As a promising nanofabrication tool, ion bombardment (IB) has attracted increasing attention because of its capability to induce quasi-periodic self-organized nanoripples. Continuous efforts have been made to improve the ordering of these IB-induced nanostructures and pursue experimental observations of IB-induced nanoripple superposition. This study experimentally demonstrates the feasibility of enhancing the ordering of ripples through the superposition of two sets of nanoripples on the surface of a Au/antireflection coating (ARC) bilayer using sequential IB (SIB). The atomic force microscopy data of the irradiated surface show that the ordering of the resulting nanoripples has been significantly improved along the directions parallel and perpendicular to that of the ripple vector, corresponding to a pronounced peak at a frequency of ∼0.01 nm-1(i.e. a period of ∼100 nm) in the power spectral density curve and a long autocorrelation length (ACL) of ∼176 nm. In particular, the ACL of the ripples on the Au/ARC surface is approximately three times greater than that on the ARC surface. We demonstrate that the superimposition of nanoripples occurs during the bombarding of a Au/ARC bilayer system with a generalized SIB strategy. Furthermore, the basic requirements for the superposition of IB-induced nanoripples under non-conservation of mass are verified by extending the bombardment of bilayer systems from photoresist/ARC to Au/ARC. This study provides inspiration for academic research on the mechanism of ripple superposition and the application of ion beam technology in different fields.

Aims . This work reports calculated transition probabilities for spectral lines of singly ionised nickel (Ni II ) incorporating newly determined experimental energy levels, addressing critical gaps in atomic data required for astrophysical spectroscopy and plasma diagnostics. Methods . Transition probabilities of Ni II were calculated using the semi-empirical orthogonal operator method for both odd and even energy levels. Calculated eigenvalues were fine-tuned to experimental energy levels, determined using Fourier transform spectroscopy, further increasing the accuracy of these calculated transition probabilities. Results . In total, transition probabilities have been calculated for nearly 118 000 electric dipole transitions between 361 even and 735 odd levels. The resulting transition probabilities show strong agreement with existing experimental and semi-empirical data, while offering improved consistency and coverage across a wide range of line strengths. The calculated transitions span the far-infrared to the vacuum ultraviolet spectral regions, providing extensive coverage for astrophysical applications. This dataset significantly enhances the calculated atomic data available for Ni II and represents a critical contribution to the advancement of our understanding of astrophysical phenomena through improved spectroscopic analysis.

Abstract Accurate atomic data and reliable spectroscopic diagnostics for tungsten are essential for fusion research, given its role as a plasma-facing material in ITER. We present a systematic study of highly charged W 31+ –W 39+ ions, combining large-scale atomic structure calculations with collisional–radiative modeling under fusion-relevant conditions. Excitation energies and magnetic dipole (M1) transition probabilities were calculated using the Flexible Atomic Code with extensive configuration expansions, achieving excitation energy deviations within 2% for W 31+ and W 35+ –W 39+ . Larger discrepancies for W 32+ and W 34+ reflect both the intrinsic challenges of modeling open-4 d shell correlations and uncertainties in available experimental benchmarks. The CR model, incorporating dielectronic recombination, accurately reproduces charge-state distributions at T e = 2800 eV and n e = 3.72 × 10 13 cm −3 consistent with Large Helical Device observations. Synthetic spectra in the 500–900 Å vacuum ultraviolet range successfully reproduce 11 experimentally observed lines and resolve several previously ambiguous spectral assignments. Importantly, selected M1 intensity ratios exhibit strong, distinct sensitivities to electron temperature and density, establishing them as robust diagnostics for tungsten impurity monitoring. This work provides comprehensive atomic data and validated spectral interpretations that enhance tungsten modeling accuracy and support plasma diagnostics development for ITER and future fusion devices.

