.013), respectively. Ionisation chamber measurements agreed within 1% (photons) and 0.5% (protons) with the calculated dose values. Relative photon dosimetry measurements using EBT-3 films revealed an agreement between measured and calculated horizontal profiles within the confidence interval for areas beyond 5 mm from the center. For photon plans, significant deviations of more than 10% were found at the interfaces between phantom material and screw. The proton measurements showed a gradual decrease of 3% across both profiles. In contrast to photon plans, no dose increase was measured within the screw, but significant dose fluctuations (>5%) in the beam’s exit region. This study showed that the behavior of dose engine is affected by metal implants and thus dosimetric measurements are highly recommended. The presented phantom can serve as foundation for dedicated end-2-end phantoms.
{"title":"A phantom for 2D dose measurements in the vicinity of metal implants for photon and proton beams","authors":"Wolfgang Lechner, Barbara Knäusl, Jacob Brunner, Dietmar Georg, Peter Kuess","doi":"10.3389/fphy.2024.1433208","DOIUrl":"https://doi.org/10.3389/fphy.2024.1433208","url":null,"abstract":"This work aimed to characterize a dedicated phantom for assessing the dose near metal implants for radiotherapy with photons and protons. A dosimetry audit phantom was redesigned to position a Gafchromic EBT-3 film within a bisected titanium pedicle screw (6.5 mm diameter). The mass density and the water equivalent thickness (WET) of the phantom material were determined. The phantom was irradiated using a photon arc and a horizontal proton beam in combination with a couch rotation of 20°, with three repeated measurements each. Treatment plans utilizing a single field covering the screw and the EBT-3 film were optimized to deliver a physical dose of 2 Gy using a collapsed cone and Monte Carlo dose engine for photons and protons, respectively. The mass density and the WET of the phantom were determined as (1.033 <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mo>±</mml:mo></mml:math></jats:inline-formula> 0.010) <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mi mathvariant=\"normal\">g</mml:mi><mml:mspace width=\"0.17em\"/><mml:msup><mml:mrow><mml:mi mathvariant=\"normal\">c</mml:mi><mml:mi mathvariant=\"normal\">m</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math></jats:inline-formula> and (1.022 <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mo>±</mml:mo></mml:math></jats:inline-formula> 0.013), respectively. Ionisation chamber measurements agreed within 1% (photons) and 0.5% (protons) with the calculated dose values. Relative photon dosimetry measurements using EBT-3 films revealed an agreement between measured and calculated horizontal profiles within the confidence interval for areas beyond 5 mm from the center. For photon plans, significant deviations of more than 10% were found at the interfaces between phantom material and screw. The proton measurements showed a gradual decrease of 3% across both profiles. In contrast to photon plans, no dose increase was measured within the screw, but significant dose fluctuations (<jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mo>></mml:mo></mml:math></jats:inline-formula>5%) in the beam’s exit region. This study showed that the behavior of dose engine is affected by metal implants and thus dosimetric measurements are highly recommended. The presented phantom can serve as foundation for dedicated end-2-end phantoms.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"20 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883632","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}
Introduction: The emergence of collective behavior often depends on the adequate interaction of individuals through self-organization and the exchange of local information. When facing external threats, communication among individuals requires both rapid and effective information exchange to characterize sudden events. In this paper, we introduce the mechanism of emotions into the modeling of dynamics to study collective avoidance behavior in response to threats.Methods: A scenario involving a hidden dynamic threat is constructed to test the avoidance and survival capabilities of the collective when faced with a lack of effective information. By employing the activation and spread of emotion in modeling, the collective may self-organized and adeptly mitigate risks and enhance their own benefits.Results: Through adjustments to the intensity of emotional activation, spread, and decay, rich behaviors emerge. Relying on the regulation of emotion, the collective exhibits different response strategies and action patterns when facing threats, in which the optimal performance from the macroscopic level is expectable.Discussion: By analyzing these phenomena, it can enhance our understanding of the emotional states of collective in response to threats and the methods of controlling in intelligent collective motion.
