Author: Molendijk, J.C.
Paper Title Page
TUPF27 An Ultra Low-Noise AC Beam Transformer and Digital Signal Processing System for CERN’s ELENA Ring 571
 
  • M.E. Angoletta, C. Carli, F. Caspers, S. Federmann, J.C. Molendijk, F. Pedersen, J. Sanchez-Quesada
    CERN, Geneva, Switzerland
 
  CERN’s Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons coming from CERN’s Antiproton Decelerator. Essential longitudinal diagnostics required for commissioning and operation include the intensity measurement for bunched and debunched beams and the measurement of Dp/p for debunched beams to assess the electron cooling performance. The beam phase information is also needed by the low-level RF system. The baseline system for providing the required beam parameters and signals is based upon two ultra-low-noise AC beam transformers and associated digital signal processing. The AC beam transformers cover different frequency regions and are an adaptation to the ELENA layout of those used in the AD. Two AC beam transformers will also be installed in the extraction lines to provide beam intensity and bunch shape measurements. The digital signal processing will be carried out with the leading-edge hardware family used for ELENA’s low-level RF system. The paper provides an overview of the beam transformer and head amplifier, as well as of the associated digital signal processing.  
 
TUPF28 A Leading-Edge Hardware Family for Diagnostics Applications and Low-Level RF in CERN’s ELENA Ring 575
 
  • M.E. Angoletta, A. Blas, M. Jaussi, P.M. Leinonen, T.E. Levens, J.C. Molendijk, J. Sanchez-Quesada, J. Simonin
    CERN, Geneva, Switzerland
 
  The CERN Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons transferred from the CERN’s Antiproton Decelerator (AD). The requirements for the acquisition and treatment of signals for longitudinal diagnostics are very demanding, owing to the revolution frequency swing as well as to the digital signal processing required. The requirements for the Low-Level RF (LLRF) system are very demanding as well, especially in terms of revolution frequency swing, dynamic range and low noise required by the cavity voltage control and digital signal processing to be performed. Both sets of requirements will be satisfied by using a leading-edge hardware family, developed to cover the LLRF needs of all synchrotrons in the Meyrin site; it will be first deployed in 2014 in the CERN’s PSB and in the medical machine MedAustron. This paper gives an overview of the main building blocks of the hardware family and of the associated firmware and IP cores. The performance of some blocks will also be detailed.  
 
WEPF28 Longitudinal Beam Diagnostic from a Distributed Electrostatic Pick-Up in CERN’s ELENA Ring 883
 
  • M.E. Angoletta, F. Caspers, S. Federmann, J.C. Molendijk, P.J. Pascal Jean, F. Pedersen, J. Sanchez-Quesada, L. Søby, M.A. Timmins
    CERN, Geneva, Switzerland
 
  The CERN Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons coming from CERN’s Antiproton Decelerator (AD). Required longitudinal diagnostics include the intensity measurement for bunched and debunched beam and the measurement of Dp/p for a debunched beam to assess the electron cooling performance. A novel method for the calculation of these parameters is proposed for ELENA, where signals from the twenty electrostatic pick-ups (PU) used for orbit measurements will be combined to improve the signal-to-noise ratio. This requires that the signals be digitally down-converted, rotated and digitally summed so that the many electrostatic PUs will function as a single, distributed PU from to the processing system viewpoint. This method includes some challenges and will not be used as the baseline longitudinal diagnostics for the initial ELENA operation. This paper gives an overview of the hardware and digital signal processing involved, as well as of the challenges that will have to be faced.