Ouverture

Surrounding effects and sensitivity of the CODALEMA experiment

“…Extensive tests to evaluate the noise produced by the autonomous station (measurements in an anechoic chamber and with the Nançay radioheliograph and radiotelescope themselves) were realized and showed a very limited, if any, emission of the station, and especially nothing in the 1-100 MHz band where cosmic rays are searched. At last, with respect to the former CODALEMA active dipole, the active Butterfly antenna presents improved performances in the 20-80 MHz band, with an excellent sensitivity and a completely flatten low noise amplifier (LNA) frequency response [2].…”

“…Such an autonomous station is composed of a so-called "Butterfly" antenna [2] and an electronic crate embedded in a dedicated, electromagnetically shielded box which also serves as a support for the antenna pole. Antenna signals in dual polarization (EW and NS) feed a trigger board where triggering decision is made on a simple voltage threshold level in a 45-55 MHz filtered band [1].…”