Fabrication of Feedhorn-Coupled Transition Edge Sensor Arrays for Measurement of the Cosmic Microwave Background Polarization
Abstract
Characterization of the minute cosmic microwave background polarization signature requires multi-frequency, high-throughput precision instrument systems. We have previously described the detector fabrication of a 40 GHz focal plane and now describe the fabrication of detector modules for measurement of the CMB at 90 GHz. The 90 GHz detectors are a scaled version of the 40 GHz architecture where, due to smaller size detectors, we have implemented a modular (wafer level) rather than the chip-level architecture. The new fabrication process utilizes the same design rules with the added challenge of increased wiring density to the 74 TES's as well as a new wafer level hybridization procedure. The hexagonally shaped modules are tile-able, and as such can be used to form the large focal planes required for a space-based CMB polarimeter. The detectors described here will be deployed in two focal planes with seven modules each in the Johns Hopkins University led ground-based Cosmology Large Angular Scale Surveyor (CLASS) telescope.
- Publication:
-
Journal of Low Temperature Physics
- Pub Date:
- August 2016
- DOI:
- 10.1007/s10909-015-1366-y
- arXiv:
- arXiv:1511.05036
- Bibcode:
- 2016JLTP..184..668D
- Keywords:
-
- TES;
- CMB;
- Wafer bonding;
- Micro-machining;
- Polarization;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 7 pages, 4 figures, Presented at Low Temperature Detectors Conference Grenoble France 2015