CCAT-prime: the 850GHz camera for prime-cam on FYST

Abstract

The Fred Young Submillimeter Telescope (FYST) at the Cerro-Chajnantor Atacama Telescope prime (CCATprime) Facility will host Prime-Cam as a powerful, first generation camera with imaging polarimeters working at several wavelengths and spectroscopic instruments aimed at intensity mapping during the Epoch of Reionization.Here we introduce the 850 GHz (350 micron) instrument module. This will be the highest frequency module in Prime-Cam and the most novel for astronomical and cosmological surveys, taking full advantage of the atmospheric transparency at the high 5600 meter CCAT-prime siting on Cerro Chajnantor. The 850 GHz module will deploy ∼40,000 Kinetic Inductance Detectors (KIDs) with Silicon platelet feedhorn coupling (both fabricated at NIST), and will provide unprecedented broadband intensity and polarization measurement capabilities. The 850 GHz module will be key to addressing pressing astrophysical questions regarding galaxy formation, Big Bang cosmology, and star formation within our own Galaxy. We present the motivation and overall design for the module, and initial laboratory characterization.

CCAT-prime: optical and cryogenic design of the 850 GHz module for Prime-Cam

“…Additionally, the inclusion of a fifth lens reduces the throughput of the instrument module by 4%, which results in a significant reduction in the mapping speed of the module. 23 It is clear that unless the number of the detectors is pushed beyond 45,000, there is no real advantage to the inclusion of a fifth lens. The final variable explored in this work is the degree of allowable field curvature at the image plane of the system.…”

“…28 From the current optical design detailed above, the 850 GHz module is proposed to include 41,400 KIDs across three wafer arrays, the details of which are given in a companion paper. 23 Assuming the readout bandwidth is doubled, the 850 GHz module will require 9 Radio Frequency System-on-Chip (RFSoC) boards, 29 36 cryogenic LNAs, 108 cryoattenuators, and 72 transmission lines. A rough thermal budget for implementation in Prime-Cam is used based on a preliminary analysis of the instrument as these constraints are tighter than those of the LD250 testbed.…”

Neutrino Properties with Ground-based Millimeter-wavelength Line Intensity Mapping

“…In addition to 21cm line of hyperfine transition of neutral Hydrogen, LIM at mm/submm wavelengths, targeting spectral emission lines with rest-frame wavelengths in the far infrared (e.g., rotational lines of carbon monoxide CO(J→J-1) (Righi et al 2008;Lidz et al 2011;Breysse et al 2014;Mashian et al 2015;Li et al 2016;Padmanabhan 2018) and fine structure of ionized carbon [CII]) (Gong et al 2011a;Silva et al 2015;Pullen et al 2018;Padmanabhan 2019), has recently attracted a growing attention both in the context of galaxy/star formation (Gong et al 2011b;Kovetz et al 2020;Bernal & Kovetz 2022) and cosmology (Karkare & Schaan & White 2021a,b;Scott et al 2022). The wide array of pathfinder experiments such as CCAT-Prime (Chapman et al 2022), COMAP (Cleary et al 2021), CONCERTO (Ade et al 2020a), COPSS (Keating et al 2016), EX-CLAIM (Ade et al 2020b), mmIME (Keating et al 2020), SPT-SLIM (Karkare et al 2022b), TIME (Crites et al 2014a), are paving the way for future wide-field surveys capable of providing high-precision constraints on cosmology by providing robust detection of the line intensity power spectrum and constraining the astrophysical model dependencies of the signal. Establishing the science cases for future surveys and determining optimized survey strategies to achieve relevant theoretical thresholds is of uttermost importance.…”