New micromegas detectors in the CAST experiment

MICROMEGAS detectors have been running in the CERN Axion Solar Telescope (CAST) experiment since 2002. The detector, constructed of low radioactivity materials, operated efficiently exploiting its good spatial and energy resolution of the detector as well as the time information contained in the pulse shape of the events. Last year Microbulk detectors were installed in the experiment achieving very low background levels thanks to the improved performances of the detector as well as the upgraded shielding. The performance during 2008 data-taking and recent background studies will be presented.