The NIKA polarimeter on science targets. Crab nebula observations at 150
  GHz and dual-band polarization images of Orion Molecular Cloud OMC-1
  We present here the polarization system of the NIKA camera and give a summary
of the main results obtained and performed studies on Orion and the Crab
nebula. The polarization system was equipped with a room temperature
continuously rotating multi-mesh half wave plate and a grid polarizer facing
the NIKA cryostat window. NIKA even though less sensitive than NIKA2 had
polarization capability in both 1 and 2 millimiter bands. NIKA polarization
observations demonstrated the ability of such a technology in detecting the
polarization of different targets, compact and extended sources like the Crab
nebula and Orion Molecular Cloud region OMC-1. These measurements together with
the developed techniques to deal with systematics, opened the way to the
current observations of NIKA2 in polarization that will provide important
advances in the studies of galactic and extra-galactic emission and magnetic
fields.
