Unique features of the J-PARC linac and its performance; Lessons learnt

Ueno, Akira  

The J-PARC linac has been successfully commissioned up to its design energy of 181 MeV and almost the first stage design peak intensity of 30 mA. The following unique methods and hardware features adopted in the J-PARC linac are explained and those results are reported in this paper. The surface production dominating Cs-free H IS with magnetic focus LEBT, macro-pulse generation method related with the J-PARC 30mA-RFQ design, stable one-shot operation method, beam suspending method for machine protection, RF-chopper system related with the operation parameter of the RFQ, one-turn injection method into the following J-PARC RCS, transverse matching using TRACE3D PMQ elements approximating the fringe field effects of the electro-quadrupole magnets, PR electroforming for high-duty compact DTQ coil and thick pure plating of DTL and SDTL and 2 cavity behaviour of SDTL fed with one Klystron.