Coupling Impedance of the Collimator Without RF-Shields at the RCS in J-PARC. (November 2019)

• Record Type: Journal Article
• Authors: Shobuda, Y; Okabe, K; Kamiya, J; Moriya, K
• Is Part Of: Journal of physics. Volume 1350(2019)
• Publication Date: 2019-11
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/1350/1/012113
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: All holes on the chamber walls of synchrotrons should be filled with the radiofrequency (RF)-shields to suppress coupling impedances that excite beam instabilities. In a synchrotron, titanium nitride (TiN)-coated RF-shields are installed with collimators. If the holes, through which the collimator jaw enters and exits the chamber, are filled with such RF-shields, the shields may break down as the dynamic coefficient of TiN increases in vacuum. At the Rapid Cycling Synchrotron (RCS), the RF-shields are eliminated from the collimator after demonstrating that the effect due to the RF-shields is negligible on the impedance at low frequencies.