The depth of field (DoF) is an important parameter in transmission electron microscopy (TEM) when considering inhomogeneous samples, tomographic schemes, or in-situ experiments. A large DoF enhances the robustness of the experiment against tight alignment demands and drift issues. The phase-contrast transfer in TEM is reviewed and updated with special regard to the correct derivation and quantification of the DoF for relevant single-transfer-band imaging like with Scherzer or Lentzen conditions. Consequences towards the optimisation of the imaging conditions are discussed. Additionally, the defocus-dependent information limit is treated as a different type of DoF. One result of this work is to prefer the original Scherzer defocus over the Scherzer defocus taught today if a large DoF matters in non-aberration-corrected instruments. In aberration-corrected instruments, the Lentzen conditions are well suited for a maximum DoF if one adapts the desired maximum spatial frequency accordingly, and higher-order spherical-aberration correction might help at lower electron acceleration voltages.

A systematic SEM imaging of partially covered CVD-grown monolayer MoS2 on SiO2/Si substrates and the exfoliated MoS2 on Si substrates by both the in-lens detector and the Everhart-Thornley detector under varying acceleration voltage and working distance has been demonstrated. Superior contrast of MoS2 layers can be feasibly realized with the in-lens detector even at high acceleration voltage of 10 kV and large working distance of 20 mm. In the in-lens images, MoS2 layers appear consistently darker than the bare SiO2/Si substrate, which is a nice example of mass-thickness contrast. For Everhart-Thornley images, a contrast reversal of MoS2 layers was observed. Specifically, at working distance≤10 mm, MoS2 layers are brighter than the bare SiO2/Si substrates, which belong to atomic number contrast; at working distance≥15 mm, MoS2 layers appear darker than the bare SiO2/Si substrates. The underlying mechanism of contrast reversal was revealed. The dependence of MoS2 contrast in in-lens images and Everhart-Thornley images on acceleration voltage and working distance have been discussed by analyzing different responses of three types SE. The findings reported here will have important implications for effective SEM characterizations of MoS2, and other transition metal dichalcogenides.

Abstract We investigated the effects of a magnetic field on electron beam energy, beam flux, electron density ( n ), electron temperature ( T ), and photoresist (PR) etching in an inductively coupled plasma (ICP) system with a grid system. The acceleration voltage ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mrow> <mml:mrow> <mml:mtext>acc</mml:mtext> </mml:mrow> </mml:mrow> </mml:msub> </mml:mrow> </mml:mrow> </mml:math> ) was applied to the grid system to extract a low-energy electron beam. Cylindrical and planar Langmuir probes were employed to measure these parameters. Optical emission spectroscopy was used to monitor the O radical density. PR etching experiments were performed in O 2 at 0.67 Pa and an ICP power of 300 W was used to evaluate the etching characteristics. When <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mrow> <mml:mrow> <mml:mtext>acc</mml:mtext> </mml:mrow> </mml:mrow> </mml:msub> </mml:mrow> </mml:mrow> </mml:math> increased from 10 V to 50 V, the electron beam energy gradually increased. However, a different trend was observed when a magnetic field was present. When <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mrow> <mml:mrow> <mml:mtext>acc</mml:mtext> </mml:mrow> </mml:mrow> </mml:msub> </mml:mrow> </mml:mrow> </mml:math> ⩽ 20 V, the beam energy decreased with increasing magnetic field strength, whereas at higher <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mrow> <mml:mrow> <mml:mtext>acc</mml:mtext> </mml:mrow> </mml:mrow> </mml:msub> </mml:mrow> </mml:mrow> </mml:math> (⩾30 V), it increased. This behavior originates from the combined effects of the plasma potential difference between the source and extraction regions and magnetic confinement, which modify the electron transport path and energy gain mechanism. The electron beam flux also increased with magnetic field, while the electron density varied only slightly and the electron temperature remained nearly constant (∼1.2 eV). The PR etching results indicated that the magnetic field enhances the etch rate primarily through its influence on the electron beam energy and flux, rather than through changes in bulk plasma parameters.

