In-situ measurements of the heavy ion content of the elusive polar solar wind

We propose to investigate the heavy ion content of the elusive polar solar windby observing the cometary Xray emission which results from charge exchangebetween solar wind heavy ions and cometary neutrals, thus providing insituinformation. We will utilize the favorable opportunity that AO17 will be closeto solar minimum, when the polar wind will have expanded to lower latitudes, andthat one bright comet, 21P/GiacobiniZinner, will be continuously observable forXMM and close to Earth on its way from +30 deg to 30 deg ecliptic latitude.This observation is perfectly tailored to XMM, as it makes full use of its highsoft Xray sensitivity, its spectral, temporal, and spatial resolution, its fullfield of view, and of all six (PN, MOS1, MOS2, RGS1, RGS2, OM) of its scientific instruments. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]