{"title":"How fear emotion impacts collective motion in threat environment","authors":"Yi-Xuan Lü, Si-Ping Zhang, Guan-Yu Meng, Bing-Hui Guo, Xiao-Long Liang, Zhi-Xi Wu, Zi-Gang Huang","doi":"10.3389/fphy.2024.1394983","DOIUrl":"https://doi.org/10.3389/fphy.2024.1394983","url":null,"abstract":"Introduction: The emergence of collective behavior often depends on the adequate interaction of individuals through self-organization and the exchange of local information. When facing external threats, communication among individuals requires both rapid and effective information exchange to characterize sudden events. In this paper, we introduce the mechanism of emotions into the modeling of dynamics to study collective avoidance behavior in response to threats.Methods: A scenario involving a hidden dynamic threat is constructed to test the avoidance and survival capabilities of the collective when faced with a lack of effective information. By employing the activation and spread of emotion in modeling, the collective may self-organized and adeptly mitigate risks and enhance their own benefits.Results: Through adjustments to the intensity of emotional activation, spread, and decay, rich behaviors emerge. Relying on the regulation of emotion, the collective exhibits different response strategies and action patterns when facing threats, in which the optimal performance from the macroscopic level is expectable.Discussion: By analyzing these phenomena, it can enhance our understanding of the emotional states of collective in response to threats and the methods of controlling in intelligent collective motion.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"75 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883503","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}
Pub Date : 2024-07-31DOI: 10.3389/fphy.2024.1444266
Chuhan Shang, Zhang Lieping, Khaled A. Gepreel, Huaian Yi
Due to the self-affine property of the grinding surface, the sample images with different roughness captured by the micron-scale camera exhibit certain similarities. This similarity affects the prediction accuracy of the deep learning model. In this paper, we propose an illumination method that can mitigate the impact of self-affinity using the two-scale fractal theory as a foundation. This is followed by the establishment of a machine vision detection method that integrates a neural network and correlation function. Initially, a neural network is employed to categorize and forecast the microscopic image of the workpiece surface, thereby determining its roughness category. Subsequently, the corresponding correlation function is determined in accordance with the established roughness category. Finally, the surface roughness of the workpiece was calculated based on the correlation function. The experimental results demonstrate that images obtained using this lighting method exhibit significantly enhanced accuracy in neural network classification. In comparison to traditional lighting methods, the accuracy of this method on the micrometer scale has been found to have significantly increased from approximately 50% to over 95%. Concurrently, the mean squared error (MSE) of the surface roughness calculated by the proposed method does not exceed 0.003, and the mean relative error (MRE) does not exceed 5%. The two-scale fractal geometry offers a novel approach to image processing and machine learning, with significant potential for advancement.
