267649 research outputs found
Sort by
Optical Determination of Hydrofluoric Acid Content in Lithium-Based Electrolytes
No full textLithium-ion batteries powering electric vehicles can contain up to ∼100 liters of electrolyte solution. This solution typically consists of LiPF6 salt dissolved in a mixture of organic carbonates such as ethylene carbonate and diethyl carbonate. LiPF6 decomposes upon exposure to water vapor or other protic impurities, leading to the formation of up to 3 equivalents of hydrofluoric acid (HF) per molecule of decomposed salt. HF is a deadly and volatile substance that is corrosive to cell and battery components. Here, we describe an all-optical method that can report on the concentration of HF in LiPF6-based electrolytes. The method is based on a specially designed fluorescent dye incorporated in the working electrolyte. The dye response to HF is quantified so that photographic imaging or even visual inspection can be used to indicate the HF concentration in the electrolyte. The method is, moreover, compatible, in principle, with in situ reporting of HF levels during cell assembly and operation
The AEgIS Experiment: Progress and Future Outlook
No full textThe AEgIS experiment at CERN is pioneering measurements of gravity, spectroscopy, and interferometry using pulsed antimatter atomic sources. This work provides an overview of the AEgIS experimental setup and highlights recent advancements in antihydrogen production, positronium laser cooling, and the creation of antiprotonic atoms. Key technological developments, including the overhaul of the control system and its impact on precision experiments, are reviewed. Future perspectives for AEgIS before CERN Long Shutdown 3 and beyond are summarized
Dual-Modality Neutron and X-ray Imaging at FRM II ANTARES
No full textAn X-ray subsystem was integrated into the ANTARES neutron imaging instrument (FRM II/MLZ)to enable dual-modality radiography and computed tomography without relocating the specimen.The upgrade comprises a compact source–detector assembly within the instrument envelope, integrationwith the existing interlock/safety architecture, and networked control used during commissioningto coordinate motion and acquisition. A pre-commissioning calibration workflow producesdetector products (dark/flat maps for DSNU/PRNU, a defect mask, and a stabilizer), performs geometriccalibration/rectification, and determines cone-beam parameters for the X-ray arm. A reproduciblepipeline was formalized: modality-aware preprocessing (normalization, masking, geometricharmonization) → per-modality reconstruction → rigid (affine-optional) multi-resolution coregistration→ intensity-space fusion for complementary contrast. Validation with resolution targetsand simple phantoms confirmed geometric consistency and stable magnification across scans; endto-end tests showed that per-dataset centre-of-rotation refinements remove residual mechanicaloffsets without altering commissioning parameters. The workflow reduces setup time via rapid X-rayradiographic checks, supports independent or dual-modality CT, and provides a standards-orientedpackaging of geometry and provenance for reconstruction. The system establishes a practical foundationfor quantitative dual-modality studies at ANTARES and outlines paths for improving calibrationmetrics, synchronization, and application-specific fusion
Light output and neutron detection efficiency of boron-based neutron scintillator screens for neutron imaging
No full textRecent research has explored the development of boron-based neutron scintillator screens, which potentially offer improved spatial resolution and neutron capture efficiency compared to traditional lithium-based screens. This work builds upon previous efforts to improve boron-based neutron scintillators by assessing a newer generation of boron-based scintillator screens fabricated using different compositions and fabrication approaches compared to previous generations of screens. Some of the test screens exhibit higher light output than previous efforts and higher neutron capture efficiency than lithium-based screens. This paper describes the current state of screen development, measurement results for the most recent generation of screens, and future activities
Feasibility of a ’Brightness Booster’ for the Intense Slow Positron Source NEPOMUC
No full textBrightness enhancement by re-moderation of highly intense slow positron sources at nuclear reactors or large electron accelerators is an inevitable requirement for most positron experiments. We demonstrate the feasibility of a new layout for re-moderation combining for the first time the high reliability of magnetic beam guiding, the high efficiency of reflection re-moderation, correction of spherical aberrations in the primary focussing lens and loss-free extraction of the re-moderated beam by an E x B-filter. In the case of the intense positron source NEPOMUC at the research reactor FRM II in Munich, up to 10-fold intensity and 100-fold brightness are predicted for the re-moderated positron beam, compared to the current situation
