Polarimetry of the Cosmic Background Radiation
Cosmic Background Radiation is the most evident proof of Big-Bang theories.
Many have been the measures at high precision of it's anisotropy features.
Polarization remains in fact the only unknown feature of this structure.
It's importance lies in the new information it can convey and by the fact that it's
nature is strictly connected with the fundamental physical happenings during the
matter-radiation decoupling period.
Polarization of CMB has not been measured yet, this goal is at present the
most ambitious for many experiments.
"PolCBR" project foresees the construction of a polarimeter-interferometer to measure
polarized radiation from CMB at millimeter wavelengths from the Earth. The instrument is
based on a modulating rotating double-Fresnel prism, and by a Martin-Puplett interferometer
that allows a continous frequency study in the 800 mm ÷ 2.5 mm range. Detectors are Germanium
bolometers cooled at 300mK with a 3He criostat. This polarimeter is built to satisfy it's
employment with the 2.6 m telescope of the M.I.T.O. observatory in Testa Grigia (Cervinia).
Comments and Questions
Giorgio Savini & Luca Lamagna
October 15, 2002