Recent studies about the scaling with aspect ratio (i.e. the ratio between the major and minor radius of the torus) of the dominant mode in Single Helical Reverse Field Pinch (RFP) plasmas are reported. The dominant toroidal mode number in the helical states is interpreted as the result of a relaxation process [1,2].
In this work, the theoretical models are compared and validated with the experimental results obtained in a low aspect ratio device .
 R. Paccagnella, Nucl. Fus. 56 (2016) 046010.
 R. Paccagnella, Phys. of Plasmas 23(2016) 092512.
 S. Masamune et al 2007 J. Phys. Soc. Japan 76 123501.