A microwave kinetic inductance camera for sub/millimeter astrophysics

摘要

The MKID Camera is a millimeter/submillimeter instrument being built for astronomical observations from the CaltechSubmillimeter Observatory. It utilizes microwave kinetic inductance detectors, which are rapidly achieving near-BLIPsensitivity for ground-based observations, and a software-defined radio readout technique for elegant multiplexing of alarge number of detectors. The Camera will have 592 pixels distributed over 16 tiles in the focal plane, with four colorsper pixel matched to the 750 μm, 850 gm, and 1.0 – 1.5 mm (split in two) atmospheric transmission windows. As aprecursor to building the full-up camera and to enable ongoing detector testing, we have built a DemoCam comprised ofa 16-pixel MKID array with which we have made preliminary astronomical observations. These observationsdemonstrate the viability of MKIDs for submillimeter astronomy, provide insight into systematic design issues that mustbe considered for MKID-based instruments, and they are the first astronomical observations with antenna-coupledsuperconducting detectors. In this paper, we describe the basic systems and specifications of the MKID Camera, wedescribe our DemoCam observations, and we comment on the status of submillimeter MKID sensitivities.