Energy Level Data Research Articles

High-precision measurements of the atomic mass and electron-capture decay Q value of 95Tc

A direct measurement of the ground-state-to-ground-state electron-capture decay Q value of 95Tc has been performed utilizing the double Penning trap mass spectrometer JYFLTRAP. The Q value was determined to be 1695.92(13) keV by taking advantage of the high resolving power of the phase-imaging ion-cyclotron-resonance technique to resolve the low-lying isomeric state of 95Tc (excitation energy of 38.910(40) keV) from the ground state. The mass excess of 95Tc was measured to be −86015.95(18) keV/c2, exhibiting a precision of about 28 times higher and in agreement with the value from the newest Atomic Mass Evaluation (AME2020). Combined with the nuclear energy-level data for the decay-daughter 95Mo, two potential ultra-low Q-value transitions are identified for future long-term neutrino-mass determination experiments. The atomic self-consistent many-electron Dirac–Hartree–Fock–Slater method and the nuclear shell model have been used to predict the partial half-lives and energy-release distributions for the two transitions. The dominant correction terms related to those processes are considered, including the exchange and overlap corrections, and the shake-up and shake-off effects. The normalized distribution of the released energy in the electron-capture decay of 95Tc to excited states of 95Mo is compared to that of 163Ho currently being used for electron-neutrino-mass determination.

MARVEL analysis of high-resolution rovibrational spectra of 16O12C18O.

Empirical rovibrational energy levels are presented for the third most abundant, asymmetric carbon dioxide isotopologue, 16O12C18O, based on a compiled dataset of experimental rovibrational transitions collected from the literature. The 52 literature sources utilized provide 19,438 measured lines with unique assignments in the wavenumber range of 2-12,676 cm-1. The MARVEL (Measured Active Rotational-Vibrational Energy Levels) protocol, which is built upon the theory of spectroscopic networks, validates the great majority of these transitions and outputs 8786 empirical rovibrational energy levels with an uncertainty estimation based on the experimental uncertainties of the transitions. Issues found in the literature data, such as misassignment of quantum numbers, typographical errors, and misidentifications, are fixed before including them in the final MARVEL dataset and analysis. Comparison of the empirical energy-level data of this study with those in the line lists CDSD-2019 and Ames-2021 shows good overall agreement, significantly better for CDSD-2019; some issues raised by these comparisons are discussed.

Potential energy curve for B1Π state of 85Rb133Cs obtained via genetic algorithm

We adopt the genetic algorithm to fit the potential energy curve for B1Π state of 85Rb133Cs molecule based on the data of rovibrational energy levels, which were observed previously by Fourier-transform spectroscopy and photoassociation spectroscopy. We explore the effect of different hyperparameter settings on the evolutionary process and final results to optimise the performance of the algorithm. Finally, the fitting procedure can reproduce the rovibrational levels with an error less than 0.06 cm−1 compared to the experimental data.

CHIANTI—An Atomic Database for Emission Lines. XVII. Version 10.1: Revised Ionization and Recombination Rates and Other Updates* *Released on 2023 July 17.

The CHIANTI atomic database provides sets of assessed data that are used for simulating spectral observations of astrophysical plasmas. This article describes updates that will be released as version 10.1 of the database. A key component of CHIANTI is the provision of ionization and recombination rates that are used to compute the ionization balance of a plasma over a range of temperatures. Parameters for calculating the ionization rates of all stages of ions from H through Zn were compiled and inserted into the CHIANTI database in 2009. These were based on all measurements that were available at the time and supplemented with distorted wave calculations. Since then, there have been a number of new laboratory measurements for ions that produce spectral lines that are commonly observed. Parameters have been fit to these new measurements to provide improved ability to reproduce the ionization cross sections and rate coefficients, and these are added to the database. CHIANTI 10.1 also includes new recombination rates for the phosphorus isoelectronic sequence, and the updated ionization and recombination rates have been used to calculate a new ionization equilibrium file. In addition, CHIANTI 10.1 has new electron collision and radiative data sets for eight ions in the nitrogen and oxygen isoelectronic sequences and updated energy level and wavelength data for six other ions.

