Speaker
Description
Abstract. The Japan Proton Accelerator Research Complex (J-PARC) cesiated RF-driven Hˉ ion source has been stably operated for about six years. The J-PARC 400 MeV LINAC successfully accelerated the 60 mA beam required for the J-PARC, when a 72 mA beam was injected from the source. The high intensity beam with transverse emittances suitable for the RFQ is produced with several unique measures, such as, slight water molecules addition into hydrogen plasma, low temperature (about 70ºC) operation of 45º-tapered plasma electrode with a 16-mm thickness, impurity (argon and/or nitrogen) elimination in the hydrogen plasma along with filter-field optimization, and so on. A 65 keV 110 mA Hˉ ion beam, whose about 103 mA has transverse emittances used for a common RFQ design, was stably operated with a duty factor of 4.5 % (1 ms x 45 Hz). Since the 52.5 keV beam energy (WT) was required to produce an Hˉ ion beam intensity (IH-) of 72 mA, the interesting relationship of IH-(65)~IH-(52.5)x(65/52.5)^2 was derived. The source is the benchmark one for the next generation high intensity and high energy Hˉ LINACs.
Summary
110 mA operation of J-PARC cesiated RF-driven Hˉ ion source to realize the next generation 100 mA Hˉ ion LINACs.
