DASI: A Degree Angular Scale Interferometer for Imaging Anisotropy in the Cosmic Microwave Background

• Main Authors: Halverson Carlstrom Dragovan, N. W. Halverson, J. E. Carlstrom, M. Dragovan, W. L. Holzapfel, J. Kovac
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: interferometry; cosmic microwave background; cosmology; South Pole; South pole
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.25.856; http://astro.uchicago.edu/dasi/spie/spie-dasi-paper-rev.ps.gz

The Degree Angular Scale Interferometer (DASI) is a compact cm-wave interferometer designed to image anisotropy in the Cosmic Microwave Background (CMB) and to measure its angular power spectrum. The power spectrum will be densely sampled over the ` range 160 to 710, corresponding to angular scales of 0.25 to 1.15 degrees. DASI consists of 13 elements. Each element consists of a 20-cm diameter lensed corrugated horn followed by a cooled low-noise HEMT amplifier operating from 26 - 36 GHz. All elements are mounted on a single alt-az mount, which fixes the projected baselines and obviates an IF tracking delay. The mount also includes rotation of the aperture plane along the line of sight to improve the u; v coverage and the control of instrumental systematics. The 10 GHz IF bandwidth will be correlated in 1 GHz bands to provide spectral index information. The instrument is scheduled to be completed in Summer 1998. After extensive testing it will be deployed at the South Pole for year-round operation starting in November 1999.