Design, Construction, and Testing of RF Structures for a Proton Linear Accelerator

The factors influencing the choice of a RF accelerating structure for acceleration of protons to high energies in a high-current proton linac are reviewed. Characteristics of resonant periodic cavity chains are described, and the properties of two modes of operation, the π-mode and the π/2-mode, are discussed. The cloverleaf cavity chain, suitable for use in the π-mode, and four possible configurations suitable for use in the π/2-mode are described. A new accelerator coupling scheme usable in π/2-mode tank operation is also discussed. Studies of possible fabrication techniques, and the results of a fabricational program utilizing machined forgings to produce a cloverleaf chain are described. Sparking and electron acceleration tests are also briefly mentioned.