Photoabsorption and photoion spectroscopy of atomic uranium in the region of 6p and 5d excitations

The photoabsorption process in atomic uranium has been investigated experimentally and theoretically in the 15–150-eV region. Using the dual laser plasma technique, the 6p photoabsorption spectrum has been recorded while for the first time the 5d region has been remeasured photoelectrically using both photoabsorption and photoion spectroscopy. Interpretation of the photoabsorption spectra is supported by Hartree-Fock calculations which take into account spin-flip decay and the interaction of many discrete states with many continua. The 6p spectrum is entirely dominated by spin-orbit split 6p⃗6d transitions. The 5d-subshell photoabsorption is shown to consist predominantly of discrete 5d⃗5f excitations; here the electrostatic and spin-orbit interactions are comparable in strength

Optical imaging in vivo with a focus on paediatric disease: technical progress, current preclinical and clinical applications and future perspectives

To obtain information on the occurrence and location of molecular events as well as to track target-specific probes such as antibodies or peptides, drugs or even cells non-invasively over time, optical imaging (OI) technologies are increasingly applied. Although OI strongly contributes to the advances made in preclinical research, it is so far, with the exception of optical coherence tomography (OCT), only very sparingly applied in clinical settings. Nevertheless, as OI technologies evolve and improve continuously and represent relatively inexpensive and harmful methods, their implementation as clinical tools for the assessment of children disease is increasing. This review focuses on the current preclinical and clinical applications as well as on the future potential of OI in the clinical routine. Herein, we summarize the development of different fluorescence and bioluminescence imaging techniques for microscopic and macroscopic visualization of microstructures and biological processes. In addition, we discuss advantages and limitations of optical probes with distinct mechanisms of target-detection as well as of different bioluminescent reporter systems. Particular attention has been given to the use of near-infrared (NIR) fluorescent probes enabling observation of molecular events in deeper tissue

SINGLE-BUNCH LONGITUDINAL PHASE SPACE DIAGNOSTICS IN MULTI-BUNCH MODE AT THE EUROPEAN XFEL

Abstract Dedicated longitudinal electron beam diagnostics is highly demanded for the control and optimization of modern X-ray free-electron lasers (XFEL). At the European XFEL (E-XFEL), 3 transverse deflecting structures (TDS) will be installed at different locations of the accelerator for measurements of slice emittance and longitudinal profile. Operation of a TDS in combined use with an energy spectrometer, e.g. a dispersive section after a single dipole magnet, allows additionally for longitudinal phase space measurements. However, utilization of a dipole magnet is not compatible with single-bunch measurements in multibunch operation mode, which will be the standard operation mode of the E-XFEL. In this paper, we propose a longitudinal phase space diagnostic beamline consisting of a TDS, fast kicker and septum magnet for the E-XFEL. The layout of the accelerator lattice with optimized optics for longitudinal phase space measurements and numerical simulation studying the performance of the beamline will be presented

Design of TDS-based Multi-screen Electron Beam Diagnostics for the European XFEL

Dedicated longitudinal electron beam diagnostics is essential for successful operation of modern free-electron lasers. Demand for diagnostic data includes the longitudinal bunch profile, bunch length and slice emittance of the electron bunches. Experimental setups based on transverse deflecting structures (TDS) are excellent candidates for this purpose. At the Free-Electron Laser in Hamburg (FLASH), such a longitudinal bunch profile monitor utilizing a TDS, a fast kicker magnet and an off-axis imaging screen, has been put into operation. It enables the measurement of a single bunch out of a bunch train without affecting the remaining bunches. At the European X-ray Free-Electron Laser (XFEL) multiscreen stations in combination with TDS are planned to be installed. In order to allow for flexible measurements of longitudinal bunch profile and slice emittance, a configurable timing and trigger distribution to the fast kicker magnets and screen stations is required. In this paper, we discuss various operation patterns and the corresponding realization based on MTCA.4 technology