Polymer gel dosimetry of an electron beam in the presence of a magnetic field

7th International Conference on 3D Radiation Dosimetry

Vandecasteele, J.^1 ; De Deene, Y.^1,2

Department for Radiation Oncology and Experimental Cancer Research, Ghent University, De Pintelaan 185, 9000 Gent, Belgium^1

Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia^2

关键词: Computational model;    Dose distributions;    Electron trajectories;    External magnetic field;    Magnetic field distribution;    MeV-Electrons;    Polymer gel dosimeter;    Polymer gel dosimetry;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012104/pdf
DOI  :  10.1088/1742-6596/444/1/012104

来源: IOP

【 摘 要 】

The effect of a strong external magnetic field on 4 MeV electron beam was measured with polymer gel dosimetry. The measured entrance dose distribution was compared with a calculated fluence map. The magnetic field was created by use of two permanent Neodymium (NdFeB) magnets that were positioned perpendicular to the electron beam. The magnetic field between the magnets was measured with Hall sensors. Based on the magnetic field measurement and the law of Biot-Savart, the magnetic field distribution was extrapolated. Electron trajectories were calculated using a relativistic Lorentz force operator. Although the simplified computational model that was applied, the shape and position of the calculated entrance fluence map are found to be in good agreement with the measured dose distribution in the first layer of the phantom. In combination with the development of low density polymer gel dosimeters, these preliminary results show the potential of 3D gel dosimetry in MRI-linac applications.