SENSEI (Sub-Electron Noise Skipper Experimental Instrument) is pioneering the development of silicon CCDs with sub-electron charge resolution for low-threshold direct detection of dark matter. These "skipper CCDs" are the first detectors capable of resolving single electrons in each of millions of pixels, and the low thresholds possible with this technology give SENSEI world-leading sensitivity to sub-GeV dark matter. This spring, SENSEI conducted the first direct-detection search using a skipper CCD from a dedicated fabrication batch optimized for dark matter searches. With 24 days of data collected ~100 m underground at Fermilab with a 2-gram CCD, the experiment measured the lowest rates in silicon detectors for events containing one, two, three, or four electrons, and achieved world-leading sensitivity for a large range of sub-GeV dark matter masses. These recent results and preparations for the upcoming full-scale SENSEI run at the SNOLAB deep-underground facility will be presented.
Dr Uemura completed his Ph.D. at SLAC on Heavy Photon Search (accelerator-based dark sector experiment). AT LANL, he worked on the silicon vertex tracker for sPHENIX and a dark sector search at Fermilab. Most recently he has been with TAU based at Fermilab working on SENSEI.