{"title":"Surface roughness measurement using microscopic vision and deep learning","authors":"Chuhan Shang, Zhang Lieping, Khaled A. Gepreel, Huaian Yi","doi":"10.3389/fphy.2024.1444266","DOIUrl":"https://doi.org/10.3389/fphy.2024.1444266","url":null,"abstract":"Due to the self-affine property of the grinding surface, the sample images with different roughness captured by the micron-scale camera exhibit certain similarities. This similarity affects the prediction accuracy of the deep learning model. In this paper, we propose an illumination method that can mitigate the impact of self-affinity using the two-scale fractal theory as a foundation. This is followed by the establishment of a machine vision detection method that integrates a neural network and correlation function. Initially, a neural network is employed to categorize and forecast the microscopic image of the workpiece surface, thereby determining its roughness category. Subsequently, the corresponding correlation function is determined in accordance with the established roughness category. Finally, the surface roughness of the workpiece was calculated based on the correlation function. The experimental results demonstrate that images obtained using this lighting method exhibit significantly enhanced accuracy in neural network classification. In comparison to traditional lighting methods, the accuracy of this method on the micrometer scale has been found to have significantly increased from approximately 50% to over 95%. Concurrently, the mean squared error (MSE) of the surface roughness calculated by the proposed method does not exceed 0.003, and the mean relative error (MRE) does not exceed 5%. The two-scale fractal geometry offers a novel approach to image processing and machine learning, with significant potential for advancement.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"67 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864172","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}
Pub Date : 2024-07-31DOI: 10.3389/fphy.2024.1358766
Amiko Aizawa, Kouichi Asakura
In 1952, Alan Turing accomplished a pioneering theoretical study to show that the coupling of nonlinear chemical reactions and diffusion leads to the instability of spatially homogeneous states. The activator and inhibitor are synthesized as intermediates of the reaction system in the Turing model. Turing found that spatially periodic stationary concentration patterns are spontaneously generated when the diffusion coefficient of the activator is lower than that of the inhibitor. The first experimental realization of the Turing pattern was achieved in 1990 in a chlorite–iodide–malonic acid (CIMA) reaction system. Iodide and chlorite anions act as the activator and inhibitor of this reaction system, respectively. Although there is no significant difference in the diffusion coefficient of iodide and chlorite anions, the Turing pattern was generated because starch was added to the gel reactor to enhance the color tone. This formed a complex with iodide to inhibit its diffusion to satisfy the condition for the Turing instability. Several examples were found after this finding. We focused on the high affinity of quaternary alkyl ammonium cations to iodide. The CIMA reaction was performed in an open gel reactor by adding a quaternary alkyl ammonium cationic surfactant. In addition, the polymer gel consists of the quaternary alkyl ammonium group as the side chain was utilized for the open gel reactor. The micelles of the surfactants and the polymer gels trapped iodide in their vicinity as a counter anion to lower the effective diffusivity to satisfy the condition for the Turing instability.
{"title":"Theory of Turing pattern formation and its experimental realization in the CIMA reaction system in the presence of materials lowering the diffusivity of activators","authors":"Amiko Aizawa, Kouichi Asakura","doi":"10.3389/fphy.2024.1358766","DOIUrl":"https://doi.org/10.3389/fphy.2024.1358766","url":null,"abstract":"In 1952, Alan Turing accomplished a pioneering theoretical study to show that the coupling of nonlinear chemical reactions and diffusion leads to the instability of spatially homogeneous states. The activator and inhibitor are synthesized as intermediates of the reaction system in the Turing model. Turing found that spatially periodic stationary concentration patterns are spontaneously generated when the diffusion coefficient of the activator is lower than that of the inhibitor. The first experimental realization of the Turing pattern was achieved in 1990 in a chlorite–iodide–malonic acid (CIMA) reaction system. Iodide and chlorite anions act as the activator and inhibitor of this reaction system, respectively. Although there is no significant difference in the diffusion coefficient of iodide and chlorite anions, the Turing pattern was generated because starch was added to the gel reactor to enhance the color tone. This formed a complex with iodide to inhibit its diffusion to satisfy the condition for the Turing instability. Several examples were found after this finding. We focused on the high affinity of quaternary alkyl ammonium cations to iodide. The CIMA reaction was performed in an open gel reactor by adding a quaternary alkyl ammonium cationic surfactant. In addition, the polymer gel consists of the quaternary alkyl ammonium group as the side chain was utilized for the open gel reactor. The micelles of the surfactants and the polymer gels trapped iodide in their vicinity as a counter anion to lower the effective diffusivity to satisfy the condition for the Turing instability.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"56 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864171","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}
Pub Date : 2024-07-30DOI: 10.3389/fphy.2024.1401834
James Cayley, Yaw-Ren E. Tan, Marco Petasecca, Dean Cutajar, Thomas Breslin, Anatoly Rosenfeld, Michael Lerch
FLASH radiotherapy, which refers to the delivery of radiation at ultra-high dose-rates (UHDRs), has been demonstrated with various forms of radiation and is the subject of intense research and development recently, including the use of very high-energy electrons (VHEEs) to treat deep-seated tumors. Delivering FLASH radiotherapy in a clinical setting is expected to place high demands on real-time quality assurance and dosimetry systems. Furthermore, very high-energy electron research currently requires the transformation of existing non-medical accelerators into radiotherapy research environments. Accurate dosimetry is crucial for any such transformation. In this article, we assess the response of the MOSkin, developed by the Center for Medical Radiation Physics, which is designed for on-patient, real-time skin dose measurements during radiotherapy, and whether it exhibits dose-rate independence when exposed to 100 MeV electron beams at the Pulsed Energetic Electrons for Research (PEER) end-station. PEER utilizes the electron beam from a 100 MeV linear accelerator when it is not used as the injector for the ANSTO Australian Synchrotron. With the estimated pulse dose-rates ranging from (7.84±0.21)×105 Gy/s to (1.28±0.03)×107 Gy/s and an estimated peak bunch dose-rate of (2.55±0.06)×108 Gy/s, MOSkin measurements were verified against a scintillating screen to confirm that the MOSkin responds proportionally to the charge delivered and, therefore, exhibits dose-rate independence in this irradiation environment.
