SAMPLE PREPARATION DECISION TREE

[Your sample is: loose grains, particles, chunks (like a hand sample or slab), or already embedded in epoxy.]

Your end product will be a 1-inch-diameter cyclindrical epoxy mount that has been polished and includes mineral standards and labels.

Each epoxy round must be 1-inch (<25.6 mm) in diameter and ideally is 5 mm thick, although a maximum thickness of 12 mm is allowable. Mounts with the maximum thickness of 12 mm may tilt in the holder, which can lead to significant analytical problems. Below is a schematic of the sample holder used in the SIMS so you have an idea of why this geometry is required.

Sample Prepartion Picture

Take note of the dashed blue line in the map view above (top panel). This line illustrates the portion of the epoxy mount within the "sweet spot" for analysis, which has a 5 mm radius in the classic sample holder shown above (Kita et al., 2009) and an 8 mm radius is possible with care using the updated design (Peres et al., 2013). The WiscSIMS lab has a number of each holder version. All sample and standard analyses must be within an 8 mm radius of the center of the epoxy mount.

Example of foraminifera grain-mount with standards (link).

Will you be analyzing:

– portions of a sample that you could or already have cut (sawed) by hand to expose the analytical surface (cm-scale)?

OR

– small loose grains like zircons or foraminifera (mm- or μm-scale)?

OR

– Do you already have a polished epoxy round that fits the above specifications, but still need to mount mineral standard grains?