Date: Fri, 2 Sep 94 13:37:59 PDT
Subject: Re: found it! nevermind....
From: pierce@magic.geol.ucsb.edu (Dave Pierce)

>Dave:
>
>A few questions:
>
>>*Moved PET #3 to reach iron. Best thing since sliced peanutbutter.
>
>How did you do this? Tilt the crystal to get a lower angle?


No. The turret holding the whole crystal assembly is positioned with metal
pins. You can loosen the single screw holding the assembly and press
against the pins toward the stage, tighten the screw and you gain enough
motion to reach Fe. I am sure that this is very much a specific PET mount,
but our PET on #2 reached Fe with no change, but it happens to be slightly
less sensitive for Fe Ka than #3 PET. For PEAK 3 to work you need to get
well over the peak which it wouldn't before I made the change.
>
>>*Shuttle plate to do 1" X 3" slides and method of converting X-Y positions
>>from light microscopt to probe coordinates. Cost: $200.
>
>How did you do this X-Y position converting? I'm very interested...
>

Turns out to be an exchange of X for Y and a simple subtraction since both
systems are in mm and Cameca has its zero in the middle 20 mm away from the
light microscope stage edge. I am not sure about the short axis, but I
think it was also 20 mm.


>>*Plastic template to locate X-Y positions of analysis sites before
>>introduction into Cameca. Not real precise, but good enough. Xerox a mm
>>graph paper onto overhead film and cut to fit. I put a handle on it using
>>double stickey tape and a cut of file folder. Tested by using a cut-out of
>>graph paper and viewing on the display to obtain corrected position on the
>>same graph paper. Cost: 5 cents + time.
>
>-- I've done this also and find you can get to within 100 microns of
>grains.
>
>
>john
>
>John Fournelle
>Electron Microprobe Lab Internet:johnf@geology.wisc.edu
>Dept of Geology & Geophysics Telephone: (608) 262-7964
>University of Wisconsin Fax: (608) 262-0693
>1215 West Dayton Street Amateur radio: WA3BTA/9
>Madison, WI 53706
>