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The competition between the radiative and nonradiative lifetimes determines the optical quantum yield and plays a crucial role in the potential optoelectronic applications of transition metal dichalcogenides (TMDCs). Here, we show that, in the presence of free carriers, an additional nonradiative decay channel opens for excitons in TMDC monolayers. Although the usual Auger decay channel is suppressed at low doping levels by the simultaneous momentum and energy conservation laws, exciton–phonon coupling relaxes this suppression. By solving a Bethe–Salpeter equation, we calculate the phonon-assisted Auger decay rates in four typical TMDCs as a function of doping, temperature, and dielectric environment. We find that even for a relatively low doping of 1012 cm−2, the nonradiative lifetime ranges from 16 to 165 ps in different TMDCs, offering competition to the radiative decay channel. [ABSTRACT FROM AUTHOR]

New data are presented on the resonant Auger decay of iodobenzene (C6H5I) in the region of the I 4d−1 ionization threshold. The excited molecules decay by participator and spectator processes to populate single-hole valence states and two-hole, one-particle excited states of the cation, providing new information on the structure of C6H5I+. Excitation of dissociative C6H5I (I 4d5/2,3/2−1)σ* resonances can, in principle, result in ultrafast dissociation to C6H5 + I** and the subsequent autoionization of I**, but no evidence for this process is observed. The results are compared with our recent study of the resonant Auger decay of methyl iodide (CH3I). [ABSTRACT FROM AUTHOR]

The dissociative double ionization of CH3I and CH2I2 irradiated with extreme ultraviolet light at hv = 100 eV is investigated by multi-electron–ion coincidence spectroscopy using a magnetic bottle type electron spectrometer. The spin–orbit state-resolved Auger electron spectra for the I 4d core-hole states, (I 4d3/2)−1 and (I 4d5/2)−1, provide clear identifications of electronic states of CH3I2+ and CH2I22+. The dominant ion species produced after the double ionization correlate with the Auger electron energy, showing that different fragmentation pathways are open depending on the electronic states populated by the Auger decay. Theoretical calculations are performed to understand the fragmentation from the doubly charged states and the observed spin–orbit specificity in the Auger decay. [ABSTRACT FROM AUTHOR]

Resonant Auger processes provide a unique perspective on electronic interactions and excited vibrational and electronic states of molecular ions. Here, new data are presented on the resonant Auger decay of excited CH3I in the region just below the I 4d−1 ionization threshold. The resonances include the Rydberg series converging to the five spin–orbit and ligand-field split CH3I (I 4d−1) thresholds, as well as resonances corresponding to excitation from the I 4d5/2,3/2 orbitals into the σ* lowest unoccupied molecular orbital. This study focuses on participator decay that populates the lowest lying states of CH3I+, in particular, the X ̃ 2E3/2 and 2E1/2 states, and on spectator decay that populates the lowest-lying (CH3I2+)σ* states of CH3I+. The CH3I (I 4d−1)σ* resonances are broad, and dissociation to CH3 + I competes with the autoionization of the core-excited states. Auger decay as the molecule dissociates produces a photoelectron spectrum with a long progression (up to v3+ ∼ 25) in the C–I stretching mode of the X ̃ 2E3/2 and 2E1/2 states, providing insights into the shape of the dissociative core-excited surface. The observed spectator decay processes indicate that CH3I+ is formed on the repulsive wall of the lower-lying (CH3I2+)σ* potentials, and the photon-energy dependence of the processes provides insights into the relative slopes of the (4d−1)σ* and (CH3I2+)σ* potential surfaces. Data are also presented for the spectator decay of higher lying CH3I (I 4d−1)nl Rydberg resonances. Photoelectron angular distributions for the resonant Auger processes provide additional information that helps distinguish these processes from the direct ionization signal. [ABSTRACT FROM AUTHOR]

This study investigated the dissociation after the Xe 4d Auger decay of weak-bonding XeF2 molecules by multielectron–ion coincidence spectroscopy using a magnetic bottle electron spectrometer. Fragmentations from the XeF22+ states were clarified in the Auger spectra coincident with individual ion species. It was observed that the two-hole population led by the Auger decay was not directly inherited during the fragmentation of XeF22+. Furthermore, the dissociations of XeF23+ states produced by the double Auger decay were investigated. [ABSTRACT FROM AUTHOR]

The La Prele site (ca. 12,940 cal BP) is a deeply buried, single-component mammoth kill and campsite in Wyoming (USA). The site was discovered eroding from a creek bank 3 m deep within a 7-m tall terrace scarp, and prior investigations have primarily focused on excavations accessible from the creek bank, using heavy machinery to remove sterile overburden to access the deeply buried deposits. This approach has allowed excavations to occur safely outside of deep pits, but it has limited our ability to assess the total size and density of the site. To determine total site extent, we conducted systematic bucket auger testing of the La Prele site terrace, attempting 189 augers between 1.6 m and 6.2 m deep across the landform. We use a simulation and other mathematical procedures to infer artifact density from auger artifact counts and interpolate artifact densities across the site using GIS. We determine that La Prele is around 4500 m2 in area and likely contains a buried bison bonebed and two additional artifact concentrations comparable to or exceeding the size and density of previously excavated areas. We use these insights to infer Early Paleoindian group size, concluding that around 30 people occupied La Prele. [ABSTRACT FROM AUTHOR]

