Dieter Lens

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We present a design of a predictive control scheme for longitudinal beam dynamics in heavy ion synchrotrons. Specifically, we consider a linear-quadratic model predictive control (MPC) approach, whereby the quadratic program is solved via a fast gradient method. Furthermore, we investigate whether the fast gradient method allows for real-time feasible(More)
Progress in digital hardware solutions such as field programmable gate arrays (FPGA) has raised the question of how to design the algorithms of RF feedback. This especially applies to the feedback of the RF cavities and the longitudinal beam feedback for SIS100. For example, FPGAs currently allow FIR (finite impulse response) filter lengths of several tens(More)
The stability of RF (radio frequency) control systems is an essential part of particle accelerator technology. In accelerators, such as heavy-ion synchrotrons, RF feedback systems are used to damp longitudinal oscillation modes of the particle beam. Longitudinal modes have been analyzed in detail by accelerator physicists and there exists a closed theory(More)
The bunched particle beam in a synchrotron can perform various longitudinal oscillation modes of which the dipole mode occurs most frequently. Although naturally damped by Landau damping, these oscillations can become unstable if driven accordingly. In any case Landau damping is accompanied by filamentation of the bunch which leads to rms emittance blow up(More)
Hadron synchrotrons accelerate protons and heavy ions to very high energies. The stabilization of the longitudinal beam dynamics in these particle accelerators is a demanding control problem since typical sample times of the beam-feedback loop are on the order of several μs to several hundred ns. This work examines if model predictive control is a suitable(More)
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