Comment on “Atomic structure and electron impact excitation of Al-like ions (Ga–Br)” by HB Wang and G Jiang in At. Data Nucl. Data Tables 148 (2022) 101532

In a recent paper, Wang and Jiang (At. Data Nucl. Data Tables 148 (2022) 101532) have reported data for energy levels, radiative rates (A-values), and effective collision strengths (Υ) for some transitions of five Al-like ions, namely Ga XIX, Ge XX, As XXI, Se XXII, and Br XXIII. On a closer examination we find that their reported data for energy levels and A-values are generally correct, but not for Υ. Their Υ values, for all transitions (allowed or forbidden) and for all ions, invariably decrease at higher temperatures. This is mainly because they have adopted a limited range of electron energies for the calculations of collision strengths. We demonstrate this with our calculations with the Flexible Atomic Code (FAC), and conclude that their Υ values are inaccurate, unreliable, and should not be adopted in any applications or modelling analysis.

A multi-sensory real-time data transmission method with sustainable and robust 5G energy signals for smart cities

New generation technologies like Fifth Generation (5G) access technology have great potential to provide a sustainable Quality of Service (QoS) for Electric Vehicles (EVs) in smart cities. The environmental features of urban cities mean that signal transmission can be affected across communication networks, with packet delays, packet loss and higher error rates occurring during data exchange. There is a need for sustainable and robust low-energy signals for smart EV communication. The present paper proposes a novel method for continuous, robust video data transmission at low energy via multi-sensory-enabled 5G technology. The transceivers (transmitters and receivers) are designed with multiple low-energy sensors for detecting data availability at the receiver device. By applying a threshold level detection technique, data availability is identified dependent upon energy level and successive data exchange occurs between transceivers. The application of low-energy signal transmission reduces power usage during video data transmission and leads to a sustainable solution for intelligent EV applications. The performance of the proposed multi-sensory technique is tested and verified using various calibrated parameters considering key metrics including collision error, propagation error, sensing error and accuracy. The proposed model significantly improves accuracy, with higher sensing capabilities and lower delays and propagation errors compared to the existing buffer model.

Updated evaluation of potential ultralow Q -value β -decay candidates

"Ultra-low" Q value $\beta$ decays are referred to as such due to their low decay energies of less than $\sim$1 keV. Such a low energy decay is possible when the parent nucleus decays into an excited state in the daughter, with an energy close to that of the Q value. These decays are of interest as potential new candidates for neutrino mass determination experiments and as a testing ground for studies of atomic interference effects in the nuclear decay process. In this paper, we provide an updated evaluation of atomic mass data and nuclear energy level data to identify potential ultra-low Q value $\beta$ decay candidates. For many of these candidates, more precise and accurate atomic mass data is needed to determine if the Q value of the potential ultra-low decay branch is energetically allowed and in fact ultra-low. The precise atomic mass measurements can be achieved via Penning trap mass spectrometry.

Identification of a potential ultralow- Q -value electron-capture decay branch in Se75 via a precise Penning trap measurement of the mass of As75

