B-Machine Polarimeter: A Telescope to Measure the Polarization of the Cosmic Microwave Background

TL;DR

The B-Machine Telescope introduces a novel half wave plate technique for measuring CMB polarization, offering improved noise performance and large sky coverage in its first-year observations.

Contribution

It presents a new polarization measurement method using a room temperature half wave plate, differing from standard correlation receiver techniques.

Findings

Demonstrated a demodulated 1/f knee of 5 mHz

Achieved an average sensitivity of 1.6 mK√s

Produced initial sky maps and power spectra

Abstract

The B-Machine Telescope is the culmination of several years of development, construction, characterization and observation. The telescope is a departure from standard polarization chopping of correlation receivers to a half wave plate technique. Typical polarimeters use a correlation receiver to chop the polarization signal to overcome the $1/f$ noise inherent in HEMT amplifiers. B-Machine uses a room temperature half wave plate technology to chop between polarization states and measure the polarization signature of the CMB. The telescope has a demodulated $1/f$ knee of 5 mHz and an average sensitivity of 1.6 $\mathrm{mK}\sqrt{\mathrm{s}}$. This document examines the construction, characterization, observation of astronomical sources, and data set analysis of B-Machine. Preliminary power spectra and sky maps with large sky coverage for the first year data set are included.