THOP01 　受賞講演　 8月1日 テルサホール 16:50-17:10

J-PARC RCSに高強度運転におけるビーム損失とビームエミッタンスの最小化

Beam loss and beam emittance minimization in the J-PARC RCS at high intensity operation

○SAHA PRANAB KUMAR（原子力機構 J-PARCセンター）

○Pranab Kumar Saha (JAEA J-PARC)

The 3-GeV RCS (Rapid Cycling Synchrotron) at J-PARC simultaneously delivers high-intensity proton beam to the muon and neutron production targets at the MLF (Material and Life Science Experimental Facility) as well as to the MR (Main Ring). Beam loss mitigation is highly essential not only to keep the machine activation lower at high intensity for a stable operation, but also to ensure a high-quality beam having a lower beam emittance and minimum beam halos. Systematic simulations and beam studies were performed for betatron resonance correction, optimization of the longitudinal and transverse paintings as well as the betatron tune. We have obtained significant beam loss and beam emittance mitigations for the beam delivered to both MLF and the MR. The improvements in the RCS have also been well recognized at both MLF and the MR by reducing the beam losses at the beam transport as well as at each facility. The residual radiation in the RCS recently at 1 MW beam power has been significantly reduced as compared to 1 MW trail operation in 2020 to realize a sustainable operation with record high of nearly 99% availability.