35,782 research outputs found
Limits for an inverse bremsstrahlung origin of the diffuse Galactic soft gamma-ray emission
RXTE, GINGA, and OSSE observations have revealed an intense low-energy
gamma-ray continuum emission from the Galactic plane, which is commonly
interpreted as evidence for the possible existence of a strong flux of
low-energy cosmic ray electrons. In this paper I discuss the scenario of a
hadronic origin of the soft Galactic gamma-ray continuum through inverse
bremsstrahlung. A flux of low-energy cosmic rays strong enough to produce the
observed spectrum of gamma-rays implies substantial gamma-ray emission at a few
MeV through nuclear de-excitation. It is shown that the existing limits on
excess 3-7 MeV emission from the Galactic plane, in concert with the
constraints from pion-decay gamma-ray emission at higher energies, are in
serious conflict with an inverse bremsstrahlung origin of the Galactic soft
gamma-ray emission for any physically plausible low-energy cosmic ray spectrum.
While in case of energetic heavy nuclei the limits are violated by about an
order of magnitude, for a large population of low-energy protons the implied
gamma-ray line flux and pion-decay continuum intensity are larger than the
existing limits by at least a factor of 2.Comment: 4 pages, accepted for publication in A&
AMS tracking in-orbit performance
AMS-02 is a high precision magnetic spectrometer for cosmic rays in the GeV
to TeV energy range. Its tracker consists of nine layers of double-sided
silicon microstrip sensors. They are used to locate the trajectories of cosmic
rays in the 0.14 T field of a cylindrical magnet, thus measuring their rigidity
and charge sign. In addition, they deliver a high resolution measurement
of the absolute charge . The detector has been designed to operate in
space with a position resolution of about 10 m for each hit and charge
identification capabilities up to . In this talk I describe the
performance in orbit of this detector component and its impact on the overall
performance of the spectrometer.Comment: 24th International Workshop on Vertex Detectors, 1-5 June 2015, Santa
Fe, New Mexico, US
Particle detection technology for space-borne astroparticle experiments
I review the transfer of technology from accelerator-based equipment to
space-borne astroparticle detectors. Requirements for detection, identification
and measurement of ions, electrons and photons in space are recalled. The
additional requirements and restrictions imposed by the launch process in
manned and unmanned space flight, as well as by the hostile environment in
orbit, are analyzed. Technology readiness criteria and risk mitigation
strategies are reviewed. Recent examples are given of missions and instruments
in orbit, under construction or in the planning phase.Comment: Technology and Instrumentation in Particle Physics 2014 (TIPP 2014),
June 2-6, 2014, Amsterdam, The Netherland
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