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Rodney C. Ewing - One of the best experts on this subject based on the ideXlab platform.
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reply to comment by konings and plyasunov on first experimental determination of the solubility constant of Coffinite geochim cosmochim acta 181 2016 36 53
Geochimica et Cosmochimica Acta, 2017Co-Authors: Stephanie Szenknect, Rodney C. Ewing, Nicolas Dacheux, Alexandra NavrotskyAbstract:R.J.M. Konings and A. Plyasunov investigated the values of thermodynamic data determined by Szenknect et al. (2016) from solubility experiments performed using a synthetic sample of Coffinite. Especially, they focused on the value of the standard molar entropy, which was derived from these solubility data and the calorimetric measurement of the standard molar enthalpy of formation of Coffinite published by Guo et al. (2015) . The two independent measurements were performed on the same synthetic sample prepared by Mesbah et al. (2015) and fully characterized using complementary techniques by the two teams. We thank Konings and Plyasunov for their comment and the relevant analysis of previously published work. As they concluded, we agree that new experimental data are required to solve the “Coffinite issue”. Here, we simply wish to clarify a few points regarding the questions arising from their analysis.
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first experimental determination of the solubility constant of Coffinite
Geochimica et Cosmochimica Acta, 2016Co-Authors: Stephanie Szenknect, Rodney C. Ewing, Adel Mesbah, Christophe Poinssot, Nicolas Clavier, T Cordara, H P Brau, Xavier Le F Goff, Nicolas DacheuxAbstract:Abstract Dissolution experiments have been performed in order to determine the solubility constant of Coffinite, USiO4. Several assemblages of phases were used in under-saturated experiments performed in 0.1 mol L−1 HCl under Ar atmosphere, as well as in air. These samples were fully-characterized and were composed of either USiO4, solely, or USiO4 and additional oxide byproducts that resulted from the synthesis procedure. The solubility constant of Coffinite was determined at 25 °C and 1 bar (log *KS°(USiO4, cr) = −5.25 ± 0.05), as well as the standard free energy of formation of Coffinite (ΔfG°(298 K) = −1867.6 ± 3.2 kJ mol−1), which enables one to infer the relative stability of Coffinite and uraninite as a function of groundwater composition. Geochemical simulations using PHREEQC 2 software and the Thermochimie data base indicate that Coffinite precipitates at 25 °C under reducing conditions, at pH = 6, for H4SiO4(aq) concentration of 7 × 10−5 mol L−1 and U(OH)4(aq) concentration of 10−11 mol L−1. The ΔfG° value determined was used to calculate the standard free energy associated with the formation of Coffinite from a mixture of uraninite and quartz. The value obtained (Δr,oxG° = 20.6 ± 5.2 kJ mol−1) indicates unambiguously that Coffinite is less stable than the quartz + uraninite mixture at 25 °C. Geochemical simulations using PHREEQC 2 software indicate that Coffinite precipitates in solutions supersaturated with respect to UO2(cr), but undersaturated with respect to UO2(am) in aqueous solutions with silica concentrations typical of groundwater. These favorable conditions during the formation of sedimentary uranium ore deposits, as well as slow dissolution kinetics, explain the common occurrence of Coffinite.
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Coffinite usio4 is abundant in nature so why is it so difficult to synthesize
Inorganic Chemistry, 2015Co-Authors: Adel Mesbah, Rodney C. Ewing, Stephanie Szenknect, Christophe Poinssot, Nicolas Clavier, Janeth Lozanorodriguez, Christophe Den Auwer, Nicolas DacheuxAbstract:Coffinite, USiO4, is the second most abundant U4+ mineral on Earth, and its formation by the alteration of the UO2 in spent nuclear fuel in a geologic repository may control the release of radionuclides to the environment. Despite its abundance in nature, the synthesis and characterization of Coffinite have eluded researchers for decades. On the basis of the recent synthesis of USiO4, we can now define the experimental conditions under which Coffinite is most efficiently formed. Optimal formation conditions are defined for four parameters: pH, T, heating time, and U/Si molar ratio. The adjustment of pH between 10 and 12 leads probably to the formation of a uranium(IV) hydroxo-silicate complex that acts as a precursor of uranium(IV) silicate colloids and then of Coffinite. Moreover, in this pH range, the largest yield of Coffinite formation (as compared with those of the two competing byproduct phases, nanometer-scale UO2 and amorphous SiO2) is obtained for 250 °C, 7 days, and 100% excess silica.
