Employing two fully relativistic methods,the multi-reference configuration Dirac-Hartree-Fock(MCDHF)methodand the relativistic many-body perturbation theory(RMBPT)method,we report energies and lifetime values for the ...
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Employing two fully relativistic methods,the multi-reference configuration Dirac-Hartree-Fock(MCDHF)methodand the relativistic many-body perturbation theory(RMBPT)method,we report energies and lifetime values for the lowest35 energy levels of the(1s^(2))nl configurations(where the principal quantum number n=2-6 and the angular quantum numberl=0,...,n-1)of lithium-like germanium(Ge XXX),as well as complete data on the transition wavelengths,radiativerates,absorption oscillator strengths,and line strengths between the *** the allowed(E1)and forbidden(magneticdipole M1,magnetic quadrupole M2,and electric quadrupole E2)ones are *** results from the two methodsare consistent with each other and align well with previous accurate experimental and theoretical *** assess theoverall accuracies of present RMBPT results to be likely the most precise ones to *** present fully relativistic resultsshould be helpful for soft x-ray laser research,spectral line identification,plasma modeling and *** datasetspresented in this paper are openly available at https://***/10.57760/sciencedb.j00113.00135.
Employing the advanced relativistic configuration interaction(RCI)combined with the many-body perturbation theory(RMBPT)method,we report energies and lifetime values for the lowest 35 energy levels from the(1s^(2))nl ...
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Employing the advanced relativistic configuration interaction(RCI)combined with the many-body perturbation theory(RMBPT)method,we report energies and lifetime values for the lowest 35 energy levels from the(1s^(2))nl configurations(where the principal quantum number n=2–6 and the angular quantum number l=0,...,n-1)of lithium-like iron Fe XXIV,as well as complete data on the transition wavelengths,radiative rates,absorption oscillator strengths,and line strengths between the *** the allowed(E1)and forbidden(magnetic dipole M1,magnetic quadrupole M2,and electric quadrupole E2)ones are *** detailed comparisons with previous results,we assess the overall accuracies of present RMBPT results to be likely the most precise ones to *** interaction effects are found to be very important for the energies and radiative properties for the *** present RMBPT results are valuable for spectral line identification,plasma modeling,and diagnosing.
The ^(232)Th(n,f)cross section is very important in basic nuclearphysics and applications based on the Th/U fuel *** the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurement of t...
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The ^(232)Th(n,f)cross section is very important in basic nuclearphysics and applications based on the Th/U fuel *** the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurement of the^(232)Th(n,f)cross sec-tion relative to^(235)U in the 1–200 MeV range was performed at the China Spallation Neutron Source Back-n white neutron source(Back-n).The fission event-neutron energy spectra of^(232)Th and^(235)U fission cells were measured in the single-bunch *** 232Th/235U fission cross-sectional ratios were obtained,and the measurement uncertainties were 2.5–3.7%for energies in the 2–20 MeV range and 3.6–6.2%for energies in the 20–200 MeV ***^(232)Th(n,f)cross section was obtained by introducing the standard cross section of^(235)U(n,f).The results were compared with those of previous theoreti-cal calculations,measurements,and *** measured 232Th fission cross section agreed with the main evaluation results in terms of the experimental uncertainty,and 232Th fission resonances were observed in the 1–3 MeV *** present results provide^(232)Th(n,f)cross-sectional data for the evaluation and design of Th/U cycle nuclear systems.
Excited states in B10 were populated with the B10(p,p′γ)B10* reaction at 8.5 MeV and their γ decay was investigated via coincidence γ-ray spectroscopy. The emitted γ rays were measured using large-volume LaBr3:Ce...
