Development of the 1 GeV proton linac for the Japanese Hadron Facility

The present status of the development of the 1-GeV proton linac for the Japanese Hadron Project is reported. The linac is composed of an H/sup -/ ion source, a 432-MHz RFQ (radio-frequency quadrupole) linac (3 MeV), a 432-MHz drift-tube linac (148 MeV), and a 1296-MHz high- beta linac (1 GeV). An electroforming method for sealing a 432-MHz drift tube was developed. Results of field measurement are presented for a cold model of a drift-tube linac. The high- beta linac is described in detail. A study of an annular-coupled structure indicates that this structure is promising for the project. >