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formation of nanoscale th Coffinite
American Mineralogist, 2012Co-Authors: Artur P Deditius, Veronique Pointeau, Jiaming M Zhang, Rodney C. EwingAbstract:U-thorite, (Th,U)SiO4, from Ambohijatrova Masindray, Madagascar, was investigated to understand the behavior of Th and U during recrystallization of amorphous radiation-damaged, (Th,U)-orthosilicates. Optical microscopy and electron microprobe analyses reveal two types of U-thorite: (i) large (about 1 cm), orange, amorphous grains with composition: (Th0.88±0.02U0.09–0.01Pb0.029±0.002 REE0.01±0.001)1.00±0.01Si1.00±0.01; and (ii) green, microcrystalline U-thorite with composition: (Th0.76±0.05 U0.08±0.01Ca0.07±0.01Pb0.014±0.005REE0.009±0.001)0.92±0.07Si1.12±0.06. Ca-free U-thorite-(i) is enriched in Th, U, and Pb (7.1, 1.2, and 1 wt%, respectively), and depleted in Si (3.0 wt%) compared to U-thorite-(ii). Recrystallization of U-thorite-(i) resulted in fracturing that facilitated migration of mobilized Th and U over a distance of about 300 μm, as evidenced by precipitation of U-thorite-(ii) in the fractures in associated apatite and garnet. Transmission electron microscopy observations and selected-area electron diffraction (SAED) patterns confirm that U-thorite-(i) is amorphous. U-thorite-(ii) forms: (1) single crystals (>1 μm in size) with variable amounts of amorphous material; or (2) randomly oriented, nanocrystalline aggregates (5–10 nm in size). TEM-EDX analyses show that the Th/U ratio in U-thorite-(i) and U-thorite-(ii) is ~6. High-angle annular dark-field scanning TEM (HAADF-STEM) and high-resolution TEM reveal that nanocrystalline Th-Coffinite (20–40 nm in size) with Th/U ratio = 0.6, formed during recrystallization of U-thorite-(i). The calculated chemical Th-U-Pb ages of U-thorite-(i) range from 2.1–1.9 Ga and from 1.8–1.6 Ga, whereas U-thorite-(ii) ages range from 1.6–0.5 Ga. The calculated cumulative radiation dose for U-thorite-(i) varies from 1.6–1.8 × 1018 α-decay events/mg, which is equivalent to 136–152 displacements per atom (dpa), and for U-thorite-(ii) from 3–4.4 × 1017 (α-decay events/mg) (=27–37 dpa). The cumulative dose for Th-Coffinite is 9.8 × 1017 α-decay events/mg (84 dpa).
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precipitation and alteration of Coffinite usio4 nh 2o in the presence of apatite
European Journal of Mineralogy, 2010Co-Authors: Satoshi Utsunomiya, Artur P Deditius, Veronique Pointeau, Rodney C. EwingAbstract:A mineral assemblage of Coffinite, USiO4-TiH2O, n= 0-2, carbonate-fluorapatite (CFAp) and (Ca, Sr)-(meta)autunite (MAut) from the Woodrow Mine, Grants uranium region, New Mexico, has been investigated in order to understand the influence of a Prich micro-geochemical environment on precipitation of Coffinite and its subsequent alteration under oxidizing conditions. Finegrained Coffinite (< 10 μm) precipitated under reducing conditions replacing CFAp, pyrite and aluminosilicates. Electron-microprobe analyses (EMPA) of Coffinite indicate limited incorporation of P 2O5 and CaO, <2.7 and <3.0 wt%, respectively, into the Coffinite structure during replacement of CFAp. The chemical formula of Coffinite is (U0.95±0.09Ca 0.15±0.02)Σ1.10± 0.1(Si0.84±0.08P 0.06±0.02)<0.90 ± 0.08- Analysis by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) revealed that Coffinite initially formed as crystals as large as 100 nm at the edges of altered CFAp. Subsequently, infiltration of (Na, Ba, Sr)-rich oxidizing fluids into fractures resulted in precipitation of Sr-rich M-Aut (up to 4 wt% of SrO) at the expense of Coffinite and CFAp. Highresolution TEM reveals that Na-rich fluids caused a distortion of the ideal Coffinite structure and stabilized amorphous domains that formed due to alpha-decay event radiation damage. Subsequently, the Na-enriched amorphous areas of Coffinite were preferentially altered, and secondary porosity formed at the scale of ∼1 urn. Porosity also was formed during alteration of CFAp to M-Aut, which facilitated the migration of oxidizing fluids over distances of ∼ 150 μm; in to CFAp, as evidenced by precipitation of M-Aut. We report, for the first time, the precipitation of Coffinite at the expense of apatite and the subsequent alteration of Coffinite under P-rich, oxidizing conditions. These results show that micro-scale dissolution of apatite can create conditions conducive to the precipitation of U(IV)- and U(VT)-minerals, leading to the reduced mobility of U-species under both reducing and oxidizing conditions.
