Scattering from cylinders with globular end-caps

The scattering function and the radius of gyration of a cylinder with globular end-caps (a barbell) are presented and discussed. The radius of the end-caps is restricted to be bigger than or equal to that of the cylinder; hence the model is a generalization of the scattering function of a cylinder with hemispherical end-caps. It is argued that the cylinder with globular end-caps is a physically more representative model for rod-like micelles. Moreover, the scattering functions of the simple sphere and the dumbbell are found to be special cases of the scattering function of the barbell. Numerical examples of the scattering curves and their pair distance distribution functions are presented.