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High-power Few-cycle MID-IR Pulse Generation for Vibrational Spectroscopy
No full textHigh-power, high-energy, ultrashort, mid-infrared (MID-IR) laser systems operating at high repetition rates are of significant interest for coherent vibrational spectroscopy investigations within the "fingerprint region'' (6-16 um). First of all, the optical properties of Li-based nonlinear crystals (NLC) for MID-IR generation are evaluated under high power laser irradiation at 1030\,nm central wavelength using a thermal imaging method. It turns out that lithium gallium sulfide (LGS) crystal exhibits a relatively low linear absorption coefficient < 0.002 cm^{-1}, the lowest nonlinear absorption coefficient < 3.2 x 10^{-4} cm/W and a nonlinear refractive index < 6.4 x 10^{-15} cm^{2}/W, positioning it as a highly promising material candidate for MID-IR optical parametric chirped-pulse amplifier (OPCPA) applications.Based on the LGS crystal, a versatile design of a MID-IR OPCPA laser system is developed, featuring two complementary operation modes differ that in the group-delay dispersion (GDD) of the signal pulse. One scheme provides a wavelength-tunable source (from 4.2 to 11 um) at ~ 1 ps pulse width, while the other scheme generates a broadband pulse (from 7 to 11 um) centered at 9 um with 114 fs pulse duration, which corresponds to about 3 optical cycles. Both MID-IR laser operation modes exhibit high average power exceeding 200 mW and high pulse energy of 1.2 uJ operating at 200 kHz, having significant potential for vibrational spectroscopy and microscopy making use of characteristic molecular fingerprints in the MID-IR spectral range.Moreover, by utilizing the broadband ultrashort MID-IR pulse, the ultra-broadband vibrational sum-frequency generation (BB-VSFG) spectroscopy is demonstrated using glucose pellets as a proof-of-principle sample, revealing 8 characteristic vibrational modes spanning from 800 to 1400 cm^{-1}. Notably, the carbon-oxygen bond stretching mode at 1035 cm^{-1} shows high sensitivity to biologically relevant 10 mM of glucose solution in the VSFG spectra. Consequently, this methodology holds promise for blood sugar monitoring in diabetic individuals
Measurement of coherent exclusive production in ultraperipheral Pb+Pb collisions at TeV with the ATLAS detector
No full textThe ATLAS experiment has performed a measurement of coherent exclusive production in ultraperipheral Pb+Pb collisions at TeV. The data was recorded at the Large Hadron Collider (LHC) during 2023, and corresponds to an integrated luminosity of 78 b. Exclusive candidates were selected with a dedicated track-sensitive trigger based on the ATLAS transition radiation tracker. The analysis involves reconstruction of the dimuon invariant mass based on muon tracks from the inner detector, as the muon transverse momentum range of interest precludes the use of the standard muon reconstruction and identification algorithms. Differential cross sections are measured as a function of rapidity and are compared with theoretical predictions. After extrapolation to TeV, they are also compared with previous measurements performed by other experiments using data from LHC Run 2. While the results agree reasonably well with theoretical predictions, they are in tension with previous Run-2 results for the central rapidity region
Calibration and characterization of the line-VISAR diagnostic at the HED-HIBEF instrument at the European XFEL
No full textIn dynamic-compression experiments, the line-imaging Velocity Interferometer System for Any Reflector (VISAR) is a well-established diagnostic used to probe the velocity history, including wave profiles derived from dynamically compressed interfaces and wavefronts, depending on material optical properties. Knowledge of the velocity history allows for the determination of the pressure achieved during compression. Such a VISAR analysis is often based on Fourier transform techniques and assumes that the recorded interferograms are free from image distortions. In this paper, we describe the VISAR diagnostic installed at the HED-HIBEF instrument located at the European XFEL along with its calibration and characterization. It comprises a two-color (532, 1064 nm), three-arm (with three velocity sensitivities) line imaging system. We provide a procedure to correct VISAR images for geometric distortions and evaluate the performance of the system using Fourier analysis. We finally discuss the spatial and temporal calibrations of the diagnostic. As an example, we compare the pressure extracted from the VISAR analysis of shock-compressed polyimide and silicon
Search for long-lived particles using displaced vertices with low-momentum tracks in proton-proton collisions at = 13 TeV
No full textA search for long-lived particles using final states including a displaced vertex with low-momentum tracks, large missing transverse momentum, and a jet from initial-state radiation is presented. This search uses proton-proton collision data at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC in 2017 and 2018, with a total integrated luminosity of 100 fb. This analysis adopts specific supersymmetric (SUSY) coannihilation scenarios as benchmark signal models, characterized by a next-to-lightest SUSY particle (NLSP) with a mass difference of less than 25GeV relative to the lightest SUSY particle, assumed to be a bino-like neutralino. In the top squark () NLSP model, the NLSP is a long-lived , while in the bino-wino NLSP scenario, the mass-degenerate NLSPs are a wino-like long-lived neutralino and a short-lived chargino. The search excludes top squarks with masses less than 4001100 GeV and wino-like neutralinos with masses less than 220550 GeV, depending on the signal parameters, including the mass difference, mass, and lifetime of the long-lived particle. It sets the most stringent limits to date for the and bino-wino NLSP models
Thunderstorm Charge Distribution Determination Using Cosmic Rays Induced Air Showers and Lightning Imaging at LOFAR
No full textThe LOw Frequency ARray (LOFAR) radio telescope possesses the unique capability to measure ultra-high energy cosmic rays as well as image lightning discharges. This study presents a comparison between the inferred thunderstorm charge structures derived from cosmic-ray measurements and from lightning flashes. Our results show a basic triple-layered distribution: a positive upper layer, a main negative layer, and a positive lower layer. However, our cosmic-ray measurement shows a bottom-heavy structure, where the charge in the upper positively charged layer is smaller than that in the lower one. This is consistent with practically all lightning observations with LOFAR, showing well-developed negative leader structures at altitudes below those where positive leaders are seen. This is very different from the vast majority of thundercloud charge structures seen around the world
