B-Machine prototype.

The telescope pictured below is a CMB polarimeter operating at 40 GHz. It was installed at the WMRS Barcroft facility in August, 2008, and has been surveying a large part of the sky for 3 months. The system is a prototype for a future array of telescopes using the same techniques. Data from this telescope are being analyzed to assess the feasibility of measuring CMB polarization on the largest angular scales with a ground based instrument.

This prototype uses available optics and detector elements from the BEAST system, with a custom mount, servo system, data acquisition system and unique rotating Reflection Half Wave Plate.