The aim of the AMY experiment is to measure the microwave radiation produced by the particles of the showers produced by cosmic rays. Such radiation (MBR) is emitted by the secondary electrons as a result of the bremsstrahlung interaction with the molecules of the medium. The radiation is expected to be isotropic and not polarized which makes it very similar to that of fluorescence. This would allow the construction of a GHz telescope that would measure the entire longitudinal development of atmospheric showers with a duty cycle of 100%, which is not possible with the techniques currently used in the cosmic rays experiments (fluorescence telescopes and surface arrays).
The MBR is measured using the electron beam extracted from the LINAC of the DAFNE accelerator at the LNF. The beam is made to interact with an alumina target in order to maximize the energy deposit in the air. The measurement is carried out in an anechoic chamber whose internal walls are covered with RF absorbers in order to eliminate reflections of radiation. The chamber is additionally coated on the outside of copper and grounded to shield the external radiations. The signal is detected by antennas efficient 1-20 GHz band and amplified by wide-band amplifiers with low noise. The signal is then digitized by an oscilloscope, a spectrum analyzer and a fast FADC.
The aim of the experiment is to measure the absolute yield of the MBR and its spectrum in the frequency range 1-20 GHz. The experimental apparatus was built in 2011 and in the same year it has been made the first beam test.