Author: Gyles, W.
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.  
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