The Atacama Cosmology Telescope / Daniel S. Swetz.

Format:

Book

Manuscript

Microformat

Thesis/Dissertation

Author/Creator:

Swetz, Daniel S.

Contributor:

Devlin, Mark, advisor.

University of Pennsylvania.

Language:

English

Subjects (All):

Penn dissertations--Physics and astronomy.

Physics and astronomy--Penn dissertations.

Local Subjects:

Penn dissertations--Physics and astronomy.

Physics and astronomy--Penn dissertations.

Physical Description:

xi, 182 pages : illustrations ; 29 cm

Production:

2009.

Summary:

The Atacama Cosmology Telescope (ACT) is a 6-meter diameter telescope designed to make detailed measurements at millimeter wavelengths with arcminute resolution. The telescope is located at an altitude of 5,190 meters in the Atacama desert in the Chilean Andes. The primary science instrument for ACT is the Millimeter Bolometer Array Camera (MBAC). MBAC measures the Cosmic Microwave Background (CMB) temperature anisotropy at angular scales corresponding to multipole 100 ≲ l ≲ 10,000. It contains three separate kilo-pixel arrays of transition-edge sensor (TES) bolometers in frequency bands centered at 145, 220, and 280 GHz. At small angular scales, the temperature anisotropies are dominated by interactions of CMB photons with large-scale structure on their transit from the surface of last scattering to the observer. The largest signal arises from the thermal Sunyaev-Zel'dovich (tSZ) effect, a spectral distortion of the CMB caused by inverse-Compton scattering of CMB photons as they pass through hot gas in clusters of galaxies. By combining the millimeter-wave tSZ galaxy-cluster measurements with optical and X-ray data, the masses, temperatures, and redshifts of the clusters can be determined. The cluster density function (number counts as a function of redshift) will help map out the growth of structure in the universe. The measure of structure formation will help constrain the dark-energy equation of state.

My thesis discusses the scientific background and motivation for ACT. I present on overview of the telescope design, the alignment of the mirrors, and the choice of the site location and scan strategy. A detailed design of the MBAC receiver is given, including the integration of the bolometer arrays and their multiplexed readout; the cold, refractive, reimaging optics; the band-defining filters; the liquid-cryogens-free system employed to cool the optics and arrays; and the structural interface and alignment to the telescope. I report on the characterization and performance of the receiver during the commissioning in the fall of 2007. I present an analysis of targeted planet observations that were used to assess the beam shape, optical alignment, telescope stability, and to develop a night-by-night corrected pointing model. Finally, I discuss the preliminary science results from the 2008 season.

Notes:

Adviser: Mark Devlin.

Thesis (Ph.D. in Physics and Astronomy) -- University of Pennsylvania, 2009.

Includes bibliographical references.

Local Notes:

University Microfilms order no.: 3363673.