Portal for high-precision atomic data and computation

In 1980, A. Sǎndulescu, D.N. Poenaru from Bucharest, Romania and Walter Greiner from Frankfurt am Main, Germany, published an article in which cluster radioactivity was predicted. Years later (1984) H. J. Rose and J. A. Jones from Oxford University reported the first experimental evidence of [Formula: see text]C radioactivity of [Formula: see text]Ra. Extensive calculations were published by D. N. Poenaru et al. in 1986 and 1991 in Atomic Data and Nuclear Data Tables. A very useful review of experimental results was published by Bonetti and Guglielmetti [Rom. Rep. Phys. 59 (2007) 301]. In this paper we compare the measured Q-values and half-lives with predictions within the Analytical Super-Asymmetric Fission (ASAF) model. Cluster radioactivity (spontaneous emission of particles larger than [Formula: see text]) is a rare phenomenon in a large background of alpha decay. For some very heavy nuclei it is possible to observe cluster radioactivity comparable or even stronger than alpha decay.

Using pulsar accelerations, we identify and constrain the properties of a dark matter subhalo in the Galaxy for the first time from analyzing the acceleration field of binary and solitary pulsars. The subhalo is characterized by analyzing a local deviation from a smooth potential. Our MCMC calculations show that this subhalo has a mass of 2.45_{-0.96}^{+1.07}×10^{7}M_{⊙} and is located at Galactocentric coordinates X=7.43_{-0.12}^{+0.2} kpc, Y=0.38_{-0.16}^{+0.11} kpc, Z=0.21_{-0.11}^{+0.06} kpc, using flat, uninformative priors, where we have modeled the sub halo as a compact object. The Bayes factors for the models are in the range of ∼20-40, which indicates tentative evidence (though not yet decisive) for the subhalo. Modeling the subhalo with a NFW profile gives a subhalo mass of 6.19_{-2.03}^{+1.92}×10^{7}M_{⊙}, located at X=7.47_{-0.14}^{+0.21}, Y=0.38_{-0.16}^{+0.11}, Z=0.21_{-0.11}^{+0.06}; the mass within the scale radius (0.1kpc) for the NFW profile is 0.48_{-0.16}^{0.15}×10^{7}M_{⊙}. We examine Gaia data and the atomic and molecular hydrogen data of our Galaxy and show that the measured deviation from a smooth potential cannot arise from the gas or the stars in our Galaxy. Additionally, by analyzing the full sample of binary pulsars with available acceleration measurements that span 3.4kpc in Galactocentric radius from the Sun and 3.6kpc in vertical height, we find that massive (with mass >10^{8}M_{⊙}) subhalos are disfavored for the MilkyWay within several kiloparsec of the Sun. While smaller sub-halos may be present, they are beyond the reach of current direct acceleration measurements. The presence of a ∼10^{7}M_{⊙} subhalo within a few kpc of the Sun is potentially consistent with the expected number counts of sub-halos in the prevailing ΛCDM paradigm, for a substantial subhalo mass fraction. As the number and precision of direct acceleration measurements continues to grow, we will obtain tighter constraints on dark matter sub-structure in our Galaxy. This Letter now provides a proof of principle for probing nearby, low-mass subhalos, and has implications across many fields of astrophysics-from understanding the nature of dark matter to galaxy formation.

Abstract Using the photon-ion merged-beams technique at the PETRA III synchrotron light source, we have measured cross sections for double and up to tenfold photoionization of La + ions by a single photon in the energy range 820–1400 eV, where resonances and thresholds occur that are associated with the excitation or ionization of one M -shell electron. These cross sections represent experimental benchmark data for the further development of quantum theoretical methods, which will have to provide the bulk of the atomic data required for the modeling of nonequilibrium plasmas such as kilonovae. In the present work, we have upgraded the Jena Atomic Calculator and pushed the state-of-the-art of quantum calculations for heavy many-electron systems to new limits. In particular, we have performed large-scale calculations of the La + photoabsorption cross section and of the deexcitation cascades, which set in after the initial creation of a 3 d hole. Our theoretical results largely agree with our experimental findings. However, our theoretical product-ion charge-state distributions are somewhat narrower than the experimental ones, which is most probably due to the simplifications necessary to keep the cascade calculations tractable.

