A mass spectrometer is designed to calculate masses ofatoms. A source produces positive ions of
mass m and charge q. The ions move with a velocity v to the right,pass through a narrow slit S1 and
enter a region between two charged plates. In this region theyexperience both an electric and a
magnetic field. The electric field E is caused by the 2 chargedplates; the upper plate is (-) charged
and the lower plate is (+) charged. The magnetic field is B1 andpoints out of the page. The ions
exit this region through slit S2 . When they exit, they experiencea new magnetic field B2, that is also
directed out of the page. The ions are then collected inside acollector.
a) Draw the electric field between the charged plates.
b) With what velocity should ions enter in order to follow astraight trajectory from S1 to S2?
c) Draw the trajectory followed by the ions in the region ofmagnetic field B2? Why does the
trajectory look like this?
d) Where should the collector be placed in the plane containing S2to collect the ions?
e) What is the mass of the ion in terms of field strengths, charge,and S2-collector distance?
