1,323 research outputs found
Radiated Immunity Testing of a Device with an External Wire: Repeatibility of Reverberation Chamber Results and Correlation with Anechoic Chamber Results
We present the experimental radiated immunity results of an electronic device with an external wire obtained in reverberation and anechoic chambers. Repeatability and reproducibility of reverberation chamber measurements are investigated by repeating the test in three reverberation chambers with different characteristics. We show how the current state of the art allows a statistical control of RC measurement repeatability within an industrial installation, and that a statistical correlation with AC results frequency by frequency is possible in particular cases relevant to automotive application
Observing Ultra High Energy Cosmic Particles from Space: SEUSO, the Super Extreme Universe Space Observatory Mission
The experimental search for ultra high energy cosmic messengers, from eV to beyond eV, at the very end of the known energy
spectrum, constitutes an extraordinary opportunity to explore a largely unknown
aspect of our universe. Key scientific goals are the identification of the
sources of ultra high energy particles, the measurement of their spectra and
the study of galactic and local intergalactic magnetic fields. Ultra high
energy particles might, also, carry evidence of unknown physics or of exotic
particles relics of the early universe. To meet this challenge a significant
increase in the integrated exposure is required. This implies a new class of
experiments with larger acceptances and good understanding of the systematic
uncertainties. Space based observatories can reach the instantaneous aperture
and the integrated exposure necessary to systematically explore the ultra high
energy universe. In this paper, after briefly summarising the science case of
the mission, we describe the scientific goals and requirements of the SEUSO
concept. We then introduce the SEUSO observational approach and describe the
main instrument and mission features. We conclude discussing the expected
performance of the mission
Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector
Cosmic rays extensive air showers (EAS) are associated with transient radio
emission, which could provide an efficient new detection method of high energy
cosmic rays, combining a calorimetric measurement with a high duty cycle. The
CODALEMA experiment, installed at the Radio Observatory in Nancay, France, is
investigating this phenomenon in the 10^17 eV region. One challenging point is
the understanding of the radio emission mechanism. A first observation
indicating a linear relation between the electric field produced and the cross
product of the shower axis with the geomagnetic field direction has been
presented (B. Revenu, this conference). We will present here other strong
evidences for this linear relationship, and some hints on its physical origin.Comment: Contribution to the 31st International Cosmic Ray Conference, Lodz,
Poland, July 2009. 4 pages, 8 figures. v2: Typo fixed, arxiv references adde
Calibration of the Logarithmic-Periodic Dipole Antenna (LPDA) Radio Stations at the Pierre Auger Observatory using an Octocopter
An in-situ calibration of a logarithmic periodic dipole antenna with a
frequency coverage of 30 MHz to 80 MHz is performed. Such antennas are part of
a radio station system used for detection of cosmic ray induced air showers at
the Engineering Radio Array of the Pierre Auger Observatory, the so-called
Auger Engineering Radio Array (AERA). The directional and frequency
characteristics of the broadband antenna are investigated using a remotely
piloted aircraft (RPA) carrying a small transmitting antenna. The antenna
sensitivity is described by the vector effective length relating the measured
voltage with the electric-field components perpendicular to the incoming signal
direction. The horizontal and meridional components are determined with an
overall uncertainty of 7.4^{+0.9}_{-0.3} % and 10.3^{+2.8}_{-1.7} %
respectively. The measurement is used to correct a simulated response of the
frequency and directional response of the antenna. In addition, the influence
of the ground conductivity and permittivity on the antenna response is
simulated. Both have a negligible influence given the ground conditions
measured at the detector site. The overall uncertainties of the vector
effective length components result in an uncertainty of 8.8^{+2.1}_{-1.3} % in
the square root of the energy fluence for incoming signal directions with
zenith angles smaller than 60{\deg}.Comment: Published version. Updated online abstract only. Manuscript is
unchanged with respect to v2. 39 pages, 15 figures, 2 table
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