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 Iím 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]

*

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