  Single Helical Axis (SHAx) states obtained in high current reversed field
pinch (RFP) plasmas display, aside from a dominant mode in the m=1 spectrum,
also a dominant m=0 mode, with the same toroidal mode number as the m=1 one.
The two modes have a fixed phase relationship. The island chain created by the
m=0 mode across the reversal surface gives rise, at shallow reversal of the
toroidal field, to an X-point structure which separates the last closed flux
surface from the first wall, creating a divertor-like configuration. The
plasma-wall interaction is found to be related to the connection length of the
field lines intercepting the wall, which displays a pattern modulated by the
dominant mode toroidal periodicity. This configuration, which occurs only for
shallow toroidal field reversal, could be exploited to realize an island
divertor in analogy to stellarators.
