Force experienced by the charged particle moving at right angles to uniform magnetic field `vecB` with velocity `vecv` is given by `vecF=q(vecvxxvecB)` Initially Dee `D_(1)` is negatively charged and Dee `D_(2)` is positively charged so, the positive ion will get accelerated towards Dee `D_(1)` since the magnetic field is uniform and acting at right angles to the plane of the Dee so the ion completes a circular in `D_(1)` when ions comes out into the gap, polarity of Dees gets reversed used the ion is further accelerated towards Dee `D_(2)` with greater speed and cover a bigger semicircular path. This process is repeated time and again and the speed of the ion becomes faster till it reaches the periphery of the dees where it is brought out by means of a deflecting plate and is made to bombard the target.
Since `F=qVB sin 90^(@)` provides the necessary centripetal force to the ion to cover a circular path so we can say
`(mv^(2))/r=1vBimpliesr=(mv)/(Bq)` .........i br> Time period `=(2pir)/v=(2pim)/(Bqr)=(2pim)/(Bq), V=1/T=(Bq)/(2pim)implies` Frequency is independent of velocity.
