A structural search leads to the prediction of a novel alkaline earth nitride BeN4 containing a square planar N42− ring. This compound has a particular chemical bonding pattern giving it potential as a high-energy-density material. The P4/ nmm phase of BeN4 may be stable under ambient conditions, with a bandgap of 3.72 eV. It is predicted to have high thermodynamic and kinetic stability due to transfer of the outer-shell s electrons of the Be atom to the N4 cluster, with the outer-shell 2 p orbital accommodating the lone-pair electrons of N42−. The total of six π electrons is the most striking feature, indicating that the square planar N42− exhibits aromaticity. Under ambient conditions, BeN4 has a high energy density (3.924 kJ/g relative to Be3N2 and N2 gas), and its synthesis might be possible at pressures above 31.6 GPa.
{"title":"A novel square planar N42− ring with aromaticity in BeN4","authors":"Jiani Lin, Fangxu Wang, Qi Rui, Jianfu Li, Qinglin Wang, Xiaoli Wang","doi":"10.1063/5.0084802","DOIUrl":"https://doi.org/10.1063/5.0084802","url":null,"abstract":"A structural search leads to the prediction of a novel alkaline earth nitride BeN4 containing a square planar N42− ring. This compound has a particular chemical bonding pattern giving it potential as a high-energy-density material. The P4/ nmm phase of BeN4 may be stable under ambient conditions, with a bandgap of 3.72 eV. It is predicted to have high thermodynamic and kinetic stability due to transfer of the outer-shell s electrons of the Be atom to the N4 cluster, with the outer-shell 2 p orbital accommodating the lone-pair electrons of N42−. The total of six π electrons is the most striking feature, indicating that the square planar N42− exhibits aromaticity. Under ambient conditions, BeN4 has a high energy density (3.924 kJ/g relative to Be3N2 and N2 gas), and its synthesis might be possible at pressures above 31.6 GPa.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"16 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86927189","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}
Aneutronic fusion reactions such as proton–boron fusion could efficiently produce clean energy with quite low neutron doses. However, as a consequence, conventional neutron spectral methods for diagnosing plasma ion temperature would no longer work. Therefore, finding a way to probe the ion temperature in aneutronic fusion plasmas is a crucial task. Here, we present a method to realize ultrafast in situ probing of 11B ion temperature for proton–boron fusion by Doppler broadening of the nuclear resonance fluorescence (NRF) emission spectrum. The NRF emission is excited by a collimated, intense γ-ray beam generated from submicrometer wires irradiated by a recently available petawatt (PW) laser pulse, where the γ-ray beam generation is calculated by three-dimensional particle-in-cell simulation. When the laser power is higher than 1 PW, five NRF signatures of a 11B plasma can be clearly identified with high-resolution γ-ray detectors, as shown by our Geant4 simulations. The correlation between the NRF peak width and 11B ion temperature is discussed, and it is found that NRF emission spectroscopy should be sensitive to 11B ion temperatures T i > 2.4 keV. This probing method can also be extended to other neutron-free-fusion isotopes, such as 6Li and 15N.
质子-硼聚变等无中子聚变反应可以有效地产生低中子剂量的清洁能源。然而，结果是，传统的中子谱法诊断等离子体离子温度将不再有效。因此，寻找一种探测无中子聚变等离子体中离子温度的方法是一项至关重要的任务。本文提出了一种利用核共振荧光(NRF)发射光谱的多普勒展宽实现质子-硼聚变11B离子温度的超快速原位探测方法。NRF发射是由准直的强γ射线束激发的，γ射线束是由亚微米导线在最近可用的PW激光脉冲照射下产生的，其中γ射线束的产生是通过三维细胞内粒子模拟来计算的。当激光功率大于1 PW时，高分辨率γ射线探测器可以清楚地识别11B等离子体的五个非射频特征，如我们的Geant4模拟所示。讨论了NRF峰宽与11B离子温度的关系，发现NRF发射光谱对11B离子温度T i > 2.4 keV敏感。这种探测方法也可以扩展到其他无中子聚变同位素，如6Li和15N。
{"title":"Ultrafast probing of plasma ion temperature in proton–boron fusion by nuclear resonance fluorescence emission spectroscopy","authors":"Tong Qin, W. Luo, H. Lan, W.-M. Wang","doi":"10.1063/5.0078961","DOIUrl":"https://doi.org/10.1063/5.0078961","url":null,"abstract":"Aneutronic fusion reactions such as proton–boron fusion could efficiently produce clean energy with quite low neutron doses. However, as a consequence, conventional neutron spectral methods for diagnosing plasma ion temperature would no longer work. Therefore, finding a way to probe the ion temperature in aneutronic fusion plasmas is a crucial task. Here, we present a method to realize ultrafast in situ probing of 11B ion temperature for proton–boron fusion by Doppler broadening of the nuclear resonance fluorescence (NRF) emission spectrum. The NRF emission is excited by a collimated, intense γ-ray beam generated from submicrometer wires irradiated by a recently available petawatt (PW) laser pulse, where the γ-ray beam generation is calculated by three-dimensional particle-in-cell simulation. When the laser power is higher than 1 PW, five NRF signatures of a 11B plasma can be clearly identified with high-resolution γ-ray detectors, as shown by our Geant4 simulations. The correlation between the NRF peak width and 11B ion temperature is discussed, and it is found that NRF emission spectroscopy should be sensitive to 11B ion temperatures T i > 2.4 keV. This probing method can also be extended to other neutron-free-fusion isotopes, such as 6Li and 15N.