135 research outputs found
First results of the Standalone Antenna Array of the CODALEMA Radio Detection Experiment
CODALEMA is one of the pioneer experiments dedicated to the recent field of
cosmic ray radio detection. It is located at the radio observatory of Nancay
(France). The detector setup combined until recently a ground particle detector
and an array of active dipole antennas covering a total area of 0.25 km^2. The
experiment is now going through a major upgrade with the deployment around the
existing apparatus of a Standalone Antenna Array, which consists of 60
standalone new generation radio-detection stations and which will cover an area
of 1.5 km^2 (33 stations deployed over the spring of 2011 and 27 stations to be
deployed in late 2011). This new setup is intended to tackle the remaining
unknowns of extensive air shower radio detection so as to make this technique a
reliable and mature tool for Ultra High Energy Cosmic Ray (UHECR) physics. The
latest results from the original CODALEMA array are discussed together with the
first results of the Standalone Antenna Array.Comment: International Cosmic Ray Conference, Beijing 2011, 4 pages, 5 figure
Radio Detection of Cosmic Ray Air Showers with Codalema
Studies of the radio detection of Extensive Air Showers is the goal of the
demonstrative experiment CODALEMA. Previous analysis have demonstrated that
detection around eV was achieved with this set-up. New results
allow for the first time to study the topology of the electric field associated
to EAS events on a event by event basis.Comment: 6 pages, 4 figures Proceedings of the Rencontres de Moriond, Very
High Energy Phenomena in the Universe, La Thuile, Italy (March 12-19, 2005
Radio Detection of Cosmic Ray Extensive Air Showers: present status of the CODALEMA experiment
Data acquisition and analysis for the CODALEMA experiment, in operation for
more than one year, has provided improved knowledge of the characteristics of
this new device. At the same time, an important effort has been made to develop
processing techniques for extracting transient signals from data containing
interference.Comment: september 200
Radiodetection of Cosmic Ray Extensive Air Showers
We present the characteristics and performance of a demonstration experiment
devoted to the observation of ultra high- energy cosmic ray extensive air
showers using a radiodetection technique. In a first step, one antenna narrowed
band filtered acting as trigger, with a 4 threshold above sky
background-level, was used to tag any radio transient in coincidence on the
antenna array. Recently, the addition of 4 particle detectors has allowed us to
observe cosmic ray events in coincidence with antennas
Radio Detection of Extensive Air Showers with CODALEMA
The principle and performances of the CODALEMA experimental device, set up to
study the possibility of high energy cosmic rays radio detection, are
presented. Radio transient signals associated to cosmic rays have been
identified, for which arrival directions and shower's electric field topologies
have been extracted from the antenna signals. The measured rate, about 1 event
per day, corresponds to an energy threshold around 5.10^16 eV. These results
allow to determine the perspectives offered by the present experimental design
for radiodetection of UHECR at a larger scale.Comment: 4 pages and 3 figures. To appear in the Proceedings of the 29th ICRC,
Pune (2005
CODALEMA: a cosmic ray air shower radio detection experiment
International audienceThe CODALEMA experimental device currently detects and characterizes the radio contribution of cosmic ray air showers : arrival directions and electric field topologies of radio transient signals associated to cosmic rays are extracted from the antenna signals. The measured rate, about 1 event per day, corresponds to an energy threshold around 5.10eV. These results allow to determine the perspectives offered by the present experimental design for radiodetection of Ultra High Energy Cosmic Rays at a larger scale
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 and sensitivity of the Virgo detector during its second science run
The Virgo detector is a kilometer-length interferometer for gravitational
wave detection located near Pisa (Italy). During its second science run (VSR2)
in 2009, six months of data were accumulated with a sensitivity close to its
design. In this paper, the methods used to determine the parameters for
sensitivity estimation and gravitational wave reconstruction are described. The
main quantities to be calibrated are the frequency response of the mirror
actuation and the sensing of the output power. Focus is also put on their
absolute timing. The monitoring of the calibration data as well as the
parameter estimation with independent techniques are discussed to provide an
estimation of the calibration uncertainties. Finally, the estimation of the
Virgo sensitivity in the frequency-domain is described and typical
sensitivities measured during VSR2 are shown.Comment: 30 pages, 23 figures, 1 table. Published in Classical and Quantum
Gravity (CQG), Corrigendum include
Virgo calibration and reconstruction of the gravitational wave strain during VSR1
Virgo is a kilometer-length interferometer for gravitational waves detection
located near Pisa. Its first science run, VSR1, occured from May to October
2007. The aims of the calibration are to measure the detector sensitivity and
to reconstruct the time series of the gravitational wave strain h(t). The
absolute length calibration is based on an original non-linear reconstruction
of the differential arm length variations in free swinging Michelson
configurations. It uses the laser wavelength as length standard. This method is
used to calibrate the frequency dependent response of the Virgo mirror
actuators and derive the detector in-loop response and sensitivity within ~5%.
The principle of the strain reconstruction is highlighted and the h(t)
systematic errors are estimated. A photon calibrator is used to check the sign
of h(t). The reconstructed h(t) during VSR1 is valid from 10 Hz up to 10 kHz
with systematic errors estimated to 6% in amplitude. The phase error is
estimated to be 70 mrad below 1.9 kHz and 6 micro-seconds above.Comment: 8 pages, 8 figures, proceedings of Amaldi 8 conference, to be
published in Journal of Physics Conference Series (JPCS). Second release:
correct typo
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