Effect of gamma radiation on low kinetic inductance superconducting microwave resonators

Understanding the impact of ionizing radiation on superconducting microwave resonators is essential for improving the coherence of superconducting quantum processors. In this work, we examine the response of Nb coplanar waveguide (CPW) resonators—with single-photon intrinsic quality factors on the order of several hundred thousand—to γ radiation from a Cs-137 source. We observed no significant degradation in the internal quality factor during the irradiation of Nb CPW resonators on sapphire or Si(100) substrates.