High Frequency Raster Magnets Design for the ARIEL Electron Target Station at TRIUMF




Ishida, Mathew

Journal Title

Journal ISSN

Volume Title



TRIUMF, Canada’s nuclear and particle physics research laboratory is currently in development of an Advanced Rare Isotope Facility (ARIEL) that will contain a newly designed electron target station. The target at this station is susceptible to destruction from instantaneous spot heating of the beam. To mitigate this, a raster system consisting of two AC electromagnets was proposed. The two magnets will work in tandem, vertical and horizontal, bending to produce raster patterns at 10 kHz. Since complex patterns consist of harmonics higher than the fundamental frequency, a design frequency of 100 kHz was chosen. AC current causes eddy currents which lead to the skin effect, causing high frequency current to concentrate on the outside of the conductor. To address this, a conductor diameter smaller than the skin depth at the given frequency must be chosen. This led to the choice of litz wire consisting of 400 insulated strands for the conductor. The radiation resistance insulation ethylene tetrafluoroethylene (ETFE) was chosen for these conductors and a 3D printed polyethylene sulfide (PPS) will be used for the coil bobbins. The effects of eddy currents were eliminated from the core material by choosing ferrite, an amorphous material consisting of iron-oxide crystals. Simulations were completed to ensure a homogenous magnetic field in the region of the beam, and the subsequent pole profile was determined. Lastly, a metalized ceramic beampipe is used to integrate with the existing beamline and allow for discharge of any static buildup on the inner surface of the beampipe due to the electron beam.



ARIEL, Ferrite, Litz, Magnet, RASTER, TRIUMF