6,619 research outputs found
Cargo Aircraft Conceptual Design Optimisation Using a Flexible Computer-Based Scaling Approach
In the early design stages of a new aircraft, there is a strong need to broaden the knowledge base of the evolving aircraft project, allowing a profound analysis of the solution concepts and of the design driving requirements. The methodology presented in this paper provides a tool for increasing and improving in an exemplary manner the necessary information on cargo aircraft. By exchanging or adapting a few particular modules of the entire program system, the tool is applicable to a range scale of different aircraft types. In an extended requirement model, performance requirements are represented along with other operational requirements. An aircraft model is introduced in sufficient detail for conceptual design considerations. The computer-aided scaling methodology is explained, which, controlled by an optimisation module, automatically resizes the aircraft model until it optimally satisfies the requirements in terms of a selectable figure of merit. Typical results obtained at the end of the scaling are discussed together with knowledge gained during the process, and an example is given
Hydrogen Spectroscopy with a Lamb-shift Polarimeter - An Alternative Approach Towards Anti-Hydrogen Spectroscopy Experiments
A Lamb-shift polarimeter, which has been built for a fast determination of
the polarization of protons and deuterons of an atomic-beam source and which is
frequently used in the ANKE experiment at COSY-J\"ulich, is shown to be an
excellent device for atomic-spectroscopy measurements of metastable hydrogen
isotopes. It is demonstrated that magnetic and electric dipole transitions in
hydrogen can be measured as a function of the external magnetic field, giving
access to the full Breit-Rabi diagram for the and the
states. This will allow the study of hyperfine structure, factors and the
classical Lamb shift. Although the data are not yet competitive with
state-of-the-art measurements, the potential of the method is enormous,
including a possible application to anti-hydrogen spectroscopy.Comment: 6 pages, 7 figures, accepted by European Physical Journal
The -cleus experiment: A gram-scale fiducial-volume cryogenic detector for the first detection of coherent neutrino-nucleus scattering
We discuss a small-scale experiment, called -cleus, for the first
detection of coherent neutrino-nucleus scattering by probing nuclear-recoil
energies down to the 10 eV-regime. The detector consists of low-threshold
CaWO and AlO calorimeter arrays with a total mass of about 10 g and
several cryogenic veto detectors operated at millikelvin temperatures.
Realizing a fiducial volume and a multi-element target, the detector enables
active discrimination of , neutron and surface backgrounds. A first
prototype AlO device, operated above ground in a setup without
shielding, has achieved an energy threshold of eV and further
improvements are in reach. A sensitivity study for the detection of coherent
neutrino scattering at nuclear power plants shows a unique discovery potential
(5) within a measuring time of weeks. Furthermore, a site
at a thermal research reactor and the use of a radioactive neutrino source are
investigated. With this technology, real-time monitoring of nuclear power
plants is feasible.Comment: 14 pages, 19 figure
The Polarized H and D Atomic Beam Source for ANKE at COSY-J\"ulich
A polarized atomic beam source was developed for the polarized internal
storage-cell gas target at the magnet spectrometer ANKE of COSY-J\"ulich. The
intensities of the beams injected into the storage cell, measured with a
compression tube, are hydrogen atoms/s (two hyperfine
states) and deuterium atoms/s (three hyperfine states). For
the hydrogen beam the achieved vector polarizations are . For the deuterium beam, the obtained combinations of vector
and tensor () polarizations are (with a
constant ), and or (both with vanishing ). The paper includes a detailed
technical description of the apparatus and of the investigations performed
during the development.Comment: 18 pages, 26 figures, 4 table
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