DEVELOPMENT OF AN R&D ELECTROSTATIC SEPTUM FOR THE 50-GEV PROTON SYNCHROTRON

The electrostatic septum for the slow extraction system of the JHF 50-GeV proton synchrotron is one of the crucial hardware components. Its required electric field strength is 6.8 MV/m in the gap of 25 mm and the length of 1.5 m. The voltage across the gap becomes 170 kV. In order to achieve these design goals, we started RD the material is W(97%)-Re(3%). The cathode material is stainless steel (SUS304), and the length is 0.7 m. We have attained a field strength of 7.3 MV/m (183 kV/25 mm), which is higher than the goal of 6.8 MV/m (170 kV/25 mm), and 10.5 MV/m with a gap of 10 mm.