A low background Micromegas detector for the CAST experiment
  A low background Micromegas detector has been operating on the CAST experiment at CERN for the search of solar axions during the first phase of the experiment (2002-2004). The detector operated efficiently and achieved a very low level of background rejection ($5\times 10^{-5}$ counts keV$^{-1}$cm$^{-2}$s$^{-1}$) thanks to its good spatial and energy resolution as well as the low radioactivity materials used in the construction of the detector. For the second phase of the experiment (2005-2007), the detector will be upgraded by adding a shielding and including focusing optics. These improvements should allow for a background rejection better than two orders of magnitude. 
P. Abbon, S. Andriamonje, S. Aune, D. Besin, S. Cazaux, P. Contrepois,   T. Dafni, T. Decker, N. Duportail, G. Fanourakis, E...