Maximum kinetic energy of the positive ion in the cyclotron is (r0 =Radius of cyclotron ,q =charge of ion ,m = mass of ion )
q2Br02m
qB2r02m
q2B2r022m
qBr0 2m2
Kmax = 12 mv2 and r0 = mvqB ⇒ v=qBr0mKmax = 12 m qBr0m2 = q2B2r022m