The Michael J. Drake
Electron Microprobe Laboratory
University of Arizona

User Information (FAQ)

How do I sign up for time on the microprobe?
How does the web based signup work?
Who does the calibrations for WDS analysis?
What do I need to know (or tell Ken) before my session in order to calibrate for WDS?
How do I find my analysis spots?
When can I carbon coat my samples?
Who does the analyses?
What time should I show up?
What time do I need to be finished?
How do I get my data?
How are the quantitative analysis results formatted?
What is the x-ray map format?
When should I pick up my samples?



Arranging for Instrument Time

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Web Signup

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Calibration and Calibration Training

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Calibration Planning

Data needed for calibration:

  1. What elements you plan to analyze for and what type of minerals or materials these elements are contained in (e.g. anhydrous silicate minerals, hydrous silicate glasses, chrome alloy steels, etc.)?2
  2. What is the general composition (roughly) of these matrix minerals or materials.3 (This information is needed primarily to determine if peak or background interferences may be present).
  3. Are the minerals or materials of interest small (< 6 Ám) in size.
  4. Are any of the elements you plan to analyze of more importance than the others (e.g. as in geothermobarometry) or do you need to know their concentrations accurately at trace levels (< 0.1 wt%)?
  5. What are you trying to determine (e.g. general composition of all phases present, trace Ni partitioning between metal and olivine, age dating of monazite, Sb content of archaeological artifacts, etc.)?
1If you have run the same type of analyses on our microprobe before, specifying "same calibration as last time" or something to that effect is usually sufficient.
2Some types of analyses are so common, particularly for geological and meteorite samples, that we can guess what elements you need and make any necessary adjustments during your probe session. For example, general analysis of all major silicate minerals in a rock section (standard silicate analysis), general analysis of all major metals and sulfides in a chondritic meteorite (standard metals and sulfides), etc. In cases like these a brief specification (e.g. standard silicates) is generally enough.
3In some cases, especially for a completely unknown sample, it may be necessary to actually get the sample on the microprobe in order to answer the above questions. However a good guess prior to starting is usually better than nothing.

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Analysis Planning - Sample Navigation

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Carbon Coating

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Hours and Procedures

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Collecting your Data

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Quantitative Analysis Data Format

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X-ray map format

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Picking up Your Samples

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