I am an observational cosmologist, and an experimental physicist. I build ultra-low-noise detectors using superconducting and quantum sensing techniques, and use them in experiments and instrumentation for cosmology. I currently spend most of my time investigating the inflation paradigm of standard cosmology, using the cosmic microwave background (CMB). Recently, I've become interested in using the weak lensing of the CMB in conjunction with galaxy surveys to study the growth of large-scale structure in the universe.
I received my PhD in particle astrophysics from Caltech in 2012, working on direct detection of WIMP dark matter with the CDMS-II experiment. I then shifted my effort to searching for inflation with the CMB. I was a postdoctoral scholar at Stanford through 2015 before being appointed as a Wolfgang Panofsky Fellow at SLAC National Accelerator Laboratory. In 2017, I won a DOE Office of Science Early Career Award to work on new signal transduction and superconducting multiplexing techniques for next-generation CMB cameras. I am currently appointed as a Lead Scientist at SLAC, where I am CMB department head. I also serve as scientific project manager for the bring up of SLAC's Detector Microfabrication facility for the development of superconducting and quantum sensors and devices.
SLAC microresonator RF (SMuRF) electronics: A tone-tracking readout system for superconducting microwave resonator arrays.
The Review of scientific instruments
2023; 94 (1): 014712
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 (mumux) 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 4-8GHz 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.
View details for DOI 10.1063/5.0125084
View details for PubMedID 36725567
- CMB-S4: Forecasting Constraints on Primordial Gravitational Waves ASTROPHYSICAL JOURNAL 2022; 926 (1)
- Advanced RFSoC readout for space-based superconducting sensor arrays SPIE-INT SOC OPTICAL ENGINEERING. 2022
- A simulation suite for readout with SMuRF tone-tracking electronics SPIE-INT SOC OPTICAL ENGINEERING. 2022
- Phase Drift Monitoring for Tone Tracking Readout of Superconducting Microwave Resonators SPIE-INT SOC OPTICAL ENGINEERING. 2022
- The Simons Observatory Microwave SQUID Multiplexing Detector Module Design ASTROPHYSICAL JOURNAL 2021; 922 (1)
- The Simons Observatory: science goals and forecasts JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS 2019
- Next-generation small CMB telescopes SPIE-INT SOC OPTICAL ENGINEERING. 2018
- Highly-multiplexed microwave SQUID readout using the SLAC Microresonator Radio Frequency (SMuRF) Electronics for Future CMB and Sub-millimeter Surveys SPIE-INT SOC OPTICAL ENGINEERING. 2018