PRIMA prototype spaceflight KID readout electronics laboratory characterization

Overview & Synopsis

We present further development and testing of prototype kinetic inductance detector (KID) readout electronics for the PRobe far-Infrared Mission for Astrophysics (PRIMA). PRIMA is a NASA Probe-class astrophysics mission concept with two science instruments, FIRESS and PRIMAger, which provide spectroscopic and polarimetric imaging from 24 to 261 um. Together these instruments will explore the far-infrared sky with spatial-spectral mapping speeds that exceed previous studies by orders of magnitude, opening a vast discovery space. This increase in mapping speed is achieved by densely packed ultra-sensitive KIDs and cryogenically cooled optics. The PRIMA flight readout electronics will use the build-to-print SpaceCube Mini v3.0 which houses a radiation-tolerant Kintex KU060 field programmable gate array (FPGA). A custom high-speed digitizer board is being designed along with an RF electronics (RFE) board. The RFE was designed to provide programmable gain, band filtering, and RF switching between instruments. The prototype readout electronics, including the RFE, use functionally equivalent parts to the flight parts. In this proceeding we measure the readout loopback noise performance in the second Nyquist zone and timestream cross-talk performance. We present preliminary sweeps with the prototype readout coupled to prototype FIRESS detectors. Lastly, we demonstrate a cosmic ray pulse detection and real-time removal with an algorithm implemented in firmware.