Noble gases in the solar corpuscular radiation

The Sun emits the solar wind (SW), a continuous stream of particles with velocities mostly between -300-800 km/s (Parker 1997). Ions of higher energy are emitted especially during so-called solar energetic particle (SEP) events (Reames 1998). The 

Studies of elemental and isotopic composition of the solar corpuscular radiation have to account for the fact that particle selection and acceleration may lead to fractionations. In the solar wind, such effects are minor for isotopic ratios but clearly significant for some elemental ratios, whereas in SEPs severe isotopic effects also occur. Therefore, abundance studies in the solar corpuscular radiation sometimes yield information about fractionation processes rather than directly about solar composition. 

In summary, the He isotopic composition in the solar wind and hence in the OCZ is reasonably well known, but further improvements are nevertheless desirable, e.g., to reduce uncertainties in the value of the protosolar D/H ratio, as is discussed next. 

The protosolar D/H ratio. The protosolar deuterium abundance is an upper limit to the primordial abundance of this isotope and provides a crucial observational test for the Big Bang cosmological model (Schramm 1993). For example, the primordial deuterium 

Stated uncertainties of SW values are not directly comparable with each other. Uncertainty in (2) mostly due to an assumed systematic uncertainty of detector efficiencies uncertainties in (6) do not consider possible alterations in samples. 

---