We present a relativistic third-order algebraic diagrammatic construction [ADC(3)] approach for calculating double ionization potentials (DIPs). Inclusion of third-order terms significantly improves the performance of the algebraic diagrammatic construction method for DIPs. By employing the exact two-component atomic mean-field (X2CAMF) Hamiltonian in combination with a Cholesky decomposition representation of two-electron integrals and the frozen natural spinor framework for virtual space truncation, we achieve a significant reduction in both memory requirements and computational cost. The DIPs obtained using the X2CAMF Hamiltonian show excellent agreement with results from fully relativistic four-component calculations. We have validated the accuracy of our implementation through comparisons with available experimental and theoretical data for inert gas atoms and diatomic species. The effect of higher-order relativistic corrections is also explored. The efficiency of our implementation is demonstrated by computing the lowest DIP of the tungsten hexacarbonyl, W(CO)6, complex using a large basis set.

Abstract A precise methodology for determining the growth mode of oxide layers on metallic materials at high temperatures is proposed. The approach combines sequential isotopic oxidation tests (using 16 O and 18 O isotopes) with secondary ion mass spectrometry (SIMS and nanoSIMS) analyses. NanoSIMS provides high-resolution localisation of oxygen diffusion pathways and oxide growth zones. However, its limited accessibility and specialised instrumentation can pose practical constraints. In contrast, dynamic SIMS offers broader accessibility and the ability to directly quantify oxygen isotope ratios across depth profiles. The detection of both conventional atomic (O − ) and diatomic (O 2 − ) oxygen signals in dynamic SIMS analysis proved highly effective in offering insights on oxide growth mode, closely replicating nanoSIMS results. The diatomic signal analysis complements the atomic signal data by improving the understanding of oxidant transport within the oxide layer. The methodology was validated through its application to a Co-10Cr alloy oxidised at 900 °C in O 2 , under sequential exposures to 16 O and 18 O isotopes. Both SIMS and nanoSIMS revealed the formation of a duplex oxide layer, consisting of an outer layer formed by outward Co cation diffusion and an inner layer growing by inward oxygen penetration, particularly in the grain-boundary regions of the outer oxide layer. The alloy is proposed to oxidise according to the Available Space Model.

Abstract Diagnostics for the solar chromosphere are relatively few compared to other parts of the atmosphere. Despite this, hundreds of Rydberg lines emitted by neutrals in this region have been observed at UV wavelengths. Here, we investigate their diagnostic potential by modelling the lines emitted by neutral carbon using recent atomic data. We use the radiative transfer code Lightweaver to explore how they form and how they respond to temperature, density and micro-turbulent velocity perturbations in the atmosphere. To simplify the modelling, we investigate lines emitted from levels with principal quantum number n ≥ 10, which are expected to be in Saha-Boltzmann equilibrium with the ground state of the singly-charged ion. Optical depth effects are apparent in the lines and their response to atmospheric perturbations suggest that they will be useful in reconstructions of the atmosphere using inversions. The study opens the way for using many such lines emitted by multiple elements over a range of heights, a large number of which will be observed by the forthcoming Solar-C EUVST instrument.

Elastin-like polypeptides (ELP) are engineered biopolymers built from repetitive pentapeptide sequences that mimic motifs found in mammalian tropoelastin. Their unique characteristics make them ideal candidates for a wide array of biomedical applications, ranging from drug and gene delivery to tissue engineering and targeted molecular imaging. Conventional purification approaches from Escherichia coli (E. coli) expression can be ineffective for ELP due to the formation of inclusion bodies. Other methods, such as inverse transition cycling (ITC), utilize the lower critical solution temperature (LCST) properties of ELP to separate it from contaminants such as lipopolysaccharides (LPS), but typically require multiple heating and cooling steps that are time-consuming and can result in low recoveries depending on the sequence, concentration, and molecular weight of the ELP construct. To tackle these challenges, we have developed an organic solvent-based extraction-precipitation workflow that exploits the intrinsic hydrophobicity of ELP to enable rapid, robust, and broadly applicable purification directly from E. coli cell pellets. This method uses polar organic solvents to aid in cell disruption and selectively solubilize ELP in a single step. A subsequent precipitation step effectively removes residual organic solvents, low-molecular-weight impurities, and endotoxins, yielding highly pure ELP with LPS levels below 1 EU/mL in under 3 h. Atomic force microscopy data suggest that ELP-fusion proteins purified in this manner can self-assemble into reverse micelle-like structures that retain fusion protein function. This rapid purification method offers researchers a straightforward and potentially scalable way to purify ELP, creating new possibilities for using ELP and their fusion proteins as flexible building blocks for material and biomedical applications.

