When the ionized particles entering a mass spectrometer are simplyaccelerated across the potential difference between two chargedplates, there is always the chance of an uncontrolled variation intheir velocities due to their random thermalmotion before they undergo linearacceleration. An elaboration of the basic mass spectrometer designbetter controls the incoming velocity of the ions by passing themthrough a velocity selector before they enterthe magnetic deflection chamber. Suppose that the same uniformmagnetic field, having a strength 0.750 T, is used in both thevelocity selector and the deflection chamber. In this chamber,singly ionized argon ions with a mass of6.63×10−26 kg are to be deflected throughsemi-circular arcs of radius 12.0 cm. (a) If the oppositelycharged plates of the velocity selector are separated by2.00 cm, what is the required potential difference betweenthem? (b) If you were to add a velocity selector to the diagram ofthe mass spectrometer, as shown in the illustration, which platewould be positively charged with respect to the other?
(i'm not sure on this one?? doesionized argon have the the equivalent of e+ ?)
next I used thevelocity selector equation that says for parallel plate capacitors. I'm notsure if these were the right steps to take and if they were, whereI should go from here. I can't plug in the because the aren't the same for boththe chamber and the velocity selector.
Any help would begreatly appreciated. Thanks!