The LEGEND collaboration is comprised of over 250 researchers from about 50 institutions from around the world, working together to develop the largest 76Ge neutrinoless double-beta decay experiment in history. By combining the technological expertise and experience from the GERDA experiment and MAJORANA DEMONSTRATOR, LEGEND is expected to reach a design sensitivity two orders of magnitude greater than its predecessors.
The first stage of the experiment, LEGEND-200, is already taking physics data. We repurpose the infrastructures of the GERDA experiment at Laboratori Nazionali del Gran Sasso (LNGS). Existing high-purity detectors from GERDA and MAJORANA DEMONSTRATOR, enriched with the isotope 76Ge, will be supplemented by new, state-of-the-art detectors to achieve a total mass of about 200 kg. In the second stage, LEGEND-1000, we plan to increase the detector mass to 1000 kg in four separate payloads and operate them in a new experimental setup, which is currently under design. The underground laboratories presently under consideration for LEGEND-1000 are SNOLAB (Canada) and LNGS (Italy).