Implement hollow bunch shape
A circular bunch shape in the transverse plane with a hollow part in the center (rotational symmetry). The following plot shows a 1d-projection:
The bunch shape is (by default) infinitely long and is characterized by the radii of the inner and outer circle:
PhysicalQuantity('InnerRadius', unit='m')
PhysicalQuantity('OuterRadius', unit='m')
The length can be adjusted if required (advanced parameter):
PhysicalQuantity('Length', unit='m', default=numpy.inf)