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Search Publications by: Tammy Lucas (Fed)

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Displaying 1 - 5 of 5

Demonstration of a 1,820 channel microwave superconducting quantum1 interference device multiplexer for transition-edge sensor bolometers

July 15, 2025
Author(s)
John Groh, Jason Austermann, James Beall, Shannon Duff, Johannes Hubmayr, Richard Lew, Michael Link, Tammy Lucas, John Mates, Robinjeet Singh, Joel Ullom, Leila Vale, Jeffrey Van Lanen, Michael Vissers
The scalability of most transition-edge sensor arrays is limited by the multiplexing technology which combines their18 signals over a reduced number of wires and amplifiers. In this letter, we present and demonstrate a new multiplexer19 design optimized

The Simons Observatory: Production-Level Fabrication of the Mid- and Ultra-High-Frequency Wafers

May 4, 2024
Author(s)
Shannon Duff, Jason Austermann, James Beall, David Daniel, Johannes Hubmayr, Gregory Jaehnig, Bradley Johnson, Dante Jones, Michael J. Link, Tammy Lucas, Rita Sonka, Suzanne Staggs, Joel Ullom, Yuhan Wang
The Simons Observatory (SO) is a cosmic microwave background instrumentation suite in the Atacama Desert of Chile. More than 65,000 polarization-sensitive transition-edge sensor (TES) bolometers will be fielded in the frequency range spanning 27 to 280 GHz

Indium Bump Bonding: Advanced Integration Techniques for Low-Temperature Detectors and Readout

April 20, 2024
Author(s)
Tammy Lucas, John Biesecker, W.Bertrand (Randy) Doriese, Shannon Duff, Malcolm Durkin, Richard Lew, Joel Ullom, Michael Vissers, Dan Schmidt
We have examined the influence of bump shape and bonding pressure on low temperature electrical properties of indium bump connections including transition temperature, normal resistance, and superconducting critical current. We describe our test structures

Symmetric time-division-multiplexed SQUID readout with two-layer switches for future TES observatories

April 4, 2023
Author(s)
Malcolm Durkin, Scott Backhaus, Simon Bandler, James Chervenak, Ed Denison, W.Bertrand (Randy) Doriese, Johnathon Gard, Gene C. Hilton, Richard Lew, Tammy Lucas, Carl D. Reintsema, Dan Schmidt, Stephen Smith, Joel Ullom, Leila R. Vale, Michael Vissers, Nicholas Wakeham
Time-division multiplexing (TDM) of transition-edge-sensor (TES) microcalorimeters is being developed as the readout tech-nology for the Athena X-ray integral field unit (X-IFU) and is under consideration for future TES-bolometer missions like CMB-S4. We

Indium Bump Process for Low-Temperature Detectors and Readout

May 20, 2022
Author(s)
Tammy Lucas, John Biesecker, W.Bertrand (Randy) Doriese, Shannon Duff, Gene C. Hilton, Joel Ullom, Michael Vissers, Dan Schmidt
We describe our indium bump process for low-temperature detectors and associated readout. A titanium nitride under bump metallization layer (UBM) is reactively sputtered onto wiring pads as a diffusion barrier and adhesion layer. Indium is thermally
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