correct me if i am wrong, but when linear accelerator is used, it doesn't matter if one or a million particles is inside the core, you use same power to accelerate them all. you can simplyfie the equation by substracting vectors and cateresian functions out, so you get F = B * q * v * sin(alpha), where B is magnetic field strength, q is charge (in our case +e), v is initial velocity of particle that comes into system, and alpha is angle of intitial particle trajectory relative to electromagnetic field lines. if emag. field with B stregth reacts with force F on one deutron that comes in, that same field will react with force F to any amount of deutrons that comes in (well not any, just that density doesn't compromise vacuum's permeability, and the limit is well beyond our system). right?
i already see a problem here. since particle cannot enter accelerator with zero angle eleveation (F=0), it must be delivered with some angle (preferably greater than 60deg). system would need to use some sort of accelerator optics, to sort out deutrons in beam-like formation, and to deliver them into linear accelerator tube. then the mutual collision percentage would be really high.
another thing, are deutrons stable enough for high energy acceleration?