Weipeng Yao, Motoaki Nakatsutsumi, Sébastien Buffechoux, Patrizio Antici, Marco Borghesi, Andrea Ciardi, Sophia N. Chen, Emmanuel d’Humières, Laurent Gremillet, Robert Heathcote, Vojtěch Horný, Paul McKenna, Mark N. Quinn, Lorenzo Romagnani, Ryan Royle, Gianluca Sarri, Yasuhiko Sentoku, Hans-Peter Schlenvoigt, Toma Toncian, Olivier Tresca, Laura Vassura, Oswald Willi, Julien Fuchs
Realizing the full potential of ultrahigh-intensity lasers for particle and radiation generation will require multi-beam arrangements due to technology limitations. Here, we investigate how to optimize their coupling with solid targets. Experimentally, we show that overlapping two intense lasers in a mirror-like configuration onto a solid with a large preplasma can greatly improve the generation of hot electrons at the target front and ion acceleration at the target backside. The underlying mechanisms are analyzed through multidimensional particle-in-cell simulations, revealing that the self-induced magnetic fields driven by the two laser beams at the target front are susceptible to reconnection, which is one possible mechanism to boost electron energization. In addition, the resistive magnetic field generated during the transport of the hot electrons in the target bulk tends to improve their collimation. Our simulations also indicate that such effects can be further enhanced by overlapping more than two laser beams.
{"title":"Optimizing laser coupling, matter heating, and particle acceleration from solids using multiplexed ultraintense lasers","authors":"Weipeng Yao, Motoaki Nakatsutsumi, Sébastien Buffechoux, Patrizio Antici, Marco Borghesi, Andrea Ciardi, Sophia N. Chen, Emmanuel d’Humières, Laurent Gremillet, Robert Heathcote, Vojtěch Horný, Paul McKenna, Mark N. Quinn, Lorenzo Romagnani, Ryan Royle, Gianluca Sarri, Yasuhiko Sentoku, Hans-Peter Schlenvoigt, Toma Toncian, Olivier Tresca, Laura Vassura, Oswald Willi, Julien Fuchs","doi":"10.1063/5.0184919","DOIUrl":"https://doi.org/10.1063/5.0184919","url":null,"abstract":"Realizing the full potential of ultrahigh-intensity lasers for particle and radiation generation will require multi-beam arrangements due to technology limitations. Here, we investigate how to optimize their coupling with solid targets. Experimentally, we show that overlapping two intense lasers in a mirror-like configuration onto a solid with a large preplasma can greatly improve the generation of hot electrons at the target front and ion acceleration at the target backside. The underlying mechanisms are analyzed through multidimensional particle-in-cell simulations, revealing that the self-induced magnetic fields driven by the two laser beams at the target front are susceptible to reconnection, which is one possible mechanism to boost electron energization. In addition, the resistive magnetic field generated during the transport of the hot electrons in the target bulk tends to improve their collimation. Our simulations also indicate that such effects can be further enhanced by overlapping more than two laser beams.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"1 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140613086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Xiaopeng Zhang, Jiarui Zhao, Shengxuan Xu, Xun Chen, Ying Gao, Shiyou Chen, Kun Zhu, Xueqing Yan, Wenjun Ma
The newly built Compact Laser Plasma Accelerator–Therapy facility at Peking University will deliver 60 J/1 Hz laser pulses with 30 fs duration. Driven by this petawatt laser facility, proton beams with energy up to 200 MeV are expected to be generated for tumor therapy. During high-repetition operation, both prompt radiation and residual radiation may cause safety problems. Therefore, human radiological safety assessment before commissioning is essential. In this paper, we simulate both prompt and residual radiation using the Geant4 and FLUKA Monte Carlo codes with reasonable proton and as-produced electron beam parameters. We find that the prompt radiation can be shielded well by the concrete wall of the experimental hall, but the risk from residual radiation is nonnegligible and necessitates adequate radiation cooling. On the basis of the simulation results, we discuss the constraints imposed by radiation safety considerations on the annual working time, and we propose radiation cooling strategies for different shooting modes.
