µ-spec spectrometers for the EXCLAIM instrument

The EXperiment for Cryogenic Large-aperture Intensity Mapping (EXCLAIM) is a cryogenic balloon-borne experiment that will map CO and [CII] line emissions across redshifts from 0 to 3.5. The focal plane will feature six µ-Spec spectrometers. µ-Spec is an integrated grating-analog spectrometer, which uses a superconducting Nb microstrip transmission line on single-crystal Si dielectric to introduce the required phase gradients, and Microwave Kinetic Inductance Detectors (MKIDs). The spectrometers will operate from 420-540 GHz with a resolution R = λ/Δλ = 512. We report the status of spectrometers under development for EXCLAIM, including the design, fabrication development and steps, and preliminary measurements.