Minibeam and microbeam radiation therapy promise improved treatment outcomes through reduced normal tissue toxicity at better tumor control rates. The lack of suitable compact radiation sources limits the clinical application of minibeams to superficial tumors and renders it impossible for microbeams. We developed and constructed the first prototype of a compact line-focus x-ray tube (LFXT) with technology potentially suitable for clinical translation of minibeams and microbeams. We give an overview of the commissioning process preceding the first operation, present optical and radiological focal spot characterization methods, and dosimetric measurements. Additionally, we report on first preclinical in vitro cell and in vivo mouse brain irradiations conducted with the LFXT prototype. The LFXT was high-voltage conditioned ≤300 kV. The focal spot characterization resulted in a strongly eccentric electron distribution with a width of 72.3 μm. Dosimetry showed sharp microbeam dose profiles with steep lateral penumbras and a peak-to-valley dose ratio above 10 throughout a 70-mm-thick polymethylmethacrylate (PMMA) phantom. An open-field dose rate of 4.3 Gy/s was measured at an acceleration voltage of 150 kV and a beam current of 17.4 mA at 150-mm distance from the focal spot. In vitro and in vivo experiments demonstrated the feasibility of the LFXT for minibeam and microbeam applications with field sizes of 1.5 to 2 cm. The mice displayed no observable side effects throughout the follow-up period after whole-brain 260-μm-minibeam irradiation. We successfully constructed and commissioned the first proof-of-concept LFXT prototype. Dosimetric characterizations of the achieved microbeam field showed the superiority of the LFXT compared with conventional x-ray tubes in terms of beam quality. In future developments, the remaining limitations of the prototype will be addressed, paving the way for improved minibeam and first ever microbeam radiation therapy in a clinical setting.

High-Resolution single particle analysis using a scintillator camera XF416 on CRYOARM300II at 300kV.

A study of in-the-column detector micrograph contrast in low-voltage scanning electron microscopy.

Sickle cell disease (SCD) is a hereditary haematological disorder characterised by the synthesis of an abnormal form of haemoglobin, haemoglobin S (HbS). This study derives and analyzes a mathematical modeling of voltage generation, cell displacement, and acceleration using the piezoelectric properties of sickle cells. Blood is an electrically active biological fluid whose mechanical and electrical properties depend strongly on the behavior of its cellular components. In sickle cell disease (SCD), red blood cells undergo structural deformation and reduced deformability, which significantly alter blood flow dynamics, ion transport, and electrical characteristics. Understanding these effects is essential for the development of low-cost and non-invasive diagnostic approaches, especially in regions with limited access to advanced medical facilities. The main objective of this study is to formulate and examine a mathematical model describing the coupled mechanical and electrical responses of packed sickle red blood cells under physiological flow conditions. The model incorporates piezoelectric constitutive relations, mechanical stress, and electrical charge generation arising from cell motion and deformation. The governing equations were derived using Newton’s laws of motion and Kirchhoff’s voltage law, transformed into a state-space form, and solved analytically. Numerical simulations were performed using Wolfram Mathematica version 12 to evaluate the effects of stiffness, noninvasive constant, applied force, and number of sensors. The results showed that cell displacement and acceleration increase with Reynolds number and applied force but decrease with increasing stiffness. Voltage generation rises with increasing turbulence, stiffness, and external force, confirming strong electromechanical coupling. These findings highlight the potential of voltage-based bioelectrical techniques for noninvasive diagnosis and monitoring of sickle cell disease.

