Impact of tone-power sensitivity of Al KIDs on observing efficiency and on-sky noise

Determine how the tone-power sensitivity and nonlinear response of aluminum kinetic inductance detectors used in the 280 GHz Prime-Cam instrument module on the Fred Young Submillimeter Telescope affect observing efficiency and on-sky noise performance during on-sky operations.

Background

The paper compares tri-layer TiN/Ti/TiN and single-layer Al kinetic inductance detectors (KIDs) that will be deployed in the 280 GHz Prime-Cam instrument module. The authors describe that Al detectors exhibit more complicated interactions between tone power linearity, optical loading, and resonator parameters due to the interplay of nonlinear kinetic inductance and nonequilibrium quasiparticle dynamics. This leads to non-monotonic relationships between tone power and resonant frequency/quality factor, distortion of the resonator line shape, and the need for frequent tuning or tone-tracking during variable observing conditions.

While operational strategies such as resonator tone-tracking are planned after deployment, the practical consequences of these Al-specific behaviors for real-world observations—specifically their impact on observing efficiency and on-sky noise performance—are explicitly identified by the authors as unknown at present.