北京大学新建的紧凑型激光等离子体加速器-治疗设备将提供 60 J/1 Hz、持续时间为 30 fs 的激光脉冲。在该设备的驱动下，预计将产生能量高达 200 MeV 的质子束用于肿瘤治疗。在高重复运行期间，即时辐射和残余辐射都可能造成安全问题。因此，调试前的人体辐射安全评估至关重要。在本文中，我们使用 Geant4 和 FLUKA Monte Carlo 代码，以合理的质子和产生的电子束参数模拟了瞬间辐射和残余辐射。我们发现，实验大厅的混凝土墙可以很好地屏蔽即时辐射，但残余辐射的风险不可忽视，必须进行充分的辐射冷却。在模拟结果的基础上，我们讨论了辐射安全因素对年工作时间的限制，并针对不同的发射模式提出了辐射冷却策略。
{"title":"Human radiological safety assessment for petawatt laser-driven ion acceleration experiments in CLAPA-T","authors":"Xiaopeng Zhang, Jiarui Zhao, Shengxuan Xu, Xun Chen, Ying Gao, Shiyou Chen, Kun Zhu, Xueqing Yan, Wenjun Ma","doi":"10.1063/5.0172687","DOIUrl":"https://doi.org/10.1063/5.0172687","url":null,"abstract":"The newly built Compact Laser Plasma Accelerator–Therapy facility at Peking University will deliver 60 J/1 Hz laser pulses with 30 fs duration. Driven by this petawatt laser facility, proton beams with energy up to 200 MeV are expected to be generated for tumor therapy. During high-repetition operation, both prompt radiation and residual radiation may cause safety problems. Therefore, human radiological safety assessment before commissioning is essential. In this paper, we simulate both prompt and residual radiation using the Geant4 and FLUKA Monte Carlo codes with reasonable proton and as-produced electron beam parameters. We find that the prompt radiation can be shielded well by the concrete wall of the experimental hall, but the risk from residual radiation is nonnegligible and necessitates adequate radiation cooling. On the basis of the simulation results, we discuss the constraints imposed by radiation safety considerations on the annual working time, and we propose radiation cooling strategies for different shooting modes.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"61 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140596529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Porous materials offer unique possibilities for the production of plasmas with controlled density profiles for experiments on laser–matter interaction. They are of growing relevance to many applications, such as inertial confinement fusion, fundamental research, and secondary sources. Understanding the processes of transformation of a porous solid into a plasma is of fundamental interest and is needed for producing materials with desired properties.
{"title":"Physics of porous materials under extreme laser-generated conditions","authors":"V. T. Tikhonchuk, S. Weber","doi":"10.1063/5.0169446","DOIUrl":"https://doi.org/10.1063/5.0169446","url":null,"abstract":"Porous materials offer unique possibilities for the production of plasmas with controlled density profiles for experiments on laser–matter interaction. They are of growing relevance to many applications, such as inertial confinement fusion, fundamental research, and secondary sources. Understanding the processes of transformation of a porous solid into a plasma is of fundamental interest and is needed for producing materials with desired properties.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"33 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140596411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Ultrahigh-temperature–pressure experiments are crucial for understanding the physical and chemical properties of matter. The recent development of boron-doped diamond (BDD) heaters has made such melting experiments possible in large-volume presses. However, estimates of temperatures above 2600 K and of the temperature distributions inside BDD heaters are not well constrained, owing to the lack of a suitable thermometer. Here, we establish a three-dimensional finite element model as a virtual thermometer to estimate the temperature and temperature field above 2600 K. The advantage of this virtual thermometer over those proposed in previous studies is that it considers both alternating and direct current heating modes, the actual sizes of cell assemblies after compression, the effects of the electrode, thermocouple and anvil, and the heat dissipation by the pressure-transmitting medium. The virtual thermometer reproduces the power–temperature relationships of ultrahigh-temperature–pressure experiments below 2600 K at press loads of 2.8–7.9 MN (∼19 to 28 GPa) within experimental uncertainties. The temperatures above 2600 K predicted by our virtual thermometer are within the uncertainty of those extrapolated from power–temperature relationships below 2600 K. Furthermore, our model shows that the temperature distribution inside a BDD heater (19–26 K/mm along the radial direction and <83 K/mm along the longitudinal direction) is more homogeneous than those inside conventional heaters such as graphite or LaCrO3 heaters (100–200 K/mm). Our study thus provides a reliable virtual thermometer for ultrahigh-temperature experiments using BDD heaters in Earth and material sciences.
