Research Infrastructure: MRI: Development of a Small Aperture Telescope Pathfinder to Advance Studies of the Polarized Cosmic Microwave Background

This Major Research Instrumentation project will help answer the big question: “how did the universe begin?” It does so by building and testing a sensitive instrument that would measure electromagnetic emission that fills space as a result of processes in the early universe. This emission is best measured at microwave wavelengths, so it is referred to as the cosmic microwave background (CMB).

A small protype instrument, referred to as pSAT, will be built to evaluate many of the technologies that have been developed for a future, large experiment to measure the CMB far more precisely. The members of this research team will engage with educators and the public on observing/measuring the origins of the universe. Within the larger CMB experiment program, this project will provide research experience for graduate and undergraduate students, as well as training for postdoctoral researchers.

Finding direct evidence for cosmic inflation is an important goal in astronomy and physics today. Inflation models predict the existence of primordial gravitational waves, which impart a unique “B-mode” pattern to the polarization of the cosmic microwave background (CMB) and provide a key test of such models. There have been an improving series of instruments to make the needed measurements.

This project will develop and test pSAT, a CMB polarimeter integrating detectors and optics developed for the next-generation CMB-S4 project with existing field-proven BICEP Array hardware. pSAT will utilize new 95 GHz/155 GHz dual-band dual-polarization prototype detectors, with prototype optics incorporating wide-band AR coatings, in a BICEP array receiver cryostat that will be adapted to include a 100mK adiabatic demagnetization refrigerator. The engineering, performance evaluation, and representative data will be provided to the CMB-S4 project.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.