Pub Date : 2025-05-31DOI: 10.1016/j.adt.2025.101743
L.V. Chernysheva , V.G. Yarzhemsky
Theoretical photoionization cross-sections and angular distribution parameters for valence, excited and subvalence shells of 4f- elements from Eu to Lu are calculated with account for intrachannel and interchannel interactions for the energy region from threshold up to 30 Ry. Many-electron effects were accounted for within the framework of RPAE (Random Phase Approximation with Exchange) method, which is extended on average terms of unfilled shells. Calculations demonstrate good agreement with the HFS results of Yeh and Lindau for 4f- orbitals and strong influence of correlation effects on the cross-sections of 5p-, 6s-, 5d- and orbitals from threshold up to about 20 Ry.
{"title":"Photoionization cross-sections of valence and excited electrons of lanthanides from Eu to Lu in VUV-soft X-ray spectral region","authors":"L.V. Chernysheva , V.G. Yarzhemsky","doi":"10.1016/j.adt.2025.101743","DOIUrl":"10.1016/j.adt.2025.101743","url":null,"abstract":"<div><div><span>Theoretical photoionization cross-sections and angular distribution parameters for valence, excited and subvalence shells of 4</span><em>f</em>- elements from Eu to Lu are calculated with account for intrachannel and interchannel interactions for the energy region from threshold up to 30 Ry. Many-electron effects were accounted for within the framework of RPAE (Random Phase Approximation with Exchange) method, which is extended on average terms of unfilled shells. Calculations demonstrate good agreement with the HFS results of Yeh and Lindau for 4<em>f</em>- orbitals and strong influence of correlation effects on the cross-sections of 5<em>p-</em>, 6<em>s-</em>, 5<em>d</em>- and orbitals from threshold up to about 20 Ry.</div></div>","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"166 ","pages":"Article 101743"},"PeriodicalIF":4.1,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145021051","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 : 2025-05-23DOI: 10.1016/j.adt.2025.101733
Tian Yu Wu , Bao Hua Sun , Hui Hui Xie , Jun Yao Xu , Ge Guo
Point-proton density distributions are deduced for 130 stable nuclei from to from nuclear charge densities determined in elastic electron scattering. There are 171 cases presented in model-dependent forms, including the modified Harmonic-oscillator function, two-parameter Fermi function (2pF), three-parameter Fermi function, three-parameter Gaussian function, and 97 in Fourier-Bessel series model-independent forms. Independent of density functions, the point-proton root-mean-square (rms) radii of the derived point-proton density show excellent agreement with each other. We identify cases where the tabulated data of charge densities and charge radii are inconsistent, and the deduced point-proton density distributions are inaccurate due to insufficient experimental momentum transfer coverage or inconsistent scattering experiments. For the widely used 2pF distribution, it is found that the surface diffuseness parameters can be empirically calculated from those of charge density, while the half-density radius parameters follow the rule. The derived point-proton density distributions can be used as input in nuclear reaction studies and compared with nuclear model predictions.
