An X-ray tube can include: a cathode planar emitter that emits an inhomogeneous electron beam; an anode to receive the electron beam; a first magnetic quadrupole having a first yoke with four evenly distributed first pole projections extending from the first yoke and oriented toward a central axis of the first yoke and each of the four first pole projections having a first quadrupole electromagnetic coil; a second magnetic quadrupole having a second yoke with four evenly distributed second pole projections extending from the second yoke and oriented toward a central axis of the second yoke and each of the four second pole projections having a second quadrupole electromagnetic coil; and at least one coil of a first pair of opposing coils with alternating current offset from the power supply.