Beam loss and beam emittance minimization at J-PARC RCS for simultaneous operation to the MLF and MR

Saha, P. K.   ; Harada, Hiroyuki  ; Shobuda, Yoshihiro   ; Chimura, Motoki   ; Okabe, Kota  ; Nakanoya, Takamitsu ; Moriya, Katsuhiro  ; Yamamoto, Kazami   ; Tamura, Fumihiko   ; Okita, Hidefumi  ; Yoshimoto, Masahiro  ; Hatakeyama, Shuichiro; Takayanagi, Tomohiro   ; Hotchi, Hideaki*; Kojima, Kunihiro 

In the RCS not only the beam loss mitigation is highly essential to keep the machine activation lower for maintaining a stable operation with high availability, but it is also required to ensure a high-quality beam having a lower beam emittance and minimum beam halos for simultaneously beam operation to the MLF and the MR. Based on the detail numerical simulations and systematic beam studies during the past couple of years, the beam loss and the rms beam emittance for the MLF at the designed 1 MW beam power is reduced to be 80% and 30%, respectively, while those are nearly 40% and 20% reduced for the MR beam. These improvements in the RCS have also been well recognized at both MLF and the MR by reducing the beam losses at the beam transports as well as in each facility.