{"title":"Point-proton density distributions of stable nuclei","authors":"Tian Yu Wu , Bao Hua Sun , Hui Hui Xie , Jun Yao Xu , Ge Guo","doi":"10.1016/j.adt.2025.101733","DOIUrl":"10.1016/j.adt.2025.101733","url":null,"abstract":"<div><div>Point-proton density distributions are deduced for 130 stable nuclei from <span><math><mrow><msup><mrow></mrow><mrow><mn>7</mn></mrow></msup><mi>Li</mi></mrow></math></span> to <span><math><mrow><msup><mrow></mrow><mrow><mn>232</mn></mrow></msup><mi>Th</mi></mrow></math></span> from nuclear charge densities determined in elastic electron scattering. There are 171 cases presented in model-dependent forms, including the modified Harmonic-oscillator function, two-parameter Fermi function (2pF), three-parameter Fermi function, three-parameter Gaussian function, and 97 in Fourier-Bessel series model-independent forms. Independent of density functions, the point-proton root-mean-square (rms) radii of the derived point-proton density show excellent agreement with each other. We identify cases where the tabulated data of charge densities and charge radii are inconsistent, and the deduced point-proton density distributions are inaccurate due to insufficient experimental momentum transfer coverage or inconsistent scattering experiments. For the widely used 2pF distribution, it is found that the surface diffuseness parameters can be empirically calculated from those of charge density, while the half-density radius parameters follow the <span><math><msup><mrow><mi>A</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>3</mn></mrow></msup></math></span> rule. The derived point-proton density distributions can be used as input in nuclear reaction studies and compared with nuclear model predictions.</div></div>","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"165 ","pages":"Article 101733"},"PeriodicalIF":2.7,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695313","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 : 2025-05-19DOI: 10.1016/j.adt.2025.101734
Andrius Poškus
This work describes a library of double- and single differential cross sections of ordinary bremsstrahlung due to interaction of electrons with neutral atoms when electron energy is from 10 eV to 30 MeV in the case of non-zero photon energy, or up to 100 MeV in the soft-photon limit. This is a major update of the BremsLib library, whose initial version was published in a previous work. Numerous improvements of the calculation procedure, which is based on the relativistic partial-wave formulation in conjunction with the approximation of static central potential of the target atom, made it possible to extend the upper limit of the electron energy range from 3 MeV to 30 MeV in the case of non-zero photon energy. When photon energy is zero, a more efficient partial-wave procedure based on the Low theorem has been applied, allowing the increase of the maximum energy of the incident electron up to 100 MeV in the soft-photon limit. At all energies, the calculation accuracy has been improved and the estimates of the uncertainty have been made more reliable. An extensive comparison with the published experimental data in the energy range from 1 MeV to 10 MeV is performed.
{"title":"Double and single differential cross sections of electron-atom bremsstrahlung at electron energies up to 30 MeV for Z = 1 – 100","authors":"Andrius Poškus","doi":"10.1016/j.adt.2025.101734","DOIUrl":"10.1016/j.adt.2025.101734","url":null,"abstract":"<div><div><span><span>This work describes a library of double- and single differential cross sections of ordinary </span>bremsstrahlung due to interaction of electrons with neutral atoms when </span>electron energy<span><span> is from 10 eV to 30 MeV in the case of non-zero photon energy, or up to 100 MeV in the soft-photon limit. This is a major update of the BremsLib library, whose initial version was published in a previous work. Numerous improvements of the calculation procedure, which is based on the relativistic partial-wave formulation in conjunction with the approximation of static central potential of the target atom, made it possible to extend the </span>upper limit<span> of the electron energy range from 3 MeV to 30 MeV in the case of non-zero photon energy. When photon energy is zero, a more efficient partial-wave procedure based on the Low theorem has been applied, allowing the increase of the maximum energy of the incident electron up to 100 MeV in the soft-photon limit. At all energies, the calculation accuracy has been improved and the estimates of the uncertainty have been made more reliable. An extensive comparison with the published experimental data in the energy range from 1 MeV to 10 MeV is performed.</span></span></div></div>","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"166 ","pages":"Article 101734"},"PeriodicalIF":4.1,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145021046","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 : 2025-04-25DOI: 10.1016/j.adt.2025.101730
Elena Atanassova Lawrie , José Nicolás Orce
Theoretical models often invoke axially-asymmetric nuclear shapes to explain elusive collective phenomena, but such an assumption is not always easy to confirm experimentally. The only model-independent measurement of the nuclear axial asymmetry (or triaxiality) is based on rotational invariants of zero-coupled products of the electric-quadrupole (E2) operator — the Kumar-Cline sum rule analysis — which generally requires knowledge of a large number of E2 matrix elements connecting the state of interest. We propose an alternative method to determine using only two E2 matrix elements, which are among the easiest to measure. This approach is based on a standard rotational description of a nucleus with stable triaxial deformation, where all underlying assumptions are either empirically proven or unnecessary. It is applied to the 2 states of the ground-state and the bands of even–even nuclei and is model-independent provided these 2 states have rotational nature. This technique was applied to a number of deformed even–even nuclei for which the ratio of the energies of the yrast 4 and 2 states was 2.4. Where sufficient experimental data were available for performing Kumar-Cline analysis, good agreement was observed between the values deduced in these two approaches. The agreement shows that (i) the 2 states of the selected nuclei have indeed rotational nature, and (ii) the proposed method represents a simple and reliable deduction of . In the present work more than 60 even–even rotating nuclei were associated with axially-asymmetric nuclear shapes.
