The 1-GeV proton linac for the Japanese Hadron Project

A proton linac for the Japanese Hadron Project (JHP) has been designed. It comprises a volume production-type H- ion source, a 432-MHz RFQ linac (3 MeV), a 432-MHz DTL (148 MeV) and a 1296-MHz high-β linac (1 GeV). The designed peak beam current is more than 20 mA (average of 200 μA), with a pulse length of 400 μsec and a repetition rate of 50 Hz. The design of the linac was determined with special emphasis on the achievement of stable operation with a minimum beam loss in the high-energy part of the linac at a maximum beam current. Therefore, the main parameters of the linac, including both longitudinal and transverse acceptances, were carefully chosen on the assumption that the normalized beam emittance is to be 1.3 πmm·mrad (90%) at the entrance of the RFQ linac. (author)