JEOL Probe Users Listserver Moderator: Ellery Frahm, [log in to unmask], Electron Microprobe Lab, University of Minnesota Post a message: send your message to [log in to unmask] Unsubscribe: send "SIGNOFF PROBEUSERS" to [log in to unmask] On-line help and FAQ: http://probelab.geo.umn.edu/listserver.html * Hi, thanks for all the replys. Yes, I see all these problems which is why I always defocus and never raster. Just checking to make sure I was standing my ground on firm ground. You know, new users to the lab saying "we always did it this way before...". Thanks for letting me check with you, I feel confident that I haven't missed something. cheers, Ron AK: I sometimes use a defocussed beam, but for the reason mentioned by Andy Buckley I stay away from rastering. The JEOL 8200 has a "beam diameter" parameter in its EOS setup, which is fairly accurate judging from materials that show the "burn" spot....... PH: I just have to add my 2 or maybe 4 cents into this discussion. Cent 1. Rastering while analyzing is the worst possible way to do a "bulk" analysis of inhomogeneous materials due to the "flag pole effect" (my term or I may have heard it a long time ago). The beam is not rastered evenly. A delay is programmed into the raster at the beginning of each horizontal line to compensate for hysteresis in the scanning coils. This produces a "flagpole" of extra dwell time at the left side of the raster........