Status of KEKB EP System

S.Mitsunobu,Y.Funahashi,T.Furuya,A. Kabe,Y. Morita,M. Nishiwaki, M. Sawabe,S. Takano and K.Ueno

KEK

New EP system

• KEK SC cavities were processed by Electro Polish at Nomura Plating Co..

• For more reliable EP for ILC cavity, KEK decided to have in-house new EP system.

• One L-band system and universal system for 500 MHz and L band system are gathered in one place.

• 500 MHz system reuse old one as possible and move from Nomura to KEK.

Conceptual drawing of EP

(Proff.Kojima’s car battery)

Teflon

Vertical EP Furuya et al

Saito et al

KEKB Superconducting Cavity

Nb Cavity

Rotating Equipment for EP at Nomura Plating Co.

超伝導空洞の電解研磨

New EP bed at KEK

First test using TRISTAN Single Cell

(TM110 mode test)

Ultrasonic tank and shower tank

New acid tank (500 L)

New EP area

Acid gas cleaning system

Modification

• Automatic controlling system• Separating Heat Exchanger • Exchange Z- seal• Move air intake valve on rotational Joint• Add Water over flow pipe• Add Butterfly type valves over flow line

EP condition

• Acid Temperature 20~30 degC• Cathode Voltage -20 ~ -30 V• Current density 30~50mA(EP1>EP2)• Acid flow rate 40L/min• 10 mm over center• KEKB cavity use O3 rinsing

4 bar shower rinsing

O3 rinsing

Hotwater and U sonic rinsing

Conclusion of New EP system

• New EP system has been constructed in KEK.• KEKB Test cavity was successfully treated by new

EP system.• KEKB Test Cavity reached Eacc>12.7MV/m.• Three NSRRC KEKB Type cavities will use this EP

system next year.• L-band cavity and crab cavity(CERN upgrade) also

can be use this system by small modification.