Perovskite‐inspired materials (PIMs) are potential alternatives to lead halide perovskites, as they not only inherit the benign optoelectronic properties but also diminish the stability and toxicity issues of lead halide perovskites. As a newly discovered PIM, Cu2AgBiI6 has exhibited promising potential for photovoltaic applications. However, studies on its fundamental properties related to photovoltaic performance are scarce, particularly from a theoretical perspective. Herein, the effective lifetime of nonequilibrium carriers (photo‐excited charge carriers) is systematically investigated, a critical property affecting the photovoltaic performance of Cu2AgBiI6, based on the nonadiabatic molecular dynamics simulations. It is found that under the standard solar spectrum illumination, the dominant recombination mechanism affecting the effective lifetime can be band‐to‐band nonradiative decay, band‐to‐band radiative decay, or Shockey–Read–Hall defect‐assisted decay. The specific mechanism is highly dependent on the radiative recombination coefficient and the density of defect recombination levels. The effective lifetime can vary from 0.1 ms to 10 ns. When considering different illumination conditions (generation rates), Auger decay can also become the dominant recombination mechanism, with the effective lifetime varying from 0.1 s to 0.1 ns. These findings can be vital for further experimental researches aimed at enhancing the power conversion efficiency of Cu2AgBiI6‐based solar devices. [ABSTRACT FROM AUTHOR]

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Perovskite‐inspired materials (PIMs) are potential alternatives to lead halide perovskites, as they not only inherit the benign optoelectronic properties but also diminish the stability and toxicity issues of lead halide perovskites. As a newly discovered PIM, Cu2AgBiI6 has exhibited promising potential for photovoltaic applications. However, studies on its fundamental properties related to photovoltaic performance are scarce, particularly from a theoretical perspective. Herein, the effective lifetime of nonequilibrium carriers (photo‐excited charge carriers) is systematically investigated, a critical property affecting the photovoltaic performance of Cu2AgBiI6, based on the nonadiabatic molecular dynamics simulations. It is found that under the standard solar spectrum illumination, the dominant recombination mechanism affecting the effective lifetime can be band‐to‐band nonradiative decay, band‐to‐band radiative decay, or Shockey–Read–Hall defect‐assisted decay. The specific mechanism is highly dependent on the radiative recombination coefficient and the density of defect recombination levels. The effective lifetime can vary from 0.1 ms to 10 ns. When considering different illumination conditions (generation rates), Auger decay can also become the dominant recombination mechanism, with the effective lifetime varying from 0.1 s to 0.1 ns. These findings can be vital for further experimental researches aimed at enhancing the power conversion efficiency of Cu2AgBiI6‐based solar devices. [ABSTRACT FROM AUTHOR]

We present a time-dependent theory for non-resonant x-ray emission spectrum (XES) and normal Auger spectrum (NAS) calculation, based on a fully quantum description of nuclear dynamics using the vibrational wave packet concept. We compare two formulations of the time-dependent theory, either employing a two-time propagation scheme or using spectral integration over the electron energy continuum. We find that the latter formulation is more efficient for numerical simulations, providing a reasonable accuracy when the integration step is shorter than the lifetime broadening of the core-ionized state. We demonstrate our approach using the example of non-resonant x-ray emission from a water molecule, considering the lowest core-ionized K−1 and first core-ionized shake-up K−1V−1V1 intermediate states. These channels exemplify the developed theory on bound–bound, bound–continuum, continuum–bound, and continuum–continuum transitions. Our results suggest that the time-dependent approach is efficient for simulating XES involving dissociative states, whereas the time-independent approach, based on Franck–Condon factors, is more efficient for bound–bound transitions expressed as discrete frequency dependence in the energy domain. The methods and discussion have general applicability, including both NAS and more complex systems, such as liquid water. [ABSTRACT FROM AUTHOR]

The metastability and the dissociation processes of the OCS3+ states produced by the S 2p double Auger decay of OCS are investigated by multi-electron-ion coincidence spectroscopy using a magnetic bottle electron spectrometer. The spectra of the OCS3+ states filtered for the production of individual ions are derived by four-fold (or five-fold) coincidence among three electrons and a product ion (or two ions). The ground OCS3+ state is confirmed to be metastable in the 10 µs regime. The OCS3+ states relevant to the individual channels of two- and three-body dissociations are clarified. [ABSTRACT FROM AUTHOR]

Vibronic coupling is a critical mechanism in chemical reactions. However, its quantitative evaluation is challenging due to mathematical complexity and programming difficulty, and its experimental proof is often elusive due to overlap among neighboring states. Here, after exciting a vibrational level (ν = 0, 1, 2) of the intermediate N 1 s → π g * core-excited state in N2 molecules, we separate the resonant Auger decay channels that lead to the lowest dissociation limit in the two-dimensional energy correlation maps. From three kinetic energy release spectra of these channels at different vibrational quantum numbers, we give the first experimental proof of the vibronic coupling between two resonant Auger final states 12Πg and 22Πg. [ABSTRACT FROM AUTHOR]