Background: Low energy $\beta$ and electron capture (EC) decays are important systems in neutrino mass determination experiments. An isotope with an ultra-low Q value $\beta$-decay to an excited state in the daughter with Qes < 1 keV could provide a promising alternative candidate for future experiments. $^{75}$Se EC and $^{75}$Ge $\beta$-decay represent such candidates, but a more precise determination of the mass of the common daughter, $^{75}$As, is required to evaluate whether their potential decay branches are energetically allowed and ultra-low. Purpose: Perform a precise atomic mass measurement of $^{75}$As and combine the result with the precisely known atomic masses of $^{75}$Se and $^{75}$Ge, along with nuclear energy level data for $^{75}$As to evaluate potential ultra-low Q value decay branches in the EC decay of $^{75}$Se and the $\beta$-decay of $^{75}$Ge. Method: The LEBIT Penning trap mass spectrometer at the Facility for Rare Isotope Beams was used to perform a high-precision measurement of the atomic mass of $^{75}$As via cyclotron frequency ratio measurements of $^{75}$As$^{+}$ to a $^{12}$C$_{6}^{+}$ reference ion. Results: The $^{75}$As mass excess was determined to be ME($^{75}$As)= -73 035.98(43) keV, from which the ground-state to ground-state Q values for $^{75}$Se EC and $^{75}$Ge $\beta$-decay were determined to be 866.50(44) keV and 1179.01(44) keV, respectively. These results were compared to energies of excited states in $^{75}$As at 865.4(5) keV and 1172.0(6) keV to determine Q values of 1.1(7) keV and 7.0(7) keV for the potential ultra-low EC and $\beta$-decay branches of $^{75}$Se and $^{75}$Ge, respectively. Conclusion: The $^{75}$Se EC decay to the 865.4 keV excited state in $^{75}$As is potentially ultra-low with Qes $\approx$ 1 keV. However, a more precise determination of the 865.4(5) keV level in $^{75}$As is required.

The feasibility of laser cooling: an investigation of ab initio of 88Sr35Cl including the hyperfine structure

ABSTRACT A promising laser cooling candidate molecule is essential for laser cooling experiments. In this study, the possibility of laser cooling an 88Sr35Cl molecule is investigated using an ab initio method. Seven low-lying Λ-S and six Ω electronic states of the 88Sr35Cl molecule are calculated at a multi-reference configuration interaction level of theory. Spectral constants of bound states of fitted values are in good agreement with experimental values, which are better than the previously obtained theoretical data for higher excitation states. The resulting permanent and transition dipole moments near the equilibrium bond length are close to the theoretical values. Potential energy curves and transition dipole moments are used for obtaining highly diagonally distributed Franck-Condon factors for the A2Π → X2Σ+ transition using the LEVEL program. A short radiative lifetime of the A2Π state is determined; a laser cooling scheme is designed in the vibration level that requires a cooling main laser beam and two repumping laser beams. Transition spectral data of hyperfine energy levels with errors relative to the experimental data do not exceed −0.25∼0.19 MHz when using a quantum effective Hamiltonian approach. This study provides a helpful reference for experimental observation and operation of laser cooling the 88Sr35Cl molecule.

Investigation of statistical correlation of negative parity energy levels in Tm nucleus with A=170

In this paper, the statistical properties of 1- to 7- negative parity levels in the 170Tm nucleus are considered with emphasis on the nearest neighbor spacing distribution in the framework of random matrix theory. The latest available experimental data for different negative parity energy levels in the E≤ 3000 keV region are used to classifiy in different sequences and are analysed. The Berry – Robnik distribution function and the least square extraction method have been used to determine the parameter of distribution function in considered sequences. The results show the adaptation of the statistical behavior of all considered negative parity levels with the Wigner distribution function and therefore, the statistical correlation of such levels. Also, the strong correlations are yield for the sequences prepared by levels with odd spin values while the 2- levels show a weak correlation and a Poisson-like behavior. The dependence of the statistical behavior of the negative parity levels to the energy was investigated which suggests the maximum correlation in the 1300 <E < 2100 keV energy region.