超高温-高压实验对于了解物质的物理和化学特性至关重要。最近开发的掺硼金刚石（BDD）加热器使得在大容量压力机中进行此类熔化实验成为可能。然而，由于缺乏合适的温度计，对 2600 K 以上的温度以及 BDD 加热器内部温度分布的估计并不准确。在此，我们建立了一个三维有限元模型，作为虚拟温度计来估算 2600 K 以上的温度和温度场。与以往研究中提出的虚拟温度计相比，该虚拟温度计的优势在于它同时考虑了交流和直流加热模式，压缩后电池组件的实际尺寸，电极、热电偶和砧的影响，以及压力传输介质的散热。虚拟温度计再现了在 2.8-7.9 MN（19 至 28 GPa）压力负荷下 2600 K 以下超高温压实验的功率-温度关系，其误差在实验不确定性范围内。此外，我们的模型显示，BDD 加热器内部的温度分布（沿径向为 19-26 K/mm，沿纵向为 <83 K/mm）比石墨或 LaCrO3 加热器等传统加热器内部的温度分布（100-200 K/mm）更均匀。因此，我们的研究为地球和材料科学领域使用 BDD 加热器进行超高温实验提供了可靠的虚拟温度计。
{"title":"A virtual thermometer for ultrahigh-temperature–pressure experiments in a large-volume press","authors":"Bingtao Feng, Longjian Xie, Xuyuan Hou, Shucheng Liu, Luyao Chen, Xinyu Zhao, Chenyi Li, Qiang Zhou, Kuo Hu, Zhaodong Liu, Bingbing Liu","doi":"10.1063/5.0184031","DOIUrl":"https://doi.org/10.1063/5.0184031","url":null,"abstract":"Ultrahigh-temperature–pressure experiments are crucial for understanding the physical and chemical properties of matter. The recent development of boron-doped diamond (BDD) heaters has made such melting experiments possible in large-volume presses. However, estimates of temperatures above 2600 K and of the temperature distributions inside BDD heaters are not well constrained, owing to the lack of a suitable thermometer. Here, we establish a three-dimensional finite element model as a virtual thermometer to estimate the temperature and temperature field above 2600 K. The advantage of this virtual thermometer over those proposed in previous studies is that it considers both alternating and direct current heating modes, the actual sizes of cell assemblies after compression, the effects of the electrode, thermocouple and anvil, and the heat dissipation by the pressure-transmitting medium. The virtual thermometer reproduces the power–temperature relationships of ultrahigh-temperature–pressure experiments below 2600 K at press loads of 2.8–7.9 MN (∼19 to 28 GPa) within experimental uncertainties. The temperatures above 2600 K predicted by our virtual thermometer are within the uncertainty of those extrapolated from power–temperature relationships below 2600 K. Furthermore, our model shows that the temperature distribution inside a BDD heater (19–26 K/mm along the radial direction and &lt;83 K/mm along the longitudinal direction) is more homogeneous than those inside conventional heaters such as graphite or LaCrO3 heaters (100–200 K/mm). Our study thus provides a reliable virtual thermometer for ultrahigh-temperature experiments using BDD heaters in Earth and material sciences.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"47 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140596530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Jurong Zhang, Hanyu Liu, Changfeng Chen, Yanming Ma
The terrestrial abundance anomalies of helium and xenon suggest the presence of deep-Earth reservoirs of these elements, which has led to great interest in searching for materials that can host these usually unreactive elements. Here, using an advanced crystal structure search approach in conjunction with first-principles calculations, we show that several Xe/He-bearing iron halides are thermodynamically stable in a broad region of P–T phase space below 60 GPa. Our results present a compelling case for sequestration of He and Xe in the early Earth and may suggest their much wider distribution in the present Earth than previously believed. These findings offer insights into key material-based and physical mechanisms for elucidating major geological phenomena.