Over the last fifty years, a number of higher energy X‐ray sources have been suggested as alternatives for the usual AlKα source found in the first commercial XPS systems and still the standard anode material for XPS today. This paper reviews the development of a number of such sources, predominantly in the authors' laboratory, and the rationale behind the desire to extend the binding energy range of the technique. The achromatic sources SiKα, ZrLα and TiKα are described along with monochromatic sources AgLα and CrKβ, both based on the standard quartz monochromator geometry but taking higher orders of diffraction. The driving force for much of this development was the desire to probe deeper core levels and CCC Auger transitions. These could be combined into initial or final state Auger parameters as described in much of the work cited in this review. The highest energy source considered is the CuKα source based around an external X‐ray tube, which provides much insight into the electronic structure of steels by measurement of the Fe1s and FeKLL peaks. The last decade or so has seen a significant increase of interest in HAXPES, and all manufacturers of turn‐key XPS instruments offer HAXPES options of one form or another, there are three dedicated HAXPES systems commercially available, which are very briefly described. [ABSTRACT FROM AUTHOR]

We present an ab initio computational study of the Auger electron spectrum of benzene. Auger electron spectroscopy exploits the Auger–Meitner effect, and although it is established as an analytic technique, the theoretical modeling of molecular Auger spectra from first principles remains challenging. Here, we use coupled-cluster theory and equation-of-motion coupled-cluster theory combined with two approaches to describe the decaying nature of core-ionized states: (i) Feshbach–Fano resonance theory and (ii) the method of complex basis functions. The spectra computed with these two approaches are in excellent agreement with each other and also agree well with experimental Auger spectra of benzene. The Auger spectrum of benzene features two well-resolved peaks at Auger electron energies above 260 eV, which correspond to final states with two electrons removed from the 1e1g and 3e2g highest occupied molecular orbitals. At lower Auger electron energies, the spectrum is less well resolved, and the peaks comprise multiple final states of the benzene dication. In line with theoretical considerations, singlet decay channels contribute more to the total Auger intensity than the corresponding triplet decay channels. [ABSTRACT FROM AUTHOR]

The most challenging task for establishing a 103Ru/103mRh generator for Auger therapy, is to reach an effective separation between the two radionuclides because of the highly unpredictable, very complicated and poorly understood chemistry. In HCl, this work was able to evidence the formation of Ru colloids. It has been evidenced that the starting material of Ru, time and temperature have a strong influence on Ru speciation, but no polynuclear species of ruthenium–chloride was observed. This work has showed that it is fully possible to control the speciation of ruthenium, especially Ru(IV), within a mononuclear species; that is a huge step forward compared to literature. [ABSTRACT FROM AUTHOR]

The mechanism of anode-initiated breakdown in liquid organic dielectrics with long molecular chains is proposed on the basis of the experimental data on high velocities of the breakdown channel propagation in organosilicon and organofluorine liquids (~107 cm/s), which are comparable to those obtained earlier in crystals in the same conditions. The high velocities of the anode-initiated breakdown channels are satisfactorily explained within the model of the cascade Auger transitions, developed for the crystalline materials. According to this model, velo city of the breakdown channel propagation is proportional to the electrical field strength. The time delay in breakdown channel formation relative to the voltage pulse rise time does not exceed ~5 × 10–10 s within the margin of error. [ABSTRACT FROM AUTHOR]

It has recently been shown that an interferometric approach can be used to obtain Auger lifetimes in molecules in certain point groups. Here, we extend this concept to those molecular states for which Auger decay is energetically forbidden and which exhibit initial quasi-exponential decay followed by quantum revivals. We demonstrate that this allows us to extract the quasi-exponential decay rate and the revival timescale. We solve analytically a model containing a state coupled to the idealized Bixon–Jortner quasicontinuum, and we obtain an interferometric signature of revival, which can be easily generalized to realistic systems. Moreover, we analyze how this revival signature is influenced by the system parameters, and we suggest optimal conditions for its observation. We, therefore, show that our new approach allows population revivals of a molecular state to be detected interferometrically. [ABSTRACT FROM AUTHOR]

The emission of an Auger electron is the predominant relaxation mechanism of core-vacant states in molecules composed of light nuclei. In this non-radiative decay process, one valence electron fills the core vacancy, while a second valence electron is emitted into the ionization continuum. Because of this coupling to the continuum, core-vacant states represent electronic resonances that can be tackled with standard quantum-chemical methods only if they are approximated as bound states, meaning that Auger decay is neglected. Here, we present an approach to compute Auger decay rates of core-vacant states from coupled-cluster and equation-of-motion coupled-cluster wave functions combined with complex scaling of the Hamiltonian or, alternatively, complex-scaled basis functions. Through energy decomposition analysis, we illustrate how complex-scaled methods are capable of describing the coupling to the ionization continuum without the need to model the wave function of the Auger electron explicitly. In addition, we introduce in this work several approaches for the determination of partial decay widths and Auger branching ratios from complex-scaled coupled-cluster wave functions. We demonstrate the capabilities of our new approach by computations on core-ionized states of neon, water, dinitrogen, and benzene. Coupled-cluster and equation-of-motion coupled-cluster theory in the singles and doubles approximation both deliver excellent results for total decay widths, whereas we find partial widths more straightforward to evaluate with the former method. [ABSTRACT FROM AUTHOR]

