Your research director has assigned you to set up the laboratory’s mass spectrometer so that it will separate strontium ions having a net charge of
+2e from a beam of mixed ions. The spectrometer above accelerates a beam of ions from rest through a potential difference

, after which the beam enters a region containing a uniform magnetic field
B of constant magnitude and perpendicular to the plane of the path of the ions. The ions leave the spectrometer at a distance
x from the entrance point. You can manually change

.