Stephanie Szenknect - One of the best experts on this subject based on the ideXlab platform.
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the role of water and hydroxyl groups in the structures of stetindite and Coffinite msio4 m ce u
Inorganic Chemistry, 2021Co-Authors: Andrew C Strzelecki, Adel Mesbah, Nicolas Clavier, Thomas Barral, Paul Estevenon, Vitaliy G Goncharov, Jason Baker, Jianming Bai, Stephanie SzenknectAbstract:Orthosilicates adopt the zircon structure types (I41/amd), consisting of isolated SiO4 tetrahedra joined by A-site metal cations, such as Ce and U. They are of significant interest in the fields of geochemistry, mineralogy, nuclear waste form development, and material science. Stetindite (CeSiO4) and Coffinite (USiO4) can be formed under hydrothermal conditions despite both being thermodynamically metastable. Water has been hypothesized to play a significant role in stabilizing and forming these orthosilicate phases, though little experimental evidence exists. To understand the effects of hydration or hydroxylation on these orthosilicates, in situ high-temperature synchrotron and laboratory-based X-ray diffraction was conducted from 25 to ∼850 °C. Stetindite maintains its I41/amd symmetry with increasing temperature but exhibits a discontinuous expansion along the a-axis during heating, presumably due to the removal of water confined in the [001] channels, which shrink against thermal expansion along the a-axis. Additional in situ high-temperature Raman and Fourier transform infrared spectroscopy also confirmed the presence of the confined water. Coffinite was also found to expand nonlinearly up to 600 °C and then thermally decompose into a mixture of UO2 and SiO2. A combination of dehydration and dehydroxylation is proposed for explaining the thermal behavior of Coffinite synthesized hydrothermally. Additionally, we investigated high-temperature structures of two Coffinite-thorite solid solutions, uranothorite (UxTh1-xSiO4), which displayed complex variations in composition during heating that was attributed to the negative enthalpy of mixing. Lastly, for the first time, the coefficients of thermal expansion of CeSiO4, USiO4, U0.46Th0.54SiO4, and U0.9Th0.1SiO4 were determined to be αV = 14.49 × 10-6, 14.29 × 10-6, 17.21 × 10-6, and 17.23 × 10-6 °C-1, respectively.
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Coffinite formation from uo 2 x
Scientific Reports, 2020Co-Authors: Stephanie Szenknect, Lena Z Evins, Adel Mesbah, Delhia Alby, Marta Lopez Garcia, Chenxu Wang, Renaud Podor, Frederic Miserque, Lara Duro, Nicolas DacheuxAbstract:Most of the highly radioactive spent nuclear fuel (SNF) around the world is destined for final disposal in deep-mined geological repositories. At the end of the fuel’s useful life in a reactor, about 96% of the SNF is still UO2. Thus, the behaviour of UO2 in SNF must be understood and evaluated under the weathering conditions of geologic disposal, which extend to periods of hundreds of thousands of years. There is ample evidence from nature that many uranium deposits have experienced conditions for which the formation of Coffinite, USiO4, has been favoured over uraninite, UO2+x, during subsequent alteration events. Thus, Coffinite is an important alteration product of the UO2 in SNF. Here, we present the first evidence of the formation of Coffinite on the surface of UO2 at the time scale of laboratory experiments in a solution saturated with respect to amorphous silica at pH = 9, room temperature and under anoxic conditions.
