We present preparation for fabrication and deployment of science-grade kilo-pixel Kinetic Inductance Detector (KID) based arrays for the Terahertz Intensity Mapper (TIM). TIM is a NASA-funded balloon-borne experiment planning its Antarctic flight for 2026. TIM employs two focal planes, each with four subarrays of ~900 hexagonal-packed, horn-coupled aluminum KIDs. Fabrication yield is high, and we have successfully mapped KID resonant frequencies to spatial locations with our LED mapper. The spatial and frequency information associated with every yielded pixel allows a study of spatial coincidences as cosmic rays interact with the array, as well as interpretation of a covariance analyses performed on the noise timestreams. We also describe the improvement on the science-usable yield of our 864-pixel array achieved by (1) the lithographic trimming that de-collides resonators, and (2) our characterization of interpixel crosstalk. This pioneering work on the postprocessing will pave the way for science with our large KID arrays.

We report on the effects of cosmic ray interactions with the kinetic inductance detector (KID)-based focal plane array for the terahertz intensity mapper (TIM). TIM is a NASA-funded balloon-borne experiment designed to probe the peak of the star formation in the Universe. It employs two spectroscopic bands, each equipped with a focal plane of four ∼ 900-pixel, KID-based array chips. Measurements of an 864-pixel TIM array show 791 resonators in a 0.5 GHz bandwidth. We discuss challenges with resonator calibration caused by this high multiplexing density. We robustly identify the physical positions of 788 (99.6 events/min/cm^2 in our array. 66 < 5 KIDs per event spread over a 0.66 cm^2 region (2 pixel pitches in radius). We observe a total cosmic ray dead fraction of 0.0011 ∼ 0.124

The Terahertz Intensity Mapper (TIM) is a NASA-funded balloon-borne telescope that aims to measure the [CII] emission from star forming galaxies over an enormous cosmic volume. TIM's cryogenic receiver, based on the BLAST-TNG design, utilizes a three-stage He sorption refrigerator backed by a 280-liter liquid helium tank to achieve a base temperature of 250 mK, which enables photon noise-limited performance for its MKID detectors. Two low-impedance multi-channel heat exchangers enhance cooling efficiency, contributing to a designed hold time of 20 days under ground conditions. Preliminary simulations and assembly tests showcase the cryostat's reliability, and data validation is anticipated by the summer of 2024. We will present the design and current status of the TIM cryogenic receiver and our ongoing characterization effort toward an Antarctic flight in 2026.

Traditional technologies for far-infrared (FIR) spectroscopy generally involve bulky dispersive optics. Integrated filter bank spectrometers promise more compact designs, but implementations using superconducting transmission line networks become lossy at terahertz frequencies. We describe a novel on-chip spectrometer architecture designed to extend this range. A filter bank spectrometer is implemented using vacuum waveguide etched into a silicon wafer stack. A single trunk line feeds an array of resonant cavities, each coupled to a kinetic inductance detector fabricated on an adjacent wafer. We discuss the design and fabrication of a prototype implementation, initial test results at ambient temperature, and prospects for future development.

The Terahertz Intensity Mapper (TIM) is a balloon-borne far-infrared imaging spectrometer designed to characterize the star formation history of the universe. In its Antarctic science flight, TIM will map the redshifted 158um line of ionized carbon over the redshift range 0.5-1.7 (lookback times of 5-10 Gyr). TIM will spectroscopically detect ~100 galaxies, determine the star formation rate history over this time interval through line intensity mapping, and measure the stacked CII emission from galaxies in its well-studied target fields (GOODS-S, SPT Deep Field). TIM consists of a 2-meter telescope feeding two grating spectrometers that that cover 240-420um at R~250 across a 1.3deg field of view, detected with 7200 kinetic inductance detectors and sampled through a novel RF system-on-chip readout. TIM will serve as an important scientific instrument, accessing wavelengths that cannot easily be studied from the ground, and as a testbed for future FIR space technology.