In aero-engine applications, turbine blades operate under high-temperature and high-pressure thermomechanical cyclic loading conditions, which demand exceptional mechanical performance. High-entropy superalloys, characterized by a stable dual-phase γ/γ' microstructure, have emerged as promising candidates for high-temperature structural materials due to their superior creep resistance. In this study, the creep behaviors of high-entropy superalloys are systematically investigated using molecular dynamics simulations, exploring the effects of stress, temperature, γ/γ' lattice misfit, and γ' volume fraction on creep deformation mechanisms. The results show that both stress and temperature significantly influence creep behavior, with temperature exerting a more dominant effect. As the applied stress increases, the dominant creep mechanism evolves from atomic diffusion to dislocation nucleation and motion, eventually leading to phase transformation. Additionally, the γ/γ' lattice misfit and γ' volume fraction are found to critically affect the alloy's creep resistance. Specifically, creep resistance initially increases and then decreases with increasing lattice misfit magnitude, while a negative misfit yields better performance than a positive one. Moreover, increasing the γ' volume fraction enhances the alloy's ability to resist creep deformation. Microstructural analysis and atomic diffusion data further reveal that the creep resistance of high-entropy superalloys is closely associated with the structural stability of the γ/γ' dual-phase system. These findings provide useful insights for optimizing the high-temperature performance of high-entropy superalloys through microstructural design.

The quantum theory of scattering of electromagnetic waves by charged particles is known as Compton effect which can give us valuable information about the electronic structure of transition metals and alloys. In this paper we study of the Electronic State for two (W-Cu) alloys, where it Compton profile (CP) for W, Cu elements it was calculated theoretically by using the Renormalized Free Atom (RFA) model, we found electronic configuration best for the two elements they (5d5-6s1) and (3d9.9-4s1.1) respectively after it has been compared the results that have been obtained with the available experimental values, Free atom (FA) data has also been added for two elements in the study. Also we found Compton profile (CP) for the two alloys (W60%-Cu40%),(W72%-Cu28%) using the Superposition model and the results were compared with the available experimental values and Augmented Plane Wave (APW) data respectively. the calculations theoretical for Superposition model she was give a better agreement with available experimental values.

Abstract Geomorphometric methods can be used for improving the visibility of distribution data maps. The results of the finite element modeling, scanning electron microscopy and atomic force microscopy data processing are presented. The mechanical stresses in the redistribution layers structure, the homogeneity of the multilayer film, and the surface morphological features were studied. It was shown that the use of morphometric variable maps is effective for localizing inhomogeneities and makes it possible to detect structural features that are almost invisible in the original distribution data maps.

Abstract Tungsten (W) is one of the leading candidate materials for plasma-facing components. However, its main drawback is its high radiative efficiency; if W penetrates the plasma, it can lead to core degradation or even collapse. Since eroded tungsten tends to ionize in the sheath and redeposit promptly, the net erosion flux that escapes prompt redeposition can differ significantly from the gross erosion. This work presents a modeling framework to estimate net erosion and photon emission from W coatings exposed to the lower divertor of DIII-D using the DiMES material exposure probe. The approach couples RustBCA for sputtering yields with a Monte Carlo transport code (LPTMC) that models redeposition and W emission. Computation is carried out with new atomic data, based on R-matrix and Mons calculations, leading to lower ionization probabilities and a twofold increase in net erosion estimates compared to calculations done with OPEN-ADAS atomic data. The model results are benchmarked against experimental measurements, showing quantitative agreement for erosion, although the trends in W emission are reproduced only qualitatively. The model is also used to assess whether W II emission can serve as a direct measurement of the net erosion of W in the lower divertor of DIII-D. Simulations show that this is not valid if the electron pressure is above ∼ 120 Pa or if the toroidal length of the eroded material is smaller than the parallel-to-B distance traveled by impurity ions before steady-state conditions are reached. Finally, simulations suggest that when W is sputtered by carbon ions with high impact energies ( ≳ 300 eV) in DIII-D, W net erosion scales with W gross erosion and can be numerically approximated using W I flux alone as input.