{"title":"Sequestration of helium and xenon via iron-halide compounds in early Earth","authors":"Jurong Zhang, Hanyu Liu, Changfeng Chen, Yanming Ma","doi":"10.1063/5.0164149","DOIUrl":"https://doi.org/10.1063/5.0164149","url":null,"abstract":"The terrestrial abundance anomalies of helium and xenon suggest the presence of deep-Earth reservoirs of these elements, which has led to great interest in searching for materials that can host these usually unreactive elements. Here, using an advanced crystal structure search approach in conjunction with first-principles calculations, we show that several Xe/He-bearing iron halides are thermodynamically stable in a broad region of P–T phase space below 60 GPa. Our results present a compelling case for sequestration of He and Xe in the early Earth and may suggest their much wider distribution in the present Earth than previously believed. These findings offer insights into key material-based and physical mechanisms for elucidating major geological phenomena.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"32 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Suo Tang, Yu Xin, Meng Wen, Mamat Ali Bake, Baisong Xie
Fully polarized Compton scattering from a beam of spin-polarized electrons is investigated in plane-wave backgrounds in a broad intensity region from the perturbative to the nonperturbative regimes. In the perturbative regime, polarized linear Compton scattering is considered for investigating polarization transfer from a single laser photon to a scattered photon, and in the high-intensity region, the polarized locally monochromatic approximation and locally constant field approximation are established and are employed to study polarization transfer from an incoming electron to a scattered photon. The numerical results suggest an appreciable improvement of about 10% in the scattering probability in the intermediate-intensity region if the electron’s longitudinal spin is parallel to the laser rotation. The longitudinal spin of the incoming electron can be transferred to the scattered photon with an efficiency that increases with laser intensity and collisional energy. For collision between an optical laser with frequency ∼1 eV and a 10 GeV electron, this polarization transfer efficiency can increase from about 20% in the perturbative regime to about 50% in the nonperturbative regime for scattered photons with relatively high energy.
{"title":"Fully polarized Compton scattering in plane waves and its polarization transfer","authors":"Suo Tang, Yu Xin, Meng Wen, Mamat Ali Bake, Baisong Xie","doi":"10.1063/5.0196125","DOIUrl":"https://doi.org/10.1063/5.0196125","url":null,"abstract":"Fully polarized Compton scattering from a beam of spin-polarized electrons is investigated in plane-wave backgrounds in a broad intensity region from the perturbative to the nonperturbative regimes. In the perturbative regime, polarized linear Compton scattering is considered for investigating polarization transfer from a single laser photon to a scattered photon, and in the high-intensity region, the polarized locally monochromatic approximation and locally constant field approximation are established and are employed to study polarization transfer from an incoming electron to a scattered photon. The numerical results suggest an appreciable improvement of about 10% in the scattering probability in the intermediate-intensity region if the electron’s longitudinal spin is parallel to the laser rotation. The longitudinal spin of the incoming electron can be transferred to the scattered photon with an efficiency that increases with laser intensity and collisional energy. For collision between an optical laser with frequency ∼1 eV and a 10 GeV electron, this polarization transfer efficiency can increase from about 20% in the perturbative regime to about 50% in the nonperturbative regime for scattered photons with relatively high energy.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"44 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
M. R. D. Rodrigues, A. Bonasera, M. Scisciò, J. A. Pérez-Hernández, M. Ehret, F. Filippi, P. L. Andreoli, M. Huault, H. Larreur, D. Singappuli, D. Molloy, D. Raffestin, M. Alonzo, G. G. Rapisarda, D. Lattuada, G. L. Guardo, C. Verona, Fe. Consoli, G. Petringa, A. McNamee, M. La Cognata, S. Palmerini, T. Carriere, M. Cipriani, G. Di Giorgio, G. Cristofari, R. De Angelis, G. A. P. Cirrone, D. Margarone, L. Giuffrida, D. Batani, P. Nicolai, K. Batani, R. Lera, L. Volpe, D. Giulietti, S. Agarwal, M. Krupka, S. Singh, Fa. Consoli
The discovery of chirped pulse amplification has led to great improvements in laser technology, enabling energetic laser beams to be compressed to pulse durations of tens of femtoseconds and focused to a few micrometers. Protons with energies of tens of MeV can be accelerated using, for instance, target normal sheath acceleration and focused on secondary targets. Under such conditions, nuclear reactions can occur, with the production of radioisotopes suitable for medical application. The use of high-repetition lasers to produce such isotopes is competitive with conventional methods mostly based on accelerators. In this paper, we study the production of 67Cu, 63Zn, 18F, and 11C, which are currently used in positron emission tomography and other applications. At the same time, we study the reactions 10B(p,α)7Be and 70Zn(p,4n)67Ga to put further constraints on the proton distributions at different angles, as well as the reaction 11B(p,α)8Be relevant for energy production. The experiment was performed at the 1 PW laser facility at Vega III in Salamanca, Spain. Angular distributions of radioisotopes in the forward (with respect to the laser direction) and backward directions were measured using a high purity germanium detector. Our results are in reasonable agreement with numerical estimates obtained following the approach of Kimura and Bonasera [Nucl. Instrum. Methods Phys. Res., Sect. A 637, 164–170 (2011)].