Spray Deposition for Solvent Annealing of Hybrid Poly(3,4‐Ethylenedioxythiophene) Polystyrene Sulfonate Cellulose Silver Nanowire Composite Electrodes Using a Roll‐to‐Roll Coater
No full textSpray deposition is a rapid and facile technique for coating surfaces on a large scale. The quality of these coatings can be improved via post-treatment. One example is solvent annealing, a well-known strategy to enhance the conductivity of polymeric electrode materials using organic solvents. Herein, the annealing of sprayed poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)-based electrodes via solvent spray deposition in a single roll-to-roll setup is reported. The annealing rates of three solvents, namely dimethyl sulfoxide (DMSO), isopropanol (IPA), and methanol (MeOH), depending on the spray time and sprayed volume, are evaluated and correlated with structural changes. The results show that the applied method reduces the sheet resistance (Rs) of pure PEDOT:PSS films by 82% using DMSO and of cellulose-based silver nanowire-PEDOT:PSS electrodes by 50% using MeOH. This approach allows for the facile and effective combination of fabrication and quality enhancement of sprayed, conductive polymer films using only one piece of equipment. This approach makes the overall production process of organic electrodes faster and cheaper and therefore the usage of sustainable materials and fabrication methods more attractive for the industry
Timing performance of the DESY ER1 chip in a 65 nm CMOS imaging technology
No full textMonolithic active pixel sensors (MAPS) are promising candidates for the next generation of vertex detectors at future lepton colliders. One particularly interesting advancement is the recently accessible 65 nm CMOS imaging technology, which offers higher logic density compared to larger feature-size processes, making it highly appealing to the High Energy Physics community. This paper highlights the progress made with prototypes, an analog test structure, DESY ER1, featuring a 2 × 2 active pixel configuration. The chip is integrated into the Caribou DAQ system, and detailed laboratory and test beam characterizations have been conducted. The DESY ER1 provides access to analog waveforms generated by the charge-sensitive amplifier with a Krummenacher feedback loop. The paper presents the initial testing results of DESY ER1 at sensor bias voltage of −3.6 V, including the charge calibration with Fe-55 and tracking performance characterization in test beam. The test beam measurements shows that the time resolution for detecting charged particles is below 8.72 ns at a threshold of 200 e
Determination of CP -violating interaction with polarised beams at the ILC
No full textWe study possible CP-violation effects of the Higgs to -boson couplingat a future collider, e.g. at the International Linear Collider (ILC). We find that the azimuthal angular distribution of the muon pair, produced by , can be sensitive to such a CP-violation effect when we apply initial transversely-polarized beams. Based on the angular distribution, we construct a CP-sensitive asymmetry numerically and obtain this asymmetry by \texttt{Whizard} simulation. By comparing the SM prediction with the 2 range for this asymmetry, we estimate the limit of a CP-odd coupling in interaction
Solvent co-intercalation in layered cathode active materials for sodium-ion batteries
No full textSolvent co-intercalation, that is, the combined intercalation of ions and solvent molecules into electrode materials, is an additional but much less explored lever for modifying the properties of metal-ion battery electrodes (metal = Li, Na, Mg, etc.). Knowledge on solvent co-intercalation is relatively scarce and largely limited to graphite anodes, for which in sodium-ion batteries, the co-intercalation of glyme molecules is fast and highly reversible. The use of co-intercalation for cathode active materials (CAMs) remains much less explored. Here we investigate for a series of sodium-layered sulfide CAMs (NaMS, M = Ti, V, Cr and mixtures) under which conditions solvent co-intercalation occurs and how this process impacts the phase behaviour, electrode breathing, redox potential and cycle life compared to ‘Na-only’ intercalation. Co-intercalation is a complex process that can, for example, cause opposing fluxes, meaning that solvents intercalate into the CAMs while sodium ions simultaneously deintercalate. Co-intercalation leads to layered structures that can include different amounts of confined solvated ions, ions and unbound solvent molecules. It is an approach to designing structurally diverse, layered materials with potential applications for batteries and beyond
Probing the modulation of enzyme kinetics by multi-temperature, time-resolved serial crystallography
No full textThe vast majority of protein structures are determined at cryogenic temperatures, which are far from physiological conditions. Nevertheless, it is well established that temperature is an essential thermodynamic parameter for understanding the conformational dynamics and functionality of proteins in their native environments. Time-resolved crystallography is a technique that aims to elucidate protein function by examining structural alterations during processes such as ligand binding, catalysis, or allostery. However, this approach is typically conducted under ambient conditions, which may obscure crucial conformational states, that are only visible at physiological temperatures. In this study, we directly address the interplay between protein structure and activity via a method that enables multi-temperature, time-resolved serial crystallography experiments in a temperature window from below 10 °C to above 70 °C. Via this 5D-SSX, time-resolved experiments can now be carried out at physiological temperatures and with long time delays, providing insights into protein function and enzyme catalysis. Our findings demonstrate the temperature-dependent modulation of turnover kinetics for the mesophilic β-lactamase CTX-M-14 and the thermophilic enzyme xylose isomerase, within the full protein structure