English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Mm and sub-mm waves polarimetry is the new frontier of research in CosmicMicrowave Background and Interstellar Dust studies. Polarimeters working in theIR to MM range need to be operated at cryogenic temperatures, to limit thesystematic effects related to the emission of the polarization analyzer. Inthis paper we study the effect of the temperature of the different componentsof a waveplate polarimeter, and describe a system able to rotate, in acompletely automated way, a birefringent crystal at 4K. We simulate the mainsystematic effects related to the temperature and non-ideality of the opticalcomponents in a Stokes polarimeter. To limit these effects, a cryogenicimplementation of the polarimeter is mandatory. In our system, the rotationproduced by a step motor, running at room temperature, is transmitted down tocryogenic temperatures by means of a long shaft and gears running on customcryogenic bearings. Our system is able to rotate, in a completely automatedway, a birefringent crystal at 4K, dissipating only a few mW in the coldenvironment. A readout system based on optical fibers allows to control therotation of the crystal to better than 0.1{\deg}. This device fulfills thestringent requirements for operation in cryogenic space experiments, like theforthcoming PILOT, BOOMERanG and LSPE.

A cryogenic waveplate rotator for polarimetry at mm and sub-mm wavelengths