  The Spherical gaseous detector (or Spherical Proportional Counter, SPC) is a
novel type of par- ticle detector, with a broad range of applications. Its main
features include a very low energy threshold independent of the volume (due to
its very low capacitance), a good energy resolution, robustness and a single
detection readout channel, in its simplest version. Applications range from
radon emanation gas monitoring, neutron flux and gamma counting and
spectroscopy to dark matter searches, in particular low mass WIMPs and coherent
neutrino scattering measure- ment. Laboratories interested in these various
applications share expertise within the NEWS (New Experiments With Sphere)
network. SEDINE, a low background prototype installed at underground site of
Laboratoire Souterrain de Modane is currently being operated and aims at
measuring events at very low energy threshold, around 100 eV. We will present
the energy cali- bration with 37Ar, the surface background reduction, the
measurement of detector background at sub-keV energies, and show anticipated
sensitivities for light dark matter search.
