Javier Tiffenberg (Fermilab) "Things to do with less than one electron: the dawn of the ultimate ionization detector"

Silicon charged coupled devices (CCDs) have proven to be exceptional for the detection and measurement of photons and other ionizing radiation. Their low energy threshold of 50eV (~14 e-) have made them ideal for astronomical aplications and for detectors exploring Neutrino interactions (CONNIE) and searching for Dark Matter particles (DAMIC). However, the counting of individual photons and energy depositions below 50 eV has proven difficult due to an inability to reduce electronic noise below the level of a single charge carrier. Here I’ll present the results of a collaboration between Fermilab and LBL to build a Sub-Electron Noise Skipper Experimental Instrument (SENSEI) which uses a non-destructive readout technique to achieve stable readout for a thick fully depleted silicon CCD in the far sub-electron regime (∼ 0.05 e − rms/pix). This is the first time that discrete sub-electron counting has been achieved reproducibly over millions of pixels on a stable, large-area detector (7 cm^2 ) with large dynamic range. This innovative technology has nearly immediate implications for a wide range of scientific disciplines including astronomy and fundamental particle physics.