An update on the start-up of the double-beta-decay experiment Nemo 3

The NEMO collaboration is in the final stages of completing a detector to search for neutrinoless double-beta decay. The experiment is called NEMO 3 and came on line at the beginning of 2002. Located in the Fréjus Underground Laboratory, the detector holds 10 kg of double-beta-decay isotopes, allowing one to study the effective neutrino mass down to approximately 0.1 eV. Thus, the detector has the potential to confirm physics beyond the Standard Model. Three of the detector’s sectors have been operating since June 2000 to perform diagnostic tests on the track recognition, the calorimeter, and the software. The results of these diagnostic tests are presented with a discussion of the detector and source backgrounds.