DocumentCode :
1131050
Title :
Current Accumulation for a Self Magnetic Field Calculation in a Finite-Element Gun Code
Author :
Nelson, Eric M. ; Petillo, John J.
Author_Institution :
Los Alamos Nat. Lab., NM, USA
Volume :
41
Issue :
8
fYear :
2005
Firstpage :
2355
Lastpage :
2361
Abstract :
We describe a novel current accumulation algorithm for the three-dimensional self magnetic field calculation in a charged-particle beam optics code. The current source is a charged-particle beam represented by a collection of numerically-integrated current-carrying rays. We compute the magnetic vector potential using edge basis functions and the curl–curl formulation of the finite-element method. The current accumulation algorithm takes advantage of a novel particle tracker that happens to be ideal for this application. We show that our source vector is compatible with the singular finite-element matrix, even with modest numerical integration errors. Thus, a conjugate gradient matrix solver works well, with no need for additional gauge conditions. We confirmed this behavior in a series of numerical tests on a small problem with incomplete linear and quadratic basis functions on a variety of element shapes.
Keywords :
computational electromagnetics; conjugate gradient methods; electron beams; electron guns; finite element analysis; integration; magnetic fields; particle tracks; 3D self magnetic field calculation; charged-particle beam optics code; conjugate gradient matrix solver; curl-curl formulation; current accumulation algorithm; current-carrying rays; edge basis functions; electron trajectory code; finite-element gun code; linear basis functions; magnetic vector potential; magnetostatics; particle beam optics; particle tracker; quadratic basis functions; Cathodes; Character generation; Electron guns; Finite element methods; Magnetic fields; Magnetostatics; Optical beams; Particle beam optics; Testing; USA Councils; Electron trajectory code; finite-element methods; gun code; magnetostatics; particle beam optics;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.2005.852181
Filename :
1492539
Link To Document :
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