The modified smooth exterior scaling (MSES) method is an efficient method to impose outgoing boundary conditions in electron–atom or electron–molecule scatterings. MSES can be used to convert divergent wave functions to square integrable ones. The electron propagator method in conjunction with MSES has been utilized to characterize 2S Be+ (1s−1), 2S Ne+ (1s−1) Auger and 2P Be− shape resonances. The dilated electron propagator has been proved to be an efficient and powerful tool in characterizing the Auger and shape resonances. The resonance energies obtained by using this method are in good agreement with experimental results and other theoretical estimates available in the literature. [ABSTRACT FROM AUTHOR]

In quantum dots (QDs), the Auger recombination is a non-radiative scattering process in which the optical transition energy of a charged exciton (trion) is transferred to an additional electron leaving the dot. Electron tunneling from a reservoir is the competing process that replenishes the QD with an electron again. Here, we study the dependence of the tunneling and Auger recombination rate on the applied electric field using high-resolution time-resolved resonance fluorescence (RF) measurements. With the given p–i–n diode structure and a tunnel barrier between the electron reservoir and the QD of 45 nm, we measured a tunneling rate into the QD in the order of ms−1. This rate shows a strong decrease by almost an order of magnitude for decreasing electric field, while the Auger emission rate decreases by a factor of five in the same voltage range. Furthermore, we study in detail the influence of the Auger recombination and the tunneling rate from the charge reservoir into the QD on the intensity and linewidth of the trion transition. In addition to the well-known quenching of the trion transition, we observe in our time-resolved RF measurements a strong influence of the tunneling rate on the observed linewidth. The steady-state RF measurement yields a broadened trion transition of about 1.5 GHz for an Auger emission rate of the same order as the electron tunneling rate. In a non-equilibrium measurement, the Auger recombination can be suppressed, and a more than four times smaller linewidth of 340 MHz (1.4 μeV) is measured. [ABSTRACT FROM AUTHOR]

Soil sampling at the landscape scale is increasingly in demand for assessing C sequestration projects in agroecosystems. Efforts to decrease sampling costs across large areas have thus far largely ignored improved soil harvesting tools as a means of decreasing sampling time and effort. Rigorous analysis of trade‐offs in speed and accuracy among soil harvesting methods is needed. Here, we compare two different methods of soil sampling soil, a standard push probe and a novel drill‐auger system, which were used to collect soils for analysis of total C by dry combustion. We designed sampling plots to compare soil C concentrations at increasing spatial scales to understand the difference in soil C concentrations between methods relative to spatial heterogeneity. We sampled two farms in Upstate New York, one conventional and one organically managed, to assess the impact of these methods across relevant farm practices. We found that probe and auger methods provide indistinguishable soil carbon estimates at both farms. The difference between paired probe and auger samples taken less than 0.15 m apart was 0.22%, an amount equivalent to the difference in C concentrations at points 2 m apart and less than the difference at points 10 m apart. Using the soil auger was up to three times faster than using the push probe—a saving of 7 h of sampling time to inventory the two farms studied. Lowering inventory cost is a critical step in demonstrating the feasibility of soil carbon sequestration as a component of climate smart agriculture. The results presented indicate that the drill‐auger system is preferable to the push probe method for farm‐scale soil carbon inventory. Core Ideas: One component of lowering soil sampling cost is to increase the efficiency of in‐field sample collection.Comparison of a soil probe to a drill‐auger demonstrates that C estimates are indistinguishable at the farm scale.The difference between methods at <0.15 m is less than the spatial heterogeneity in %C at a distance of 2 or 10 m.The drill‐auger is 1.75–3x faster than the probe that translates to an approximate savings of $1.18 per acre.Considering the trade‐offs of sampling methods can save significant time and resources in large‐scale projects. [ABSTRACT FROM AUTHOR]

Afforestation operations in hilly regions are both arduous and unsafe. The mechanized afforestation method that takes into account soil and water conservation measures is deemed highly important. This paper examines the operational process and the auger's mechanism of digging below the ground using the discrete element method (DEM). Using this model, soil disturbance parameters and reaction forces are satisfactorily predicted, exhibiting similar trends to experimental observations. This research also examines the influence of key parameters on soil disturbance and distribution patterns and analyzes the conditions and mechanisms of the formation of fish-scale pits to preserve soil and water. A field experiment of pit digging in woodland is carried out to test the performance of the device. The error rates for the actual and simulated values of the efficiency of conveying soil and the distance of throwing soil on plain terrain and slopes were 12.7% and 8.2%, and 8.6% and 15.7%, respectively. Overall, this research provides a theoretical basis for the innovative exploration, development, and optimized design of earth augers in hilly regions. [ABSTRACT FROM AUTHOR]

