Development Status of Ion Source at J-PARC Linac Test Stand

Abstract

The Japan Proton Accelerator Research Complex (J-PARC) linac power upgrade program is now in progress in parallel with user operation. To realize a nominal performance of 1 MW at 3 GeV Rapid Cycling Synchrotron and 0.75 MW at the Main Ring synchrotron, we need to upgrade the peak beam current (50 mA) of the linac. For the upgrade program, we are testing a new front-end system, which comprises a cesiated RF-driven H − ion source and a new radio -frequency quadrupole linac (RFQ). The H − ion source was developed to satisfy the J-PARC upgrade requirements of an H − ion-beam current of 60 mA and a lifetime of more than 50 days. On February 6, 2014, the first 50 mA H − beams were accelerated by the RFQ during a beam test. To demonstrate the performance of the ion source before its installation in the summer of 2014, we tested the long-term stability through continuous beam operation, which included estimating the lifetime of the RF antenna and evaluating the cesium consumption.