Speaker
Description
Considering the fundamental role of the electric drift field in the formation and collection of the signals produced in the active volume of a dual-phase time projection chamber (TPC), significant effort was dedicated to the design and simulation of the field cage of the XENONnT TPC. The outcome of this work is an innovative double-array structure connected by an easily accessible voltage partitioner. Additionally, the field cage is independently biased, allowing for real-time tuning of the electric field during operation. As XENONnT has been operational since late 2020, the finite element simulations were compared to the calibration data using Kr-83m, indicating the presence of charge accumulation on the panels of the TPC. This was modeled with a linear distribution, returning a good match in the reconstructed spatial distribution and resolving inconsistencies in the electron lifetime measurements from different calibration sources. This presentation explores the electric drift field of the XENONnT TPC, tracing its journey from design and simulations to the validation against calibration data, and including insights from a dedicated test on the impact of tuning the field cage.
