First results of the EDELWEISS experiment

We ran a 24 g Sapphire bolometer, deep underground, in a selected environment for low radioactivity. The experimental setup is quickly described. The energy spectrum was measured down to 4 keV. Preliminary analysis based on 160 hours of effective running time exhibits a one order of magnitude decrease in the radioactive background level at energy between 10 and 20 keV relative to the previous attempt in 1991. However, the event rate is still two orders of magnitude higher than the best detectors at these energies. We are currently working at identifying the origin of the radioactive contaminants and developing new bolometers.