Paper | Title | Page |
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THP043 | Model-based Klystron Linearization in the SwissFEL Test Facility | 820 |
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Funding: Paul Scherrer Institut An automatic procedure is developed to provide the optimal operating point of a klystron. Since klystrons are nonlinear with respect to the input amplitude, a model-based amplitude controller is introduced which uses the klystron characteristic curves to obtain the appropriate high voltage power supply and amplitude, such that the operating point is close to the saturation. An advantage of the proposed design is that the overall open-loop system (from the input to the RF station to the klystron output amplitude) is linearized. The method has been successfully tested on a full scale RF system running at nominal power. *Ch.Rapp, Effects of HPA-Nonlinearity on a 4-DPSK/OFDM-Signal …,Euro. Conf. on Satellite Communi.,1991. <CR> **A.Cann, Nonlinearity Model With Variable Knee…,IEEE Trans. Aerosp. Electron. Syst.,1980 |
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THP044 | RF Pulse Flattening in the SwissFEL Test Facility based on Model-free Iterative Learning Control | 824 |
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Funding: Paul Scherrer Institut This paper introduces an iterative approach to producing flat-topped radio frequency (RF) pulses for driving the pulsed linear accelerators in the Swiss free electron laser (SwissFEL). The method is based on model-free iterative learning control which iteratively updates the input pulse shape in order to generate the desired amplitude and phase pulses at the output of the RF system. The method has been successfully applied to the klystron output to improve the flatness of the amplitude and phase pulse profiles. * P. Janssens,et.al, "Model-free iterative learning control for LTI systems …", 18th IFAC. <CR> ** N. Amann, et.al , "ILC for discrete-time systems …", IEE Control Theory Apps. |
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