mesh
  spherical
    ri = 0.0
    ro = 0.2
    theta = 2.0
    nr = 400
    ntheta = 1
    br = 5
    btheta = 1
  end
  set assign
    nodeset, jlo, 1    $ $ lower theta boundary
    nodeset, jhi, 2    $ $ upper theta boundary
    nodeset, ilo, 3    $ $ inner radial boundary (r = 0)
  end
end
