Open AccessBeam profile analysis for the C{ampersand}MS B231 electron beam welding machines
Author(s) -
J. W. Elmer,
Alan T. Teruya,
M. Gauthier
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/584737
Subject(s) - protein filament , beam (structure) , optics , focus (optics) , materials science , welding , ribbon , cathode ray , beam diameter , physics , electron , composite material , nuclear physics , laser , laser beams
The electron beams produced by two different welders were examined using computer assisted tomographic (CT) analysis. The machines used are Hamilton Standard welders with 150 kV/50mA maximum. One machine uses a ribbon filament while the other uses a hairpin filament. The objective of this study was to characterize the beam power distribution on each machine to see if weld parameters could easily be transferred between machines. Beam focus, voltage, and current settings were pre-selected to duplicate the welding conditions used in LLNL program applications. The results show that the actual beam currents measured by Faraday cup are 5 to 10% higher for the first machine and 30% lower for the second. The CT analysis of the beam shapes shows that the hairpin filament welder produces an elliptical beam shape in the sharp focus condition that defocuses to a diamond shape. The ribbon filament welder produced less of an elliptical beam shape in the sharp focus condition, but when defocused, acquires an elliptical shape. CT analysis of the effects of defocus on the peak power density shows that the hairpin filament drops in peak power density much more quickly than the ribbon filament for a given amount of defocus. Furthermore, it was more difficult to find and repeat the sharp focus condition for the hairpin filament, particularly at higher beam currents