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Structural Biomedical Two-Photon Microscopy Using a Sub-35 fs, High-Energy (>40 nJ), Pre-Chirp Managed Yb:Fiber Laser System
No full textTwo-photon microscopy (2PM) is a vital imaging tool for modern life science [1]. As enabling technology, compact Yb:fiber lasers combined with novel labelling techniques have emerged as rapidly advancing sources for high-performance biomedical 2PM applications [2]. Here, we demonstrate a novel, highly-optimized Yb:fiber laser (YFL) design that uses simulation-guided nonlinear amplification to generate pulses with up to 40 nJ pulse energy at sub-35 fs duration for multimodal two-photon imaging of labelled mouse kidney and protein crystals
Decade-long periodicity study of 2FHL blazars with historical optical data
No full textIn our recent investigation, we utilized a century's worth of archival optical data to search for a decade-long periodicity from the blazar PG 1553+113, finding a hint of a 22-yr period. Building on this foundation, the current study extends our analysis to include 10 blazars from the Fermi-Large Area Telescope Second Catalog of Hard Sources (2FHL) catalogue to uncover similar long-term periodic behaviour. To ensure the reliability of our findings, we consider the impact of observational limitations, such as temporal gaps and uneven sampling, which could potentially introduce artefacts or false periodic signals. Our analysis initially identifies decade-scale periodicity in four of these blazars (AP Librae, MKN 421, MKN 501, PG 1246+586). However, further investigation reveals that three of these are likely influenced by noise and poor sampling. The most promising candidate, approximately 51 9 yr signal in MKN 421, corresponds to fewer than three full cycles and cannot be considered significant. Furthermore, global significance suggests none of the candidate periodicities meet the threshold for statistical significance. These results underscore the importance of accounting for sampling artefacts and highlight the need for robust methodologies in long-term periodicity searches
Laser Pulse Shaping Capability at 2050 nm for Dielectric Laser Acceleration
No full textDielectric laser accelerators (DLAs) have demonstrated higher acceleration gradients compared to traditional RF-based systems, reaching up to GV/m [1]. By precisely controlling the spatio-temporal properties of the driving laser via dispersion management, the synchronous interaction between the charged particle beam and laser can be enhanced, leading to higher electron energy gain [2], [3]. In this contribution, we demonstrate the capability of pulse shaping in our 2050 nm Ho:YLF laser system employing a DAZZLER for DLA applications
A Simple 1 mJ Ti:Sapphire Booster Amplifier for the KALDERA plasma Acceleration Drive Laser at 1 kHz
No full textThe KALDERA laser at DESY will drive a laser-plasma accelerator with up to kHz-level repetition rates [1]. The setup and commissioning of the first project phase of the Ti:Sa based CPA laser, aiming for 100 Hz, 0.5 J, <30 fs pulses, has taken place during the last two years. These parameters should be reached at excellent beam quality and an energy stability of <0.5% rms
Observation of double parton scattering in same-sign W boson pair production in pp collisions at s=13 TeV with the ATLAS detector
No full textThis letter reports the measurement of double parton scattering in same-sign W boson pair production with the ATLAS detector. The data set used corresponds to an integrated luminosity of 140 fb−1 of proton–proton collisions at a center-of-mass energy of 13 TeV, collected during Run 2 of the Large Hadron Collider. The study is performed in final states including two same-charge leptons, electron or muon, missing transverse momentum, and up to one jet. An excess of events is observed over the expected background contributions with a significance of 8.8 standard deviations. The measured fiducial cross section times leptonic branching fraction is 4.59±0.64 fb. The measurement corresponds to a double parton scattering effective cross section of 10.6±1.8 mb
Set-up, characterization and mitigation of cross-talk between PM-based and ferrite-enforced appliances for FLASH 2020
