Mime-Version: |
1.0 (Apple Message framework v936) |
Sender: |
|
Subject: |
|
From: |
|
Date: |
Tue, 15 Dec 2009 07:31:29 -0600 |
Content-Transfer-Encoding: |
7bit |
Content-Type: |
text/plain; charset=US-ASCII; format=flowed; delsp=yes |
Reply-To: |
|
Parts/Attachments: |
|
|
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 Steve,
Yes, I've seen that before on our 8900. It is dirt in the lower
column charging, which deflects the beam as it becomes increasingly
charged. Then it discharges, and the beam "snaps back" to its
starting position again. You'll probably see it happen faster with a
larger beam current. The dirt is most likely in the lower column,
probably just inside the objective lens pole piece or very near it --
something from the chamber deposited there. Cleaning the objective
lens pole piece should fix that problem.
Best,
Ellery
-----------------
Ellery Frahm
Senior Research Fellow, Department of Geology & Geophysics
Manager & Principal Analyst, Electron Microprobe Lab
University of Minnesota - Twin Cities campus
Lab website: http://probelab.geo.umn.edu/
Personal: http://web.mac.com/elleryfrahm/
|
|
|