Answer:
The number is 
Explanation:
From then question we are told that
The current carried is 
The speed is 
The circumference is 
Mathematically current is expressed as
where Q is the quantity of charge passing through a conductor and t is the time in seconds
The time t can be mathematically represented as

Substituting this into the equation fro current

Now making the quantity of charge the subject of the formula

Generally the number of proton in the beam is mathematically represented as

Where n is the charge on one proton with a value of 
Now substituting for q in the equation for N

Substituting values

