Author: Watt, R.L.
Paper Title Page
TU4PB04 Methods of Increasing Accuracy in Precision Magnetic Field Measurements of Cyclotron Magnets 283
  • N.V. Avreline, W. Gyles, R.L. Watt
    ACSI, Richmond, B.C., Canada
  A new magnetic field mapper was designed and built to provide increased accuracy of cyclotron magnetic field measurements. This mapper was designed for mapping the magnetic fields of TR-19, TR-24, and TR-30 cyclotron magnets manufactured by Advanced Cyclotron Systems Inc. A Group3 MPT-141 Hall Probe (HP) with measurement range from 2 G to 21 kG was used in the mapper’s design. The analogue monitor output was used to allow fast reading of the Hall voltage. Use of a fast ADC NI9239 module and error reduction algorithms, based on a polynomial regression method, allowed the reduction of noise to 0.2 G. The HP arm was made as a carbon fibre foam sandwich. This rigid structure kept the HP arm in a flat plane within 0.1 mm. In order to measure the high gradient field, the design of this mapper provided high resolution of HP arm angle within 0.0005° and of radial position within 25 μm. A set of National Instrument interfaces connected through a network to a desktop computer were used as a base of control and data acquisition systems. The mapper was successfully used to map TR-19 and TR-24 cyclotron magnets.  
slides icon Slides TU4PB04 [4.572 MB]  
WEPPT005 Emittance Measurements at the Strasbourg TR24 Cyclotron for the Addition of a 65 MeV Linac Booster 329
  • A. Degiovanni, U. Amaldi, S. Benedetti, D. Bergesio, A. Garonna, G. Molinari
    TERA, Novara, Italy
  • S. Braccini, E.V. Kirillova
    LHEP, Bern, Switzerland
  • D. Brasse, M. Pellicioli, M. Rousseau, J. Schuler
    IPHC, Strasbourg Cedex 2, France
  • R.L. Watt, E. van Lier
    ACSI, Richmond, B.C., Canada
  The long term plans of IPHC foresee the installation of a linac that will boost the energy of the protons of the Strasbourg TR24 from 24 MeV to 65 MeV. The 3 GHz Cell Coupled Linac, designed by the TERA Foundation, will be 5 meters long and will be powered by two 10 MW klystrons running at 100 Hz. Advanced Cyclotron Systems will modify the cyclotron source, so that the extracted 300 μA beam will be chopped in 4 μs long pulses. To compute the transverse acceptances of the linac, the horizontal and vertical emittances of the extracted proton beam have been measured with the secondary emission detector BISE (Beam Imaging with Secondary Electrons) built by TERA and previously calibrated at the Bern 18 MeV IBA cyclotron. In this detector a thin 5 cm diameter foil is placed at 45° with respect to the beam direction and an electrostatic lens images the secondary electrons -extracted by the protons- on a phosphor, which is viewed by a CCD camera. The results of the measurements of the transverse emittances will be reported together with the description of the linac structure and the calculation of the expected output current based on the dynamics of the accelerated proton beam.