Rhodium-103m is one of the most attractive Auger electron emitters for internal radiotherapy. The half-life of 103mRh is relatively short (56.114 min). Therefore, it needs to be produced using a generator for clinical use. Most studies of 103Pd/103mRh generators using anion-exchange resins were carried out over 50 years ago. However, these resins are no longer commercially available. In the present study, we tested a 103Pd/103mRh generator using alternative anion-exchange resins (i.e., IRA904, IRA410, SA20A, and SA11AL). No-carrier-added 103Pd was used to make the generators. The 103mRh product was eluted from the generators using 6 mL of 0.1 M HCl with a flow rate 0.5 mL/min. The generator made from SA11AL showed good performance, with a yield of 39 %, an impurity level of 103Pd in the product of 0.29 %, and an operation time of 14 min. This makes this generator competitive with previously developed ones. [ABSTRACT FROM AUTHOR]

This study explores various testing techniques' ability to identify activity areas across deeply stratified, open air archaeological sites. To determine the efficacy of different site testing techniques, a systematic ground penetrating radar and auger survey was completed at three sites in central Alaska: Swan Point, Bachner, and Niidhaayh Na'. The results show that both ground penetrating radar and auger survey can indicate subsurface geology, important for sites without exposed vertical deposits. Additionally, systematic auger surveys can be used to identify activity areas at large sites and in components up to 4 m below surface prior to full-scale excavation. This can help archaeologists identify earlier archaeological components and target specific areas that are directly related to their research questions while preserving the rest of the site for future investigations. Compared to traditional shovel testing, auger surveys provide a consistent, efficient, and rigorous method for assessing buried cultural remains. [ABSTRACT FROM AUTHOR]

The paper reports the calculation of the probabilities of Auger transitions taking place in the process of filling a vacancy on the 2pπ-orbital in an Ne+–Ne quasimolecule, a short-lived system which arises when the ion and atom approach each other and decays when they fly apart. Calculations for various ionization degrees of the quasimolecule particles were performed for the first time. It was found out that the system ionization degree increases very significantly (from 2 to 6) with increasing collision energy and decreasing distance of the particles closest approach. Using of the quantum mechanical approach and taking into account the collision dynamics made it possible to quantitatively describe for the first time the experimental Auger electron spectra of a complex many-electron quasimolecule. The contribution of the transition from the initial 3dπ–3dπ state to the 2pπ-orbital was shown to be predominant among the whole variety of possible Auger decay channels. [ABSTRACT FROM AUTHOR]

This article presents an engineering, empirical method of estimating the bearing capacity and settlement characteristics Q-s of screw displacement piles and columns, based on soil resistance encountered during the drilling to form piles/columns in the ground. The method was developed on the basis of correlation analyses of the test results of 24 piles made during the "DPDT-Auger" research project (Krasiński et al., 2022a). In the proposed method, the load capacity of a screw displacement pile is estimated using two main parameters of auger screwing resistance: torque MT and the number of auger rotations per depth unit nR. The method applies to piles and columns made with a standard screw displacement pile (SDP) auger and with the proprietary, prototype DPDT (displacement pile drilling tool) aguer, patented in Poland (2020). Based on the estimated ultimate capacities of the pile shaft and base, an approximate method of predicting the pile settlement characteristics Q-s was also proposed, using the transfer function method. This article describes a correlation procedure of field test results together with their statistical analysis and presents a method of estimating the pile-bearing capacity based on correlation results. A calculation example is also provided. The conclusion looks at the useful practical applications that could be found for the proposed method. [ABSTRACT FROM AUTHOR]

Monochromatic Cr Kα radiation (5414.8 eV) has been used to acquire XPS and Auger data on sputtered Ta and Ta2O5 samples. Survey data, high-resolution scans of all observed photoelectron peaks, and high-resolution scans of Auger lines are presented herein. [ABSTRACT FROM AUTHOR]

Prostate-specific membrane antigen (PSMA), highly expressed in prostate cancer, is a promising target for radionuclide therapy. Auger electron-emitting radionuclides are well suited for targeted radionuclide therapy if they can be delivered close to the DNA of the targeted cells. This preclinical study evaluated the theranostic pair [55/58mCo]Co-DOTA-PSMA-617 for PET imaging and Auger electron therapy of prostate cancer. [58mCo]Co-DOTA-PSMA-617 was successfully prepared with > 99% radiochemical yield and purity. In vitro, uptake and subcellular distribution assays in PSMA-positive prostate cancer cells showed PSMA-specific uptake with high cell-associated activity in the nucleus. Incubation with [58mCo]Co-DOTA-PSMA-617 reduced cell viability and clonogenic survival in a significant dose-dependent manner (p < 0.05). Biodistribution of xenografted mice showed high specific tumor uptake of the cobalt-labeled PSMA ligand for all time points with rapid clearance from normal tissues, which PET imaging confirmed. In vivo, therapy with [58mCo]Co-DOTA-PSMA-617 in tumor-bearing mice demonstrated significantly increased median survival for treated mice compared to control animals (p = 0.0014). In conclusion, [55/58mCo]Co-DOTA-PSMA-617 displayed excellent in vitro and in vivo properties, offering significant survival benefits in mice with no observed toxicities. [ABSTRACT FROM AUTHOR]

