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Simulation of CMOS strip sensors
No full textIn high-energy physics, there is a need to investigate silicon sensor concepts that offer large-area coverage and cost-efficiency for particle tracking detectors. Sensors based on CMOS imaging technology present a promising alternative silicon sensor concept. As this technology follows an industry process, it can lower sensor production costs and enable fast and large-scale production from various vendors. The CMOS strips project investigates passive CMOS strip sensors fabricated by LFoundry in a 150nm technology. The stitching technique was employed to develop two different strip sensor formats. The strip implant layout varies in doping concentration and width, allowing the study of various depletion concepts and electric field configurations. The performance of the first CMOS strip sensor prototype was evaluated based on several test beam campaigns conducted at the DESY II Test Beam Facility. In order to understand and validate the test beam data results, the detector response was simulated. This study shows how performance differences of the various strip sensor layouts can be investigated using Monte Carlo methods combined with TCAD Device simulations. In particular, the detector response simulated with Allpix2 is presented and compared to test beam data
Energy Time Ptychography for one-dimensional Phase Retrieval
No full textPhase retrieval is at the heart of adaptive optics and modern high-resolution imaging. Without phase information, optical systems are limited to intensity-only measurements, hindering full reconstruction of object structures and wavefront dynamics essential for advanced applications. Here, we address a one-dimensional phase problem linking energy and time, which arises in X-ray scattering from ultrasharp nuclear resonances of . Leveraging the Mössbauer effect, where nuclei absorb or emit radiation without energy loss to the lattice, sensitivity to their magneto-chemical environments is achieved. Rather than using traditional spectroscopy with radioactive gamma-ray sources, we measure nuclear forward scattering of synchrotron X-ray pulses in the time domain, providing superior sensitivity and faster data acquisition. Extracting spectral information from a single measurement is challenging due to the missing phase information, typically requiring extensive modeling. Instead, we use multiple overlapping measurements to retrieve both the transmission spectrum and phase of the nuclei, similar to ptychographic phase retrieval in imaging. Our robust approach can overcome bandwidth limitations of gamma-ray sources, opening new research directions with modern X-ray sources and Mössbauer isotopes other than
Consolidation of Services in the Photon and Neutron Open Science Cluster
No full textThe EU project OSCARS (Open Science Clusters’ Action for Research and Society) brings your research data to new audiences and targets new use-cases in a broad range of scientific clusters including Photon and Neutron Sciences (PaN). As recommended by a new White Paper (submitted to IUCrJ) from the user organisations, ESUO and ENSA, adherence to the FAIR principles (Findable, Accessible, Interoperable, Reusable) facilitates the use of research data in novel ways, with increased citations acknowledging original researchers and facilities that provided that data. Further, increased (meta)data and software findability and accessibility promotes a better use of resources by reducing the duplication of experiments.We are currently engaged in the Consolidation task by cataloguing existing services and data sources, aiming to highlight common approaches between the clusters and to identify “composable” services. For the PaN Open Science Cluster (PaNOSC) this will create such a portfolio from scratch starting with link collections from the most relevant Research Infrastructures (RIs) of PaNOSC, e.g. LEAPS, LENS, and European Research Infrastructure Consortia (ERICs). The representatives of the different RIs within the PaNOSC Competence Center (also established within OSCARS) contributed significantly by adding new resources and also by completing information on already listed resources (e.g. TRL, licences). Currently, the portfolio contains more than 500 resources.The portfolio provides the basis to identify services required for a specific task within a specific research scenario. We are currently collecting PaNOSC-typical scenarios that can be simplified by composing and slightly adapting the involved services. One or two scenarios will be realised as demonstrators within the project. The services and data sources could be onboarded to the thematic PaN EOSC node, which is being proposed as candidate node of the EOSC Federation
TelePix2: Full scale fast region of interest trigger and timing for the EUDET-style telescopes at the DESY II Test Beam Facility
No full textWith increasing demands by future and current upgrades of particle physics experiments on rate capabilities and time resolution, the requirements on test beams are also increasing. The current infrastructure at the DESY II test beam facility includes particle tracking telescopes with long integration times, no additional timing but excellent spatial resolution. This results in readouts with multiple particles per trigger, causing ambiguities in tracking and assigning particles to triggers. Also, it is likely not to trigger on particles that pass through a small device under test, leading to inefficient data taking. These issues can be solved by adding TelePix2 as a timing and flexible region of interest trigger layer. TelePix2 is a full scale HV-CMOS chip based on the successful small scale prototype TelePix. The DAQ system and the sensors performance featuring efficiencies above 99 % and a time resolution of 3.844(2) ns are presented. The integration into EUDAQ2 and the AIDA-TLU to seamlessly work in the test beam environment as well as into the analysis chain is described. First successful use cases are highlighted to conclude that TelePix2 is a well-suited timing and trigger layer for test beams
Structural changes in amorphous CoFeB thin film interfaced with tungsten upon thermal annealing: A depth resolved XRD and XAS study