3D electron diffraction (3D ED) has undergone impressive development in the last decade. However, its accuracy and reproducibility have never been tested, up to now, in different laboratories on the same batch of samples. This paper reports a round robin on three test structures, two inorganic and one organic, solved and refined with 3D ED in seven different laboratories employing different transmission electron microscopes, with different acceleration voltages, different methodologies and different detectors. The results of the round robin show a remarkable accuracy of the technique that, in the case of kinematical refinement, is around 0.05 Å error on atomic positions for the inorganic samples and 0.15 Å for the beam-sensitive organic crystal. Dynamical refinement further improves the accuracy. The analysis of diverse samples and numerous data sets again confirms that dynamical refinement is a well established procedure, significantly reducing the refinement R factors, improving the accuracy of the structure models in most cases, and providing fine structural details, such as hydrogen-atom positions and the absolute structure, for both inorganic and organic samples.

Here, a compact two-electrode field-emission X-ray source employing a blade-type tungsten cathode was designed for soft X-ray spectroscopy. The device suppressed filament-derived optical and thermal background that is intrinsic to thermionic tubes, while providing stable and tunable output. The cathode-anode spacing was optimized and an optimal gap was identified at 150 µm, enabling the source to reach 400 µA at 4 kV without short circuits at <1 × 10-7 mbar. Spatial intensity mapping with targets tilted at 30°, 45° and 60° showed that smaller tilts yielded a more concentrated flux, with full width at half-maximum values of 28°, 54° and 76° at 2.5 kV, respectively, while the peak emission direction remained near 30° independent of the applied voltage andthe tilt angle. Energy-resolved measurements with a silicon drift detector showed that the high-energy cutoff of the Bremsstrahlung continuum shifted linearly with the applied acceleration voltage, and that a reproducible Cu Lα peak appeared at 927.7 eV, confirming stable and proper operation of the source. High signal-to-noise soft X-ray emission spectroscopy of Ti Lα and O Kα lines were obtained using the source integrated at the Ultrafast X-ray Spectroscopy (UXS) endstation of the Shanghai Soft X-ray Free-Electron Laser (SXFEL) facility. The blade cathode and simplified architecture improve manufacturability and cost efficiency, providing a laboratory-scale low-background source for element-specific soft X-ray spectroscopy and pre-beamline experiments.

Room-temperature focused ion beam preparation of sensitive organic-inorganic hybrid perovskites.

Raman spectroscopy imaging and microstructure characterisation of Ag+ implanted TiO2 hybrid layers

Combined effect of low energy X-ray irradiation and natural antibacterial formulation for decontamination of mother's milk.

In this article, we present a new modeling approach to analyze the effect of pulsed stress frequency on the time to breakdown of high-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K$</tex-math> </inline-formula> metal gates in CMOS transistor devices. First, we compare DC time-dependent dielectric breakdown (TDDB) and AC TDDB results obtained from samples fabricated using 28 nm FDSOI technology from STMicroelectronics. Then, we review the possible hypotheses that could explain the improvement in gate dielectric time to breakdown under pulsed stress. We provide details of a trapping-based TDDB model and compare the modeled effects of stress frequency on key TDDB parameters, such as median time to breakdown and voltage acceleration exponent, with experimental results. Finally, we apply the model findings to digital and RF circuit test cases to investigate the impact of frequency effects on product reliability margins.

Abstract A promising negative-ion-based neutral beam injection (NNBI) system should achieve high energy, high power and long pulse simultaneously for the plasma heating and current drive in the large-scale fusion devices. A NNBI test facility has been constructed in the Comprehensive Research Facility for Fusion Technology (CRAFT) in China. The installed capability of the whole CRAFT NNBI test facility is the beam energy of 400 keV, the ion beam current of 28 A, and the continuous beam pulse of 1 h. A dual-driver RF negative ion source (beam size: 0.75 × 0.3 m 2 , design acceleration voltage: 200 kV) has been developed and tested for the first operation of the test facility. Several significant improvements were applied to the test facility or the negative ion source during the system maintenance. In the second experimental campaign of CRAFT NNBI test facility, beam extraction and acceleration have reached 100 s duration and megawatt power levels. The typical values were 135 keV, 10.6 A (≈180 A m −2 ) and 110 s at the filling pressure of 0.4 Pa. For ten second beam pulses higher energy and current levels were established (173 keV and 12 A). The results demonstrated the negative ion source can reliably operate for long pulse. Some problems about the high-voltage holding, particle and heat flux were revealed in the high-power and long-pulse beam acceleration.

