Cavity diagnostics using rotating mapping system for 1.3 GHz ERL 9-cell superconducting cavity

Sakai, Hiroshi*; Furuya, Takaaki*; Takahashi, Takeshi*; Sakanaka, Shogo*; Umemori, Kensei*; Shinoe, Kenji*; Sawamura, Masaru

We are developing the superconducting (SC) cavity for Energy Recovery Linac (ERL) in Japan. In order to survey the electron emission and the heating spot of the cavity inner surface in detail, cavity diagnostics with the rotating mapping system was applied. Two types of sensors, one of which is the carbon resistor and the other is the Si PIN photo diode, were set to detect the temperature rise and electron emission. By rotating the sensor arrays around the cavity axis, a lot of information is obtained all over the cavity surface in detail. This paper reports the results of vertical tests by using this rotating mapping system with Nb 9-cell ERL cavity.