PhD Defenses


Wed August 18th 2021, 12:00pm

Ph.D. Candidate:  Kelly Stifter

Research Advisor:  Dan Akerib

Date: Wednesday, August 18, 2021
Time: 12pm Pacific Daylight Time
Zoom Link:

Zoom Password: email mariaf67 [at]


The LZ dark matter experiment: From detector development to early data


Due to a compelling body of astrophysical and cosmological evidence, dark matter has come to be accepted as a crucial ingredient of modern cosmology, yet its physical nature remains one of the most pressing questions in the field of physics. One historically favored model of dark matter is weakly interacting massive particles, or WIMPs. LUX-ZEPLIN (LZ) is a next-generation dark matter detector designed to achieve field-leading sensitivity to much of the remaining accessible parameter space within the WIMP dark matter paradigm.

To help realize the full-scale LZ detector, the System Test R&D platform was constructed at SLAC National Accelerator Laboratory to validate the performance of critical LZ subsystems at scales approaching or comparable to the LZ design. In this talk, I will present results showing that the passivation of the high voltage electrodes in citric acid leads to a significant reduction in spontaneous emission of single electrons, potentially limiting a major instrumental background by up to several orders of magnitude and enabling a more sensitive dark matter search.

The LZ detector has now been assembled at the Sanford Underground Research Facility (SURF) in Lead, South Dakota and is taking early data. I will also give a first look at commissioning data that captured the first light from electrons in the LZ detector, and share methods to validate the in situ performance of the high voltage electrodes.