[Vo]: Particles vs photons in propulsion

[abundance]

A particle accelerator ejecting a beam of particles moving 
at near the speed of light which are made 100 times 
heavier than rest mass by application of energy from the 
accelerator will have the equivalent reaction mass of 
particles moving at 10 times the speed of light. A 
propulsion system producing relativistic proton beams and 
relativistic electron beams may be more practical than a 
propulsion system using extreme flux photon beams. 

Aloha, Charlie