This study demonstrates the feasibility of using smaller capillary emitters to achieve higher specific impulse (Isp) in electrospray propulsion. Four ionic liquids were characterized using capillary emitters with tip diameters from 15 to 50 μm. Smaller-diameter capillaries produced smaller and more stable Taylor cones. This stabilization enabled steady cone-jet operation at significantly lower flow rates compared to larger emitters. This was unexpected because when the jet diameter is much smaller than far-field geometric features, the minimum flow rate is thought to be solely determined by the physical properties of the propellant. Using the smaller emitters and acceleration voltages of 1.5 kV, specific impulses up to 1100 s can be achieved with efficiencies above 50%, approximately doubling the Isp observed with larger emitters. For one of the liquids and the smallest emitters, the beam consisted solely of ions at the lowest flow rates, similarly to studies using externally wetted and porous emitters. Another important finding was that at sufficiently low flow rates, a significant fraction of the propellant fed to the emitter is not accelerated by the electrostatic field. These propellant losses make the time-of-flight technique unreliable for determining the Isp.

This paper proposes an approach to automotive starter diagnostics based on comparing the results of mathematical modelling with experimental data obtained on the ASG-019 diagnostic test bench. A simplifi ed mathematical model of the starting mode is developed, describing the time dependences of the supply voltage, armature current, electromagnetic torque, and shaft angular acceleration. The model is implemented as a software tool with a graphical interface for visualising transient processes. The purpose of the study is to develop an informative mathematical model of the starter starting mode and to analyse electromechanical processes under transient conditions with the possibility of comparing theoretical and experimental characteristics. Methods of mathematical and computer modelling using numerical signal processing are applied. The implementation is carried out in Python using the NumPy and Matplotlib libraries and the Tkinter interface. The model adequacy is evaluated by qualitative comparison with experimental data obtained on the ASG-019 test bench. Results. Time dependences of the supply voltage, armature current, electromagnetic torque, and shaft angular acceleration are obtained, refl ecting the main stages of the starting process, including the initial current peak, transient voltage drop, and subsequent dynamic acceleration of the electric motor. The theoretical characteristics enable assessment of the infl uence of electrical circuit parameters and mechanical load on the shape of the starting curves. Comparative analysis with experimental data from the ASG-019 bench demonstrates qualitative agreement in the shape and time structure of the signals, as well as reproduction of the main trends of current and voltage variation under transient conditions. Conclusions. The proposed mathematical and computer model adequately represents the general nature of the electromechanical processes during automotive starter starting. The observed quantitative discrepancies between theoretical and experimental characteristics are explained by the adopted simplifi cations, in particular neglecting inductive parameters, mechanical losses, the effect of the solenoid relay, and the actual characteristics of the battery. The results confi rm the feasibility of the proposed approach for diagnosing the technical condition of the starter and provide a basis for further refi nement of the model to improve the accuracy of starting characteristic evaluation.

• Standard quality indicators fail to optimize XCT dimensional measurements. • XCT accuracy improves when X-ray tube voltage is based on attenuation characteristics. • A novel voltage selection approach minimizes XCT measurement deviations. • Experimental and simulation validation confirm improved XCT accuracy. X-ray computed tomography (XCT) is a nondestructive technique that enables the reconstruction of the external and internal geometries of objects, facilitating the creation of virtual three-dimensional models. Its ability to precisely measure geometric features makes XCT highly attractive for industrial metrology. However, despite its widespread use across various industries and scientific fields, the lack of standardized of XCT procedures and norms limits the reliability and comparability results. The selection of optimal measurement parameters in XCT to minimize measurement deviations remains particularly challenging, as such parameters depend on the examined object, with the appropriate X-ray tube acceleration voltage playing a crucial role. This study highlights that while practical XCT parameter selection often considers aspects like image quality and qualitative transmission checks, a more systematic approach based on the physical principles of radiation-matter interaction − such as aligning the effective X-ray spectrum with the attenuation characteristics of the object − can lead to more consistent and optimized results. This conclusion is supported by the observation that the recorded edge increasingly shifts toward the surrounding background as radiation absorption begins to dominate over scattering during the attenuation process. Based on this observation, a new approach for selecting the acceleration voltage in XCT was validated experimentally and via numerical simulations. This approach can effectively minimize deviations recorded during the measurement of the external features of objects comprising various materials and can serve as a foundation for the development of XCT measurement procedures encompassing both external and internal geometries.

