If you were to place a long cylinder, open at one end and closed at the other end, and position this cylinder so that the open end is facing the Sun, and then you were to inject plasma ions, such as oxygen ions, into the cylinder near the closed end, would the solar wind entering the open end of the cylinder be strong enough to keep the oxygen ions pinned against the closed end of the cylinder, effectively trapping them there? How close to the Sun would this cylinder need to be for the solar wind to be strong enough to 'entrap' these oxygen ions?
So you basically said that we could use the Sun to propel a rocket. We already have rockets like this equipped with solar sails. These solar sails have a "sail" that catches the stuff thrown out of the Sun. I'm no expert on this way of travel, but that is the basic description of how it works.