{"title":"MOSkin dosimetry for an ultra-high dose-rate, very high-energy electron irradiation environment at PEER","authors":"James Cayley, Yaw-Ren E. Tan, Marco Petasecca, Dean Cutajar, Thomas Breslin, Anatoly Rosenfeld, Michael Lerch","doi":"10.3389/fphy.2024.1401834","DOIUrl":"https://doi.org/10.3389/fphy.2024.1401834","url":null,"abstract":"FLASH radiotherapy, which refers to the delivery of radiation at ultra-high dose-rates (UHDRs), has been demonstrated with various forms of radiation and is the subject of intense research and development recently, including the use of very high-energy electrons (VHEEs) to treat deep-seated tumors. Delivering FLASH radiotherapy in a clinical setting is expected to place high demands on real-time quality assurance and dosimetry systems. Furthermore, very high-energy electron research currently requires the transformation of existing non-medical accelerators into radiotherapy research environments. Accurate dosimetry is crucial for any such transformation. In this article, we assess the response of the MOS<jats:italic>kin</jats:italic>, developed by the Center for Medical Radiation Physics, which is designed for on-patient, real-time skin dose measurements during radiotherapy, and whether it exhibits dose-rate independence when exposed to 100 MeV electron beams at the Pulsed Energetic Electrons for Research (PEER) end-station. PEER utilizes the electron beam from a 100 MeV linear accelerator when it is not used as the injector for the ANSTO Australian Synchrotron. With the estimated pulse dose-rates ranging from <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:mo stretchy=\"false\">(</mml:mo><mml:mrow><mml:mn>7.84</mml:mn><mml:mo>±</mml:mo><mml:mn>0.21</mml:mn></mml:mrow><mml:mo stretchy=\"false\">)</mml:mo></mml:mrow><mml:mo>×</mml:mo><mml:mn>1</mml:mn><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mn>5</mml:mn></mml:mrow></mml:msup></mml:math></jats:inline-formula> Gy/s to <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:mo stretchy=\"false\">(</mml:mo><mml:mrow><mml:mn>1.28</mml:mn><mml:mo>±</mml:mo><mml:mn>0.03</mml:mn></mml:mrow><mml:mo stretchy=\"false\">)</mml:mo></mml:mrow><mml:mo>×</mml:mo><mml:mn>1</mml:mn><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mn>7</mml:mn></mml:mrow></mml:msup></mml:math></jats:inline-formula> Gy/s and an estimated peak bunch dose-rate of <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mrow><mml:mo stretchy=\"false\">(</mml:mo><mml:mrow><mml:mn>2.55</mml:mn><mml:mo>±</mml:mo><mml:mn>0.06</mml:mn></mml:mrow><mml:mo stretchy=\"false\">)</mml:mo></mml:mrow><mml:mo>×</mml:mo><mml:mn>1</mml:mn><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mn>8</mml:mn></mml:mrow></mml:msup></mml:math></jats:inline-formula> Gy/s, MOS<jats:italic>kin</jats:italic> measurements were verified against a scintillating screen to confirm that the MOS<jats:italic>kin</jats:italic> responds proportionally to the charge delivered and, therefore, exhibits dose-rate independence in this irradiation environment.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"195 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864258","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}
Pub Date : 2024-07-30DOI: 10.3389/fphy.2024.1395690
Michael Fiederle, Tilo Baumbach
Compound semiconductors are playing a major role in the production of X-ray pixel detectors for the application in laboratories and beamlines at photon sources. The performance of these detectors has constantly been improved for the last decades but experiments are still limited by the properties of the detector material, especially under high flux illumination. The fast development of perovskite crystals opens the possibility for new materials to be used as highly efficient X-ray pixel detectors. The published data until now, of the transport properties, demonstrate the large potential of perovskite semiconductors. The achieved values are comparable with the ones of CdTe-based detectors. This paper presents potential perovskite-based detector materials and compares their performance with the state-of-the-art CdTe-based detectors. The perspectives of perovskite semiconductors are promising for the production of large area X-ray detectors but still some challenges remain.
