Astrophysical observations and cosmological data have led to the unambiguous conclusion that nearly a quarter of the Universe consists of dark matter. The search for dark matter addresses one of the fundamental questions in particle astrophysics. Current models predict that our galaxy is encased in a halo of dark matter. As the Sun orbits around the galaxy and the Earth around the Sun, we expect there to be an annual modulation in the flux of dark matter that passes through the Earth. If the modulation observed by the DAMA experiment in Italy is due to dark matter, an experiment in the Southern Hemisphere with the same target material would expect to observe modulations with the same phase and amplitude. This would be unambiguous evidence for the observation of dark matter. If the modulation is due to an environmental background related to the seasons, it will be opposite in the two hemispheres.
This award will fund an integrated research and education program focused on the development of sodium iodide-(NaI)-based detectors for dark matter physics. The research program consists of three main activities: analysis of data from a 17 kilogram NaI detector currently operating 2500 meters below the surface in the South Pole ice, a systematic study of the characteristics and pulse shape discrimination techniques of NaI detectors, and the simulations and sensitivity studies for a proposed 250 kilogram NaI detector to be mounted in the Southern Hemisphere.
Broader impacts: This award will also fund a series of educational and outreach activities designed to recruit and retain physics majors and physicists in STEM fields by showcasing the wide range of careers available to physicists. A special focus will be given to recruit and retain women, persons with disabilities, and underrepresented minorities in physics.
