Author: Kramer, T.
Paper Title Page
THPPD074 Effect of a Metallized Chamber upon the Field Response of a Kicker Magnet: Simulation Results and Analytical Calculations 3686
  • M.J. Barnes, M.G. Atanasov, T. Fowler, T. Kramer, T. Stadlbauer
    CERN, Geneva, Switzerland
  Metallized racetrack vacuum chambers will be used in the pulsed magnets of the Austrian cancer therapy and research facility, MedAustron. It is important that the metallization does not unduly degrade field rise and fall times or the flattop of the field pulse in the pulsed magnets. This was of particular concern for a tune kicker magnet, which has a specified rise and fall time of 100 ns. The impact of the metallization, upon the transient field response, has been determined by finite element method (FEM) simulations: the dependency of the field response to the metallization thickness and resistivity are presented. Formulae for the field response, which permit the use of a ramped transient excitation current, are presented: thus the coating thickness and resistivity can be determined which result in a maximum permissible field attenuation and delay for a given current rise time. In addition, results of simulations of the effect of a magnetic brazing collar, located between the ceramic vacuum chamber and flange, are reported.  
THPPD075 Design and Measurements of a Fast High-voltage Pulse Generator for the MedAustron Low Energy Transfer Line Fast Deflector 3689
  • T. Fowler, M.J. Barnes, T. Kramer, F. Müller, T. Stadlbauer
    CERN, Geneva, Switzerland
  MedAustron, a centre for ion-therapy and research, will comprise an accelerator facility based on a synchrotron for the delivery of protons and light ions for cancer treatment. The Low Energy Beam Transfer line (LEBT) to the synchrotron contains an electrostatic fast deflector (EFE) which, when energized, deviates the continuous beam arriving from the ion source onto a Faraday Cup: the specified voltage is ±3.5 kV. De-energizing the EFE for variable pulse durations from 500 ns up to d.c. allows beam passage for multi-turn injection into the synchrotron. To maintain beam quality in the synchrotron, the EFE pulse generator requires rise and fall times of less than 300 ns between 90 % of peak voltage and a ±1 V level. To achieve this, a pulsed power supply (PKF), with high voltage MOSFET switches connected in a push-pull configuration, will be mounted in close proximity to the deflector itself. A fast, large dynamic range monitoring circuit will verify switching to the ±1 V level and subsequent flat bottom pulse quality. A prototype will be installed in the injector test stand in 2012; this paper presents the design and first measurements of the PKF and its monitoring circuit.