2,587 research outputs found
State-of-the-art and challenges of non-destructive techniques for in-situ radiological characterization of nuclear facilities to be dismantled
[EN]This paper reports on the state-of-the-art of the main non-destructive assay (NDA) techniques usually used for in-situ radiological characterization of nuclear facilities subject to a decommissioning programme. For the sake of clarity and coherence, they have been classified as environmental radiation monitoring, surface contamination measurements, gamma spectrometry, passive neutron counting and radiation cameras. Particular mention is also made here to the various challenges that each of these techniques must currently overcome, together with the formulation of some proposals for a potential evolution in the future.This study has been funded by the European INSIDER project, through the Euratom Research and Training Programme 2014-2018, under grant agreement No 755554
Three-dimensional and tomographic imaging device for X-ray and gamma-ray emitting objects
An instrument for obtaining quantitative, three-dimensional and tomographic information relating to X-ray and gamma-ray emitting objects and for the orthoscopic viewing of such objects includes a multiple-pinhole aperture plate held spaced from an X-ray or gamma-ray to visible-light converter which is coupled to a visible-light image intensifier. The spacing between the aperture plate and the converter is chosen such that the mini-images of an emitting object formed by the pinholes do not substantially overlap as they impinge on the converter. The output of the image intensifier is digitized by a digitizing camera in terms of position and intensity and fed into a digital computer. The computer may output quantitative information relating to the emitting object directly, such as that relating to tomograms, or provide information in analogue form when coupled with a suitable viewing device to give an orthoscopic, three-dimensional image of the object
Solar High-energy Astrophysical Plasmas Explorer (SHAPE). Volume 1: Proposed concept, statement of work and cost plan
The concept of the Solar High-Energy Astrophysical Plasmas Explorer (SHAPE) is studied. The primary goal is to understand the impulsive release of energy, efficient acceleration of particles to high energies, and rapid transport of energy. Solar flare studies are the centerpieces of the investigation because in flares these high energy processes can be studied in unmatched detail at most wavelenth regions of the electromagnetic spectrum as well as in energetic charged particles and neutrons
GRIPS - Gamma-Ray Imaging, Polarimetry and Spectroscopy
We propose to perform a continuously scanning all-sky survey from 200 keV to
80 MeV achieving a sensitivity which is better by a factor of 40 or more
compared to the previous missions in this energy range. The Gamma-Ray Imaging,
Polarimetry and Spectroscopy (GRIPS) mission addresses fundamental questions in
ESA's Cosmic Vision plan. Among the major themes of the strategic plan, GRIPS
has its focus on the evolving, violent Universe, exploring a unique energy
window. We propose to investigate -ray bursts and blazars, the
mechanisms behind supernova explosions, nucleosynthesis and spallation, the
enigmatic origin of positrons in our Galaxy, and the nature of radiation
processes and particle acceleration in extreme cosmic sources including pulsars
and magnetars. The natural energy scale for these non-thermal processes is of
the order of MeV. Although they can be partially and indirectly studied using
other methods, only the proposed GRIPS measurements will provide direct access
to their primary photons. GRIPS will be a driver for the study of transient
sources in the era of neutrino and gravitational wave observatories such as
IceCUBE and LISA, establishing a new type of diagnostics in relativistic and
nuclear astrophysics. This will support extrapolations to investigate star
formation, galaxy evolution, and black hole formation at high redshifts.Comment: to appear in Exp. Astron., special vol. on M3-Call of ESA's Cosmic
Vision 2010; 25 p., 25 figs; see also www.grips-mission.e
Review of biomedical Čerenkov luminescence imaging applications
Abstract: Čerenkov radiation is a fascinating optical signal, which has been
exploited for unique diagnostic biological sensing and imaging, with
significantly expanded use just in the last half decade. Čerenkov
Luminescence Imaging (CLI) has desirable capabilities for niche
applications, using specially designed measurement systems that report on
radiation distributions, radiotracer and nanoparticle concentrations, and are
directly applied to procedures such as medicine assessment, endoscopy,
surgery, quality assurance and dosimetry. When compared to the other
imaging tools such as PET and SPECT, CLI can have the key advantage of
lower cost, higher throughput and lower imaging time. CLI can also provide
imaging and dosimetry information from both radioisotopes and linear
accelerator irradiation. The relatively short range of optical photon transport
in tissue means that direct Čerenkov luminescence imaging is restricted to
small animals or near surface human use. Use of Čerenkov-excitation for
additional molecular probes, is now emerging as a key tool for biosensing
or radiosensitization. This review evaluates these new improvements in CLI
for both medical value and biological insigh
Nuclear-Astrophysics Lessons from INTEGRAL
Measurements of high-energy photons from cosmic sources of nuclear radiation
through ESA's INTEGRAL mission have advanced our knowledge: New data with high
spectral resolution showed that characteristic gamma-ray lines from radioactive
decays occur throughout the Galaxy, in its interstellar medium and from
sources. Although the number of detected sources and often the significance of
the astrophysical results remain modest, conclusions derived from this unique
astronomical window of radiation originating from nuclear processes are
important, complementing the widely-employed atomic-line based spectroscopy. We
review the results and insights obtained in the past decade from gamma-ray line
measurements of cosmic sources, in the context of their astrophysical
questions.Comment: Invited review. 30 pages, 26 figures. This is an author-created,
un-copyedited version of an article accepted for publication in Reports on
Progress in Physics. IOP Publishing Ltd is not responsible for any errors or
omissions in this version of the manuscript or any version derived from it.
The Version of Record is available online at DOI
10.1088/0034-4885/76/2/02630
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