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"2 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86917242","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}
Jianan Yuan, K. Xia, C. Ding, Xiaomeng Wang, Qing Lu, Jian Sun
Polymeric nitrogen has attracted much attention owing to its possible application as an environmentally safe high-energy-density material. Based on a crystal structure search method accelerated by the use of machine learning and graph theory and on first-principles calculations, we predict a series of metal nitrides with chain-like polynitrogen ( P21-AlN6, P21-GaN6, P-1-YN6, and P4/ mnc-TiN8), all of which are estimated to be energetically stable below 40.8 GPa. Phonon calculations and ab initio molecular dynamics simulations at finite temperature suggest that these nitrides are dynamically stable. We find that the nitrogen in these metal nitrides can polymerize into two types of poly-[Formula: see text] chains, in which the π electrons are either extended or localized. Owing to the presence of the polymerized N4 chains, these metal nitrides can store a large amount of chemical energy, which is estimated to range from 4.50 to 2.71 kJ/g. Moreover, these compounds have high detonation pressures and detonation velocities, exceeding those of conventional explosives such as TNT and HMX.
{"title":"High-energy-density metal nitrides with armchair chains","authors":"Jianan Yuan, K. Xia, C. Ding, Xiaomeng Wang, Qing Lu, Jian Sun","doi":"10.1063/5.0087168","DOIUrl":"https://doi.org/10.1063/5.0087168","url":null,"abstract":"Polymeric nitrogen has attracted much attention owing to its possible application as an environmentally safe high-energy-density material. Based on a crystal structure search method accelerated by the use of machine learning and graph theory and on first-principles calculations, we predict a series of metal nitrides with chain-like polynitrogen ( P21-AlN6, P21-GaN6, P-1-YN6, and P4/ mnc-TiN8), all of which are estimated to be energetically stable below 40.8 GPa. Phonon calculations and ab initio molecular dynamics simulations at finite temperature suggest that these nitrides are dynamically stable. We find that the nitrogen in these metal nitrides can polymerize into two types of poly-[Formula: see text] chains, in which the π electrons are either extended or localized. Owing to the presence of the polymerized N4 chains, these metal nitrides can store a large amount of chemical energy, which is estimated to range from 4.50 to 2.71 kJ/g. Moreover, these compounds have high detonation pressures and detonation velocities, exceeding those of conventional explosives such as TNT and HMX.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"51 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91030708","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}
Synchrotron radiation x-ray diffraction investigations of iron (Fe) and nickel (Ni) are conducted at pressures up to 354 and 368 GPa, respectively, and the equations of state (EOSs) at 298 K for the two elements are obtained for data extending to pressures as high as those at the center of the Earth, using the latest Pt-EOS pressure scale. From a least-squares fit to the Vinet equation using the observed pressure–volume data, the isothermal bulk modulus K0 and its pressure derivative [Formula: see text] are estimated to be 159.27(99) GPa and 5.86(4) for hcp-Fe, and 173.5(1.4) GPa and 5.55(5) for Ni. By comparing the present EOSs and extrapolated EOSs reported in the literature for Fe and Ni, the volumes of Fe and Ni at 365 GPa are found to be 2.3% and 1.5% larger than those estimated from extrapolated EOSs in previous studies, respectively. It is concluded that these discrepancies are due to the pressure scale. The present results suggest that the densities of Fe and Ni at a pressure of 365 GPa corresponding to the center of the Earth are 2.3% and 1.5%, respectively, lower than previously thought.
