Related Experiment Video
Updated: Nov 21, 2025
Optimized Setup and Protocol for Magnetic Domain Imaging with In Situ Hysteresis Measurement
Published on: November 7, 2017
Feasibility of energy adaptive angular meshing for perpendicular and parallel magnetic fields in a grid based
R Yang1, D M Santos2, B G Fallone1,2
1Department of Oncology, University of Alberta, 11560 University Ave, Edmonton, Alberta T6G 1Z2, Canada.
Purpose:
To develop the enabling algorithmic techniques which allow forward-peaked adaptive angular meshing to be compatible with angular advection of magnetic fields within a deterministic Grid Based Boltzmann Solver (GBBS) for MRI-guided radiotherapy, and establish appropriate energy adaptive meshing schemes which minimize total numerical degrees of freedom while preserving high dosimetric accuracy for parallel and perpendicular magnetic fields.
Methods:
A framework to independently adapt angular mesh resolution and basis function refinement of forward and backscattering hemispheres is developed, uniquely accommodating angular advection introduced by magnetic fields. Upwind stabilization techniques to accurately transfer fluence between hemispheres having different discretization are established. To facilitate oblique beam and magnetic field orientations, cardinal forward-peaked mesh orientations were devised to balance requirements for acyclic space-angle sweep ordering, while ensuring the beam predominantly overlaps the forward hemisphere. Energy-dependent fluence anisotropy is investigated, leading to adaptive angular meshing schemes for parallel and perpendicular magnetic fields. Calculated dose distributions were validated against GEANT4 Monte Carlo calculations on slab geometry and anthropomorphic phantoms.
Results:
Forward-peaked and isotropic energy adaptive angular meshing schemes were developed for parallel and perpendicular magnetic fields respectively, which reduce the number of elements solved by 52.8% and 47.7% respectively compared to static discretization using 32 quadratic elements while retaining over 97% of points passing the gamma 1%/1 mm criterion against Monte Carlo.
Conclusions:
Techniques to preserve angular upwind-stabilization between hemispheres of a forward-peaked mesh and establish an acyclic directed space-angle sweep graph enabled energy-adaptive meshing schemes to be developed while accurately solving for magnetic fields. This substantially reduced the numerical degrees of freedom while retaining excellent dosimetric agreement with Monte Carlo. These algorithmic underpinnings contribute towards a fast deterministic GBBS for MRI-guided radiotherapy.
More Related Videos
10:36Author Spotlight: Optimization of Airflow Velocities in Battery Cooling Systems for Enhanced Thermal Performance and Reduced Energy Consumption
Published on: November 3, 2023
07:42Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
Related Concept Videos
01:28Magnetostatic Boundary Conditions
01:16Magnetic Field Of A Current Loop
00:59Biot-Savart Law: Problem-Solving
Consider a mobile phone battery bank as a source of steady current, which flows through the wire connected between the two. What is the magnitude of the magnetic field created by this current at a field point P?
To estimate the magnitude of the total magnetic field, we first consider a small current element of length dl, at a distance r from the field point. Now the following...
01:27Magnetic Fields
A magnetic field is defined by the force that a charged particle experiences...
01:13Torque On A Current Loop In A Magnetic Field
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
01:18Magnetic Flux
Suppose a surface is divided into elements of area dA. For each element, the component of the magnetic field that is normal to the...