Observation of an ultralow- Q -value electron-capture channel decaying to As75 via a high-precision mass measurement

A precise determination of the atomic mass of $^{75}$As has been performed utilizing the double Penning trap mass spectrometer, JYFLTRAP. The mass excess is measured to be -73035.519(42) keV/c$^2$, which is a factor of 21 more precise and 1.3(9) keV/c$^2$ lower than the adopted value in the newest Atomic Mass Evaluation (AME2020). This value has been used to determine the ground-state-to-ground-state electron-capture decay $Q$ value of $^{75}$Se and $\beta^-$ decay $Q$ value of $^{75}$Ge, which are derived to be 866.041(81) keV and 1178.561(65) keV, respectively. Using the nuclear energy-level data of 860.00(40) keV, 865.40(50) keV (final states of electron capture) and 1172.00(60) keV (final state of $\beta^-$ decay) for the excited states of $^{75}$As$^*$, we have determined the ground-state-to-excited-state $Q$ values for two transitions of $^{75}$Se $\rightarrow$ $^{75}$As$^*$ and one transition of $^{75}$Ge $\rightarrow$ $^{75}$As$^*$. The ground-state-to-excited-state $Q$ values are determined to be 6.04(41) keV, 0.64(51) keV and 6.56(60) keV, respectively, thus confirming that the three low $Q$-value transitions are all energetically valid and one of them is a possible candidate channel for antineutrino mass determination. Furthermore, the ground-state-to-excited-state $Q$ value of transition $^{75}$Se $\rightarrow$ $^{75}$As$^*$ (865.40(50) keV) is revealed to be ultra-low (< 1 keV) and the first-ever confirmed EC transition possessing an ultra-low $Q$ value from direct measurements.

High-precision electron-capture Q value measurement of 111In for electron-neutrino mass determination

A precise determination of the ground state 111In (9/2+) electron capture to ground state of 111Cd (1/2+) Q value has been performed utilizing the double Penning trap mass spectrometer, JYFLTRAP. A value of 857.63(17) keV was obtained, which is nearly a factor of 20 more precise than the value extracted from the Atomic Mass Evaluation 2020 (AME2020). The high-precision electron-capture Q value measurement along with the nuclear energy level data of 866.60(6) keV, 864.8(3) keV, 855.6(10) keV, and 853.94(7) keV for 111Cd was used to determine whether the four states are energetically allowed for a potential ultra-low Q-value β decay or electron-capture decay. Our results confirm that the excited states of 866.60(6) keV with spin-parity (Jπ) of 3/2+ and 864.8(3) keV with Jπ=3/2+ are ruled out due to their deduced electron-capture Q value being smaller than 0 keV at the level of around 20σ and 50σ, respectively. Electron-capture decays to the excited states at 853.94(7) keV (Jπ=7/2+) and 855.6(10) keV (Jπ=3/2+), are energetically allowed with Q values of 3.69(19) keV and 2.0(10) keV, respectively. The allowed decay transition 111In (9/2+) → 111Cd (7/2+), with a Q value of 3.69(19) keV, is a potential new candidate for neutrino-mass measurements by future EC experiments featuring new powerful detection technologies. The results show that the indium level 2p1/2 for this decay branch leads to a significant increase in the number of EC events in the energy region sensitive to the electron neutrino mass.

An Application of Interacting Boson Model-2 (IBM-2) Configuration Mixing in Tin Nuclei

Using IBM-2 configuration mixing calculations, the normal and intruder 2p-2h bands in even-even tin isotopes are examined. The states of the normal and intruder bands were computed separately and then mixed using a basic band-mixing Hamiltonian. The experimental data for energy levels and electronic transition probability from current and past investigations are compared.

