Patent ID: 8111025

Claim:
A charged particle accelerator, comprising: a source of charged particles; an accelerator body comprising: a buncher cell defining a buncher cell cavity; wherein the source of charged particles is coupled to the buncher cell to inject charged particles into the buncher cell cavity; and the buncher cell cavity captures and radiofrequency (RF) focuses charged particles injected by the charged particle source, into charged particle beam; a plurality of linearly arranged cells defining periodic, linearly arranged accelerating cavities downstream of the buncher cell to receive and accelerate the charged particle beam; and an output cell downstream of the accelerating cells to receive and output the accelerated charged particle beam; wherein: the buncher cell, the periodic cells, and the output cell further define a plurality of linearly arranged on-axis coupling cavities between respective cells; the buncher cell and a first periodic cell following the buncher cell are configured such that a field step ratio between the peak amplitude of an electric field in a first accelerating cell cavity and the peak amplitude of an electric field in the buncher cell cavity is greater than one (1), during operation; and a cell period ratio between a cell length from a center of one accelerating cavity to a center of next accelerating cavity, and half the free space wavelength of the accelerator body during operation, is less than one (1).