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@claude claude Bot commented Jul 23, 2026

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Adds docs/eds_daq.md explaining the EDS data-acquisition chain — SDD detector, digital pulse processing (fast/slow channels), process time, dead time, pile-up rejection, MCA binning, and counting statistics — and how each stage determines the acquisition parameters we set.

Addresses issue #1.

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Co-authored-by: Ronnie Guymon <244881888+ronnie-guymon@users.noreply.github.com>
@claude claude Bot mentioned this pull request Jul 23, 2026
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@claude I want to be able to process the data from EDS in a way where I can do the mapping and elemental composition in a software other than TEAM. What is all the information that can be exported directly from the microscope (x-ray incidents, parameters, dead time, etc)? How is post processing typically done in research settings, what data is exported, what software is used?

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claude Bot commented Jul 23, 2026

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Todo

  • Read existing docs/eds_daq.md for context
  • Research what EDAX TEAM can export directly (formats, metadata, dead time, raw counts)
  • Research typical research post-processing workflows and open-source software
  • Post answer with validated links

Short answer

You can get everything you need out of TEAM to do mapping and quantification elsewhere. The key export is the spectrum-image datacube (.spd + .spc + .ipr trio), which contains the raw, unprocessed MCA counts for every pixel plus all the acquisition metadata (live/real time, dead time, kV, geometry, energy calibration). The de facto research workflow is to load that trio into HyperSpy/eXSpy (Python) and do mapping, decomposition, and quantification there. The one thing you cannot export is the photon-by-photon event stream — the MCA-binned counts are the rawest data any vendor exposes.

1. What TEAM can export directly

Data Format Contents
Spectrum image (map) .spd The full datacube: x × y × ~4096 energy channels of raw counts per pixel — this is the "x-ray incidents" record, binned by energy and position
Spectral + detector metadata .spc Energy calibration (eV/channel, offset), live time, real time (→ dead time), kV, amp/process time, detector geometry (take-off angle, azimuth, elevation), window type, element list
Spatial calibration .ipr Pixel size / field width, so maps come out in µm not pixels
Single spectra .spc, .msa, .csv .msa is the vendor-neutral EMSA/MAS standard ASCII format — readable by essentially every microanalysis tool, with metadata (live time, kV, take-off angle) in its header
Line scans .lsd + .csv Per-point spectra + positions
Images TIFF/BMP SE/BSE reference images

Practical notes:

  • When exporting a map, export all three files with the same base name into the same folder — downstream tools use the .spc/.ipr to calibrate the .spd. Without them the cube still loads, but uncalibrated (RosettaSciIO EDAX docs).
  • Dead time: recorded per acquisition (live vs. real time in the .spc/.msa header), not per pixel. That's fine — quantification uses live time, which is exactly what the DAQ chain in docs/eds_daq.md preserves.
  • Not exportable: list-mode event data (individual photon timestamps) and fast-channel diagnostics. No commercial SEM-EDS vendor exposes these; the spd cube is the ground truth everyone works from.
  • FYI, EDAX's newer APEX software replaces this trio with an open HDF5 container (APEX), which is even friendlier to external processing — relevant if the microscope PC is ever upgraded.

2. How research groups typically post-process

The dominant open-source stack is Python:

  • HyperSpy + eXSpy (the EDS/EELS extension since HyperSpy 2.0), with RosettaSciIO as the file reader — it natively reads TEAM's .spd/.spc/.lsd. Typical workflow:
    1. s = hs.load("map.spd") → calibrated 3D signal (auto-finds the .spc/.ipr)
    2. Elemental maps: s.get_lines_intensity() gives background-corrected line-intensity maps per element; or fit a full model (Gaussian peaks + physical background) per pixel for overlapping lines — directly relevant to the Al/Si/Mg region in AlSi10Mg
    3. Denoising / phase mapping: PCA for denoising, then NMF to unmix the cube into physically interpretable phase components — the standard multivariate approach (example on SEM/EDS phase maps, ML-based SEM-EDX quantification)
    4. Quantification: eXSpy does Cliff-Lorimer / ζ-factor / cross-section (TEM-oriented); for SEM bulk samples the rigorous route is standards-based ZAF/φ(ρz)
  • NIST DTSA-II — the reference tool for accurate SEM-EDS quantification: import spectra as .msa, quantify against measured or simulated standards, model detector artifacts (escape peaks, sum peaks). This is the tool behind the Newbury & Ritchie accuracy papers already cited in docs/eds_daq.md, and the natural choice for CALIBER's goal of fixing standardless-quant errors.
  • PyMCA (ESRF) — fundamental-parameters spectrum fitting; strong for tricky backgrounds and batch-fitting maps.

A common division of labor: HyperSpy for maps and phase decomposition (spatial questions), DTSA-II for point-spectrum composition (accuracy questions).

3. Suggested recipe for this project

import hyperspy.api as hs
s = hs.load("mymap.spd")           # picks up mymap.spc / mymap.ipr automatically
s.set_elements(["Al", "Si", "Mg", "Fe"])
maps = s.get_lines_intensity()      # background-corrected intensity maps
s.decomposition(True)               # PCA (denoise / pick n components)
s.decomposition(algorithm="NMF", output_dimension=3)  # phase unmixing
s.sum().save("sum_spectrum.msa")    # → DTSA-II for standards-based quant

The .msa export of point spectra (or the summed/per-phase spectra from the cube) is the bridge into DTSA-II for quantification against standards.

Happy to add a docs/eds_export_postprocessing.md distilling this into the repo if you'd like — just say the word.

