A three-dimensional magnetostatics computer code for insertion devices

Abstract

RADIA is a three-dimensional magnetostatics computer code optimized for the design of undulators and wigglers. It solves boundary magnetostatics problems with magnetized and current-carrying volumes using the boundary integral approach. The magnetized volumes can be arbitrary polyhedrons with non-linear (iron) or linear anisotropic (permanent magnet) characteristics. The current-carrying elements can be straight or curved blocks with rectangular cross sections. Boundary conditions are simulated by the technique of mirroring. Analytical formulae used for the computation of the field produced by a magnetized volume of a polyhedron shape are detailed. The RADIA code is written in object-oriented C++ and interfaced to Mathematica [Mathematica is a registered trademark of Wolfram Research, Inc.]. The code outperforms currently available finite-element packages with respect to the CPU time of the solver and accuracy of the field integral estimations. An application of the code to the case of a wedge-pole undulator is presented.

High-quality electron beams from a helical inverse free-electron laser accelerator

“…The r.m.s. difference between on-axis fields measured with a hall effect sensor and those calculated with Radia, a three-dimensional magnetostatic simulation 20 , was reduced to less than 1% by finely adjusting the gaps between opposing magnet poles 21 . The helical electron trajectory is calculated by the second integral of the field for a beam energy of 50 MeV and is shown in Fig.…”

Helical inverse free electron laser accelerator for efficient production of high quality electron beams

“…A stepper motor controls the motion of the hall probe along one axis of the translation stage. The measurement system is automated, and the field scans assist the tuning of the magnetic gaps in order to match the measured fields to the designed fields, modeled with Radia, a 3D magnetostatic field solving code [8].…”

Polarisation analysis on the LET time-of-flight spectrometer

“…In order to optimise the coil geometry, we again employed the Radia software for Mathematica [23]. Three configurations were simulated; a simple pair of Helmholtz coils, four coils arranged in two symmetric pairs, and six coils arranged in three symmetric pairs.…”

“…To solve this problem, a model of the flipper and its environs was built in Radia [23], which calculates the magnetic field generated by an assembly of magnetic (both current-carrying and permanent) components using analytical approximations. The model comprised the holding field environment for the polariser, a µ-metal screen (relative permeability µ = 5 × 10 4 ) with an aperture to reduce the stray field at the flipper position, the flipper itself, several movable permanent magnets to fine tune the magnetic field, and the three existing soft iron guide field housings following the flipper (Figure 7).…”