Progress report on the Large Scale Polarization Explorer
  The Large Scale Polarization Explorer (LSPE) is a cosmology program for the
measurement of large scale curl-like features (B-modes) in the polarization of
the Cosmic Microwave Background. Its goal is to constrain the background of
inflationary gravity waves traveling through the universe at the time of
matter-radiation decoupling. The two instruments of LSPE are meant to
synergically operate by covering a large portion of the northern microwave sky.
LSPE/STRIP is a coherent array of receivers planned to be operated from the
Teide Observatory in Tenerife, for the control and characterization of the
low-frequency polarized signals of galactic origin; LSPE/SWIPE is a
balloon-borne bolometric polarimeter based on 330 large throughput multi-moded
detectors, designed to measure the CMB polarization at 150 GHz and to monitor
the polarized emission by galactic dust above 200 GHz. The combined performance
and the expected level of systematics mitigation will allow LSPE to constrain
primordial B-modes down to a tensor/scalar ratio of $10^{-2}$. We here report
the status of the STRIP pre-commissioning phase and the progress in the
characterization of the key subsystems of the SWIPE payload (namely the
cryogenic polarization modulation unit and the multi-moded TES pixels) prior to
receiver integration.
