Review of tandem-linac projects

Abstract

The paper is a brief review of superconducting linacs that are of interest for heavy-ion acceleration. Starting with the general features of the tandem-linac accelerator system, the mode of operation of the system is outlined and the main requirements for the tandem, the beam-bunching system, and the superconducting linac are mentioned. Following this introduction, the characteristics of the three tandem-linac systems now operating and the six other under construction are summarized. The technologies of two of these (the Argonne system based on niobium resonators and the Stony Brook system based on lead resonators) are compared, and differences in performance characteristics are related to differences in design choices. Some recent advances in the technologies related to superconducting heavy-ion linacs are summarized, including advances in helium refrigeration, liquid-helium distribution, beam diagnostics, and resonator design and performance. The final major topic of the paper is a brief discussion of the concept of a positive-ion superconducting injector linac being developed at Argonne as a replacement of the present tandem. Several probable applications of this new technology are mentioned. Most of the subject matter covered by the paper was included in another review paper.1 This work was supported by the U. S. Department of Energy, Nuclear Physics Division, under contract No. W-31-109-ENG-38.