Isotope shift in the electron affinity of chlorine

The specific mass shift in the electron affinity between ^{35}Cl and ^{37}Cl has been determined by tunable laser photodetachment spectroscopy to be -0.51(14) GHz. The isotope shift was observed as a difference in the onset of the photodetachment process for the two isotopes. In addition, the electron affinity of Cl was found to be 29138.59(22) cm^{-1}, giving a factor of 2 improvement in the accuracy over earlier measurements. Many-body calculations including lowest-order correlation effects demonstrates the sensitivity of the specific mass shift and show that the inclusion of higher-order correlation effects would be necessary for a quantitative description.Comment: 16 pages, 6 figures, LaTeX2e, amsmat

Spatiotemporal visualization of the dynamics of absorbing layers in a two-stage atomizer

This paper describes an experimental apparatus for studying the dynamics of the variation of the spatial distribution of the absorbing layers in a two-stage atomizer. An optical system with a telecentric beam, using a diode laser as the radiation source, is proposed and analyzed. The spatiotemporal resolution and the contribution of refraction effects to the resulting absorption pattern are estimated. The dynamics of the evaporation and condensation processes are visualized in a two-stage atomizer of Cd atoms and NaCl molecules

CIRCULAR COMPARISON OF CONVENTIONAL PRESSURE STANDARDS USING A TRANSPORTABLE OPTICAL REFRACTOMETER: PREPARATION AND TRANSPORTATION

Using a transportable Fabry-Pérot cavity refractometer, a circular comparison of existing primary standards at several national metrology institutes is currently underway. This paper provides information about the refractometer, the preparation for the comparison, and the transportation procedur

Service-oriented visualization applied to medical data analysis

With the era of Grid computing, data driven experiments and simulations have become very advanced and complicated. To allow specialists from various domains to deal with large datasets, aside from developing efficient extraction techniques, it is necessary to have available computational facilities to visualize and interact with the results of an extraction process. Having this in mind, we developed an Interactive Visualization Framework, which supports a service-oriented architecture. This framework allows, on one hand visualization experts to construct visualizations to view and interact with large datasets, and on the other hand end-users (e.g., medical specialists) to explore these visualizations irrespective of their geographical location and available computing resources. The image-based analysis of vascular disorders served as a case study for this project. The paper presents main research findings and reports on the current implementation status

FIRE-the Frankfurt Ion stoRage Experiments

Abstract Existing electrostatic storage rings have proven to be a valuable tool for molecular and atomic physics in the low-energy regime. At the new Stern-Gerlach Center of Frankfurt University a small machine for ion energies up to 50 keV will be build up. It will serve as a tool to analyze the structure and dynamics of many particle systems from atoms to complex organic biomolecules. It will be possible to prepare the particle beams of interest in novel and unique ways. In direct comparison to traditional setups, the luminosity of the measurements will be improved by many orders of magnitude. In combination with the newest reaction microscopes, the F rankfurt Ion stoRage Experiments (FIRE) will allow analysis of many particle fragmentation processes of atoms and molecules with unrivaled resolution and completeness. In contrast to experiments with traps, an electrostatic storage ring has the advantage of being able to record the momenta of all neutral fragments. This paper gives an overview of the design parameters, the optical elements used and the project status.

Quantum-based realizations of the pascal: status and progress of the EMPIR-project: quantumpascal

The QuantumPascal (QP) project combines the capabilities of 12 European institutions to enable traceable pressure measurements utilizing quantum-based methods that evaluate the number density instead of force per area to target the wide pressure range between 1 Pa and 3 MPa. This article summarizes the goals and results since the project start in June 201

Using integrating spheres with wavelength modulation spectroscopy: effect of pathlength distribution on 2nd harmonic signals

We have studied the effect on 2nd harmonic wavelength modulation spectroscopy of the use of integrating spheres as multipass gas cells. The gas lineshape becomes distorted at high concentrations, as a consequence of the exponential pathlength distribution of the sphere, introducing nonlinearity beyond that expected from the Beer-Lambert law. We have modelled this numerically for methane absorption at 1.651μm, with gas concentrations in the range of 0-2.5%vol in air. The results of this model compare well with experimental measurements. The nonlinearity for the 2f WMS measurements is larger than that for direct scan measurements; if this additional effect were not accounted for, the resulting error would be approximately 20% of the reading at a concentration of 2.5 %vol methane