Hydrogen Lyman-α polarimeter for SCORE

Abstract

The linear polarization by resonance scattering of coronal permitted line-emission in the ultraviolet (UV) can be modified by magnetic fields through the Hanle effect. Space-based UV spectro-polarimeters would provide an additional tool for the diagnostics of coronal magnetism. As a case study of space-borne UV spectro-polarimeters, this presentation will describe the future upgrade of the Sounding-rocket Coronagraphic Experiment (SCORE) to include the capability of imaging polarimetry of the HI Lyman-¿, 121.6 nm. SCORE is a multi-wavelength imager for the emission-lines, HeII 30.4 nm and HI 121.6 nm, and visible-light broad-band emission of the polarized K-corona. SCORE has flown successfully in 2009. This presentation will describe how in future reflights SCORE could observe the expected Hanle effect in corona with a HI Lyman-¿ polarimeter. This UV polarimeter comprises a novel transmissive analyser with a narrow-band UV polarization coating. The polarization modulation is achieved by mechanically rotating a MgF2 half-wave plate