Our group has mounted a series of measurements of the polarization of the cosmic microwave background (CMB)

Some interesting photographs:

33 GHz Polarimeter on Roof This photograph shows the 33 GHz polarimeter on the LBL building 50 roof with George Smoot (right) calibrating it and Phil Lubin (left) at the equipment electronics.

10 GHz Polarimeter This photograph shows the 10 GHz polarimeter on the LBL building 50 roof and the 33 GHz polarimeter behind it. The ground shield is removed so that one can see the antenna. Both polarimeters rotate about their axis within the protective (thermal & RF) metal cans and bases. They can be tilted to point at different declinations and locked into position. That way the rotation of the Earth sweeps out a circle on the sky along which the polarimeter measures the polarization repeatedly. Philip Melese d'Hopital and Hal Dougherty are with it.

CMB polarization pattern for a universe that expands more rapidly (or less rapidly) on one axis than the other two axes.

33 GHz Polarimeter Schematic

33 GHz Polarimeter Schematic showing signal and electrical flow.

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