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Excited states in B10 were populated with the B10(p,p′γ)B10* reaction at 8.5 MeV and their γ decay was investigated via coincidence γ-ray spectroscopy. The emitted γ rays were measured using large-volume LaBr3:Ce and CeBr3 detectors placed in anti-Compton shields. This allowed the observation of weak γ-ray transitions, such as the M3 transition between the Jπ,T=0+,1 isobaric analog state (IAS) and the Jπ,T=3+,0 ground state and the E2 transition between the Jπ,T=21+,0 state and the IAS, i.e., performing measurements of branching ratios at the level of λ≥10−4. For the first time in B10, the competing M1 and M3 transitions from the decay of the IAS have been observed in a γ spectroscopy experiment. The experimental results are compared with ab initio no-core shell model calculation using the newest version of the local position-space chiral N3LO nucleon-nucleon interaction. The calculations reproduce correctly the ordering of the bound states in B10, and are in reasonable agreement with the observed branching ratios and reduced transition probabilities.
Tungsten(W)is the leading plasma-facing candidate material for the International Thermonuclear Experimental Reactor and next-generation fusion *** impact of synergistic helium(He),irradiation-induced microstructural c...
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Tungsten(W)is the leading plasma-facing candidate material for the International Thermonuclear Experimental Reactor and next-generation fusion *** impact of synergistic helium(He),irradiation-induced microstructural changes,and the corresponding thermal-mechanical property degradation of W are critically important but are not well understood *** the performance of W in fusion environments requires understanding the fundamentals of He-defect interactions and the resultant He bubble nucleation and growth in *** this study,He retention in helium-ion-implanted W was assessed using neutron depth profiling(NDP),laser ablation mass spectrometry(LAMS),and thermal desorption spectroscopy(TDS)following 10 keV room-temperature He implantation at various *** three experimental techniques enabled the determination of the He depth profile and retention in He-implanted W.A cluster dynamics model based on the diffusion-reaction rate theory was applied to interpret the experimental *** model successfully predicted the He spatial depth-dependent profile in He-implanted W,which was in good agreement with the LAMS *** model also successfully captured the major features of the He desorption spectra observed in the THDS *** NDP quantified total He concentration values for the samples;they were similar to those estimated by ***,the depth profiles from NDP and LAMS were not comparable due to several *** combination of modeling and experimentation enabled the identification of possible trapping sites for He in W and the evolution of He-defect clusters during the TDS thermal annealing process.
The neutron capture cross sections(n,γ)of bromine were obtained using the time-of-flight technique at the Back-n facility of the China Spallation Neutron ***γ-rays originating from neutron-induced capture events wer...
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The neutron capture cross sections(n,γ)of bromine were obtained using the time-of-flight technique at the Back-n facility of the China Spallation Neutron ***γ-rays originating from neutron-induced capture events were detected using four C_(6)D_(6) *** pulse-height weighting technique and double-bunch unfolding method based on Bayesian theory were used in the data *** deductions,normalization,and corrections were carefully considered to obtain reliable measurement *** multilevel R-matrix Bayesian code SAMMY was used to extract the resonance parameters in the resolved resonance region(RRR).The average cross sections in the unresolved resonance region(URR)were obtained from 10 to 400 *** experimental results were compared with data from several evaluated libraries and previous experi-ments in the RRR and *** TALYS code was used to describe the average cross sections in the *** astrophysical Maxwell average cross sections(MACSs)of ^(79,81)Br from kT=5 to 100 keV were calculated over a sufficiently wide range of neutron *** a thermal energy of kT=30 keV,the MACS value for ^(79)Br 682±68 mb was in good agreement with the KADoNiS v1.0 recommended *** contrast,the value of 293±29 mb for ^(81)Br was substantially higher than that of the evaluated database and the KADoNiS v1.0 recommended value.
We synthesized CaRuO3 (001) thin films on a set of substrates and investigated their electronic and magnetic properties via combining magnetotransport measurements with first-principles density-functional theory calcu...
