BOOMERANG: A balloon-borne millimeter-wave telescope and total power receiver for mapping anisotropy in the cosmic microwave background

We describe BOOMERANG, a balloon-borne microwave telescope designed to map the cosmic microwave background at a resolution of 10' from the Long Duration Balloon (LDB) platform. The millimeter-wave receiver employs new technology in bolometers, readout electronics, cold reimaging optics, millimeter-wave filters, and cryogenics to obtain high sensitivity to cosmic microwave background anisotropy. Sixteen detectors observe in four spectral bands centered at 90, 150, 240, and 410 GHz. The wide frequency coverage, the long-duration flight, the optical design, and the observing strategy provide strong rejection of systematic effects. We report the flight performance of the instrument during a 10.5 day stratospheric balloon flight launched from McMurdo Station, Antarctica, that mapped similar to2000 square degrees of the sky.