Bolometric interferometry: the millimeter-wave bolometric interferometer G.S. Tucker a, * , J. Kim a , P. Timbie b , S. Ali b , L. Piccirillo c , C. Calderon c a Brown University, Providence, RI 02912, USA b Department of Physics, University of Wisconsin, Madison, WI 53706-1390, USA c Cardiff University, Wales, 5 The Parade, Cardiff, CF24 3YB, UK Abstract Bolometric interferometry is not a new idea, but this technique has not been demonstrated at millimeter wavelengths. The millimeter-wave bolometric interferometer combines the advantages of two well-developed technologies – inter- ferometers and bolometric detectors – and will open a new region of sensitivity and angular resolution not previously accessible to other instruments. Ó 2003 Elsevier B.V. All rights reserved. 1. Introduction We are in the process of building an instrument called the millimeter-wave bolometric interferom- eter (Ali et al., 2002). Initially we are building a small baseline (<1 m) version of the instrument, which is called MBI-B. Given the small baseline, this instrument will probe relatively large angular scales (>1°). MBI-B will demonstrate bolometric interferometry at millimeter wavelengths. Later we hope to build a longer baseline (few m) version of this instrument, which is called simply MBI. Concepts for MBI-B and MBI are illustrated in Fig. 1. The scientific goals of MBI-B are to search for primordial B-mode polarization in the CMB and to map magnetic fields near the core of the galaxy. MBI addresses somewhat different scientific goals. It is designed to: (1) characterize the polar- ization of the CMB, (2) characterize clustering in the far-infrared background (FIRB), (3) measure wavelength dependent properties of dust polari- zation, and (4) conduct searches for and charac- terize the Sunyaev-ZelÕdovich effect. The technology goals for both MBI-B and MBI are to: (1) demonstrate aperture synthesis at mil- limeter wavelengths using an array of bolometers, (2) demonstrate deep integration on a single field without spatial chopping, (3) demonstrate advan- tages of millimeter-wave interferometry for the control of systematic effects. 2. Bolometric interferometry A bolometric interferometer is an adding inter- ferometer as opposed to a multiplying interferom- eter (Rohlfs and Wilson, 1996) as illustrated in New Astronomy Reviews 47 (2003) 1173–1176 www.elsevier.com/locate/newastrev * Corresponding author. E-mail address: tucker@physics.brown.edu (G.S. Tucker). 1387-6473/$ - see front matter Ó 2003 Elsevier B.V. All rights reserved. doi:10.1016/j.newar.2003.09.024