Since the first book was written it has become clear that science, medicine and industry have a rapidly growing appetite for accelerators for other applications. Part B of this sequel, building on Part A, expands considerably on the applications of accelerators: as synchrotron radiation sources (used for material science studies, chemistry, biology), spallation sources (for neutron scattering studies), national security (screening of borders for illicit transfer of materials), medical applications (cancer therapy with external beams and isotope production for diagnostic imaging), energy, and environment (cleaning up waste streams, powering nuclear reactors and fusion).

In Part B we also discuss the future development of accelerators; particularly laser/plasma devices which potentially offer considerable savings in the scale and cost accelerator construction for the more modest energies required in these new applications. Finally there is a description of the nature of the accelerator community and how it interacts.