Nucleophilic copper‐mediated radioiodination (CMRI) of organoboronic precursors with radioiodides is a promising method of radioiodination. The previously reported CMRI has demonstrated its great potential and scope of labeling for the radiosynthesis of radioiodine‐labeled compounds. However, the reported protocols (using a small amount/volume of radioactivity) are practically not reproducible in large‐scale CMRI, in which the radioactivity was usually provided in a bulk alkaline solution. A large amount of water and a strong base are incompatible with CMRI. To overcome these issues in large‐scale CMRI, we have developed a simple protocol for large‐scale CMRI. The bulk water was removed under a flow of inert gas at 110°C, and the strong base (i.e., NaOH) was neutralized with an acid, pyridinium p‐toluenesulfonate or p‐toluenesulfonic acid. In the model reactions of [123I]KX‐1, a PARP‐1 radioligand for Auger radiotherapy, radiochemical conversions were significantly improved after neutralization of the base, and the addition of additional acids was tolerated and favorable for the reactions. Using this protocol, [123I]KX‐1 was radiosynthesized from 20 mCi (0.74 GBq) of [123I]iodide in high radiochemical yields, high radiochemical purity, and high molar activity. This protocol should be applicable to the radiosynthesis of other compounds with radioiodine via CMRI. [ABSTRACT FROM AUTHOR]

Axial bearing performance and mechanism of continuous flight auger (CFA) pile in weathered granitic soils, i.e., a widespread special soil in South China, were investigated by field test in this study. Load–settlement responses of four CFA piles were examined, and evolutions of shaft/base resistances were captured by ultra-weak fiber Bragg gratings (UWFBG) with a reflectivity ≤−40 dB. Performances of CFA piles were compared with those of a slurry displacement (SD) pile at the same site, thirteen pretensioned spun high-strength concrete (PHC) piles in the literature and empirical data in design code. Test results show that the ultimate bearing capacity of the CFA pile is highest among different pile types, and typically is twice that of the SD pile. Again, CFA pile produces the highest shaft resistances at 140 kPa and 153 kPa in two weathered granitic soils, while the base resistance of 3080 kPa is between those of the SD pile and the PHC pile. By field excavation, the superior mechanism of the CFA pile is suggested to avoid the formation of in-between bentonite layers and prevent preferential baseflow along fissures, both of which can weaken the soil–pile interface. Overall, this study provides fundamental data through UWFBG and explanations based on field observations which underpin the need for developing a design code specified for CFA piles in South China. [ABSTRACT FROM AUTHOR]

The evolution of the luminescence blinking of single CsPbBr3 perovskite nanocrystals with a characteristic size of ~25 nm during photodegradation has been experimentally investigated. It has been demonstrated that the blue shift of the luminescence peak and a decrease in the average luminescence intensity are accompanied by the increasing role of nonradiative Auger processes underlying the charging mechanism of blinking. A method based on the analysis of photon antibunching g2(0) and exciton and biexciton recombination rates is used to determine the blinking mechanism. The data obtained have made it possible to reveal a transition from the trapping to charging blinking mechanism with a change in the sizes of a CsPbBr3 single nanocrystal. [ABSTRACT FROM AUTHOR]

In this contribution, we present the latest updates on the energy spectrum characterization obtained with data from the Pierre Auger Observatory. We present the measurement of the spectrum from 6 × 10 15 eV up to above 10 20 eV, obtained by combining five different methods. The exposure of over 80,000 km2 sr yr has been accumulated above the ankle region, making this the best estimate of the spectrum ever achieved in this energy range. The wide zenith angle range covered by the Pierre Auger Observatory and the enormous exposure also allow us to measure the spectrum in different regions of the sky. After a description of the techniques used to reconstruct the spectrum, the spectral features will be presented, and the astrophysical implications of the spectral shape will be briefly discussed. [ABSTRACT FROM AUTHOR]

• An approach using deep fluted auger to sample lunar regolith is introduced and analyzed. • Experiments are designed and conducted to study the influencing factors on sampling performance. • The influence of drilling operation parameters and drill tool structure on sampling performance is revealed. Currently, sampling and water detection of lunar regolith in the permanently shadowed regions (PSRs) of lunar polar regions is a hotspot in lunar exploration. Using deep fluted augers (DFAs) for lunar regolith sampling was proposed long ago. However, a comprehensive study on how to effectively capture regolith using a DFA has not been reported so far. In this study, based on the principles of regolith capturing with a DFA (RCDFA), we analyzed the factors possibly affecting the mass of the captured sample in terms of lunar soil conditions, drilling operating parameters, and structural design. Using the CUG-1A lunar regolith simulant (LRS), an experimental study was conducted on the influence of drilling operating parameters and the structure of the auger flutes on the mass of the captured sample during sampling operation. The experimental results revealed that the regolith sample might not be captured at all with unreasonable operating parameters; however, when using operating parameters within the feasible range, the mass of the captured sample was positively correlated with the cut per revolution (CPR) at the sampling and retracting stages and with the length and depth at the sampling stage. Among all factors, the CPR at the sampling stage had the most significant impact on the mass of the captured sample. Moreover, the width-to-depth ratio (WDR) of the auger flutes should be neither too small nor too large to obtain a good trade-off between the mass of the captured sample and the stability of the brushing efficiency. This study lays the foundation for further research on the mechanism of how DFAs capture lunar regolith and the optimal design of drilling tools. [ABSTRACT FROM AUTHOR]

