A low level radio frequency system drift compensation technique by time-multiplexing pick-up/reference signals

Area of Science:

• Physics
• Engineering
• Accelerator Technology

Background:

• Long-term stability of Low Level Radio Frequency (RF) systems is crucial for accelerator facilities.
• Observed RF cavity field phase drift at the Tsinghua Thomson scattering X-ray source correlated with device temperature.
• Temperature fluctuations can introduce phase instability in RF systems.

Purpose of the Study:

• To propose and validate a drift compensation technique for RF cavity phase.
• To mitigate phase drift caused by environmental factors like temperature.
• To enhance the operational stability of accelerator facilities.

Main Methods:

• Developed a drift compensation technique using time-multiplexing of cavity pick-up and phase reference signals.
• Ensured shared signal routes for pick-up and reference signals to experience identical changes.
• Conducted a preliminary ∼84-hour Dual-Receiver out-of-loop stability test.

Main Results:

• The proposed technique effectively compensated for phase drift.
• Phase drift was reduced to 100 fs peak-to-peak (∼45 fs rms).
• This stability was achieved despite a reference signal phase change of ∼40 ps peak-to-peak.

Conclusions:

• The time-multiplexing technique offers a viable solution for RF cavity phase drift compensation.
• This method significantly enhances the long-term stability of accelerator RF systems.
• The findings contribute to more reliable operation of X-ray sources and other accelerator facilities.