IIHE Invited seminar: Probing the Dark Sector One Electron at a Time: Skipper CCDs and the DAMIC-M Experiment

Abstract: Detecting dark matter—particularly in the light mass regime—requires sensitivity to extremely faint ionization signals, potentially down to a single electron. Skipper CCDs are a new class of silicon detectors that enable this level of sensitivity by achieving sub-electron noise, thanks to their ability to perform multiple non-destructive charge measurements per pixel.
In this talk, I will introduce the operating principles and technological advances behind Skipper CCDs, contrasting them with conventional CCDs. I will then present how these sensors are used in the DAMIC-M experiment, a direct dark matter search operating at the Laboratoire Souterrain de Modane, and show recent results from its prototype phase. These results set world-leading constraints on dark matter–electron scattering for sub-MeV dark matter, probing both freeze-out and freeze-in production mechanisms in the dark sector for the first time.
Finally, I will highlight why Skipper CCDs are not just a niche detector but a transformative technology: from their applications in low-background rare-event searches to their potential to replace standard CCDs in broader scientific contexts, especially with new developments like MAS-CCDs enabling fast, multiplexed readout. Skipper CCDs are poised to reshape the landscape of precision low-energy detection.

Short-bio: Xavier Bertou is Research Director at IJCLab (CNRS/IN2P3, Université Paris-Saclay), where he leads the Direct Dark Matter group within the Astrophysics, Astroparticle and Cosmology department. A specialist in experimental astroparticle physics, he has contributed extensively to major international efforts in cosmic ray and dark matter research. After completing his PhD at LPNHE in Paris and a Grainger Fellowship at the University of Chicago, he spent over two decades at Centro Atómico Bariloche in Argentina (CNEA/CONICET). There, he played a central role in the Pierre Auger Observatory, leading key aspects of the design, deployment, and operation of the surface detector array. He later spearheaded the development of novel detection technologies and underground science initiatives. Dr. Bertou is a long-standing member of the DAMIC-M Collaboration, where he co-leads the Central Data Acquisition System, and is actively involved in advancing Skipper CCD technology for low-threshold dark matter searches.