Theoretical investigation of energy levels and transition for Ce IV

Aims. We present extensive energy level and transition data for the Ce IV spectrum. By providing accurate atomic data, we evaluate the impact of atomic data on the opacity in the neutron star merger ejecta. Methods. We performed energy spectra and transition data calculations using the GRASP2018 package, which is based on the multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods, and the HULLAC code, which is based on a parametric potential method. Results. We present energy spectra calculated for the 225 levels for the Ce3+ ion. Energy levels are compared with recommended values from the NIST Atomic Spectra Database and other available works. The root-mean-square (rms) deviations obtained for the GRASP2018 energy levels of the 5p6nl configurations from the NIST data are 1270 cm−1. The rms deviations for the HULLAC results from the NIST data are 5780 cm−1. Furthermore, electric dipole (E1) transition data, line strengths, weighted oscillator strengths, and transition rates are computed between the above levels. The computed transition rates are compared with other theoretical computations. We also evaluate the accuracy of the wave functions and transition parameters by analyzing the dependencies of the line strength S on the gauge parameter G. The gauge dependency method also allows us to determine the transitions for which the ratio between the Babushkin and Coulomb gauges shows real agreement between forms and the transitions for which the agreement between both gauges is random. Using the GRASP2018 and HULLAC data, the opacities in the neutron star merger ejecta are also calculated. We find that the opacity of Ce IV is higher than that presented by previous works, which is because of the higher completeness of our atomic data. Although the differences in the energy levels and transition probabilities cause different features in the opacity spectrum, the Planck mean opacities of both data sets agree within 20%.

Two-color resonance enhanced multiphoton ionization spectroscopy of o-hydroxybenzonitrile and Franck-Condon simulation

The cyano group is a typical electron-withdrawing group, which has aroused the interest of relevant researchers. Many papers reported the dispersed fluorescence spectra of o-hydroxybenzonitrile, its dimers, and complexes with small molecules, aiming to study the intermolecule hydrogen bond and the vibration features of the electronic ground state. There are also reports on using fluorescence excitation spectra to study excited state vibrations, but no report on the systematical analyzing of the vibration features of excited state spectra. Compared with fluorescence spectroscopy, resonance enhanced multiphoton ionization (REMPI) spectroscopy detects ions to obtain excited state energy level data, which has mass-resolution capability, and eliminates the interference of impurities with different charge-to-mass ratios. The strong electron-withdrawing ability of cyano group results in higher ionization energy for molecules containing cyano groups. Many REMPI experiments on benzonitrile derivatives require two-color lasers. In this paper, two-color resonance enhanced two-photon ionization experiment is performed by using a home-made linear time-of-flight mass spectrometer, and the vibration-resolved REMPI spectrum of o-hydroxybenzonitrile is obtained for the first time. Combining the high-precision density functional theory calculations with the Franck-Condon spectral simulations, the spectral characteristics are analyzed in detail, and a large number of fundamental, overtone and combined vibrations are found. The spectral assignment is carried out as accurately as possible. Most of the fundamental vibrations located at ring are assigned to the in-plane distortion or swing of the ring, which is related to the expansion of the ring during the molecular excitation. Theoretical and experimental results show that the low-frequency signal of REMPI spectrum is strong, the background is low, the band is less, and the resolution is good. As the vibration frequency increases, the signal changes in the worse direction. This is because the low-frequency spectrum mainly comes from the low-frequency fundamental vibrations and a little contribution from overtones. As the vibration frequency increases, the contributions from overtone and combined vibrations gradually increase, resulting in dense bands and low resolution. Theoretical calculations show that the high-order vibration and combination of multi-mode vibrations usually have a lower Franck-Condon factor, so the signal gradually becomes weak as the frequency increases, and the signal-to-noise ratio becomes worse.

Intra- and inter-configurational electronic transitions of Ce3+-doped Y2SiO5 : Spectroscopy and crystal field analysis

We report on an interpretation of the 4 f → 5 d absorption and fluorescence spectra as well as the previously un-reported intra-4 f transitions between the Stark levels of the 2 F 5/2 and 2 F 7/2 multiplets of the single seven-fold coordinated, C 1 symmetry site for Ce 3+ in Y 2 SiO 5 . Further, We also give the corresponding crystal-field parameters determined by fitting to the observed energy level data and the ground state Zeeman g tensor obtained from previously reported electron paramagnetic resonance (EPR) measurements. Finally we present a temperature-dependent analysis of the linewidth and position of the 4 f → 4 f absorption lines. • High-resolution infrared absorption measurements for Y 2 SiO 5 :Ce 3+ . • UV fluorescence and absorption spectroscopy of Y 2 SiO 5 :Ce 3+ . • Crystal-field analysis of 4f 1 and 4f5d 1 electronic energy levels of Y 2 SiO 5 :Ce 3+ . • Temperature-dependent linewidth and line shift analysis of Y 2 SiO 5 :Ce 3+ .

