That 50 ton per day I recalled from long ago. So I had to make some search, here's what I found :

1. Ground Level Enhancement
   These effects are usually measured as elevated levels of neutrons and muons. These events can increase the radiation dose of an individual at sea level or while in an aircraft, though not by enough to significantly increase an individual's lifetime risk of cancer. ...and
2. "solar wind"
   400 km/s x 5 ions/cm^3^ x 1g/mol x ...(6400km)^2^ x 3.1416 x 1e15cm^3^/km^3^
   ... x 86400s/day x 1/(6.02e23 ions/mol) This is about 37 tons per day, mostly proton and alpha particles.
   ...
   I used the diameter of the earth instead of that of the magnetic field around the Earth, this is simplistic but should give an order of magnitude. I did not find better information and the real value should be found by someone else.