CCAT: FYST Prime-Cam Readout Software: A framework for massively scalable KID arrays

TL;DR

This paper presents a scalable readout software framework for large KID arrays on the CCAT FYST telescope, enabling control of tens of thousands of detectors with modest hardware and paving the way for future millions.

Contribution

It introduces a novel RFSoC-based readout architecture that scales linearly with detector count, supporting massively large KID arrays for submillimeter astronomy.

Findings

Supports up to 4000 KIDs per RFSoC board

Enables control of tens-of-thousands of KIDs with modest hardware

Demonstrates linear scalability of computational demands

Abstract

We outline the development of the readout software for the Prime-Cam and Mod-Cam instruments on the CCAT Fred Young Submillimeter Telescope (FYST), primecam_readout. The instruments feature lumped-element kinetic inductance detector (LEKID) arrays driven by Xilinx ZCU111 RFSoC boards. In the current configuration, each board can drive up to 4000 KIDs, and Prime-Cam is implementing approximately 25 boards. The software runs on a centralized control computer connected to the boards via dedicated ethernet, and facilitates such tasks as frequency-multiplexed tone comb driving, comb calibration and optimization, and detector timestream establishment. The control computer utilizes dynamically generated control channels for each board, allowing for simultaneous parallel control over all, while uniquely tracking diagnostics for each. This work demonstrates a scalable RFSoC readout architecture where computational demands increase linearly with the number of detectors, enabling control of tens-of-thousands of KIDs with modest hardware, and opening the door to the next generation of KID arrays housing millions of detectors.