Progress Report on Superconducting Proton Linacs

The work on superconducting proton and heavy ion accelerators will be reviewed. The helix seems to be an adequate structure for low velocity particles. For energies above 15 MeV/N other types of accelerating structures may be used. Superconducting Nb helices were developed at several places. A maximum gradient of 2.8 MV/m witha Q of 2.109 has been obtained recently in Karlsruhe with a ¿/2 Nb helix at 90 MHz. First proton acceleration in superconducting helical structures indicates the status of the new technology.