Development of superconducting microwave resonators for terahertz intensity mapping from balloon and space

The far-infrared (FIR) wavelength band provides valuable insight into our cosmic origins. A powerful new technique for FIR cosmology is 3-D line intensity mapping (LIM), in which the aggregate emission of a spectral line is mapped as a function of space and cosmic time. After a brief introduction to this technique, I demonstrate the Terahertz Intensity Mapper (TIM): a balloon-borne FIR spectrometer designed to observe key spectral line tracers at the epoch of peak cosmic star formation (z ∼1-3), in order to unveil the processes of galactic evolution. In preparation for TIM’s first flight, currently planned for 2024-2025, I present the design and optimization of the KID arrays. This thesis discusses the design for the Inter-Digitated Capacitors (IDC) and evaluates the KID’s inductor performance by implementing electromagnetic simulations, as well as a custom transmission line model and mode-matching calculations, which provide guidance for its optimization for low-resistance absorber materials. As the main topic for this thesis, the characterizations of the fabricated KIDs, with an emphasis on optical efficiency measurements with two experimental configurations, demonstrate the expected detector performance. In addition, a method that can characterize the absorber’s performance at ambient temperature is described. Lastly, I introduce the development of a novel on-chip spectrometer technology for space-borne FIR intensity observations at higher frequencies. I describe the design & fabrication progress of this spectrometer and preliminary measurement results. Key contributions include (i) TIM detector (for both capacitor and inductor) design and optimization; (ii) TIM detector characterization, with an emphasis on the optical efficiency measurement; (iii) design and fabrication of a novel terahertz on-chip spectrometer; (iv) implementation of various nano/micro-scale fabrication and characterization techniques for FIR cosmology detectors.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Nie, Rong

Contributors dc:contributor

• Filippini, Jeffrey Peter
• Vieira, Joaquin Daniel
• Holder, Gilbert Patrick
• Mahmood, Fahad

• Far-infrared
• Line Intensity Mapping
• Kinetic Inductance Detector
• Terahertz Intensity Mapper
• On-chip Spectrometer

Statement dc:rights

• Copyright 2023 Rong Nie

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/120267

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F120267