{"title":"Triaxial nuclear shapes from simple ratios of electric-quadrupole matrix elements","authors":"Elena Atanassova Lawrie , José Nicolás Orce","doi":"10.1016/j.adt.2025.101730","DOIUrl":"10.1016/j.adt.2025.101730","url":null,"abstract":"<div><div>Theoretical models often invoke axially-asymmetric nuclear shapes to explain elusive collective phenomena, but such an assumption is not always easy to confirm experimentally. The only model-independent measurement of the nuclear axial asymmetry (or triaxiality) <span><math><mi>γ</mi></math></span> is based on rotational invariants of zero-coupled products of the electric-quadrupole (<span>E2</span>) operator — the Kumar-Cline sum rule analysis — which generally requires knowledge of a large number of <span>E2</span> matrix elements connecting the state of interest. We propose an alternative method to determine <span><math><mi>γ</mi></math></span> using only two <span>E2</span> matrix elements, which are among the easiest to measure. This approach is based on a standard rotational description of a nucleus with stable triaxial deformation, where all underlying assumptions are either empirically proven or unnecessary. It is applied to the 2<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span> states of the ground-state and the <span><math><mi>γ</mi></math></span> bands of even–even nuclei and is model-independent provided these 2<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span> states have rotational nature. This technique was applied to a number of deformed even–even nuclei for which the ratio of the energies of the yrast 4<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span> and 2<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span> states was <span><math><mrow><msub><mrow><mi>R</mi></mrow><mrow><msub><mrow></mrow><mrow><mn>4</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></msub><mo>></mo></mrow></math></span> 2.4. Where sufficient experimental data were available for performing Kumar-Cline analysis, good agreement was observed between the <span><math><mi>γ</mi></math></span> values deduced in these two approaches. The agreement shows that (i) the 2<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span> states of the selected nuclei have indeed rotational nature, and (ii) the proposed method represents a simple and reliable deduction of <span><math><mi>γ</mi></math></span>. In the present work more than 60 even–even rotating nuclei were associated with axially-asymmetric nuclear shapes.</div></div>","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"164 ","pages":"Article 101730"},"PeriodicalIF":2.7,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138722","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 : 2025-04-22DOI: 10.1016/j.adt.2025.101731
S. Meddah , A. Kahoul , F. Parente , S. Daoudi , J.P. Marques , J.M. Sampaio , S. Croft , A. Favalli , Y. Kasri , N. Kup Aylikci , V. Aylikci , A. Hamidani
This article compiles an extensive dataset on L subshell Coster-Kronig (C-K) and Auger decays (AD). This paper's primary objective is to aggregate 1058 experimental values from literature covering the years 1955 to 2024, taken from 130 scholarly articles and presenting them in seven tables. The reported values are systematically organized and provided with their associated errors in two to four-digit format. Additionally, the tables include computed weighted average values, uncertainty values, combined standard deviations, and average z-scores. The dataset refers to elements from 28Ni to 100Fm, investigated under photon bombardment. The compiled experimental data distribution includes most elements. Nevertheless, there were some isolated cases where either no data or fewer than two data points were present.
{"title":"L-subshell experimental Coster–Kronig probabilities and Auger decays for elements in the atomic number range 28≤Z≤100","authors":"S. Meddah , A. Kahoul , F. Parente , S. Daoudi , J.P. Marques , J.M. Sampaio , S. Croft , A. Favalli , Y. Kasri , N. Kup Aylikci , V. Aylikci , A. Hamidani","doi":"10.1016/j.adt.2025.101731","DOIUrl":"10.1016/j.adt.2025.101731","url":null,"abstract":"<div><div>This article compiles an extensive dataset on L subshell Coster-Kronig (C-K) and Auger decays (AD). This paper's primary objective is to aggregate 1058 experimental values from literature covering the years 1955 to 2024, taken from 130 scholarly articles and presenting them in seven tables. The reported values are systematically organized and provided with their associated errors in two to four-digit format. Additionally, the tables include computed weighted average values, uncertainty values, combined standard deviations, and average <em>z</em>-scores. The dataset refers to elements from <sub>28</sub>Ni to <sub>100</sub>Fm, investigated under photon bombardment. The compiled experimental data distribution includes most elements. Nevertheless, there were some isolated cases where either no data or fewer than two data points were present.</div></div>","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"164 ","pages":"Article 101731"},"PeriodicalIF":2.7,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138721","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 : 2025-04-17DOI: 10.1016/j.adt.2025.101729
Kai Wang , Xuan Bai , Chong Yang Chen , Jun Yan
Highly accurate calculations are performed for the lowest 151 fine-structure levels arising from the , , , , and configurations in P-like Se XX using the multiconfiguration Dirac–Hartree–Fock and the relativistic configuration interaction methods. Complete and consistent atomic data, including excitation energies, wavelengths, E1, E2, M1, M2 line strengths, oscillator strengths, transition rates, and radiative lifetimes for these 151 levels, are provided. Our data set is compared with the NIST compiled values and other available results. The present data are accurate enough for identification and deblending of emission lines involving the levels and are also useful for modeling and diagnosing fusion plasmas. These data can be considered as a benchmark for other calculations.