{"title":"Equations of state of iron and nickel to the pressure at the center of the Earth","authors":"N. Hirao, Y. Akahama, Y. Ohishi","doi":"10.1063/5.0074340","DOIUrl":"https://doi.org/10.1063/5.0074340","url":null,"abstract":"Synchrotron radiation x-ray diffraction investigations of iron (Fe) and nickel (Ni) are conducted at pressures up to 354 and 368 GPa, respectively, and the equations of state (EOSs) at 298 K for the two elements are obtained for data extending to pressures as high as those at the center of the Earth, using the latest Pt-EOS pressure scale. From a least-squares fit to the Vinet equation using the observed pressure–volume data, the isothermal bulk modulus K0 and its pressure derivative [Formula: see text] are estimated to be 159.27(99) GPa and 5.86(4) for hcp-Fe, and 173.5(1.4) GPa and 5.55(5) for Ni. By comparing the present EOSs and extrapolated EOSs reported in the literature for Fe and Ni, the volumes of Fe and Ni at 365 GPa are found to be 2.3% and 1.5% larger than those estimated from extrapolated EOSs in previous studies, respectively. It is concluded that these discrepancies are due to the pressure scale. The present results suggest that the densities of Fe and Ni at a pressure of 365 GPa corresponding to the center of the Earth are 2.3% and 1.5%, respectively, lower than previously thought.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"214 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78773652","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}
B. Albertazzi, P. Mabey, T. Michel, G. Rigon, J. Marquès, S. Pikuz, S. Ryazantsev, E. Falize, L. Van Box Som, J. Meinecke, N. Ozaki, G. Gregori, M. Koenig
The interaction between a molecular cloud and an external agent (e.g., a supernova remnant, plasma jet, radiation, or another cloud) is a common phenomenon throughout the Universe and can significantly change the star formation rate within a galaxy. This process leads to fragmentation of the cloud and to its subsequent compression and can, eventually, initiate the gravitational collapse of a stable molecular cloud. It is, however, difficult to study such systems in detail using conventional techniques (numerical simulations and astronomical observations), since complex interactions of flows occur. In this paper, we experimentally investigate the compression of a foam ball by Taylor–Sedov blast waves, as an analog of supernova remnants interacting with a molecular cloud. The formation of a compression wave is observed in the foam ball, indicating the importance of such experiments for understanding how star formation is triggered by external agents.
{"title":"Triggering star formation: Experimental compression of a foam ball induced by Taylor–Sedov blast waves","authors":"B. Albertazzi, P. Mabey, T. Michel, G. Rigon, J. Marquès, S. Pikuz, S. Ryazantsev, E. Falize, L. Van Box Som, J. Meinecke, N. Ozaki, G. Gregori, M. Koenig","doi":"10.1063/5.0068689","DOIUrl":"https://doi.org/10.1063/5.0068689","url":null,"abstract":"The interaction between a molecular cloud and an external agent (e.g., a supernova remnant, plasma jet, radiation, or another cloud) is a common phenomenon throughout the Universe and can significantly change the star formation rate within a galaxy. This process leads to fragmentation of the cloud and to its subsequent compression and can, eventually, initiate the gravitational collapse of a stable molecular cloud. It is, however, difficult to study such systems in detail using conventional techniques (numerical simulations and astronomical observations), since complex interactions of flows occur. In this paper, we experimentally investigate the compression of a foam ball by Taylor–Sedov blast waves, as an analog of supernova remnants interacting with a molecular cloud. The formation of a compression wave is observed in the foam ball, indicating the importance of such experiments for understanding how star formation is triggered by external agents.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"15 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83299717","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}
C. Samulski, B. Srinivasan, M. Manuel, R. Masti, J. Sauppe, J. Kline
Experiments have identi fi ed the Rayleigh – Taylor (RT) instability as one of the greatest obstacles to achieving inertial con fi nement fusion. Consequently, mitigation strategies to reduce RT growth and fuel – ablator mixing in the hotspot during the deceleration phase of the implosion are of great interest. In this work, the effect of seed magnetic fi elds on deceleration-phase RT growth are studied in planar and cylindrical geometries under conditions relevant to the National Ignition Facility (NIF) and Omega experiments. The magnetohydrodynamic (MHD) and resistive-MHD capabilities of the FLASH code are used to model imploding cylinders and planar blast-wave-driven targets. Realistic target and laserparametersarepresentedthatsuggesttheoccurrenceofmorphologicaldifferencesinlate-timeRTevolutioninthecylindricalNIFcaseandameasurabledifferenceinspikeheightofsingle-modegrowthintheplanarNIFcase.TheresultsofthisstudyindicatetheneedfortargetdesignstoutilizeanRT-unstablefoam – foam interface in order to achieve suf fi cient magnetic fi eld ampli fi cation to alter RT evolution. Benchmarked FLASH simulations are used to study these magnetic fi eld effects in both resistive and ideal MHD. on the hotspot. The deceleration phase when the interior begins pushing back on the
