11:00 am–12:00 pm
Please join us:
Ryan Thomas’ PhD Thesis Defense
Wednesday, July 14, 2021, 11:00 am CDT
CAMERAS IN THE DARK: DIRECT DETECTION OF DARK MATTER WITH CHARGE-COUPLED DEVICES
There are compelling motivations for the existence of dark matter particles which would explain the invisible gravitational mass present throughout the universe. Interest in the field has increasingly turned to searches for lighter dark matter candidates which deposit less energy in the detector and are therefore difficult to see with most detectors. The Dark Matter in CCDs (DAMIC) experiment uses silicon charge-coupled devices (CCDs) to search for such low mass dark matter candidates. With low noise and high spatial resolution, CCDs are highly sensitive to many possible dark matter candidates. The next generation of DAMIC (DAMIC-M) will use a large array of "skipper" CCDs, able to achieve single-electron noise resolution. This detector requires ensuring we can utilize the skipper CCDs to achieve a low energy threshold, and understand and lower our radioactive backgrounds.
First we describe the development and testing of a scalable new readout system for skipper CCDs, with early tests showing << 1e- of noise/pixel, which will allow DAMIC-M to achieve it's desired noise threshold. Next, we describe the development and validation of Monte Carlo simulations of the DAMIC at SNOLAB detector, which have been used to set WIMP dark matter limits, understand external backgrounds in CCD detectors, and identify an unknown excess in our current detector. Finally, we describe a first-ever measurement of the activation of tritium in silicon by cosmic ray neutrons, an inherent background in all silicon-based detectors.
Committee members:
Paolo Privitera (Chair)
Juan Collar
Dan Hooper
Philippe Guyot-Sionnest