采用多组态Dirac-Hartree-Fock和相对论组态相互作用方法，对类p Se XX中3s23p3、3s3p4、3s23p23d、3s3p33d、3p5和3s23p3d2组态产生的最低151个精细结构能级进行了高精度计算。提供了完整和一致的原子数据，包括激发能、波长、E1、E2、M1、M2线强度、振荡器强度、跃迁速率和这151个能级的辐射寿命。将我们的数据集与NIST编译值和其他可用结果进行比较。目前的数据足够精确，可用于识别和解混涉及n=3能级的发射线，也可用于模拟和诊断聚变等离子体。这些数据可以作为其他计算的基准。
{"title":"Extended calculations of energy levels, radiative properties, and lifetimes for phosphorus-like Se XX","authors":"Kai Wang , Xuan Bai , Chong Yang Chen , Jun Yan","doi":"10.1016/j.adt.2025.101729","DOIUrl":"10.1016/j.adt.2025.101729","url":null,"abstract":"<div><div>Highly accurate calculations are performed for the lowest 151 fine-structure levels arising from the <span><math><mrow><mn>3</mn><msup><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msup><mn>3</mn><msup><mrow><mi>p</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span>, <span><math><mrow><mn>3</mn><mi>s</mi><mn>3</mn><msup><mrow><mi>p</mi></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span>, <span><math><mrow><mn>3</mn><msup><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msup><mn>3</mn><msup><mrow><mi>p</mi></mrow><mrow><mn>2</mn></mrow></msup><mn>3</mn><mi>d</mi></mrow></math></span>, <span><math><mrow><mn>3</mn><mi>s</mi><mn>3</mn><msup><mrow><mi>p</mi></mrow><mrow><mn>3</mn></mrow></msup><mn>3</mn><mi>d</mi></mrow></math></span>, <span><math><mrow><mn>3</mn><msup><mrow><mi>p</mi></mrow><mrow><mn>5</mn></mrow></msup></mrow></math></span> and <span><math><mrow><mn>3</mn><msup><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msup><mn>3</mn><mi>p</mi><mn>3</mn><msup><mrow><mi>d</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span> configurations in P-like Se XX using the multiconfiguration Dirac–Hartree–Fock and the relativistic configuration interaction methods. Complete and consistent atomic data, including excitation energies, wavelengths, E1, E2, M1, M2 line strengths, oscillator strengths, transition rates, and radiative lifetimes for these 151 levels, are provided. Our data set is compared with the NIST compiled values and other available results. The present data are accurate enough for identification and deblending of emission lines involving the <span><math><mrow><mi>n</mi><mo>=</mo><mn>3</mn></mrow></math></span> levels and are also useful for modeling and diagnosing fusion plasmas. These data can be considered as a benchmark for other calculations.</div></div>","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"164 ","pages":"Article 101729"},"PeriodicalIF":2.7,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138720","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 : 2025-04-11DOI: 10.1016/j.adt.2025.101728
M. Buchowiecki , Y. Wu , G.C. Schatz
Differential, integrated, and transport cross sections were calculated for collisions involving ground state nitrogen atoms N(4S) and first excited state N(2D) nitrogen atoms, based on high quality electronic structure potential curves and couplings. The same data set for the excitation exchange cross section was also calculated.
