The «Laboratoire des 2 Infinis Irène Joliot-Curie» or IJCLab is a joint research unit of the «Centre National de la Recherche Scientifique/Institut national de physique nucléaire et de physique des particules» (CNRS/IN2P3), Université Paris-Saclay and Université de Paris, located on the Orsay Campus.

The scientific activities of IJCLab are organised around seven scientific poles: Astroparticles, Astrophysics and Cosmology; Accelerator Physics; High-Energy Physics; Nuclear Physics; Theoretical Physics; Energy and Environment; Interface Life Sciences/Physics. They rely on an Engineering pole which gathers technical services, organised following four departments: electronics, IT and computing, instrumentation and mechanical engineering. This leads to a unique potential for the design, the development and the exploitation of the instruments required to takle the scientific challenges of the coming decades in accelerator and detector physics, enabling IJCLab to be recognised worldwide as a "builder laboratory".

The presence of a vast set of local research infratructures and technological platforms (Andromède, ALTO, Laserix, SCALP, Supratech...) is also an essential feature of IJCLab. It is completed with services (administration, support, transverse activities) which provides a vital support to these scientific and technical activities.
The laboratory is located at the heart of a scientific cluster recognised at the global level. This puts IJCLab in an exceptionnaly favourable environment for teaching, training, transfer of knowledge and popular science.
Finally, IJCLab is involved in many national and international experiments or projects: ALICE, ATLAS, Auger, GANIL, ILC, ISOLDE, LHCb, LSST, RIKEN, SuperNEMO, Virgo.