Calculating Proton Energy in a Cyclotron

[Kajan thana]

Homework Statement

A proton is accelerated to an energy 5Mev in a cyclotron with AC pd of 1KV and the frequency of 8MHz applied to dees.

Calculate the number of times proton would have to pass the dees to reach the energy 5MeV?

Homework Equations

F=BQV=MV^2/r

The Attempt at a Solution

5x1.60x10^-13=0.5m(2πrf)
But then I have two variables to deal with.

 

[gneill]

Where in the proton's path in a cyclotron does it pick up kinetic energy?