Voyager UVS measurements of Galactic Cosmic rays and their recent evolution
Résumé
Detectors of the Ultra-Violet Spectrographs on board the Voyagers have been recently found to provide independent measurements of galactic cosmic ray fluxes. Correlative studies with other Voyager Instruments show that the UVS detectors respond to the 100 MeV range. We will show the evolution of the measured flux over two solar cycles and compare it with the latitudinal and temporal variations of the solar wind derived from SOHO/SWAN data. We will include and discuss the most recent data up to Nov. 2012, in particular the recent abrupt increase observed by Voyager 1 at the beginning of May 2012 and the plateau that started. If the plateau is found to be constant, it could be the sign that Voyager 1 is measuring the genuine insterstellar cosmic flux, beyond the heliopause.