{"title":"Deceleration-stage Rayleigh–Taylor growth in a background magnetic field studied in cylindrical and Cartesian geometries","authors":"C. Samulski, B. Srinivasan, M. Manuel, R. Masti, J. Sauppe, J. Kline","doi":"10.1063/5.0062168","DOIUrl":"https://doi.org/10.1063/5.0062168","url":null,"abstract":"Experiments have identi fi ed the Rayleigh – Taylor (RT) instability as one of the greatest obstacles to achieving inertial con fi nement fusion. Consequently, mitigation strategies to reduce RT growth and fuel – ablator mixing in the hotspot during the deceleration phase of the implosion are of great interest. In this work, the effect of seed magnetic fi elds on deceleration-phase RT growth are studied in planar and cylindrical geometries under conditions relevant to the National Ignition Facility (NIF) and Omega experiments. The magnetohydrodynamic (MHD) and resistive-MHD capabilities of the FLASH code are used to model imploding cylinders and planar blast-wave-driven targets. Realistic target and laserparametersarepresentedthatsuggesttheoccurrenceofmorphologicaldifferencesinlate-timeRTevolutioninthecylindricalNIFcaseandameasurabledifferenceinspikeheightofsingle-modegrowthintheplanarNIFcase.TheresultsofthisstudyindicatetheneedfortargetdesignstoutilizeanRT-unstablefoam – foam interface in order to achieve suf fi cient magnetic fi eld ampli fi cation to alter RT evolution. Benchmarked FLASH simulations are used to study these magnetic fi eld effects in both resistive and ideal MHD. on the hotspot. The deceleration phase when the interior begins pushing back on the","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"21 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74407527","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}
B. Zhu, Zhe Zhang, Chang Liu, D. Yuan, Weiman Jiang, Huigang Wei, Fang Li, Yihang Zhang, B. Han, Lei Cheng, Shangqing Li, J. Zhong, X. Yuan, Bowei Tong, Wei Sun, Z. Fang, Chen Wang, Zhi-yong Xie, N. Hua, Rong Wu, Zhanfeng Qiao, G. Liang, Baoqiang Zhu, Jianqiang Zhu, S. Fujioka, Yutong Li
{"title":"Observation of Zeeman splitting effect in a laser-driven coil","authors":"B. Zhu, Zhe Zhang, Chang Liu, D. Yuan, Weiman Jiang, Huigang Wei, Fang Li, Yihang Zhang, B. Han, Lei Cheng, Shangqing Li, J. Zhong, X. Yuan, Bowei Tong, Wei Sun, Z. Fang, Chen Wang, Zhi-yong Xie, N. Hua, Rong Wu, Zhanfeng Qiao, G. Liang, Baoqiang Zhu, Jianqiang Zhu, S. Fujioka, Yutong Li","doi":"10.1063/5.0060954","DOIUrl":"https://doi.org/10.1063/5.0060954","url":null,"abstract":"","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"31 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76256553","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}
E. Baksht, B. Alekseev, A. Burachenko, A. Vukolov, A. Potylitsyn, V. Tarasenko, S. Uglov, M. Shevelev
{"title":"Emission of fused silica and KBr samples in the UV and visible spectral ranges under irradiation with 2.7 MeV electrons","authors":"E. Baksht, B. Alekseev, A. Burachenko, A. Vukolov, A. Potylitsyn, V. Tarasenko, S. Uglov, M. Shevelev","doi":"10.1063/5.0061100","DOIUrl":"https://doi.org/10.1063/5.0061100","url":null,"abstract":"","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"32 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77242186","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}
{"title":"Partnership for eXtreme Xtallography (PX2)—A state-of-the-art experimental facility for extreme-conditions crystallography: A case study of pressure-induced phase transition in natural ilvaite","authors":"Jingui Xu, Dongzhou Zhang, S. Tkachev, P. Dera","doi":"10.1063/5.0075795","DOIUrl":"https://doi.org/10.1063/5.0075795","url":null,"abstract":"","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"3 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81076513","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}
{"title":"Theoretical investigations on x-ray transport in radiation transport experiments on the Shenguang-III prototype laser facility","authors":"G. Meng, Jun She, T. Song, Jiamin Yang, Min Wang","doi":"10.1063/5.0043745","DOIUrl":"https://doi.org/10.1063/5.0043745","url":null,"abstract":"","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"11 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85335064","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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