Speaker
Description
Liquid argon underpins a broad program of neutrino and rare-event searches, while ongoing R&D continues to push toward lower thresholds and finer granularity. At this frontier, some of the most interesting low-energy signals may be carried by only tens of ionisation electrons. Accessing signatures such as coherent elastic neutrino-nucleus scattering therefore requires not only amplifying this charge, but understanding its journey from creation to collection.
We report on two complementary hardware efforts that inform one another. LArCADe (Liquid Argon Charge Amplification Devices) develops nanofabricated doped-silicon tip arrays to create intense localised fields for charge focusing and amplification, with recent KOH wet-etch fabrication at the UCSB Nanofabrication Facility. MOSAIC (Material-Oriented Signal Architecture in Cryogenic Detectors) studies doped Si wafers as candidate electrode materials, probing how their electrical properties influence charge collection and signal formation and feed back into tip design.
In parallel, TRANSLATE (TRANSport in Liquid Argon of near-Thermal Electrons) is being developed within the group as a dedicated microscopic Monte Carlo framework for electron transport in argon. Its recent extension to electron-ion recombination incorporates the Coulomb field of the ionisation track directly into the transport allowing the influence of drift field, ionisation density, and track orientation to arise naturally from simulated electron-ion interactions.
Together, these efforts take steps toward a closed loop between microscopic theory, detector design, and experiment: where models guide what we build, measurements test those assumptions, and the resulting feedback shapes future low-threshold liquid-argon readout.