Experimental energy levels of 12C14N through marvel analysis.

The cyano radical (CN) is a key molecule across many different factions of astronomy and chemistry. Accurate, empirical rovibronic energy levels with uncertainties are determined for eight doublet states of CN using the marvel (Measured Active Rotational-Vibrational Energy Levels) algorithm. 40 333 transitions were validated from 22 different published sources to generate 8083 spin-rovibronic energy levels. The empirical energy levels obtained from the marvel analysis are compared to current energy levels from the mollist line list. The mollist transition frequencies are updated with marvel energy level data which brings the frequencies obtained through experimental data up to 77.3percent from the original 11.3percent, with 92.6percent of the transitions with intensities over 10-23 cm molecule-1 at 1000K now known from experimental data. At 2000K, 100.0percent of the partition function is recovered using only marvel energy levels, while 98.2percent is still recovered at 5000K.

Efficient solution of the multichannel Lüscher determinant condition through eigenvalue decomposition

We present a method for efficiently finding solutions of L\"uscher's quantisation condition, the equation which relates two-particle scattering amplitudes to the discrete spectrum of states in a periodic spatial volume of finite extent such as that present in lattice QCD. The approach proposed is based on an eigenvalue decomposition in the space of coupled-channels and partial-waves, which proves to have several desirable and simplifying features that are of great benefit when considering problems beyond simple elastic scattering of spinless particles. We illustrate the method with a toy model of vector-vector scattering featuring a high density of solutions, and with an application to explicit lattice QCD energy level data describing $J^P=1^-$ and $1^+$ scattering in several coupled channels.

Fe iii emission in quasars: evidence for a dense turbulent medium

ABSTRACT Recent improvements to atomic energy-level data allow, for the first time, accurate predictions to be made for the Fe iii line emission strengths in the spectra of luminous, $L_\text{bol}\simeq 10^{46}\!-\!10^{48}\mbox{${\rm \, erg}{\rm \, s}^{-1}\, $}$, active galactic nuclei. The Fe iii emitting gas must be primarily photoionized, consistent with observations of line reverberation. We use cloudy models exploring a wide range of parameter space, together with ≃26 000 rest-frame ultraviolet spectra from the Sloan Digital Sky Survey, to constrain the physical conditions of the line emitting gas. The observed Fe iii emission is best accounted for by dense (nH ≃ 1014 cm−3) gas which is microturbulent, leading to smaller line optical depths and fluorescent excitation. Such high density gas appears to be present in the central regions of the majority of luminous quasars. Using our favoured model, we present theoretical predictions for the relative strengths of the Fe iii UV34 λλ1895, 1914, 1926 multiplet. This multiplet is blended with the Si iii] λ1892 and C iii] λ1909 emission lines and an accurate subtraction of UV34 is essential when using these lines to infer information about the physics of the broad line region in quasars.

Spectroscopy learning: A machine learning method for study diatomic vibrational spectra including dissociation behavior

Molecular spectroscopy plays an important role in the study of physical and chemical phenomena at the atomic level. However, it is difficult to acquire accurate vibrational spectra directly in theory and experiment, especially these vibrational levels near the dissociation energy. In our previous study (Variational Algebraic Method), dissociation energy and low energy level data are employed to predict the ro-vibrational spectra of some diatomic system. In this work, we did the following:1) We expand the method to a more rigorous combined model-driven and data-driven machine learning approach (Spectroscopy Learning Method).2) Extracting information from a wide range of existing data can be used in this work, such as heat capacity.3) Reliable vibrational spectra and dissociation energy can be predicted by using heat capacity and the reliability of this method is verified by the ground states of CO and Br2 system.