{"title":"Radioisotope production using lasers: From basic science to applications","authors":"M. R. D. Rodrigues, A. Bonasera, M. Scisciò, J. A. Pérez-Hernández, M. Ehret, F. Filippi, P. L. Andreoli, M. Huault, H. Larreur, D. Singappuli, D. Molloy, D. Raffestin, M. Alonzo, G. G. Rapisarda, D. Lattuada, G. L. Guardo, C. Verona, Fe. Consoli, G. Petringa, A. McNamee, M. La Cognata, S. Palmerini, T. Carriere, M. Cipriani, G. Di Giorgio, G. Cristofari, R. De Angelis, G. A. P. Cirrone, D. Margarone, L. Giuffrida, D. Batani, P. Nicolai, K. Batani, R. Lera, L. Volpe, D. Giulietti, S. Agarwal, M. Krupka, S. Singh, Fa. Consoli","doi":"10.1063/5.0196909","DOIUrl":"https://doi.org/10.1063/5.0196909","url":null,"abstract":"The discovery of chirped pulse amplification has led to great improvements in laser technology, enabling energetic laser beams to be compressed to pulse durations of tens of femtoseconds and focused to a few micrometers. Protons with energies of tens of MeV can be accelerated using, for instance, target normal sheath acceleration and focused on secondary targets. Under such conditions, nuclear reactions can occur, with the production of radioisotopes suitable for medical application. The use of high-repetition lasers to produce such isotopes is competitive with conventional methods mostly based on accelerators. In this paper, we study the production of 67Cu, 63Zn, 18F, and 11C, which are currently used in positron emission tomography and other applications. At the same time, we study the reactions 10B(p,α)7Be and 70Zn(p,4n)67Ga to put further constraints on the proton distributions at different angles, as well as the reaction 11B(p,α)8Be relevant for energy production. The experiment was performed at the 1 PW laser facility at Vega III in Salamanca, Spain. Angular distributions of radioisotopes in the forward (with respect to the laser direction) and backward directions were measured using a high purity germanium detector. Our results are in reasonable agreement with numerical estimates obtained following the approach of Kimura and Bonasera [Nucl. Instrum. Methods Phys. Res., Sect. A 637, 164–170 (2011)].","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"133 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140196374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Ya Xu, Lu Zheng, Yunkun Zhang, Zhuangfei Zhang, QianQian Wang, Yuewen Zhang, Liangchao Chen, Chao Fang, Biao Wan, Huiyang Gou
The presence of interstitial electrons in electrides endows them with interesting attributes, such as low work function, high carrier concentration, and unique magnetic properties. Thorough knowledge and understanding of electrides are thus of both scientific and technological significance. Here, we employ first-principles calculations to investigate Mott-insulating Ae5X3 (Ae = Ca, Sr, and Ba; X = As and Sb) electrides with Mn5Si3-type structure, in which half-filled interstitial electrons serve as ions and are spin-polarized. The Mott-insulating property is induced by strong electron correlation between the nearest interstitial electrons, resulting in spin splitting and a separation between occupied and unoccupied states. The half-filled antiferromagnetic configuration and localization of the interstitial electrons are critical for the Mott-insulating properties of these materials. Compared with that in intermetallic electrides, the orbital hybridization between the half-filled interstitial electrons and the surrounding atoms is weak, leading to highly localized magnetic centers and pronounced correlation effects. Therefore, the Mott-insulating electrides Ae5X3 have very large indirect bandgaps (∼0.30 eV). In addition, high pressure is found to strengthen the strong correlation effects and enlarge the bandgap. The present results provide a deeper understanding of the formation mechanism of Mott-insulating electrides and provide guidance for the search for new strongly correlated electrides.