化合物半导体在实验室和光子源光束线应用的 X 射线像素探测器生产中发挥着重要作用。过去几十年来，这些探测器的性能不断提高，但实验仍然受到探测器材料特性的限制，特别是在高通量照明下。包晶晶体的快速发展为新材料用作高效 X 射线像素探测器提供了可能。迄今为止已公布的传输特性数据证明了包晶体半导体的巨大潜力。所达到的数值可与基于碲化镉的探测器相媲美。本文介绍了潜在的光致发光半导体探测器材料，并将其性能与最先进的碲化镉探测器进行了比较。透辉石半导体在生产大面积 X 射线探测器方面前景广阔，但仍存在一些挑战。
{"title":"Perspective of perovskite-based X-ray hybrid pixel array detectors","authors":"Michael Fiederle, Tilo Baumbach","doi":"10.3389/fphy.2024.1395690","DOIUrl":"https://doi.org/10.3389/fphy.2024.1395690","url":null,"abstract":"Compound semiconductors are playing a major role in the production of X-ray pixel detectors for the application in laboratories and beamlines at photon sources. The performance of these detectors has constantly been improved for the last decades but experiments are still limited by the properties of the detector material, especially under high flux illumination. The fast development of perovskite crystals opens the possibility for new materials to be used as highly efficient X-ray pixel detectors. The published data until now, of the transport properties, demonstrate the large potential of perovskite semiconductors. The achieved values are comparable with the ones of CdTe-based detectors. This paper presents potential perovskite-based detector materials and compares their performance with the state-of-the-art CdTe-based detectors. The perspectives of perovskite semiconductors are promising for the production of large area X-ray detectors but still some challenges remain.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"32 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864174","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}
Pub Date : 2024-07-30DOI: 10.3389/fphy.2024.1422286
L. De Gianni, G. Ciraolo, G. Giruzzi, G. Falchetto, N. Rivals, K. Gałązka, L. Balbinot, N. Varadarajan, S. Sureshkumar, J. F. Artaud, H. Bufferand, R. Düll, A. Gallo, P. Ghendrih, V. Quadri, G. Rubino, P. Tamain
In its first phase of exploitation, JT-60SA will be equipped with an inertially cooled divertor, which can sustain heat loads of 10 MW/m2 on the targets for a few seconds, which is much shorter than the intended discharge duration. Therefore, in order to maximize the duration of discharges, it is crucial to develop operational scenarios with a high radiated fraction in the plasma edge region without unacceptably compromising the scenario performance. In this study, the core and edge conditions of unseeded and neon-seeded deuterium H-mode scenarios in JT-60SA were investigated using METIS and SOLEDGE3X–EIRENE codes. The aim was to determine whether, and under which operational conditions, it would be possible to achieve heat loads at the targets significantly lower than 10 MW/m2 and potentially establish a divertor-detached regime while keeping favorable plasma core conditions. In first analysis, an investigation of the edge parameter space of unseeded scenarios was carried out. Simulations at an intermediate edge power of 15 MW indicate that, without seeded impurities, the heat loads at the targets are higher than 10 MW/m2 in attached cases, and achieving detachment is challenging, requiring upstream electron densities at least above 4 × 1019 m−3. This points toward the need for impurity injection during the first period of exploitation of the machine. Therefore, neon seeding simulations were carried