HB2025 - the 71st ICFA Advanced Beam Dynamics workshop on High-Intensity and High-Brightness Hadron Beams

Recent optics measurements and corrections for high-intensity operation of the J-PARC Main Ring

TUIAB03

Oct 21, 2025, 9:30 AM

30m

Room B (Conference Center)

Invited Oral Presentation WGA:Beam Dynamics in Rings TUIAB WGA invited oral

Speaker

Takashi Asami (High Energy Accelerator Research Organization)

Description

In the intensity-frontier proton synchrotron J-PARC Main Ring (MR), a power upgrade plan is underway to achieve 1.3 MW beam power for neutrino experiments. The upgrade has generally progressed as planned, with the beam power for the user operation reaching 830 kW as of May 2025. A major obstacle to upgrading the beam power of the MR is the radioactivation of accelerator components caused by beam loss. One significant contributor to beam loss is the betatron resonances, which are sensitive to the symmetry of optics. Precise optics corrections during beam tuning have therefore been playing a critical role in suppressing these resonances and reducing beam losses. This paper presents the strategies and recent results of optics measurements and corrections for the MR.