X-ray photon absorption leads to the creation of highly excited species, which often decay through the Auger process. The theoretical treatment of Auger decay is challenging because of the resonance nature of the initial core-excited or core-ionized states and the continuous nature of the ejected electron. In Paper I [W. Skomorowski and A. I. Krylov, J. Chem. Phys. 154, 084124 (2021)], we have introduced a theoretical framework for computing Auger rates based on the Feshbach–Fano approach and the equation-of-motion coupled-cluster ansätze augmented with core–valence separation. The outgoing Auger electron is described with a continuum orbital. We considered two approximate descriptions—a plane wave and a Coulomb wave with an effective charge. Here, we use the developed methodology to calculate Auger transition rates in core-ionized and core-excited benchmark systems (Ne, H2O, CH4, and CO2). Comparison with the available experimental spectra shows that the proposed computational scheme provides reliable ab initio predictions of the Auger spectra. The reliability, cost efficiency, and robust computational setup of this methodology offer advantages in applications to a large variety of systems. [ABSTRACT FROM AUTHOR]

X-ray absorption creates electron vacancies in the core shell. These highly excited states often relax by Auger decay—an autoionization process in which one valence electron fills the core hole and another valence electron is ejected into the ionization continuum. Despite the important role of Auger processes in many experimental settings, their first-principles modeling is challenging, even for small systems. The difficulty stems from the need to describe many-electron continuum (unbound) states, which cannot be tackled with standard quantum-chemistry methods. We present a novel approach to calculate Auger decay rates by combining Feshbach–Fano resonance theory with the equation-of-motion coupled-cluster single double (EOM-CCSD) framework. We use the core–valence separation scheme to define projectors into the bound (square-integrable) and unbound (continuum) subspaces of the full function space. The continuum many-body decay states are represented by products of an appropriate EOM-CCSD state and a free-electron state, described by a continuum orbital. The Auger rates are expressed in terms of reduced quantities, two-body Dyson amplitudes (objects analogous to the two-particle transition density matrix), contracted with two-electron bound-continuum integrals. Here, we consider two approximate treatments of the free electron: a plane wave and a Coulomb wave with an effective charge, which allow us to evaluate all requisite integrals analytically; however, the theory can be extended to incorporate a more sophisticated description of the continuum orbital. [ABSTRACT FROM AUTHOR]

Fano-ADC is a family of ab initio methods for the prediction of electronic decay widths in excited, singly and doubly ionized systems. It has been particularly successful in elucidating the geometry dependence of the inter-atomic decay widths in clusters and facilitated the prediction of new electronic decay phenomena. However, the available Fano-ADC schemes are limited to the second-order treatment of the initial state and the first-order treatment of the final states of the decay. This confines the applicability of the Fano-ADC approach to first-order decay processes, e.g., normal but not double Auger decay (DAD), and compromises the numerical accuracy of the schemes through the unbalanced treatment of electronic correlation. Here, we introduce the ADC(2,2) approximation for singly ionized states, which describes both initial and final states of the decay up to second order. We use the new scheme to construct the Fano-ADC(2,2) approximation for the decay widths and show that it provides superior accuracy for the decay widths of a series of processes. Moreover, the Fano-ADC(2,2) method provides access to second-order decay processes, such as DAD, which are qualitatively beyond the reach of the previously available Fano-ADC implementations. [ABSTRACT FROM AUTHOR]

Multi-electron coincidence measurements have been performed at the photon energies for the core-to-valence (1s → π*) and core-to-Rydberg (1s → 3sσ and 3pπ) resonant excitations in N2 in order to investigate the dynamics of multiple Auger-electron emissions from these core-excited states in detail. Peaks due to slow electrons from superexcited atomic fragments are observed in the decay processes by emission of two or three Auger electrons, indicating stepwise (cascade) multiple Auger decays that involve faster dissociations than electronic relaxations. Energy partitions between the emitted electrons enable us to reveal the detailed decay mechanisms for these processes. Branching ratios among the decays by emission of one, two, or three Auger electrons and those between the simultaneous (direct) and stepwise (cascade) processes have been determined for each of the core-excited states. Branching ratios of decay channels resulting in molecular or fragment ions have also been substantiated. [ABSTRACT FROM AUTHOR]

As x-ray probe pulses approach the subfemtosecond range, conventional x-ray photoelectron spectroscopy (XPS) is expected to experience a reduction in spectral resolution due to the effects of the pulse broadening. However, in the case of resonant x-ray photoemission, also known as resonant Auger scattering (RAS), the spectroscopic technique maintains spectral resolution when an x-ray pulse is precisely tuned to a core-excited state. We present theoretical simulations of XPS and RAS spectra on a showcased CO molecule using ultrashort x-ray pulses, revealing significantly enhanced resolution in the RAS spectra compared to XPS, even in the sub-femtosecond regime. These findings provide a novel perspective on potential utilization of attosecond x-ray pulses, capitalizing on the well-established advantages of detecting electron signals for tracking electronic and molecular dynamics. [ABSTRACT FROM AUTHOR]

