A precision clock source design

HEPS is a fourth-generation photon source under construction. HEPS adopts the magnetic focusing structure of 7BA, and the beam dynamics aperture is very small. HEPS injection scheme adopts the on-axis injection scheme. To minimize perturbation on adjacent bunches during on-axis swap out injection, a set of superfast kicker and high-voltage fast pulse power supply are needed. The high-voltage fast pulse power supply uses pulsed power stacking technologies, and the power supply needs the multichannel and low jitter clock signal. Therefore, it is necessary to develop a precise clock source. The clock source adopts FPGA controller with full digital control, and the output pulse mode of the system can be adjusted in real time. A detection module based on program control is used to check repetition rate and bottom width of input clock and output clock in real time. High-speed and precision clock signal output circuit is used to guarantee signal integrity and reduce clock signal jitter. The prototype experiment proves that the output clock can well meet requirements of design. The minimum bottom width of the independent clock is 5 ns, the minimum time interval of the two groups of clocks is 5 ns, and the jitter of output clock is lower than 50 ps. The developed clock source can well meet the application requirements of high-voltage fast pulse power supply in HEPS injection system.