Context. For the analysis of highly resolved solar spectra the simultaneous observation and interpretation (inversion) of only a few (often only one) spectral lines is still the norm. With modern instruments spatially highly resolved spectropolarimetric data covering many lines are available. Aims. For the first time we combine the information from 85 simultaneously observed absorption lines in spatially highly resolved data to test a proposed solar many-line inversion strategy. Methods. We inverted full Stokes spectra recorded with the FISS spectro-polarimeter (FISS-SP) at the 1.6-m Goode Solar Telescope in California, using the SPINOR code. We contrasted two different setups: one following the traditional approach of using a line doublet, and a new method inverting many-lines simultaneously. Results. Compared to results from an inversion using two lines of a line doublet, we discovered more fine-structure and better constrained values using the many-line technique. An average quiet Sun spectrum was successfully reproduced using a model atmosphere, but when inverting spatially resolved data, uncertainties in line parameters and blend configurations did not average out. Thus, a deliberate selection process of lines and line blends was required, in order to make the many-line case converge to a physically expected and coherent atmosphere. We successfully developed and tested such a selection method. Conclusions. Our results highlight that the many-line inversions method delivers more coherent results with superior line of sight (LOS) resolution of the atmospheric structure. Moreover, it effectively detects and utilizes even weak polarimetric signals in noisy data and thereby partly circumvents low noise requirements. It reveals uncertainties in atomic parameters of individual spectral lines and models, as the degree of freedom to compensate for these uncertainties by compromising the inferred atmospheric parameters is considerably reduced. It is thereby pointing to a need for improved atomic data, including log( gf ) values, of many lines in the solar spectrum. The many-line method presents significant potential for solar physics and may become the preferred option for future observations with upcoming spectrographs.

Recent advances in non-local thermodynamic equilibrium (non-LTE) plasma simulations, for example in modeling kilonova ejecta, have emphasized the need for consistent and reliable atomic data. Unlike LTE modeling, non-LTE calculations must include a consistent treatment of various photon-induced and collisional processes in order to describe realistic electron and photon distributions in the plasma. However, the available atomic data are often incomplete, inconsistently formatted, or even fail to indicate the main dependencies on the level structure and plasma parameters, thus limiting their practical use. To address these issues, we have extended Jac, the Jena Atomic Calculator (version v0.3.0), to provide direct access to relevant cross sections, plasma rates, and rate coefficients. Emphasis is placed on photoexcitation and ionization processes as well as their time-reversed counterparts—photo-de-excitation and photorecombination. Whereas most of these data are still based on empirical expressions, their dependence on the ionic level structure and plasma temperature is made explicit here. Moreover, the electron and photon distributions can be readily controlled and adjusted by the user. This transparent representation of atomic data for photon-mediated processes, together with a straightforward use, facilitates their integration into existing plasma codes and improves the interpretation of high-energy astrophysical phenomena. It may support also more accurate and flexible non-LTE plasma simulations.

Abstract We present the ExoAtom database, www.exomol.com/exoatom, an extension of the ExoMol database to provide atomic line lists in the ExoMol format. ExoAtom is designed for detailed astrophysical, planetary, and laboratory applications. ExoAtom currently includes atomic data for 80 neutral atoms and 74 singly charged ions. These data are extracted from both the nist and Kurucz databases, with 79/71 atoms/ions sourced from nist and 38/37 atoms/ions sourced from Kurucz. ExoAtom uses the file types .all, .def, .states, .trans and .pf as fundamental components for structuring atomic data in a consistent hierarchy. The .states file contains quantum numbers, uncertainties, lifetimes, etc. The .trans file specifies Einstein A coefficients and their associated wavenumbers. The .pf file provides partition functions over a wide grid of temperatures. Post-processing of the ExoAtom data is provided by the program PyExoCross. Future development of ExoAtom will include additional ionization stages.

