QUBIC III: Laboratory Characterization

Abstract

A prototype version of the Q & U Bolometric Interferometer for Cosmology (QUBIC) underwent a campaign of testing in the laboratory at Astroparticle Physics and Cosmology in Paris. We report the results of this Technological Demonstrator which successfully shows the feasibility of the principle of Bolometric Interferometry. Characterization of QUBIC includes the measurement of the synthesized beam, the measurement of interference fringes, and the measurement of polarization performance. A modulated and frequency tunable millimetre-wave source in the telescope far-field is used to simulate a point source. The QUBIC pointing is scanned across the point source to produce beam maps. Polarization modulation is measured using a rotating Half Wave Plate. The measured beam matches well to the theoretical simulations and gives QUBIC the ability to do spectro imaging. The polarization performance is excellent with less than 0.5\% cross-polarization rejection. QUBIC is ready for deployment on the high altitude site at Alto Chorillo, Argentina to begin scientific operations.

Part of a series of 8 papers on QUBIC accepted by JCAP for a special issue: https://iopscience.iop.org/journal/1475-7516/page/QUBIC_status_and_forecast

References in corpus (12)

• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• The Quest for B Modes from Inflationary Gravitational Waves
• Measurements of the E-Mode Polarization and Temperature-E-Mode Correlation of the CMB from SPT-3G 2018 Data
• QUBIC I: Overview and ScienceProgram
• Self-calibration: an efficient method to control systematic effects in bolometric interferometry
• QUBIC IV: Performance of TES Bolometers and Readout Electronics
• QUBIC V: Cryogenic system design and performance
• QUBIC VIII: Optical design and performance
• QUBIC II: Spectro-Polarimetry with Bolometric Interferometry
• QUBIC VI: cryogenic half wave plate rotator, design and performances
• QUBIC Technical Design Report
• On the emissivity of wire-grid polarizers for astronomical observations at mm-wavelengths

Cited by in corpus (7)

• QUBIC I: Overview and ScienceProgram
• QUBIC IV: Performance of TES Bolometers and Readout Electronics
• QUBIC VIII: Optical design and performance
• QUBIC V: Cryogenic system design and performance
• QUBIC II: Spectro-Polarimetry with Bolometric Interferometry
• QUBIC VI: cryogenic half wave plate rotator, design and performances
• QUBIC VII: The feedhorn-switch system of the technological demonstrator