Measurement of the Polarization of the Cosmic Microwave Background with the SPIDER Instrument

Abstract

SPIDER is a balloon-borne polarimeter designed to measure the degree-scale polarization of the cosmic microwave background (CMB). If gravitational waves in the early Universe were of appreciable amplitude, they would have imprinted a unique signature in the large-scale B-mode CMB polarization, parameterized by the tensor-to-scalar ratio, r. With two flights, SPIDER should have the sensitivity to constrain r < 0.03 with 3σ confidence. To achieve this sensitivity, SPIDER used more than 1000 polarization-sensitive bolometers at 150 GHz and over 600 at 95 GHz. With the advantage of the low loading environment at 36 km altitude, SPIDER achieved the best instantaneous sensitivity of any CMB experiment to date.

SPIDER’s first flight in January 2015 lasted for 16 days, covering 12% of the southern sky. The first half of this dissertation discusses the instrumentation used in the first flight and the achieved performance of the subsystems. The second half details the analysis pipeline, from low-level processing of the raw data to the latest science results.

SPIDER’s second flight will add 285 GHz receivers to better characterize Galactic dust in our region. Dust polarization is expected to be the limiting factor in SPIDER’s achieved upper limit on r. Though this dissertation will not discuss instrumentation for SPIDER’s second flight, it will provide suggestions for improvement based on lessons learned from the first flight.