Reference signal

Signal Generator

• high frequency stability
• frequency is monitored by frequency counter whose reference clock is taken from GPS.
• high spectral purity
• example of measured phase noise
• phase continuity at changing of set frequency

distribution of reference signal

• There are four RF stations 400m apart each other
• Using optical fiber with small thermal expansion coefficient
• E/O & O/E module

frequency adjustment

•  deflation of concrete of building
•  tide
•  seasons motion of ground
• trend of frequency 2001 2002 2003 2004 2005
• "LONG TERM VARIATION OF THE CIRCUMFERENCEOF THE SPRING-8 STORAGE RING" by M. Takao, EPAC2000
• "A long-term observation of the DC component of the horizontal COD in the storage ring of SPring-8" by S. Date , N. I. M. A421 (1999)417