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quantification of Coffinite usio4 in roll front uranium deposits using visible to near infrared vis nir portable field spectroscopy
Journal of Geochemical Exploration, 2019Co-Authors: Benoit Hebert, Fabien Baron, Valentin Robin, Karl Lelievre, Nicolas Dacheux, Stephanie Szenknect, Adel Mesbah, Adrien Pouradier, Ruslan Jikibayev, Regis RoyAbstract:Abstract Coffinite (USiO4) is a common uranium-bearing mineral of roll-front uranium deposits. This mineral can be identified by the visible near infrared (Vis-NIR) portable field spectrometers used in mining exploration. However, due to the low detection limits and associated errors, the quantification of Coffinite abundance in the mineralized sandstones or sandy sediments of roll-front uranium deposits using Vis-NIR spectrometry requires a specific methodological development. In this study, the 1135 nm absorption band area is used to quantify the abundance of Coffinite. This absorption feature does not interfere with NIR absorption bands of any other minerals present in natural sands or sandstones of uranium roll-front deposits. The correlation between the 1135 nm band area and Coffinite content was determined from a series of spectra measured from prepared mineral mixtures. The samples were prepared with a range of weighted amounts of arenitic sands and synthetic Coffinite simulating the range of uranium concentration encountered in roll-front uranium deposits. The methodology presented in this study provides the quantification of the Coffinite content present in sands between 0.03 wt% to 1 wt% Coffinite with a detection limit as low as 0.005 wt%. The integrated area of the 1135 nm band is positively correlated with the Coffinite content of the sand in this range, showing that the method is efficient to quantify Coffinite concentrations typical of roll-front uranium deposits. The regression equation defined in this study was then used as a reference to predict the amount of natural Coffinite in a set of mineralized samples from the Tortkuduk uranium roll-front deposit (South Kazakhstan).
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reply to comment by konings and plyasunov on first experimental determination of the solubility constant of Coffinite geochim cosmochim acta 181 2016 36 53
Geochimica et Cosmochimica Acta, 2017Co-Authors: Stephanie Szenknect, Rodney C. Ewing, Nicolas Dacheux, Alexandra NavrotskyAbstract:R.J.M. Konings and A. Plyasunov investigated the values of thermodynamic data determined by Szenknect et al. (2016) from solubility experiments performed using a synthetic sample of Coffinite. Especially, they focused on the value of the standard molar entropy, which was derived from these solubility data and the calorimetric measurement of the standard molar enthalpy of formation of Coffinite published by Guo et al. (2015) . The two independent measurements were performed on the same synthetic sample prepared by Mesbah et al. (2015) and fully characterized using complementary techniques by the two teams. We thank Konings and Plyasunov for their comment and the relevant analysis of previously published work. As they concluded, we agree that new experimental data are required to solve the “Coffinite issue”. Here, we simply wish to clarify a few points regarding the questions arising from their analysis.
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first experimental determination of the solubility constant of Coffinite
Geochimica et Cosmochimica Acta, 2016Co-Authors: Stephanie Szenknect, Rodney C. Ewing, Adel Mesbah, Christophe Poinssot, Nicolas Clavier, T Cordara, H P Brau, Xavier Le F Goff, Nicolas DacheuxAbstract:Abstract Dissolution experiments have been performed in order to determine the solubility constant of Coffinite, USiO4. Several assemblages of phases were used in under-saturated experiments performed in 0.1 mol L−1 HCl under Ar atmosphere, as well as in air. These samples were fully-characterized and were composed of either USiO4, solely, or USiO4 and additional oxide byproducts that resulted from the synthesis procedure. The solubility constant of Coffinite was determined at 25 °C and 1 bar (log *KS°(USiO4, cr) = −5.25 ± 0.05), as well as the standard free energy of formation of Coffinite (ΔfG°(298 K) = −1867.6 ± 3.2 kJ mol−1), which enables one to infer the relative stability of Coffinite and uraninite as a function of groundwater composition. Geochemical simulations using PHREEQC 2 software and the Thermochimie data base indicate that Coffinite precipitates at 25 °C under reducing conditions, at pH = 6, for H4SiO4(aq) concentration of 7 × 10−5 mol L−1 and U(OH)4(aq) concentration of 10−11 mol L−1. The ΔfG° value determined was used to calculate the standard free energy associated with the formation of Coffinite from a mixture of uraninite and quartz. The value obtained (Δr,oxG° = 20.6 ± 5.2 kJ mol−1) indicates unambiguously that Coffinite is less stable than the quartz + uraninite mixture at 25 °C. Geochemical simulations using PHREEQC 2 software indicate that Coffinite precipitates in solutions supersaturated with respect to UO2(cr), but undersaturated with respect to UO2(am) in aqueous solutions with silica concentrations typical of groundwater. These favorable conditions during the formation of sedimentary uranium ore deposits, as well as slow dissolution kinetics, explain the common occurrence of Coffinite.
