  Large detectors employing xenon are a leading technology in existing and
planned searches for new physics, including searches for neutrinoless double
beta decay ($0\nu\beta\beta$) and dark matter. While upcoming detectors will
employ target masses of a ton or more, further extending gas or liquid phase Xe
detectors to the kton scale would enable extremely sensitive next-generation
searches for rare phenomena. The key challenge to extending this technology to
detectors well beyond the ton scale is the acquisition of the Xe itself. We
describe the motivation for extending Xe time projection chambers (TPCs) to the
kton scale and possible avenues for Xe acquisition that avoid existing supply
chains. If acquisition of Xe in the required quantities is successful,
kton-scale detectors of this type could enable a new generation of experiments,
including searches for $0\nu\beta\beta$ at half-life sensitivities as long as
$10^{30}$ yr.