The rate constant for excitation in collisions of ground state atoms and the rate constant for quenching (reverse process) in collisions between ground and excited atoms were calculated using a quantum scattering method and compared with the results of the Landau–Zener and Zhu–Nakamura semiclassical methods.
{"title":"Elastic cross sections, excitation exchange cross sections, and rate constants for excitation and quenching in N(4S)-N(2D) collisions","authors":"M. Buchowiecki , Y. Wu , G.C. Schatz","doi":"10.1016/j.adt.2025.101728","DOIUrl":"10.1016/j.adt.2025.101728","url":null,"abstract":"<div><div>Differential, integrated, and transport cross sections were calculated for collisions involving ground state nitrogen atoms N(<sup>4</sup>S) and first excited state N(<sup>2</sup>D) nitrogen atoms, based on high quality electronic structure potential curves and couplings. The same data set for the excitation exchange cross section was also calculated.</div><div>The rate constant for excitation in collisions of ground state atoms and the rate constant for quenching (reverse process) in collisions between ground and excited atoms were calculated using a quantum scattering method and compared with the results of the Landau–Zener and Zhu–Nakamura semiclassical methods.</div></div>","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"164 ","pages":"Article 101728"},"PeriodicalIF":2.7,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138683","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 : 2025-03-01DOI: 10.1016/j.adt.2025.101716
S.N. Afanasiev , I.O. Afanasieva
The method of diffusion chamber in the magnetic field making use of a bremsstrahlung beam with a maximum photon energy of 150 MeV is applied to study the reactions of multiparticle photodisintegration of 12C, 14N and 16O nuclei with the formation of several α-particles in the final state (12С(γ,3α), 16O(γ,4α) і 14N(γ,np)3α). An experimental complex with a digital data bank of stereo frames and a set of graphic programs that allows to restore events and carry out physical analysis of the obtained data is created. The distribution of events in regard of the excitation energy of the subsystem of two alpha particles has been measured. For all three reactions, the resonance is found which is identified as the ground state of the 8Be nucleus and the partial channels for the formation of this state have been separated (12C(γ,α)8Be0, 16O(γ,2α)8Be0 and 14N(γ,np)α8Be0). For the channels 12С(γ,α)8Be0 and 16О(γ,2α)8Be0, the partial cross-sections are measured. The dependences demonstrate the presence of four maxima, whose positions coincide for both reactions. The rcorrelation between the energy Eγ corresponding to the cross-section maximum and the excitation energy E0 of 8Be nucleus is determined as Eγ – Q = E0, where Q are the threshold values. The obtained results are qualitatively explained in the framework of the model which describes the absorption of a γ-quantum by a virtual α-particle pair. For the channels 16О(γ,2α)8Be0 and 14N(γ,np)α8Be0 the distribution of the excitation energy of three α-particles is measured. The maximum is found in the near-threshold 3α-particle region. This maximum can correspond to the Hoyle state of 12C nucleus. Events corresponding to the partial channel of the 14N((γ,np)12C*(0+) reaction with the subsequent two-particle decay 12C→α+8Be*(0+) are separated, and the energy and angular distributions of α-particles at each decay stage are analyzed. The channel of 12C nucleus formation in the Hoyle state in photonuclear reactions has not been identified earlier.