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We synthesized CaRuO3 (001) thin films on a set of substrates and investigated their electronic and magnetic properties via combining magnetotransport measurements with first-principles density-functional theory calculations. The experimental results indicate that a moderate strain can introduce the Kondo effect in the system, leading to a significant modulation of the non-Fermi liquid behavior. Moreover, when the strain reaches a certain threshold, the system undergoes a metal-semiconductor transition, accompanied by a transition from a nonmagnetic state to a plausible G-type antiferromagnetic state. We attribute the observed phenomena in CaRuO3 to strain-induced disruption of the delicate balance between the itinerant and the local Ru 4d electrons. These findings shed light on the intriguing magnetic and non-Fermi liquid behavior of CaRuO3, systematically tailored by heteroepitaxial strain.
Purpose Accurate localization of radioactive materials is critical to nuclear safety and nuclear security.A coded aperture imaging system provides a visualization ***,the correlation method has poor reconstruction per...
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Purpose Accurate localization of radioactive materials is critical to nuclear safety and nuclear security.A coded aperture imaging system provides a visualization ***,the correlation method has poor reconstruction performance for sources with low counts and for extended *** In this study,a Monte Carlo optimization-based MLEM algorithm(MC-MLEM)is *** system matrix was obtained by accurate Monte Carlo simulation,so the physical effects such as mask penetration that affect the imaging process were taken into account in the MLEM *** the simulation process,the normalization of the system matrix was realized by controlling the source at different position of the source plane to have the same activity and emission *** The experimental results showed that compared with the correlation method,the MC-MLEM algorithm could improve the signal-to-noise ratio and angular resolution and locate the source position quickly and accurately under low count ***,the MC-MLEM algorithm could reconstruct the shape of the extended source and the expected activity ratio of cold-hot sources with large activity *** The MC-MLEM algorithm improved the imaging results and enhanced the reconstruction performance.
Neutrinos are known to undergo flavor conversion among their three flavors. In the theoretical modeling of core-collapse supernova, there has been a great deal of attention to recent discoveries of a new type of neutr...
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Neutrinos are known to undergo flavor conversion among their three flavors. In the theoretical modeling of core-collapse supernova, there has been a great deal of attention to recent discoveries of a new type of neutrino flavor conversions, namely collisional flavor instability (CFI), in which the instability is induced by the flavor-dependent decoherence due to the disparity of neutrino-matter interactions among flavors. In this paper, we study how the appearance of on-shell muons and associated neutrino-matter interactions can impact CFIs based on linear stability analysis of flavor conversions. Some striking results emerge from the present study. First, we analytically show that breaking beta and pair equilibrium is a necessary condition to trigger CFIs. This also indicates that CFIs with on-shell muons could appear in eτ and μτ neutrino mixing sectors in very high-density region (≳1013 g/cm3), exhibiting a possibility of large impacts of CFIs on core-collapse supernova. Second, resonancelike CFIs, having a much higher growth rate than normal CFIs, can be triggered by muons. The resonance point of CFIs is different between eτ and μτ sectors; the former (latter) occurs at μe(μ)=μn−μp, where μi denotes the chemical potential of i constitute (n and p represent neutrons and protons, respectively). Our result suggests that the nonlinear evolution of CFI with on-shell muons would induce flavor conversions with the complex interplay among all three different neutrino-mixing sectors.
Carbon nanotubes are explored as a means of coherently converting the orbital angular momentum of light to an excitonic form that is more amenable to quantum information *** analytical analysis,based on dynamical cond...
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Carbon nanotubes are explored as a means of coherently converting the orbital angular momentum of light to an excitonic form that is more amenable to quantum information *** analytical analysis,based on dynamical conductivity,is used to show that orbital angular momentum is conserved,modulo N,for a carbon nanotube illuminated by radially polarized,twisted *** result is numerically demonstrated using real-time time-dependent density functional theory which captures the absorption of twisted light and the subsequent transfer of twisted *** results suggest that carbon nanotubes are promising candidates for constructing optoelectronic circuits in which quantum information is more readily processed while manifested in excitonic form.
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