No full textWe present the design basics, assembly procedure and the results of the characterization measurements for two magnetic appliances that are part of the current upgrade of the FLASH free electron laser at DESY Hamburg. A permanent magnet-based phase shifter will allow for a tuning of the electron trajectory between two insertion devices to provide constructive interference, while ferrite-enforced corrector coils with variable field direction will not only correct gap-dependent kicks of the undulator but will also be strong enough to serve as steerers in a slow feedback system. We have manufactured ten phase shifters and more than 30 corrector coils which have all been measured with Hall probes and stretched-wire set-ups to measure the achievable phase range and maximum kick, respectively, to correct any multipole contributions and to check for consistency within each series. A particular challenge was the introduction of significant cross-talk between the permanent magnets of the phase shifter and the ferrite core of the coils due to the close proximity of the two devices along the beam line. The ferrite would dampen the fringe field of the phase shifter leading to an unwanted kick to the electron beam. The issue was mitigated by placing a set of ferromagnetic dowels between phase shifter and coil that would compensate for the dampening. Size and position of the dowels were modelled beforehand and verified in stretched-wire measurements
Development of cryogenically cooled permanent magnet undulators for PETRA IV
No full textCryogenically cooled permanent magnet undulators (CPMUs) are an improvement of the in-vacuum undulators (IVUs) which are widely used at various synchrotron radiation facilities and free-electron lasers in order to improve the photon flux towards shorter wavelengths. Especially beamlines with the need for high energy photons will benefit from shorter period insertion devices (IDs). For the planned ultra-low emittance photon source PETRA IV at Deutsches Elektronen-Synchrotron (DESY), we are designing CPMUs with a hybrid magnet structure based on PrFeB magnet material. First prototyping was done on magnet keepers and the pole-tuning mechanism. In addition, options for force-compensation are assessed. Crucial components are the link rods connecting the in-vacuum girders with load bearing out-of-vacuum girders. Simulations on the impact of their arrangement on the bending of the magnet structure and their thermal behaviour are presented
Variational Quantum Eigensolver Approach to Prime Factorization on IBM's Noisy Intermediate Scale Quantum Computer
No full textThis paper presents a hybrid quantum-classical approach to prime factorization. The proposed algorithm is based on the Variational Quantum Eigensolver (VQE), which employs a classical optimizer to find the ground state of a given Hamiltonian. A numerical study is presented, evaluating the performance of the proposed method across various instances on both IBM's real quantum computer and its classical simulator. The results demonstrate that the method is capable of successfully factorizing numbers up to 253 on a real quantum computer and up to 1048561 on a classical simulator. These findings show the potential of the approach for practical applications on near-term quantum computers
in the Asymptotically Safe Standard Model
No full textWe study the electron-positron to muon--anti-muon cross-section in the asymptotically safe Standard Model. In particular, we include the graviton contributions to the scattering amplitude, which is computed from momentum-dependent timelike one-particle-irreducible correlation functions. Specifically, we employ reconstruction techniques for the graviton spectral functions. We find that the full asymptotically safe quantum cross section decreases in the ultraviolet with the centre-of-mass energy, and is compatible with unitarity bounds. Importantly, our findings provide non-trivial evidence for the unitarity of the asymptotically safe Standard Model
High Performance Data Integration for Large-Scale Analyses of Incomplete Omic Profiles Using Batch-Effect Reduction Trees (BERT)
No full textData from high-throughput technologies assessing global patterns of biomolecules (omic data), is often afflicted with missing values and with measurement-specific biases (batch-effects), that hinder the quantitative comparison of independently acquired datasets. This work introduces batch-effect reduction trees (BERT), a high-performance method for data integration of incomplete omic profiles.We characterize BERT on large-scale data integration tasks with up to 5000 datasets from simulated and experimental data of different quantification techniques and omic types (proteomics, transcriptomics, metabolomics) as well as other datatypes e.g., clinical data, emphasizing the broad scope of the algorithm. Compared to the only available method for integration of incomplete omic data, HarmonizR, our method1) retains up to five orders of magnitude more numeric values,2) leverages multi-core and distributed-memory systems for up to 11x runtime improvement3) considers covariates and reference measurements to account for severely imbalanced or sparsely distributed conditions (up to 2x improvement of average-silhouette-width)