Cyclotrons2013 - List of Authors (Nakamura, M.)

Paper	Title	Page
MOPPT022	Design of New Superconducting Ring Cyclotron for the RIBF	79
	J. Ohnishi, M. Nakamura, H. Okuno RIKEN Nishina Center, Wako, Japan
	At the RIBF, uranium beams are accelerated up to the energy of 345 MeV per nucleon with a RFQ linac, DTL, and four ring cyclotrons (RRC, fRC, IRC, SRC). However, the present beam current of the uranium is 10-15 pnA at the exit of the SRC, still low, because we have to use two charge strippers located upstream and downstream of the fRC to convert the U³⁵⁺ ions extraced from the 28 GHz ECR ion source to U⁶⁴⁺ and U⁸⁶⁺, respectively. Accordingly, in order to increase the beam current more than tenfold, we performed the design study of the new superconducting ring cyclotron with the K-value of 2200 which can accelerate the U³⁵⁺ ions from 11 MeV/u to 48 MeV/u without the first charge stripper. The number of sector magnets is four and the RF frequency is fixed. The maximum magnetic field strength on the beam orbit is 3.2 T, and the superconducting main coils of the dense winding of NbTi and the trim coils of normal-conducting Cu are used. The total weight of the iron yokes is approximately 4800 t. This paper also describes the beam injection and extraction system which includes one superconducting magnetic channel.

Paper

Title

Page

Design of New Superconducting Ring Cyclotron for the RIBF

79

J. Ohnishi, M. Nakamura, H. Okuno
RIKEN Nishina Center, Wako, Japan

At the RIBF, uranium beams are accelerated up to the energy of 345 MeV per nucleon with a RFQ linac, DTL, and four ring cyclotrons (RRC, fRC, IRC, SRC). However, the present beam current of the uranium is 10-15 pnA at the exit of the SRC, still low, because we have to use two charge strippers located upstream and downstream of the fRC to convert the U³⁵⁺ ions extraced from the 28 GHz ECR ion source to U⁶⁴⁺ and U⁸⁶⁺, respectively. Accordingly, in order to increase the beam current more than tenfold, we performed the design study of the new superconducting ring cyclotron with the K-value of 2200 which can accelerate the U³⁵⁺ ions from 11 MeV/u to 48 MeV/u without the first charge stripper. The number of sector magnets is four and the RF frequency is fixed. The maximum magnetic field strength on the beam orbit is 3.2 T, and the superconducting main coils of the dense winding of NbTi and the trim coils of normal-conducting Cu are used. The total weight of the iron yokes is approximately 4800 t. This paper also describes the beam injection and extraction system which includes one superconducting magnetic channel.