BackgroundThe increasing use of real-time health data from wearable devices and self-reported questionnaires offers significant opportunities for preventive care in aging populations. However, current health data platforms often lack built-in mechanisms for data and model traceability, version control, and coordinated management of heterogeneous data streams, which are essential for clinical accountability, regulatory compliance, and reproducibility. The absence of these features limits the reuse of health data and the reproducibility of analytical workflows across research and clinical environments.ObjectiveThis work presents DeltaTrace, a unified big data health platform designed with traceability as a key architectural feature. The platform integrates end-to-end tracking of data and model versions with real-time and batch processing capabilities. Built entirely on open source technologies, DeltaTrace combines components for data management, model management, orchestration, and visualization. The main objective is to demonstrate that embedding traceability within the architecture enables scalable, auditable, and version-controlled processing of health data, thereby facilitating reproducible analytics and long-term maintenance of health monitoring systems.MethodsDeltaTrace adopts a medallion architecture implemented with Delta Lake to ensure atomic and version-controlled data transformations. Apache Spark is used for distributed computation, Apache Kafka for continuous data ingestion, and Apache Airflow for orchestration of batch and streaming workflows. MLflow manages the lifecycle and versioning of machine learning models, while Grafana provides visualization dashboards for real-time and aggregated data inspection. The platform is evaluated using continuous physiological signals from wearable devices and batch-ingested questionnaire data, combining synthetic and real data from the LifeSnaps dataset. Performance tests are conducted on central processing unit–only servers with 8-core and 24-core configurations to assess ingestion, aggregation, visualization, and anomaly detection latency.ResultsDeltaTrace supports continuous processing for approximately 1500 users with end-to-end delays below 10 minutes. Ingestion and visualization tasks operate between mean 4.9 (SD 0.12) and 7.5 (SD 0.28) minutes, while aggregation and anomaly detection required less than mean 5.6 (SD 0.04) and 10.5 (SD 1.70) minutes, respectively. Increasing from 8 to 24 cores improved ingestion and cleaning latency by up to 25% and anomaly detection performance by up to 50%. The system maintains consistent performance across different data types, processing modes, and loads.ConclusionsDeltaTrace provides a scalable and modular architecture that incorporates traceability as a core component together with functions for model management, orchestration, and visualization. The platform enables complete version control across data and models and maintains performance under limited hardware conditions. These characteristics support reproducible and auditable health data processing and make DeltaTrace suitable for continuous monitoring and preventive health care in aging populations.

Nominally weakly coordinating anions are useful for modulating the solubility and chemical properties of metal complexes, but identification and analysis of the systematics of the interactions of anions with cationic metal complexes has not received the attention it deserves. Here, a chemical informatics approach is demonstrated for identifying and quantitatively analyzing the ways that the bis(trifluoromethylsulfonyl)imide anion (TFSI) can interact with metal-containing species. An open access computer program (PyCIFTer) was developed to facilitate large-scale structural analysis of TFSI-containing species by utilization of experimental atomic coordinate data from single-crystal X-ray diffraction (XRD) studies obtained from the Cambridge Structural Database (CSD). PyCIFTer establishes a three-dimensional vector space from the raw atomic coordinates, generating acyclic, undirected graphs that are used to rapidly analyze the structural properties (bond lengths and angles) of TFSI in individual structures in sequential/batch fashion. The structures are sorted by PyCIFTer into groups based on pre-set and chemically sensible criteria, affording a comprehensive and systematic view of TFSI structural chemistry. This approach avoids tedious one-at-a-time interrogation of structures, a prospect unreasonable in this case, and many others of contemporary chemical relevance; there were over 1500 structures in the CSD containing TFSI as of November 2024. The results demonstrate that TFSI only rarely binds to cations in the solid state, favoring the formation of species in which TFSI is found in cations' outer coordination spheres. The prospect of applying PyCIFTer to other moieties is also discussed. PyCIFTer is also schematically compared to the commercial CSD Python application programming interface (API). Taken together, this work demonstrates the usefulness of modular workflows for sequential/batch analysis of structural data from XRD, an approach that appears poised to accelerate the translation of legacy structural results into new chemical insights and hypotheses.