No full textHeavy metal/ferromagnet interfaces are important in the context of several phenomena like, perpendicular magnetic anisotropy, spin-orbit torque, interfacial Dzyaloshinskii-Moriya interaction, which form the basis for several spintronic devices. In the present work, an amorphous CoFeB layer interfaced on both sides with tungsten has been studied using complementary techniques of XRD and XAS, and the structural changes occurring upon thermal annealing have been elucidated. X-ray standing wave excitation has been used to get selective information about the interfaces or the bulk of the CoFeB layer. We found that the proximity with W layers significantly alters the structure of the interfacial regions. Differences in the local structure around Fe and Co atoms were revealed by XAS data. Upon thermal annealing at 350 °C for 1 h, the CoFeB layer transforms into a bcc CoFe granular phase characterized by a large fraction of disordered grain boundaries. Most of the boron atoms migrate into the adjacent W layers, while some B is retained in the bcc phase, likely at the interstitial positions, or amorphous grain boundaries, as evidenced by XAS measurements. As a result, no boride phase is formed. In both the amorphous and crystalline phases, the average interatomic distances in the interfacial region are higher than that in the bulk of the magnetic layer. This may be attributed to a possible alloying with W and a higher concentration of B in the interfacial region
In Situ Monitoring of Retained Austenite Decomposition During Tempering of High-Strength Tool Steels
No full textThis study investigates the decomposition of retained austenite (RA) in tool steels for plasticmolding in correlation with the alloy chemical composition and the tempering parameters. Twogrades differing in their silicon content with initial mixed bainitic/martensitic microstructureswere investigated using in situ synchrotron high-energy X-ray diffraction (HEXRD) duringtempering in the 550 C to 600 C temperature range for one-hour holding time. Resultsindicated carbide formation during heating or isothermal holding; however, retained austeniteremained untransformed up to the end of the tempering holding time in all investigatedconditions for both grades. In situ HEXRD provides direct evidence of the transformation ofretained austenite into fresh martensite on cooling from the tempering stage. This behavior iscorrelated to the evolution of carbon enrichment of retained austenite and the effect of silicon isdiscussed
Membrantransport von Thiamin im menschlichen Körper
No full textThiamine (vitamin B) is an essential coenzyme for central metabolic pathways. Metazoans, including humans, have to take up thiamine via the solute carriers SLC19A2 and SLC19A3, because they lost the ability to synthesize thiamine de novo. Perturbation of these transport systems has severe effects on human health. Here we discuss the molecular mechanisms of thiamine recognition, transport and inhibition based on recently available cryo-Electron Microscopy structures of SLC19A3
Orthogonality of Q-Functions up to Wrapping in Planar = 4 Super Yang-Mills Theory
No full textWe construct orthogonality relations in the Separation of Variables framework for the (2) sector of planar = 4 supersymmetric Yang-Mills theory. Specifically, we find simple universal measures that make Q-functions of operators with different spins vanish at all orders in perturbation theory, prior to wrapping corrections. To analyze this rank-one sector, we relax some of the assumptions thus far considered in the Separation of Variables framework. Our findings may serve as guidelines for extending this formalism to other sectors of the theory as well as other integrable model
Temperature-Resolved Crystal Structure of Ethylene Carbonate
No full textEthylene carbonate (EC) is an organic solvent of the class of carbonate esters, which is used in state-of-the-art Li-ion batteries as part of the electrolyte mixture, being primarily responsible for the formation of a solid electrolyte interface. Thermal analysis showed that the sample’s melting point is 309 K. The crystal structure of EC is investigated using powder diffraction in a temperature range from 3 K up to its melting point, using neutron- and synchrotron-based radiation. Over the whole temperature range, the sample shows single-phase behavior with the space group being C2/c (No. 15), and given the detailed temperature dependence of the structural evolution, thermodynamic and mechanical properties of solid EC are studied. The local structure in both solid and liquid states was additionally investigated by total scattering diffraction and analysis of the pair distribution function. The results obtained are discussed in line with those of molecular dynamics simulations
Impact of Microstructural Variations on Hydrogen Permeation into Duplex Steel
No full textHydrogen embrittlement remains a significant challenge in steel applications with itsunderlying mechanisms still not fully understood. This study examines the influence ofmicrostructural variations in duplex steel on hydrogen uptake during electrolytic chargingover a duration of four hours. To address this, three distinct microstructural states areanalyzed: initial (coarse-grained), high-pressure torsion (HPT) as-processed, and heattreatedHPT states, with hydrogen penetration affecting depths of approximately 100 μm.In-situ synchrotron cross-sectional X-ray micro-diffraction reveals that, in thenanocrystalline HPT as-processed sample, austenite and ferrite exhibit lattice parameterexpansions of 0.015 and 0.003 Å, respectively. In contrast, the initial (coarse-grained) sampleshows a 0.005 Å increase in austenite, while no detectable change is observed in ferrite. Thepronounced lattice swelling in both phases of the nanocrystalline microstructure isaccompanied by an increase in compressive in-plane stresses of 200 MPa in austenite and850 MPa in ferrite. Furthermore, thermal desorption spectroscopy indicates a hydrogenuptake of 16 ppm in the HPT as-processed state, exceeding the coarse-grained condition by4 ppm. Subsequent heat treatment reduces hydrogen uptake to 4 ppm, yielding a fivefolddecrease in the variation of the austenite lattice parameter while preserving the ferrite response observed in the as-processed HPT sample. The distinct responses of austenite andferrite to hydrogen charging are attributed to their respective microstructural characteristics,as revealed by electron microscopy analyses. These findings provide new insights into themicrostructural control of hydrogen transport in duplex steels, with important implicationsfor the design and development of hydrogen-resistant materials