LINAC2014 - List of Authors (Broennimann, M.)

Paper	Title	Page
TUPP111	SwissFEL C-band LLRF Prototype System	683
	A. Hauff, M. Broennimann, I. Brunnenkant, A. Dietrich, Z. Geng, F. Gärtner, M. Jurcevic, R. Kalt, S. Mair, A. Řežaeizadeh, L. Schebacher, T. Schilcher, W. Sturzenegger PSI, Villigen PSI, Switzerland
	SwissFEL is driven by more than 30 RF stations at different frequencies (S-, C-, X-band). To control the RF a new, in-house developed digital Low Level RF (LLRF) system measures up to 24 RF signals per station and performs a pulse-to-pulse feedback at a repetition rate of 100 Hz. The RF signals are down-converted to a common intermediate frequency. The state-of-the-art digital processing units are integrated into the PSI’s EPICS controls environment. Emphasis has been put on modularity of the system to provide a well-defined path for upgrades. Thus the RF front ends are separated from the digital processing units with their FMC standard interfaces for ADCs and DACs. A first prototype of the LLRF system consisting of the digital back end together with a C-band RF front end was installed in the SwissFEL C-band test facility. In this report the performance of the prototype system has been compared with the LLRF system requirements for SwissFEL. The critical parameters are high intra-pulse phase and amplitude resolutions, good channel-to-channel isolations, very low phase to amplitude modulation and a negligible temperature drift.

THPP113	Architecture Design for the SwissFEL LLRF System	1114
	Z. Geng, M. Broennimann, I. Brunnenkant, A. Dietrich, F. Gärtner, A. Hauff, M. Jurcevic, R. Kalt, S. Mair, A. Řežaeizadeh, L. Schebacher, T. Schilcher, W. Sturzenegger PSI, Villigen PSI, Switzerland
	The SwissFEL under construction at the Paul Scherrer Institut (PSI) requires high quality electron beams to generate x-ray Free Electron Laser (FEL) for various experiments. The LLRF system is used to control the klystron to provide highly stable RF field in accelerator structures for beam acceleration. There are more than 30 RF stations in the SwissFEL accelerator with different frequencies (S-band, C-band and X-band) and different types of cavities (standing wave cavities and traveling wave structures). Each RF station will be controlled by a LLRF control node and all RF stations will be connected to the real-time network in the scope of the global beam based feedback system. High level applications and automation procedures will be defined to fit the LLRF control nodes into the global control applications for the accelerator operation. In order to handle the complexity of the LLRF system, the system architecture is carefully designed considering the external interfaces, functions and performance requirements to the LLRF system. The architecture design of the LLRF system will be described in this paper with the focus on the fast networks, digital hardware, firmware and software.

Paper

Title

Page

SwissFEL C-band LLRF Prototype System

683

A. Hauff, M. Broennimann, I. Brunnenkant, A. Dietrich, Z. Geng, F. Gärtner, M. Jurcevic, R. Kalt, S. Mair, A. Řežaeizadeh, L. Schebacher, T. Schilcher, W. Sturzenegger
PSI, Villigen PSI, Switzerland

SwissFEL is driven by more than 30 RF stations at different frequencies (S-, C-, X-band). To control the RF a new, in-house developed digital Low Level RF (LLRF) system measures up to 24 RF signals per station and performs a pulse-to-pulse feedback at a repetition rate of 100 Hz. The RF signals are down-converted to a common intermediate frequency. The state-of-the-art digital processing units are integrated into the PSI’s EPICS controls environment. Emphasis has been put on modularity of the system to provide a well-defined path for upgrades. Thus the RF front ends are separated from the digital processing units with their FMC standard interfaces for ADCs and DACs. A first prototype of the LLRF system consisting of the digital back end together with a C-band RF front end was installed in the SwissFEL C-band test facility. In this report the performance of the prototype system has been compared with the LLRF system requirements for SwissFEL. The critical parameters are high intra-pulse phase and amplitude resolutions, good channel-to-channel isolations, very low phase to amplitude modulation and a negligible temperature drift.

THPP113

Architecture Design for the SwissFEL LLRF System

1114

Z. Geng, M. Broennimann, I. Brunnenkant, A. Dietrich, F. Gärtner, A. Hauff, M. Jurcevic, R. Kalt, S. Mair, A. Řežaeizadeh, L. Schebacher, T. Schilcher, W. Sturzenegger
PSI, Villigen PSI, Switzerland

The SwissFEL under construction at the Paul Scherrer Institut (PSI) requires high quality electron beams to generate x-ray Free Electron Laser (FEL) for various experiments. The LLRF system is used to control the klystron to provide highly stable RF field in accelerator structures for beam acceleration. There are more than 30 RF stations in the SwissFEL accelerator with different frequencies (S-band, C-band and X-band) and different types of cavities (standing wave cavities and traveling wave structures). Each RF station will be controlled by a LLRF control node and all RF stations will be connected to the real-time network in the scope of the global beam based feedback system. High level applications and automation procedures will be defined to fit the LLRF control nodes into the global control applications for the accelerator operation. In order to handle the complexity of the LLRF system, the system architecture is carefully designed considering the external interfaces, functions and performance requirements to the LLRF system. The architecture design of the LLRF system will be described in this paper with the focus on the fast networks, digital hardware, firmware and software.