15,005 research outputs found

    Traveling Wave Magnetic Particle Imaging for determining the iron-distribution in rock: Traveling Wave Magnetic Particle Imaging for determining the iron-distribution in rock

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    Determining the composition of solid materials is of high interest in areas such as material research or quality assurance. There are several modalities at disposal with which various parameters of the material can be observed, but of those only magnetic resonance imaging (MRI) or computer tomography (CT) offer anon-destructive determination of material distribution in 3D. A novel non-destructive imaging method is Magnetic Particle Imaging (MPI), which uses dynamic magnetic fields for a direct determination of the distribution of magnetic materials in 3D. With this approach, it is possible to determine and differentiate magnetic and non-magnetic behaviour. In this paper, the first proof-of-principle measurements of magnetic properties in solid environments are presented using a home-built traveling wave magnetic particle imaging scanner

    A time lens for high resolution neutron time of flight spectrometers

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    We examine in analytic and numeric ways the imaging effects of temporal neutron lenses created by traveling magnetic fields. For fields of parabolic shape we derive the imaging equations, investigate the time-magnification, the evolution of the phase space element, the gain factor and the effect of finite beam size. The main aberration effects are calculated numerically. The system is technologically feasible and should convert neutron time of flight instruments from pinhole- to imaging configuration in time, thus enhancing intensity and/or time resolution. New fields of application for high resolution spectrometry may be opened.Comment: 8 pages, 11 figure

    The Coronal Analysis of SHocks and Waves (CASHeW) Framework

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    Coronal Bright Fronts (CBF) are large-scale wavelike disturbances in the solar corona, related to solar eruptions. They are observed in extreme ultraviolet (EUV) light as transient bright fronts of finite width, propagating away from the eruption source. Recent studies of individual solar eruptive events have used EUV observations of CBFs and metric radio type II burst observations to show the intimate connection between low coronal waves and coronal mass ejection (CME)-driven shocks. EUV imaging with the Atmospheric Imaging Assembly(AIA) instrument on the Solar Dynamics Observatory (SDO) has proven particularly useful for detecting CBFs, which, combined with radio and in situ observations, holds great promise for early CME-driven shock characterization capability. This characterization can further be automated, and related to models of particle acceleration to produce estimates of particle fluxes in the corona and in the near Earth environment early in events. We present a framework for the Coronal Analysis of SHocks and Waves (CASHeW). It combines analysis of NASA Heliophysics System Observatory data products and relevant data-driven models, into an automated system for the characterization of off-limb coronal waves and shocks and the evaluation of their capability to accelerate solar energetic particles (SEPs). The system utilizes EUV observations and models written in the Interactive Data Language (IDL). In addition, it leverages analysis tools from the SolarSoft package of libraries, as well as third party libraries. We have tested the CASHeW framework on a representative list of coronal bright front events. Here we present its features, as well as initial results. With this framework, we hope to contribute to the overall understanding of coronal shock waves, their importance for energetic particle acceleration, as well as to the better ability to forecast SEP events fluxes.Comment: Accepted for publication in the Journal of Space Weather and Space Climate (SWSC

    Is there a resting frame in the universe? A proposed experimental test based on a precise measurement of particle mass

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    According to the Special Theory of Relativity, there should be no resting frame in our universe. Such an assumption, however, could be in conflict with the Standard Model of cosmology today, which regards the vacuum not as an empty space. Thus, there is a strong need to experimentally test whether there is a resting frame in our universe or not. We propose that this can be done by precisely measuring the masses of two charged particles moving in opposite directions. If all inertial frames are equivalent, there should be no detectable mass difference between these two particles. If there is a resting frame in the universe, one will observe a mass difference that is dependent on the orientation of the laboratory frame. The detailed experimental setup is discussed in this paper.Comment: 9 pages, 4 figure
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