An idea of bunch manipulation for J-PARC MR

The J-PARC accelerator complex supplies 210 kW beam for MLF, 200 kW for neutrino and 6 kW for hadron facility, respectively. The repetition rate of J-PARC MR will be increased to supply more beam and to achieve the design value of 750 kW. For the high repetition rate, we need a replacement of magnet power supplies and an upgrade of RF system. On the other hand, neutrino physics requires over 1 MW beam. As another power upgrade scenario, we present a merging technique which combines two RCS bunches to one bunch during the acceleration in RCS. The doubled intensity beam will be injected to MR. Because this is one bunch injection, the harmonic number of MR can be increased and more bunches can be injected. One high-intensity bunch extraction from RCS is also helpful for future LFV (Lepton Flavor Violation) experiments to supply more muons. (author)