I am a bit confused by the description of Halbach arrays. It is said that the line of magnets aligned in a certain way results in cancellation of magnetic field on one side of the array, and amplification on the other side.
And there is a schematic distribution of magnetic flux: 
I don't understand what happens to the poles of magnets, or the direction of magnetic flux. Does it change its direction in each next or third element of the array? Or is it possible to make something like a magnetic monopole, so that the direction of magnetic flux will be uniform on one side of the array?
There are some other images showing different arrays with arrows which, I suppose, represent the direction of the magnetic flux.
Diagram 1
Diagram 2
The Diagram 2 looks like a monopole, because there is the same direction of flux all the time.
Is it true, or am I misunderstanding something?
Best Answer
At first, I agreed with Walter (above) and thought that the structure was symmetric yet produced an asymmetric result, an impossibility. But then I looked more closely at these Wikipedia images (copied below), and the structure is not symmetric concerning the strong/weak sides:
The strong side groups the red and green areas, while the weak side has them always alternating, never grouped. It makes no difference if red is assigned the North or South magnetic pole, as one would expect.
Thank you to Wikipedia and the contributor of these diagrams!