Nicolas Dacheux - One of the best experts on this subject based on the ideXlab platform.
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Coffinite formation from uo 2 x
Scientific Reports, 2020Co-Authors: Stephanie Szenknect, Lena Z Evins, Adel Mesbah, Delhia Alby, Marta Lopez Garcia, Chenxu Wang, Renaud Podor, Frederic Miserque, Lara Duro, Nicolas DacheuxAbstract:Most of the highly radioactive spent nuclear fuel (SNF) around the world is destined for final disposal in deep-mined geological repositories. At the end of the fuel’s useful life in a reactor, about 96% of the SNF is still UO2. Thus, the behaviour of UO2 in SNF must be understood and evaluated under the weathering conditions of geologic disposal, which extend to periods of hundreds of thousands of years. There is ample evidence from nature that many uranium deposits have experienced conditions for which the formation of Coffinite, USiO4, has been favoured over uraninite, UO2+x, during subsequent alteration events. Thus, Coffinite is an important alteration product of the UO2 in SNF. Here, we present the first evidence of the formation of Coffinite on the surface of UO2 at the time scale of laboratory experiments in a solution saturated with respect to amorphous silica at pH = 9, room temperature and under anoxic conditions.
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quantification of Coffinite usio4 in roll front uranium deposits using visible to near infrared vis nir portable field spectroscopy
Journal of Geochemical Exploration, 2019Co-Authors: Benoit Hebert, Fabien Baron, Valentin Robin, Karl Lelievre, Nicolas Dacheux, Stephanie Szenknect, Adel Mesbah, Adrien Pouradier, Ruslan Jikibayev, Regis RoyAbstract:Abstract Coffinite (USiO4) is a common uranium-bearing mineral of roll-front uranium deposits. This mineral can be identified by the visible near infrared (Vis-NIR) portable field spectrometers used in mining exploration. However, due to the low detection limits and associated errors, the quantification of Coffinite abundance in the mineralized sandstones or sandy sediments of roll-front uranium deposits using Vis-NIR spectrometry requires a specific methodological development. In this study, the 1135 nm absorption band area is used to quantify the abundance of Coffinite. This absorption feature does not interfere with NIR absorption bands of any other minerals present in natural sands or sandstones of uranium roll-front deposits. The correlation between the 1135 nm band area and Coffinite content was determined from a series of spectra measured from prepared mineral mixtures. The samples were prepared with a range of weighted amounts of arenitic sands and synthetic Coffinite simulating the range of uranium concentration encountered in roll-front uranium deposits. The methodology presented in this study provides the quantification of the Coffinite content present in sands between 0.03 wt% to 1 wt% Coffinite with a detection limit as low as 0.005 wt%. The integrated area of the 1135 nm band is positively correlated with the Coffinite content of the sand in this range, showing that the method is efficient to quantify Coffinite concentrations typical of roll-front uranium deposits. The regression equation defined in this study was then used as a reference to predict the amount of natural Coffinite in a set of mineralized samples from the Tortkuduk uranium roll-front deposit (South Kazakhstan).
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reply to comment by konings and plyasunov on first experimental determination of the solubility constant of Coffinite geochim cosmochim acta 181 2016 36 53
Geochimica et Cosmochimica Acta, 2017Co-Authors: Stephanie Szenknect, Rodney C. Ewing, Nicolas Dacheux, Alexandra NavrotskyAbstract:R.J.M. Konings and A. Plyasunov investigated the values of thermodynamic data determined by Szenknect et al. (2016) from solubility experiments performed using a synthetic sample of Coffinite. Especially, they focused on the value of the standard molar entropy, which was derived from these solubility data and the calorimetric measurement of the standard molar enthalpy of formation of Coffinite published by Guo et al. (2015) . The two independent measurements were performed on the same synthetic sample prepared by Mesbah et al. (2015) and fully characterized using complementary techniques by the two teams. We thank Konings and Plyasunov for their comment and the relevant analysis of previously published work. As they concluded, we agree that new experimental data are required to solve the “Coffinite issue”. Here, we simply wish to clarify a few points regarding the questions arising from their analysis.