out, performing a seeding rate scan and an injected power scan while keeping the upstream electron density at the separatrix at 3 × 1019 m−3. They show that at 15 MW of power injected into the edge plasma, the inner target is easily detached and presents low heat loads when neon is injected. However, at the outer target, the heat fluxes are not lowered below 10 MW/m2, even when the power losses in the edge plasma are equal to 50% of the power crossing the separatrix. Therefore, the tokamak will probably need to be operated in a deep detached regime in its first phase of exploitation for discharges longer than a few seconds. In the framework of core–edge integrated modeling, using METIS, the power radiated in the core was computed for the most interesting cases.
{"title":"Core and edge modeling of JT-60SA H-mode highly radiative scenarios using SOLEDGE3X–EIRENE and METIS codes","authors":"L. De Gianni, G. Ciraolo, G. Giruzzi, G. Falchetto, N. Rivals, K. Gałązka, L. Balbinot, N. Varadarajan, S. Sureshkumar, J. F. Artaud, H. Bufferand, R. Düll, A. Gallo, P. Ghendrih, V. Quadri, G. Rubino, P. Tamain","doi":"10.3389/fphy.2024.1422286","DOIUrl":"https://doi.org/10.3389/fphy.2024.1422286","url":null,"abstract":"In its first phase of exploitation, JT-60SA will be equipped with an inertially cooled divertor, which can sustain heat loads of 10 MW/m<jats:sup>2</jats:sup> on the targets for a few seconds, which is much shorter than the intended discharge duration. Therefore, in order to maximize the duration of discharges, it is crucial to develop operational scenarios with a high radiated fraction in the plasma edge region without unacceptably compromising the scenario performance. In this study, the core and edge conditions of unseeded and neon-seeded deuterium H-mode scenarios in JT-60SA were investigated using METIS and SOLEDGE3X–EIRENE codes. The aim was to determine whether, and under which operational conditions, it would be possible to achieve heat loads at the targets significantly lower than 10 MW/m<jats:sup>2</jats:sup> and potentially establish a divertor-detached regime while keeping favorable plasma core conditions. In first analysis, an investigation of the edge parameter space of unseeded scenarios was carried out. Simulations at an intermediate edge power of 15 MW indicate that, without seeded impurities, the heat loads at the targets are higher than 10 MW/m<jats:sup>2</jats:sup> in attached cases, and achieving detachment is challenging, requiring upstream electron densities at least above 4 × 10<jats:sup>19</jats:sup> m<jats:sup>−3</jats:sup>. This points toward the need for impurity injection during the first period of exploitation of the machine. Therefore, neon seeding simulations were carried out, performing a seeding rate scan and an injected power scan while keeping the upstream electron density at the separatrix at 3 × 10<jats:sup>19</jats:sup> m<jats:sup>−3</jats:sup>. They show that at 15 MW of power injected into the edge plasma, the inner target is easily detached and presents low heat loads when neon is injected. However, at the outer target, the heat fluxes are not lowered below 10 MW/m<jats:sup>2</jats:sup>, even when the power losses in the edge plasma are equal to 50% of the power crossing the separatrix. Therefore, the tokamak will probably need to be operated in a deep detached regime in its first phase of exploitation for discharges longer than a few seconds. In the framework of core–edge integrated modeling, using METIS, the power radiated in the core was computed for the most interesting cases.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"49 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864173","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}
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