A new non-invasive approach for the measurement of ion beam energy

A non-invasive approach for the measurement of the kinetic energy of space-charge dominated ion beams is proposed based on measurements of beam current signals at two different positions. We found that the evolution of space-charge waves, which are generated by weak voltage variations in induction accelerator gaps, can be computed precisely by Fourier analysis of the current signals. The beam energy profile can then be derived from the current signals including the effect of transient space-charge waves. Through analytic studies of the space-charge wave propagation, confirmed by 3-D PIC simulations, we show that the current signals are remarkably sensitive to the weak voltage variations.