165 research outputs found
Radio detection of cosmic rays in the Pierre Auger Observatory
In small-scale experiments such as CODALEMA and LOPES, radio detection of
cosmic rays has demonstrated its potential as a technique for cosmic ray
measurements up to the highest energies. Radio detection promises measurements
with high duty-cycle, allows a direction reconstruction with very good angular
resolution, and provides complementary information on energy and nature of the
cosmic ray primaries with respect to particle detectors at ground and
fluorescence telescopes. Within the Pierre Auger Observatory, we tackle the
technological and scientific challenges for an application of the radio
detection technique on large scales. Here, we report on the results obtained so
far using the Southern Auger site and the plans for an engineering array of
radio detectors covering an area of ~20 km^2.Comment: 4 pages, Proceedings of the 11th Pisa Meeting on Advanced Detector
REAS3: Monte Carlo simulations of radio emission from cosmic ray air showers using an "end-point" formalism
In recent years, the freely available Monte Carlo code REAS for modelling
radio emission from cosmic ray air showers has evolved to include the full
complexity of air shower physics. However, it turned out that in REAS2 and all
other time-domain models which calculate the radio emission by superposing the
radiation of the single air shower electrons and positrons, the calculation of
the emission contributions was not fully consistent. In this article, we
present a revised implementation in REAS3, which incorporates the missing radio
emission due to the variation of the number of charged particles during the air
shower evolution using an "end-point formalism". With the inclusion of these
emission contributions, the structure of the simulated radio pulses changes
from unipolar to bipolar, and the azimuthal emission pattern becomes nearly
symmetric. Remaining asymmetries can be explained by radio emission due to the
variation of the net charge excess in air showers, which is automatically taken
into account in the new implementation. REAS3 constitutes the first
self-consistent time-domain implementation based on single particle emission
taking the full complexity of air shower physics into account, and is freely
available for all interested users.Comment: 18 pages, 13 figures accepted by Astroparticle Physics (2010
The TIANSHAN Radio Experiment for Neutrino Detection
An antenna array devoted to the autonomous radio-detection of high energy
cosmic rays is being deployed on the site of the 21 cm array radio telescope in
XinJiang, China. Thanks in particular to the very good electromagnetic
environment of this remote experimental site, self-triggering on extensive air
showers induced by cosmic rays has been achieved with a small scale prototype
of the foreseen antenna array. We give here a detailed description of the
detector and present the first detection of extensive air showers with this
prototype.Comment: 37 pages, 15 figures. Astroparticle Physics (in press
Dependence of geosynchrotron radio emission on the energy and depth of maximum of cosmic ray showers
Based on CORSIKA and REAS2 simulations, we investigate the dependence of
geosynchrotron radio emission from extensive air showers on the energy of the
primary cosmic ray and the depth of the shower maximum. It is found that at a
characteristic lateral distance, the amplitude of the bandpass-filtered radio
signal is directly proportional to the energy deposited in the atmosphere by
the electromagnetic cascade, with an RMS uncertainty due to shower-to-shower
fluctuations of less than 3%. In addition, the ratio of this radio amplitude
and that at a larger lateral distance is directly related to the atmospheric
depth of the shower maximum, with an RMS uncertainty of ~15-20 g cm-2. By
measuring these quantities, geosynchrotron radio emission from cosmic ray air
showers can be used to infer the energy of the primary particle and the depth
of the air shower maximum on a shower-to-shower basis.Comment: version accepted by Astroparticle Physics; slightly changed title and
wording; one additional figur
Radioelectric Field Features of Extensive Air Showers Observed with CODALEMA
Based on a new approach to the detection of radio transients associated with
extensive air showers induced by ultra high energy cosmic rays, the
experimental apparatus CODALEMA is in operation, measuring about 1 event per
day corresponding to an energy threshold ~ 5. 10^16 eV. Its performance makes
possible for the first time the study of radio-signal features on an
event-by-event basis. The sampling of the magnitude of the electric field along
a 600 meters axis is analyzed. It shows that the electric field lateral spread
is around 250 m (FWHM). The possibility to determine with radio both arrival
directions and shower core positions is discussed.Comment: Accepted for publication in Astroparticle Physic
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 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
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 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
An active dipole for cosmic ray radiodetection with CODALEMA
A paraître dans NIM AInternational audienceThe CODALEMA experiment detects the electromagnetic pulses radiated during the development of Extensive Air Showers (EAS). Since 2005, in addition to spiral log-periodic antennas, ultra broad bandwidth active dipoles have been designed to detect the full electric pulse shape of these signals. A few performances of these new detectors are presented
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