{"title":"Investigation of α-particle states of 8Be and 12C Nuclei in photonuclear reactions on 12C, 14N and 16O nuclei","authors":"S.N. Afanasiev , I.O. Afanasieva","doi":"10.1016/j.adt.2025.101716","DOIUrl":"10.1016/j.adt.2025.101716","url":null,"abstract":"<div><div>The method of diffusion chamber in the magnetic field making use of a bremsstrahlung beam with a maximum photon energy of 150 MeV is applied to study the reactions of multiparticle photodisintegration of <sup>12</sup>C, <sup>14</sup>N and <sup>16</sup>O nuclei with the formation of several α-particles in the final state (<sup>12</sup>С(γ,3α), <sup>16</sup>O(γ,4α) і <sup>14</sup>N(γ,np)3α). An experimental complex with a digital data bank of stereo frames and a set of graphic programs that allows to restore events and carry out physical analysis of the obtained data is created. The distribution of events in regard of the excitation energy of the subsystem of two alpha particles has been measured. For all three reactions, the resonance is found which is identified as the ground state of the <sup>8</sup>Be nucleus and the partial channels for the formation of this state have been separated (<sup>12</sup>C(γ,α)<sup>8</sup>Be<sub>0</sub>, <sup>16</sup>O(γ,2α)<sup>8</sup>Be<sub>0</sub> and <sup>14</sup>N(γ,np)α<sup>8</sup>Be<sub>0</sub>). For the channels <sup>12</sup>С(γ,α)<sup>8</sup>Be<sub>0</sub> and <sup>16</sup>О(γ,2α)<sup>8</sup>Be<sub>0</sub>, the partial cross-sections are measured. The dependences demonstrate the presence of four maxima, whose positions coincide for both reactions. The rcorrelation between the energy E<sub>γ</sub> corresponding to the cross-section maximum and the excitation energy E<sub>0</sub> of <sup>8</sup>Be nucleus is determined as E<sub>γ</sub> – Q = E<sub>0</sub>, where Q are the threshold values. The obtained results are qualitatively explained in the framework of the model which describes the absorption of a γ-quantum by a virtual α-particle pair. For the channels <sup>16</sup>О(γ,2α)<sup>8</sup>Be<sub>0</sub> and <sup>14</sup>N(γ,np)α<sup>8</sup>Be<sub>0</sub> the distribution of the excitation energy of three α-particles is measured. The maximum is found in the near-threshold 3α-particle region. This maximum can correspond to the Hoyle state of <sup>12</sup>C nucleus. Events corresponding to the partial channel of the <sup>14</sup>N((γ,np)<sup>12</sup>C*(0<sup>+</sup>) reaction with the subsequent two-particle decay <sup>12</sup>C→α+<sup>8</sup>Be*(0<sup>+</sup>) are separated, and the energy and angular distributions of α-particles at each decay stage are analyzed. The channel of <sup>12</sup>C nucleus formation in the Hoyle state in photonuclear reactions has not been identified earlier.</div></div>","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"163 ","pages":"Article 101716"},"PeriodicalIF":2.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579100","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 : 2025-03-01DOI: 10.1016/j.adt.2025.101708
B. Pritychenko
We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections, astrophysical reaction rates, and solar system -process abundances using the latest data from the major evaluated nuclear libraries for 849 ENDF target materials. The recent release of ENDF/B-VIII.1 library, progress in 252Cf(SF) evaluation, extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate the nuclear industry and neutron physics parameters, produce -process Maxwellian-averaged cross sections and astrophysical reaction rates, extract -process abundances, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data.
{"title":"Tables of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian averaged cross sections, astrophysical reaction rates, and r-process abundances calculated from the ENDF/B-VIII.1, JEFF-3.3, JENDL-5.0, BROND-3.1, and CENDL-3.2 evaluated data libraries","authors":"B. Pritychenko","doi":"10.1016/j.adt.2025.101708","DOIUrl":"10.1016/j.adt.2025.101708","url":null,"abstract":"<div><div>We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections, astrophysical reaction rates, and solar system <span><math><mi>r</mi></math></span>-process abundances using the latest data from the major evaluated nuclear libraries for 849 ENDF target materials. The recent release of ENDF/B-VIII.1 library, progress in <sup>252</sup>Cf(SF) evaluation, extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate the nuclear industry and neutron physics parameters, produce <span><math><mi>s</mi></math></span>-process Maxwellian-averaged cross sections and astrophysical reaction rates, extract <span><math><mi>r</mi></math></span>-process abundances, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data.</div></div>","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"163 ","pages":"Article 101708"},"PeriodicalIF":2.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579098","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 : 2025-03-01DOI: 10.1016/j.adt.2025.101720
José Nicolás Orce , Boris Pritychenko , Tibor Kibédi , Jun Chen
{"title":"In search of truth: In memory of Balraj Singh","authors":"José Nicolás Orce , Boris Pritychenko , Tibor Kibédi , Jun Chen","doi":"10.1016/j.adt.2025.101720","DOIUrl":"10.1016/j.adt.2025.101720","url":null,"abstract":"","PeriodicalId":55580,"journal":{"name":"Atomic Data and Nuclear Data Tables","volume":"165 ","pages":"Article 101720"},"PeriodicalIF":2.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695310","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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