This Python program allows for an interactive exploration of the magnetic fields created by rings of permanent magnets. The background is described in: Halbach 2.0 -- Creating homogeneous fields with finite size magnets, Ingo Rehberg and Peter Blümler(https://arxiv.org/abs/2502.18262). The version 1.0.1 includes a configuration described by: Sumit Tewari, Thomas O'Reilly, Andrew Webb,Improving the field homogeneity of fixed- and variable-diameter discrete Halbach magnet arrays for MRI via optimization of the angular magnetization distribution,Journal of Magnetic Resonance, Volume 324, 2021, 106923, ISSN 1090-7807, https://doi.org/10.1016/j.jmr.2021.106923. 

To start the program, unzip Halbach_two_point_oh.zip, and start the interactive program halbach_two_point_oh.py. When rotating the ring cluster by checking of of the "r_e", "r_a" or "r_r"- buttons, make sure to stop the roation by checking the "stp"-checkbox.