As the most-effective power-generation device, solid oxide fuel cells (SOFCs) are the key to realizing a low-carbon society. One issue concerning SOFCs is their high operation temperature, so they require long start up/shut down time and heat-resistant parts. To lower the operation temperature, we have been developing thin-film SOFCs composed of thin-film solid-electrolyte layers with thicknesses of less than 500 nm [1]. However, as the electrolyte layers become thinner, the electron/hole leakage current increases. In case large roughness (in which the electrolyte layer is locally thin than designed value) exists, the electron/hole leakage current is significantly large and that causes non-negligible power loss and failure. So, we worked on suppression of the electron/hole leakage current by planarizing roughness.Thin-film porous electrodes and thin-film dense electrolyte layers can be formed by sputtering [2, 3]. A cross-sectional view of the extremely thin-film SOFC is shown in Figure 1. Since thin-film layers are not suitable for the support layer, a 100-µm-thick anodic-aluminum-oxide (AAO) wafer (with many 120-nm-diameter through-pores) was used as the support substrate [4-7]. On the AAO substrate, a stack of 100-nm-thick dense and 200-nm-thick porous gadolinia-doped-ceria (GDC)-platinum (Pt) composite layers were deposited for the anode. Through-pores were formed in the composite anode layer due to the pores on the surface of the underlying AAO support substrate. At composition ratio of GDC-Pt of 16:84 volume %, the GDC and platinum layers were sputtered using a (Gd2O3)0.9(CeO2)0.1 target and a platinum target, respectively, under argon atmosphere. The anode-side interfacial layer of the 100-nm-thick dense GDC layer was deposited on the porous anode layer by using a (Gd2O3)0.9(CeO2)0.1 target under argon atmosphere. A solid-electrolyte layer composed of 200-nm-thick dense yttria-stabilized zirconia (YSZ) was deposited on the anode-side interfacial layer by using a (ZrO2)0.92(Y2O3)0.08 target under argon atmosphere. The YSZ layer plays a key role in inhibiting both gas and electron/hole leakage between the anode and cathode electrodes. A cathode-side interfacial layer composed of 200-nm-thick dense GDC was deposited on the YSZ layer. A cathode layer composed of a 200-nm-thick GDC-Pt (16:84 volume %) composite was then deposited on the cathode-side interfacial layer.To form an extremely thin-film electrolyte layer, ion milling was used for the surface of the AAO substrate and anode layer. The untreated AAO substrate has many pores and the surface is rough. In addition, the substrate surface also has local spike-like protrusions. When the thin-film electrolyte layer is deposited on the substrate, the surface regions with roughness or protrusions have lower electrolyte-layer thickness than the design value, and that thickness irregularity causes significant gas and electron/hole leakage and the associated power losses and failures. However, ion milling of the AAO substrate reduces this roughness and eliminates the spike-like protrusions. When local dents exist on the surface of the AAO substrate, it is difficult to remove them by ion milling; therefore, to prevent short circuits between the anode and cathode layers, the electrode formed on the side-wall of local dents is removed by ion milling of the anode layer. At the same time, the roughness of the porous-structure surface can be planarized by ion-milling. As the irradiated ions, Ar+ ions are used at beam angle of 15 degrees from the surface of the substrate. The ion-milling process time is 75 minutes for the AAO substrate and 3 minutes for the anode layer with acceleration voltage and current of 500 V of 250 mA (applied to a 300-mm-diameter ion source). As a result of these two ion-milling steps, the thickness of the YSZ layer becomes uniform.The I-V-P curve of the developed SOFC is shown in Figure 2. As shown in the figure, open-circuit voltage (OCV) is 1.13 V and output-power density is 1.03 W/cm2 at 519°C under the conditions that hydrogen (humidified with 1% water vapor) and dry air were supplied to the anode and cathode, respectively. The OCV is close to the theoretical value (1.18 V), and that result shows that gas and electron/hole leakage were considerably low. Furthermore, the output power was over 1 W/cm2 at 519°C. The electrolyte resistance was reduced by thinning YSZ layer and as a result, the applied voltage across the interface between the GDC layers and electrodes increased. As the applied voltage increased, the polarization resistance, particularly in low output current regions, was reduced.As for future work, we are working on lowering the operation temperature of the SOFC—while maintaining the output-power density—by optimizing the composition and thickness of the electrodes as well as further thinning the YSZ layer.

