New measurements from the CAPMAP experiment of the CMB E-mode power spectrum at high multipoles, and new limits on B-mode power

The Cosmic Microwave Background (CMB) is among the most fruitful sources of cosmological data ever found, and observations have only begun to tap its potential. Measurements of its temperature anisotropies have helped to revolutionize our understanding of the composition and evolution of the universe.; The Lambda-CDM standard model of cosmology produces tightly constrained predictions of the angular power spectrum of E-mode (curl free) polarization anisotropies, and over the past 5 years, detections and measurements of this spectrum have served as further compelling evidence in support of this model.; The Cosmic Anisotropy Polarization MAPper (CAPMAP) experiment was designed to measure the CMB E-mode angular power spectrum in the high-l (small angular scale) regime. As presented in this work, the data collected through its final season of operation have allowed CAPMAP to produce a measurement of the E-mode spectrum as strong as any to date, with unique sensitivity at fine angular scales.; This thesis details the development and characterization of the instrument used through the final season of CAPMAP observations, followed by discussions of those observations and of the analysis of the resulting dataset. We conclude with the presentation and discussion of the EE measurement itself, which agrees strikingly well with that predicted by the Lambda-CDM model, and present upper limits on the power in CMB B-mode (divergence free) polarization.