RIKEN Ring Cyclotron

The main accelerator, a K540 ring cyclotron, has four separate sector magnets and two rf dees. The sector angle of the magnet is 50 degrees; the maximum magnetic field 1.67 Tesla. Isochronous fields are created by main coils and 26 paires of trim coils mounted on the pole surfaces. A couple of delta-shaped rf resonators are placed at the opposite side to each other in the magnet valleys.

The radio frequency is coasely changed over the range of 18-45 MHz with movable-boxed accommodated inside the resonators. An acceleration voltage of as much as 275 kV is generated at a frequency of 32.6 MHz, which corresponds to the top enegy of 135 MeV/nucleon for light ions. The acceleration harmonics of 5 is used for the AVF injection, while 9,10, and 11 for the RILAC injection. The RILAC works at the same frequency as the RRC, while AVF at half ot the RRC frequency. The extraction radius is desinged to be four times the injection radius, so that the final velocity increased by four times an incident velocity.

Specification of the Ring Cyclotron

Injection
	type               45 deg. against the medium plane

Main Magnet
	K-value           540 MeV
	Sector Magnets      4 sector
	Sector Angle       50 deg.
	Pole Gap            8 cm
	Max. Flux Density   1.67 Tesla
	Injection Radius    0.89 m on the average
	Extraction Radius   3.56 m on the average
	Trim Coils         26 pairs per sector magnet
	Total Weight    2,100 tons

Accelerator System
        RF Amp. final tube RS2042SK tetrode (Siemens)
        RF output power   300KW(CW) for each Amp.
	Resonator        Lambda/2 type, two sets
	Dee angle          23.5 deg
	Freqeuncy Range   18-45 MHz
	Max. Dee Voltae	   275 KV
	Harmonic No.      9,10,11 for RILAC injection,
			     5    for AVF injection
        RF final tube     RS2042SK tetrode (Siemens)
        RF output power   300KW(CW) for each amp

Dimensions
	Diameter         12.6 m
	Hight             6.0 m
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last updated on 22 Han 1997 by T.Ichihara (www-admin@rikvax.riken.go.jp)