In this presentation, we will introduce the complete work of exploration of electrodeposition of smooth near-equiatomic CoCuFeNi multi-principal element alloy. The films with target composition (error <5 at%) were successfully achieved with an acidic glycine-citrate electrolyte using a strong surfactant of cetyltrimethylammonium bromide (CTAB). The deposit shows crystalline domain sizes at the nanometer level without any signs of superlattice peak from the intermetallic phases, which is significantly different than its equilibrium phases predicted from CALPHAD results. From XPS, the majority of CoNiFe exists in the metallic state without any signatures of CuO characteristic peaks. The key parameters for irreproducibility in this challenging ELDP system were systematically examined, attributed to the local convection strength under hydrogen evolution reaction and settings for SEM-EDS acceleration voltage for EDS analysis. Figure caption: (a) surface quality and (b) composition of the electrodeposited smooth near-equiatomic CoCuFeNi MPEA. Figure 1

Scanning electron microscopy (SEM) is the premier method for characterizing the nanoscale surface pores in ultrafiltration (UF) membranes and the support layers of reverse osmosis (RO) membranes. Based on SEM, the conventional understanding is that membranes typically have low surface porosities of <10%. We demonstrated and quantified how the high acceleration voltage during SEM imaging and the sputtered-metal coating thickness required for SEM systematically underestimate membrane surface porosity and pore size. We showed that imaging a commercial UF membrane at 1, 5, and 10 kV reduced the measured surface porosity from 10.3 ± 0.3% (1 kV) to 6.3 ± 0.4% (10 kV), while increasing the Pt coating thickness from 1.5 to 5 nm reduced the porosity by 54% for the UF membrane (12.9 ± 0.9% to 5.8 ± 0.6%) and 46% for an RO support (13.1 ± 0.6% to 7.0 ± 0.2%). To account for the coating thickness, we then developed a digital correction method that simulates pore dilation, enabling the surface pore structure to be estimated for uncoated membranes. Pore dilation yielded uncoated surface porosity values of 23% for the UF membrane and 20% for the RO support, which are approximately 3-fold greater than the directly observed values for a typical coating thickness of 4 nm. Similarly, mean pore diameters for uncoated membranes were 2-fold greater for the UF membrane and 1.5-fold greater for the RO support than directly observed. Critically, the dilation-derived pore-size distributions agreed with low-flux dextran-retention measurements fitted with the Bungay-Brenner model. Our results suggest that the surface porosities and pore sizes of nanoporous membranes are much larger than previously understood, which has major implications for structure/transport relationships. For future nanoscale pore analysis of membranes (and other nanoporous materials), we recommend low acceleration voltage (1 kV), minimal coatings (1-2 nm), and digital dilation to account for coating-induced artifacts.