{"title":"Strong electron correlation-induced Mott-insulating electrides of Ae5X3 (Ae = Ca, Sr, and Ba; X = As and Sb)","authors":"Ya Xu, Lu Zheng, Yunkun Zhang, Zhuangfei Zhang, QianQian Wang, Yuewen Zhang, Liangchao Chen, Chao Fang, Biao Wan, Huiyang Gou","doi":"10.1063/5.0187372","DOIUrl":"https://doi.org/10.1063/5.0187372","url":null,"abstract":"The presence of interstitial electrons in electrides endows them with interesting attributes, such as low work function, high carrier concentration, and unique magnetic properties. Thorough knowledge and understanding of electrides are thus of both scientific and technological significance. Here, we employ first-principles calculations to investigate Mott-insulating Ae5X3 (Ae = Ca, Sr, and Ba; X = As and Sb) electrides with Mn5Si3-type structure, in which half-filled interstitial electrons serve as ions and are spin-polarized. The Mott-insulating property is induced by strong electron correlation between the nearest interstitial electrons, resulting in spin splitting and a separation between occupied and unoccupied states. The half-filled antiferromagnetic configuration and localization of the interstitial electrons are critical for the Mott-insulating properties of these materials. Compared with that in intermetallic electrides, the orbital hybridization between the half-filled interstitial electrons and the surrounding atoms is weak, leading to highly localized magnetic centers and pronounced correlation effects. Therefore, the Mott-insulating electrides Ae5X3 have very large indirect bandgaps (∼0.30 eV). In addition, high pressure is found to strengthen the strong correlation effects and enlarge the bandgap. The present results provide a deeper understanding of the formation mechanism of Mott-insulating electrides and provide guidance for the search for new strongly correlated electrides.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"54 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140171198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Yuchi Wu, Shaoyi Wang, Bin Zhu, Yonghong Yan, Minghai Yu, Gang Li, Xiaohui Zhang, Yue Yang, Fang Tan, Feng Lu, Bi Bi, Xiaoqin Mao, Zhonghai Wang, Zongqing Zhao, Jingqin Su, Weimin Zhou, Yuqiu Gu
High-energy gamma-ray radiography has exceptional penetration ability and has become an indispensable nondestructive testing (NDT) tool in various fields. For high-energy photons, point projection radiography is almost the only feasible imaging method, and its spatial resolution is primarily constrained by the size of the gamma-ray source. In conventional industrial applications, gamma-ray sources are commonly based on electron beams driven by accelerators, utilizing the process of bremsstrahlung radiation. The size of the gamma-ray source is dependent on the dimensional characteristics of the electron beam. Extensive research has been conducted on various advanced accelerator technologies that have the potential to greatly improve spatial resolution in NDT. In our investigation of laser-driven gamma-ray sources, a spatial resolution of about 90 µm is achieved when the areal density of the penetrated object is 120 g/cm2. A virtual source approach is proposed to optimize the size of the gamma-ray source used for imaging, with the aim of maximizing spatial resolution. In this virtual source approach, the gamma ray can be considered as being emitted from a virtual source within the convertor, where the equivalent gamma-ray source size in imaging is much smaller than the actual emission area. On the basis of Monte Carlo simulations, we derive a set of evaluation formulas for virtual source scale and gamma-ray emission angle. Under optimal conditions, the virtual source size can be as small as 15 µm, which can significantly improve the spatial resolution of high-penetration imaging to less than 50 µm.
