A system for generating a traveling field free line, traveling along a propagation direction different from the orientation of said traveling field free line, said system comprising at least a first and a second coil assembly (12,14), wherein said first coil assembly is configured for generating a first stationary field free line at a characteristic first location associated with the first coil assembly, when a current is flowing in the first coil assembly and the second coil assembly is current free, and wherein said second coil assembly is configured for generating a second stationary field free line at a characteristic second location associated with the second coil assembly, when a current is flowing in the second coil assembly and the first coil assembly is current free, wherein said system further comprises a controller configured for driving the first and second coil assemblies (12, 14) with corresponding driving currents synchronized with each other such that: - at a first point in time, the first coil assembly's driving current amplitude is high and the second coil assembly's driving current amplitude is low, such that at said first point in time the traveling field free line is at or close to said first location, - at a second point in time, the second coil assembly's driving current amplitude is high and the first coil assembly's driving current amplitude is low, such that at said second point in time the traveling field free line is at or close to said second location, and - in a time interval between said first and second point in time, the amplitude of the first driving current in the first coil assembly decreases and the amplitude of the second driving current in the second coil assembly increases as compared to said first point in time such that said traveling field free line travels along the propagation direction from said first location (Li) towards said second location, wherein between said first location (Li) and said second location the traveling field free line is translated along the propagation direction. when a current is flowing in the first coil assembly and the second coil assembly is current free, and wherein said second coil assembly is configured for generating a second stationary field free line at a characteristic second location associated with the second coil assembly, when a current is flowing in the second coil assembly and the first coil assembly is current free, wherein said system further comprises a controller configured for driving the first and second coil assemblies (12, 14) with corresponding driving currents synchronized with each other such that: - at a first point in time, the first coil assembly's driving current amplitude is high and the second coil assembly's driving current amplitude is low, such that at said first point in time the traveling field free line is at or close to said first location, - at a second point in time, the second coil assembly's driving current amplitude is high and the first coil assembly's driving current amplitude is low, such that at said second point in time the traveling field free line is at or close to said second location, and - in a time interval between said first and second point in time, the amplitude of the first driving current in the first coil assembly decreases and the amplitude of the second driving current in the second coil assembly increases as compared to said first point in time such that said traveling field free line travels along the propagation direction from said first location (Li) towards said second location, wherein between said first location (Li) and said second location the traveling field free line is translated along the propagation direction. - at a first point in time, the first coil assembly's driving current amplitude is high and the second coil assembly's driving current amplitude is low, such that at said first point in time the traveling field free line is at or close to said first location, - at a second point in time, the second coil assembly's driving current amplitude is high and the first coil assembly's driving current amplitude is low, such that at said second point in time the traveling field free line is at or close to said second location, and - in a time interval between said first and second point in time, the amplitude of the first driving current in the first coil assembly decreases and the amplitude of the second driving current in the second coil assembly increases as compared to said first point in time such that said traveling field free line travels along the propagation direction from said first location (Li) towards said second location, wherein between said first location (Li) and said second location the traveling field free line is translated along the propagation direction.