Fast digital meter of the phase difference between the ion beam and accelerating voltage signals

A fast meter of the phase difference of two arbitrarily shaped signals at a frequency of 0.2 to 6 MHz is proposed. The device allows measuring the phase difference for the first harmonic with an error of not more than 1° within ∼20 μs. The signal frequency and amplitude may vary at a speed of up to 20 MHz/s and 40 dB/sec, respectively. Basic signal processing and phase calculation are implemented digitally in a field programmable gate array. The electronics design features are presented, the signal processing methods are described, and the meter parameters and the results obtained on the physical facility are given.