Fabrication Development for SPT-SLIM, a Superconducting Spectrometer for Line Intensity Mapping
Line Intensity Mapping (LIM) is a new observational technique that uses low-resolution observations of line emission to efficiently trace the large-scale structure of the Universe out to high redshift. Common mm/sub-mm emission lines are accessible from ground-based observatories, and the requirements on the detectors for LIM at mm-wavelengths are well matched to the capabilities of large-format arrays of superconducting sensors. We describe the development of an R = lambda/Delta lambda = 300 on-chip superconducting filter-bank spectrometer covering the 120-180 GHz band for future mm-LIM experiments, focusing on SPT-SLIM, a pathfinder LIM instrument for the South Pole Telescope. Radiation is coupled from the telescope optical system to the spectrometer chip via an array of feedhorn-coupled orthomode transducers. Superconducting microstrip transmission lines then carry the signal to an array of channelizing half-wavelength resonators, and the output of each spectral channel is sensed by a lumped element kinetic inductance detector (leKID). Key areas of development include incorporating new low-loss dielectrics to improve both the achievable spectral resolution and optical efficiency and development of a robust fabrication process to create a galvanic connection between ultra-pure superconducting thin-films to realize multi-material (hybrid) leKIDs. We provide an overview of the spectrometer design, fabrication process, and prototype devices.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- Natural Sciences and Engineering Research Council of Canada (NSERC); USDOE Office of Science - Office of Basic Energy Sciences; USDOE Office of Science - Office of High Energy Physics; National Science Foundation (NSF); Canadian Institute for Advanced Research (CIFAR)
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 2427967
- Country of Publication:
- United States
- Language:
- English
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