1,287 research outputs found
Scintillation light produced by low-energy beams of highly-charged ions
Measurements have been performed of scintillation light intensities emitted
from various inorganic scintillators irradiated with low-energy beams of
highly-charged ions from an electron beam ion source (EBIS) and an electron
cyclotron resonance ion source (ECRIS). Beams of xenon ions Xe with
various charge states between =2 and =18 have been used at energies
between 5 keV and 17.5 keV per charge generated by the ECRIS. The intensity of
the beam was typically varied between 1 and 100 nA. Beams of highly charged
residual gas ions have been produced by the EBIS at 4.5 keV per charge and with
low intensities down to 100 pA. The scintillator materials used are flat
screens of P46 YAG and P43 phosphor. In all cases, scintillation light emitted
from the screen surface was detected by a CCD camera. The scintillation light
intensity has been found to depend linearly on the kinetic ion energy per time
deposited into the scintillator, while up to =18 no significant contribution
from the ions' potential energy was found. We discuss the results on the
background of a possible use as beam diagnostics e.g. for the new HITRAP
facility at GSI, Germany.Comment: 6 pages, 8 figure
Creative Relations
Through reporting about a project with male home carers, I’m going to present some of the interactions which took place between myself (as the artist) and the participants as we got to know each other, and became part of each other’s lives. The text takes the form of a series of extracts taken directly from my own personal journals followed by a commentary on each. These have been selected to highlight the similarities between Ingold’s descriptions of creativity and Kester’s model for a dialogical aesthetic, which highlights key points in the engagement processes of a socially engaged artist. These reflective notes, made while the experiences were still fresh in my mind, help to illustrate the impact not only on the participants but also upon the artist as a participant in the social process
Correcting for the Effects of Interstellar Extinction
This paper addresses the issue of how best to correct astronomical data for
the wavelength-dependent effects of Galactic interstellar extinction. The main
general features of extinction from the IR through the UV are reviewed, along
with the nature of observed spatial variations. The enormous range of
extinction properties found in the Galaxy, particularly in the UV spectral
region, is illustrated. Fortunately, there are some tight constraints on the
wavelength dependence of extinction and some general correlations between
extinction curve shape and interstellar environment. These relationships
provide some guidance for correcting data for the effects of extinction.
Several strategies for dereddening are discussed along with estimates of the
uncertainties inherent in each method. In the Appendix, a new derivation of the
wavelength dependence of an average Galactic extinction curve from the IR
through the UV is presented, along with a new estimate of how this extinction
law varies with the parameter R = A(V)/E(B-V). These curves represent the true
monochromatic wavelength dependence of extinction and, as such, are suitable
for dereddening IR--UV spectrophotometric data of any resolution, and can be
used to derive extinction relations for any photometry system.Comment: To appear in PASP (January 1999) 14 pages including 4 pages of
figures Uses emulateapj style. PASP, in press (January 1999
Status of the emittance transfer experiment emtex
In order to improve the injection efficiency of the round UNILAC heavy ion beam into the asymmetric acceptance of the SIS18 it would be of great advantage to decreasethe horizontal emittance by a so called emittance transferto the vertical plane. In this contribution the present statusof the emittance transfer experiment EMTEX at GSI will be reported. A short introduction about the theoretical background of the technique will be given, while the mainpart is dedicated to the practical solutions setting up a testbeam line at GSI. Finally, the results of a first commissioning beam time will be presented. The scheduled beam time to apply the emittance transfer technique foreseen in spring 2014 had to be shifted to calendar week 26 in 2014, just after this conference as some components have not been delivered in time by the contractor. The results and comparison to the theoretical predictions you may find in later publications
The Far-Infrared Properties of Spatially Resolved AKARI Observations
We present the spatially resolved observations of IRAS sources from the
Japanese infrared astronomy satellite AKARI All-Sky Survey during the
performance verification (PV) phase of the mission. We extracted reliable point
sources matched with IRAS point source catalogue. By comparing IRAS and AKARI
fluxes, we found that the flux measurements of some IRAS sources could have
been over or underestimated and affected by the local background rather than
the global background. We also found possible candidates for new AKARI sources
and confirmed that AKARI observations resolved IRAS sources into multiple
sources. All-Sky Survey observations are expected to verify the accuracies of
IRAS flux measurements and to find new extragalactic point sources.Comment: 11 pages, 7 figures, accepted publication in PASJ AKARI special issu
Interdisciplinary study of warm core ring physics, chemistry, and biology
We are conducting an interdisciplinary study of the structure and
dynamics of Gulf Stream \Warm Core Rings by a time series investigation of
selected rings. This program consists of highly integrated components
which include physical, chemical, and biological investigation and
modeling studies. These components are designed to provide information
on the structure of rings and exchange mechanisms at ring boundaries, on their marine chemistry, and on the environmental controls of biological
activity of selected constituents associated with Warm Core Rings. This
research is being conducted by approximately two dozen investigators from
thirteen marine institutions. An interdisciplinary program of the scope
proposed is required in order to understand the interdependence among
biological, chemical, and physical processes in the ocean. This study of
the structure and evolution of Warm Core Rings will enhance the understanding
of fundamental oceanic processes and the role of rings in the
region where they occur
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