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first experimental determination of the solubility constant of Coffinite
Geochimica et Cosmochimica Acta, 2016Co-Authors: Stephanie Szenknect, Rodney C. Ewing, Adel Mesbah, Christophe Poinssot, Nicolas Clavier, T Cordara, H P Brau, Xavier Le F Goff, Nicolas DacheuxAbstract:Abstract Dissolution experiments have been performed in order to determine the solubility constant of Coffinite, USiO4. Several assemblages of phases were used in under-saturated experiments performed in 0.1 mol L−1 HCl under Ar atmosphere, as well as in air. These samples were fully-characterized and were composed of either USiO4, solely, or USiO4 and additional oxide byproducts that resulted from the synthesis procedure. The solubility constant of Coffinite was determined at 25 °C and 1 bar (log *KS°(USiO4, cr) = −5.25 ± 0.05), as well as the standard free energy of formation of Coffinite (ΔfG°(298 K) = −1867.6 ± 3.2 kJ mol−1), which enables one to infer the relative stability of Coffinite and uraninite as a function of groundwater composition. Geochemical simulations using PHREEQC 2 software and the Thermochimie data base indicate that Coffinite precipitates at 25 °C under reducing conditions, at pH = 6, for H4SiO4(aq) concentration of 7 × 10−5 mol L−1 and U(OH)4(aq) concentration of 10−11 mol L−1. The ΔfG° value determined was used to calculate the standard free energy associated with the formation of Coffinite from a mixture of uraninite and quartz. The value obtained (Δr,oxG° = 20.6 ± 5.2 kJ mol−1) indicates unambiguously that Coffinite is less stable than the quartz + uraninite mixture at 25 °C. Geochemical simulations using PHREEQC 2 software indicate that Coffinite precipitates in solutions supersaturated with respect to UO2(cr), but undersaturated with respect to UO2(am) in aqueous solutions with silica concentrations typical of groundwater. These favorable conditions during the formation of sedimentary uranium ore deposits, as well as slow dissolution kinetics, explain the common occurrence of Coffinite.
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Coffinite usio4 is abundant in nature so why is it so difficult to synthesize
Inorganic Chemistry, 2015Co-Authors: Adel Mesbah, Rodney C. Ewing, Stephanie Szenknect, Christophe Poinssot, Nicolas Clavier, Janeth Lozanorodriguez, Christophe Den Auwer, Nicolas DacheuxAbstract:Coffinite, USiO4, is the second most abundant U4+ mineral on Earth, and its formation by the alteration of the UO2 in spent nuclear fuel in a geologic repository may control the release of radionuclides to the environment. Despite its abundance in nature, the synthesis and characterization of Coffinite have eluded researchers for decades. On the basis of the recent synthesis of USiO4, we can now define the experimental conditions under which Coffinite is most efficiently formed. Optimal formation conditions are defined for four parameters: pH, T, heating time, and U/Si molar ratio. The adjustment of pH between 10 and 12 leads probably to the formation of a uranium(IV) hydroxo-silicate complex that acts as a precursor of uranium(IV) silicate colloids and then of Coffinite. Moreover, in this pH range, the largest yield of Coffinite formation (as compared with those of the two competing byproduct phases, nanometer-scale UO2 and amorphous SiO2) is obtained for 250 °C, 7 days, and 100% excess silica.
Chongying Dong - One of the best experts on this subject based on the ideXlab platform.
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a characterization of vertex operator algebra l frac 1 2 0 otimes l frac 1 2 0
Communications in Mathematical Physics, 2010Co-Authors: Chongying Dong, Cuipo JiangAbstract:We study a simple, rational and C2-cofinite vertex operator algebra whose weight 1 subspace is zero, the dimension of weight 2 subspace is greater than or equal to 2 and with c = c = 1. Under some additional conditions it is shown that such a vertex operator algebra is isomorphic to \({L(\frac{1}{2},0)\otimes L(\frac{1}{2},0)}\).
Cuipo Jiang - One of the best experts on this subject based on the ideXlab platform.
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a characterization of vertex operator algebra l frac 1 2 0 otimes l frac 1 2 0
Communications in Mathematical Physics, 2010Co-Authors: Chongying Dong, Cuipo JiangAbstract:We study a simple, rational and C2-cofinite vertex operator algebra whose weight 1 subspace is zero, the dimension of weight 2 subspace is greater than or equal to 2 and with c = c = 1. Under some additional conditions it is shown that such a vertex operator algebra is isomorphic to \({L(\frac{1}{2},0)\otimes L(\frac{1}{2},0)}\).