Measurements and Studies for Rare Event Searches Using Directional Detectors
- Thesis and Dissertation Defenses
June 16, 2026 1:00 PM -
June 16, 2026 2:00 PM
PAIS 2540
- Host:
- Dinesh Loomba
- Presenter:
- Elizabeth Tilly
In this talk, I will describe my PhD work on an experimental search for the Migdal effect: ionization through neutral scattering. This rare atomic physics phenomena is an exciting channel for placing constraints in light dark matter (LDM) searches. I will provide an update on experimental efforts to measure this effect, focusing on the Migdal In Galactic Dark mAtter expLoration (MIGDAL) experiment located in the UK. MIGDAL uses a tabletop gaseous detector consisting of a CMOS camera, 1D strip charge readout, and PMT capable of full 3D track reconstruction. A high flux DD neutron generator provides ~2.45 MeV neutrons to scatter off the carbon and fluorine nuclei in the detector. The rarity of the effect, ~1 in 105 nuclear recoils, is critical to the design of the experiment.
My PhD research with MIGDAL has involved developing algorithms for 3D track reconstruction using data and simulations. Besides their importance for measuring the Migdal effect, these studies also assess the feasibility of measuring the Migdal electron's angular distribution. This is relevant to tests of Migdal theory and can inform potential future uses of the Migdal effect in dark matter and other searches. Finally, I will describe laboratory-based studies done at UNM to inform a future MIGDAL Phase II search of the effect at lower energies, closer to the LDM regime. This work uses techniques tuned to maximize track resolution in gas mixtures with high fractions of the noble atomic targets of interest for dark matter searches.
