Rectangular Dielectric-Lined Two-Beam Wake Field Accelerator Structure

A novel dielectric structure is described for a two-beam wake field accelerator which consists of three or four rectangular dielectric slabs positioned within a rectangular conducting pipe. This structure is equivalent to two symmetric, dielectric-lined, three-zone, rectangular waveguides, joined side-by-side. The design mode in the two-beam structure is the LSM31mode, a combination of two symmetric LSM11modes in each of the three-zone waveguides. This two-channel mode can be employed to decelerate drive particles in one channel and accelerate test particles in the other, without need for additional power extraction/transfer structures. It is possible to find structure parameters that in principle give a ratio T, of acceleration gradient for the test beam to deceleration gradient for the drive beam, even as high as T = 100.