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A Limit on the Polarization of the Cosmic Microwave Background Radiation


Cartwright, John Kenneth (2003) A Limit on the Polarization of the Cosmic Microwave Background Radiation. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/D3CT-YV96.


We describe polarization observations of the CMBR with the Cosmic Background Imager, a 13-element interferometer which operates in the 26-36 GHz band and is located on the Llano de Chajnantor in northern Chile. The array consists of 90 cm Cassegrain antennas mounted on a steerable platform which can be rotated about the optical axis to facilitate polarization observations. The CBI employs single-mode circularly polarized receivers and it samples multipoles from ℓ ~ 400 to ℓ ~ 4250. The instrumental polarization of the CBI was calibrated with 3C279, a bright polarized point source which was monitored with the VLA. Observations of two deep fields during the 2000 season yielded three limits (95% c.l.) for CEE under the assumption that CBB = 0: 7.0 µK (ℓ = 603); 12.8 µK (ℓ = 1144); and 25.1 µK (ℓ = 2048). The low-ℓ limit approaches the levels of fluctuations predicted by standard models.

This thesis also entailed the design and implementation of several major components of the CBI signal chain including the downconverter, the noise calibration system, and the low noise HEMT amplifiers. We discuss the design and performance of these critical systems.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:CMB; CMBR; cosmic microwave background radiation; cosmology; microwave; microwave instrumentation; polarization
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Astronomy
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Readhead, Anthony C. S.
Group:Owens Valley Radio Observatory (OVRO), Astronomy Department
Thesis Committee:
  • Phinney, E. Sterl (chair)
  • Lange, Andrew E.
  • Readhead, Anthony C. S.
  • Zmuidzinas, Jonas
  • Padin, Steve
Defense Date:12 November 2002
Record Number:CaltechETD:etd-05292003-131234
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2230
Deposited By: Imported from ETD-db
Deposited On:29 May 2003
Last Modified:05 Nov 2021 22:39

Thesis Files

PDF (jkc_thesis.pdf) - Final Version
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