{"title":"Virtual source approach for maximizing resolution in high-penetration gamma-ray imaging","authors":"Yuchi Wu, Shaoyi Wang, Bin Zhu, Yonghong Yan, Minghai Yu, Gang Li, Xiaohui Zhang, Yue Yang, Fang Tan, Feng Lu, Bi Bi, Xiaoqin Mao, Zhonghai Wang, Zongqing Zhao, Jingqin Su, Weimin Zhou, Yuqiu Gu","doi":"10.1063/5.0179781","DOIUrl":"https://doi.org/10.1063/5.0179781","url":null,"abstract":"High-energy gamma-ray radiography has exceptional penetration ability and has become an indispensable nondestructive testing (NDT) tool in various fields. For high-energy photons, point projection radiography is almost the only feasible imaging method, and its spatial resolution is primarily constrained by the size of the gamma-ray source. In conventional industrial applications, gamma-ray sources are commonly based on electron beams driven by accelerators, utilizing the process of bremsstrahlung radiation. The size of the gamma-ray source is dependent on the dimensional characteristics of the electron beam. Extensive research has been conducted on various advanced accelerator technologies that have the potential to greatly improve spatial resolution in NDT. In our investigation of laser-driven gamma-ray sources, a spatial resolution of about 90 µm is achieved when the areal density of the penetrated object is 120 g/cm2. A virtual source approach is proposed to optimize the size of the gamma-ray source used for imaging, with the aim of maximizing spatial resolution. In this virtual source approach, the gamma ray can be considered as being emitted from a virtual source within the convertor, where the equivalent gamma-ray source size in imaging is much smaller than the actual emission area. On the basis of Monte Carlo simulations, we derive a set of evaluation formulas for virtual source scale and gamma-ray emission angle. Under optimal conditions, the virtual source size can be as small as 15 µm, which can significantly improve the spatial resolution of high-penetration imaging to less than 50 µm.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"47 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140149595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Zhiyu Zhang, Yang Zhao, Xiaoying Han, Liling Li, Bo Qing, Lifei Hou, Yulong Li, YuXue Zhang, Huan Zhang, Xiangming Liu, Bo Deng, Gang Xiong, Min Lv, Tuo Zhu, Chengwu Huang, Tianming Song, Yan Zhao, Yingjie Li, Lu Zhang, Xufei Xie, Jiyan Zhang, Jiamin Yang
A self-consistent and precise method to determine the time-dependent radiative albedo, i.e., the ratio of the reemission flux to the incident flux, for an indirect-drive inertial confinement fusion Hohlraum wall material is proposed. A specially designed symmetrical triple-cavity gold Hohlraum is used to create approximately constant and near-equilibrium uniform radiation with a peak temperature of 160 eV. The incident flux at the secondary cavity waist is obtained from flux balance analysis and from the shock velocity of a standard sample. The results agree well owing to the symmetrical radiation in the secondary cavity. A self-consistent and precise time-dependent radiative albedo is deduced from the reliable reemission flux and the incident flux, and the result from the shock velocity is found to have a smaller uncertainty than that from the multi-angle flux balance analysis, and also to agree well with the result of a simulation using the HYADES opacity.
{"title":"Self-consistent and precise measurement of time-dependent radiative albedo of gold based on specially symmetrical triple-cavity Hohlraum","authors":"Zhiyu Zhang, Yang Zhao, Xiaoying Han, Liling Li, Bo Qing, Lifei Hou, Yulong Li, YuXue Zhang, Huan Zhang, Xiangming Liu, Bo Deng, Gang Xiong, Min Lv, Tuo Zhu, Chengwu Huang, Tianming Song, Yan Zhao, Yingjie Li, Lu Zhang, Xufei Xie, Jiyan Zhang, Jiamin Yang","doi":"10.1063/5.0177038","DOIUrl":"https://doi.org/10.1063/5.0177038","url":null,"abstract":"A self-consistent and precise method to determine the time-dependent radiative albedo, i.e., the ratio of the reemission flux to the incident flux, for an indirect-drive inertial confinement fusion Hohlraum wall material is proposed. A specially designed symmetrical triple-cavity gold Hohlraum is used to create approximately constant and near-equilibrium uniform radiation with a peak temperature of 160 eV. The incident flux at the secondary cavity waist is obtained from flux balance analysis and from the shock velocity of a standard sample. The results agree well owing to the symmetrical radiation in the secondary cavity. A self-consistent and precise time-dependent radiative albedo is deduced from the reliable reemission flux and the incident flux, and the result from the shock velocity is found to have a smaller uncertainty than that from the multi-angle flux balance analysis, and also to agree well with the result of a simulation using the HYADES opacity.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"4 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140010304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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