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 * Henry, One can see reaction to the electron beam in apatite by the loss of CL, evidence of physical damage even with a scanning beam, and orientation-dependent migration of halogens that was well documented by Stormer et al. (1993, Am. Min.). We have confirmed Stormer's observations in our lab. I would recommend a 5 micron scanning beam at 5 nA and 15 kV for apatite analyses. eric On Sep 6, 2006, at 3:01 PM, Henry Barwood wrote: > 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 > > > > * > Dear Eric, > > > > Thanks. I had not noticed significant beam damage in my apatites, > but then I’m a (very) modest user of the probe. I do usually try > and use as large a spot size as possible. Some phosphates are > significantly degraded under the beam no matter how careful you are. > > > > Henry > > > > Henry Barwood > > Associate Professor of Science, Earth Sciences > > Department of Math and Physics > > MSCX 312G > > Troy University > > Troy, Alabama > > [log in to unmask] > > > > From: JEOL-Focused Probe Users List > [mailto:[log in to unmask]] On Behalf Of Eric J Essene 1 > Sent: Wednesday, September 06, 2006 12:02 PM > To: [log in to unmask] > Subject: Re: [PROBE-USERS] Help with probe analysis of minerals > > > > Henry, > > Microprobe analysis of both the apatite- and bastnaesite-group > phases is quite touchy. Beam damage, degassing and elemental > migration (potential F and Cl increase in apatite with time) are > significant problems for these minerals. > > eric > > > > > > On Sep 6, 2006, at 11:52 AM, Henry Barwood wrote: > > > > > 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 > > > > > > > > * > > > > Perhaps someone on the list would be interested in collaborating > with me on > > the analysis of some mineral specimens for publication. I have been > > conducting studies of syenite minerals from the Arkansas alkalic > syenites > > for over 20 years and would like to work on some of the > accumulation of > > unknowns that has built up. Unfortunately, here at Troy, my research > > capabilities are somewhat limited. If there is anyone who would > like to > > analyze some of the specimens as a co-author, please let me know. > Some of > > the partially completed studies that I have waiting include: > > > > Analysis of brithiolite and silician fluorapatites > > Mosandrite analysis > > Examination of the eudialites from Magnet Cove and Jones Mills > > Reexamination of the rare-earth fluorocarbonates from several > locations > > > > Thanks. > > > > Henry Barwood > > Associate Professor of Science, Earth Sciences > > Department of Math and Physics > > MSCX 312G > > Troy University > > Troy, Alabama > > [log in to unmask] > > > > > > > > >