The Pierre Auger Observatory (PAO) and Telescope Array (TA) collaborations report significant differences in the observed energy spectra of ultra-high-energy cosmic rays (UHECRs) above 30 EeV. In this work we present a joint fit of TA and PAO data using the rigidity-dependent maximum energy model, including a full marginalization over all relevant parameters. We test two possible scenarios to explain these differences. One is that they are due to complex energy-dependent experimental systematics; the other is the presence of a local astrophysical source in the Northern Hemisphere, which is only visible by the TA experiment. We show that the astrophysical and systematic scenarios improve the explanation of the data equally well, compared to the scenario where both experiments observe the same UHECR flux from a cosmological source distribution and have energy-independent systematics. We test different mass compositions emitted from the local source and conclude that the data are best described by a source lying at a distance below 26 Mpc that emits cosmic rays dominated by the silicon mass group. We also discuss possible source candidates and the possible role of the putative local UHECR source in the observed TA anisotropy and in the differences in TA spectral data from different decl. bands. [ABSTRACT FROM AUTHOR]

The main objective of the "DPDT-Auger" research project was to test the prototype DPDT auger for forming screw displacement piles in the ground (patented in Poland in 2020). An additional aim was to develop design methods and rules for the making of such piles. The augers and piles were first tested on a model scale, and then more extensively in the real scale on experimental field plots. The results found the overall functionality of the DPDT auger to be good, and in several aspects better than that of the SDP auger. The load-bearing capacities and Q-s characteristics of piles made with both augers were considered comparable. All the conducted tests and their derived dependencies together with the results of in situ subsoil tests allowed for the development of empirical calculation methods and prognostic procedures, useful for designing and producing piles with DPDT and SDP augers. FEM numerical simulation rules for the considered piles were also developed, verified and calibrated by the results of real pile tests. This article describes only the most important final results of the research project but not the detailed results of the numerous tests and analyses that were carried out. Also omitted are the results of model tests and numerical simulations, as well as the implementation and acceptance recommendations, as they have already been or will be the subject of separate publications. [ABSTRACT FROM AUTHOR]

Auger decay is a relaxation process of core-vacant states in atoms and molecules, in which one valence electron fills the core vacancy while a second one is emitted. These states pose a challenge to electronic-structure theory, because they are embedded in the ionisation continuum. Recently, we showed that molecular Auger decay can be described using complex-variable coupled-cluster (CC) methods and that partial widths and branching ratios can be computed based on a decomposition of the CC energy. Here, we introduce channel-specific core-valence projectors, dubbed Auger channel projectors, as a more general technique to evaluate partial widths from complex-variable treatments. We apply this new method to core-ionised states of neon, water, ammonia and methane using CC singles and doubles (CCSD), equation-of-motion ionisation potential CCSD and configuration interaction singles (CIS) wave functions. Even though a single CIS calculation can never describe all Auger decay channels at once, we show that a combination of CIS calculations based on different reference states is able to recover partial and total decay widths from CC calculations to an excellent degree. [ABSTRACT FROM AUTHOR]

Monochromatic Cr Kα radiation (5414.8 eV) has been used to acquire XPS and Auger data on a sputtered Pd sample. Survey data, high-resolution scans of all observed photoelectron peaks, and high-resolution scans of Auger lines are presented herein. [ABSTRACT FROM AUTHOR]

To safely and efficiently recover trapped coal under final endwalls in open cut mines, theoretical analysis and numerical calculation were used to study the stability of web pillar during auger mining. The partial ordered set (poset) evaluation model was used to develop a risk assessment methodology, and auger mining at Pingshuo Antaibao open cut coal mine was used as a field example for validation. Based on the catastrophe theory, the failure criterion of web pillar was established. From the limit equilibrium theory, the maximum allowable plastic yield zone width and minimum web pillar width were proposed under various Factor of Safety (FoS) thresholds. This in turn provides a new method for web pillar design. Based on the poset theory and combining with the risk evaluation and proposed hazard levels, input data were standardized and weighted. Subsequently, the comparison matrix, HASSE matrix and HASSE diagram were established. The study shows that: when the width of the plastic zone of web pillar exceeds 88% of the total width, web pillar may be unstable. Based on the calculation formula for the required width of web pillar, the required pillar width was 4.93 m and it was deemed as "mostly stable". This was consistent with the field condition on site. Such that this method was validated. [ABSTRACT FROM AUTHOR]

Mn4+‐doped fluorides are popular phosphors for warm‐white lighting, converting blue light from light‐emitting diodes (LEDs) into red light. However, they suffer from droop, that is, decreasing performance at increasing power, limiting their applicability for high‐power applications. Previous studies highlight different causes of droop. Here, a unified picture of droop of Mn4+‐doped K2TiF6, accounting for all previously proposed mechanisms, is provided. Combining continuous‐wave and pulsed experiments on samples of different Mn4+ content with kinetic Monte Carlo modeling, the contributions of absorption bleach, thermal quenching, and Auger quenching at different excitation densities, are quantified. This work contributes to understanding the fundamental limitations of these materials and may inspire strategies to make Mn4+‐doped fluorides more efficient in high‐power applications. [ABSTRACT FROM AUTHOR]