Characterization of MKIDs for CMB observation at 220 GHz with the South Pole Telescope

Kavli Affiliate: Bradford A. Benson

| First 5 Authors: Karia R. Dibert, Peter S. Barry, Adam J. Anderson, Bradford A. Benson, Thomas Cecil

| Summary:

We present an updated design of the 220 GHz microwave kinetic inductance
detector (MKID) pixel for SPT-3G+, the next-generation camera for the South
Pole Telescope. We show results of the dark testing of a 63-pixel array with
mean inductor quality factor $Q_i = 4.8 times 10^5$, aluminum inductor
transition temperature $T_c = 1.19$ K, and kinetic inductance fraction
$alpha_k = 0.32$. We optically characterize both the microstrip-coupled and
CPW-coupled resonators, and find both have a spectral response close to
prediction with an optical efficiency of $eta sim 70%$. However, we find
slightly lower optical response on the lower edge of the band than predicted,
with neighboring dark detectors showing more response in this region, though at
level consistent with less than 5% frequency shift relative to the optical
detectors. The detectors show polarized response consistent with expectations,
with a cross-polar response of $sim 10%$ for both detector orientations.

| Search Query: ArXiv Query: search_query=au:”Bradford A. Benson”&id_list=&start=0&max_results=3

Read More