Department of Physics, Stanford University, Stanford, California 94305, USA.
Kavli Institute for Particle Astrophysics and Cosmology, Stanford, California 94305, USA.
Rev Sci Instrum. 2023 Jan 1;94(1):014712. doi: 10.1063/5.0125084.
We describe the newest generation of the SLAC Microresonator RF (SMuRF) electronics, a warm digital control and readout system for microwave-frequency resonator-based cryogenic detector and multiplexer systems, such as microwave superconducting quantum interference device multiplexers (μmux) or microwave kinetic inductance detectors. Ultra-sensitive measurements in particle physics and astronomy increasingly rely on large arrays of cryogenic sensors, which in turn necessitate highly multiplexed readout and accompanying room-temperature electronics. Microwave-frequency resonators are a popular tool for cryogenic multiplexing, with the potential to multiplex thousands of detector channels on one readout line. The SMuRF system provides the capability for reading out up to 3328 channels across a 4-8 GHz bandwidth. Notably, the SMuRF system is unique in its implementation of a closed-loop tone-tracking algorithm that minimizes RF power transmitted to the cold amplifier, substantially relaxing system linearity requirements and effective noise from intermodulation products. Here, we present a description of the hardware, firmware, and software systems of the SMuRF electronics, comparing achieved performance with science-driven design requirements. In particular, we focus on the case of large-channel-count, low-bandwidth applications, but the system has been easily reconfigured for high-bandwidth applications. The system described here has been successfully deployed in lab settings and field sites around the world and is baselined for use on upcoming large-scale observatories.
我们介绍了 SLAC 微谐振器 RF（SMuRF）电子设备的最新一代产品，这是一种用于微波频率谐振器的低温探测器和多路复用器系统的暖数字控制和读出系统，例如微波超导量子干涉装置多路复用器（μmux）或微波动力学电感探测器。粒子物理和天文学中的超灵敏测量越来越依赖于大型低温传感器阵列，这反过来又需要高度多路复用的读出和伴随的室温电子设备。微波频率谐振器是低温多路复用的一种流行工具，具有在一条读出线上多路复用数千个探测器通道的潜力。SMuRF 系统提供了在 4-8GHz 带宽内读取多达 3328 个通道的能力。值得注意的是，SMuRF 系统在实现闭环调谐算法方面具有独特性，该算法将传输到冷放大器的 RF 功率最小化，从而大大放宽了系统线性度要求和来自互调产物的有效噪声。在这里，我们介绍了 SMuRF 电子设备的硬件、固件和软件系统的描述，比较了实现的性能与科学驱动的设计要求。特别是，我们关注大通道计数、低带宽应用的情况，但该系统已轻松针对高带宽应用进行了重新配置。这里描述的系统已在世界各地的实验室和现场成功部署，并已作为即将推出的大型观测站的基准。