Sources: RosettaSciIO EDAX format docs · HyperSpy EDS user guide · eXSpy · NIST DTSA-II · Multivariate analysis of SEM/EDS phase maps · ML quantification of SEM-EDX · EDAX APEX · HyperSpy EDAX import discussion

@ronnie-guymon ronnie-guymon changed the title Add explainer on data acquisition during EDS EDS DAQ Jul 23, 2026
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@claude do those programs show the wt% of elements accurately? Is it possible to strip a peak based on an energy reading? for example if I wanted to analyze a small Mg peak that was placed next to a large Al peak, how possible and accurate would it be?

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Todo

  • Assess wt% accuracy of HyperSpy/eXSpy, DTSA-II, PyMCA (standardless vs. standards-based)
  • Explain peak stripping / deconvolution options for overlapping peaks
  • Address the specific Mg Kα (1.254 keV) vs. Al Kα (1.487 keV) case with numbers
  • Post answer with validated links

Short answer

Yes on both counts, with caveats. Accurate wt% depends far more on how you quantify (standards-based vs. standardless) than on which program you use — DTSA-II with standards is demonstrably accurate; standardless (what TEAM gives you by default) is not. And yes, overlapping peaks can be separated, but the accurate way is peak fitting/deconvolution, not literal energy-window stripping. Your specific case — small Mg Kα (1.254 keV) next to large Al Kα (1.487 keV) — is a mild overlap by EDS standards and is very tractable if you collect enough counts.

1. Do these programs give accurate wt%?

It depends on the quantification protocol, not the software brand:

  • Standards-based (DTSA-II): Newbury & Ritchie showed that SEM/SDD-EDS with measured standards and multiple-linear-least-squares (MLLS) fitting achieves RDEV within ±3% relative in ≥95% of analyses on homogeneous, flat-polished samples — rivaling WDS electron microprobe accuracy (NIST DTSA-II, Newbury & Ritchie 2015). For concentration tiers, that paper reports roughly ±5% relative for major, ±10% for minor, ±25% for trace constituents, with detection limits below 0.05 wt% in practical measurement times — even with severe peak interference.
  • Standardless (TEAM's default eZAF, and vendor software generally): errors routinely reach ±25–50% relative on a meaningful fraction of analyses — this is the accuracy problem the Newbury & Ritchie papers cited in docs/eds_daq.md document. Fine for "what's in this?", not for real compositions.
  • HyperSpy/eXSpy: excellent at the fitting step (extracting unbiased peak intensities from overlaps), but its built-in quant methods (Cliff-Lorimer, ζ-factor) are TEM-oriented. For SEM bulk samples the practical split is: fit/map in HyperSpy, quantify point or per-phase spectra in DTSA-II against standards.
  • PyMCA: fundamental-parameters fitting — good intensities and tricky-background handling; quant accuracy is FP-model-limited, between the two above.

Accuracy also presumes the physics assumptions hold: flat, polished sample; known geometry; adequate counts. Rough surfaces break ZAF corrections regardless of software.

2. Can you strip a peak based on energy?

You can (background-strip then subtract a scaled reference peak at a given energy), but simple energy-window ROI stripping is exactly the method that fails for a small peak beside a big one — the big peak's tail leaks into the small peak's window and biases it. What research software actually does, and what you want, is simultaneous fitting:

  • DTSA-II: MLLS fitting against measured reference spectra (pure Mg, pure Al). Both peak shapes are fit at once, so the Al contribution under the Mg window is modeled rather than guessed, and uncertainties are propagated. This is the most rigorous overlap treatment available in free software.
  • HyperSpy/eXSpy: s.create_model() puts a Gaussian at each line with energy fixed and width tied to detector resolution, plus a physical background; fitting returns each peak's area separately even where they overlap (EDS model fitting docs). Works per-pixel on the .spd map cube, so you get overlap-corrected Mg maps, not just point values. You can also literally subtract the fitted Al component if you want a "stripped" spectrum for display.
  • PyMCA: full-spectrum FP fit, same principle.

3. Your specific case: small Mg next to large Al

The numbers are favorable:

  • Mg Kα = 1.254 keV, Al Kα = 1.487 keV → 233 eV separation. An SDD at ~125–130 eV FWHM (Mn Kα) has roughly 80–90 eV FWHM at these energies, so the peaks are ~2.5–3 FWHM apart — visibly distinct with overlapping tails. That's a mild overlap; the pathological cases are separations under ~50 eV (e.g. Mo Lα/S Kα), which EDS genuinely can't resolve (overlap discussion).
  • With fitting (not window stripping), the limiting factor becomes counting statistics, not the overlap. For ~0.3–0.5 wt% Mg in an Al matrix (the AlSi10Mg case), you're well above the ~0.05 wt% detection floor; expect roughly ±10% relative accuracy standards-based if you collect a high-count spectrum (Newbury & Ritchie 2015).
  • Practical DAQ settings that matter here (they tie directly to docs/eds_daq.md): use a longer process time (best energy resolution — narrower Al tail under Mg) and keep dead time moderate (~20–30%), then simply acquire longer. Deconvolution accuracy degrades measurably when resolution is sacrificed for throughput (deconvolution accuracy). A lower beam voltage (~5–10 kV) also improves peak-to-background for these low-energy lines.
  • One honest caveat: for trace Mg (≲0.1 wt%) sitting on the Al tail, expect the ±25%-relative trace tier — quantifiable but noisy. If you ever need better than that at trace level, WDS is the escalation path, not different software.

Bottom line: export the .spd/.spc/.ipr cube, fit (don't window-strip) the Mg/Al region — HyperSpy for maps, DTSA-II with Mg/Al standards for wt% — and the small-Mg-next-to-big-Al problem is routinely solvable to ~±10% relative at minor-element concentrations.

Sources: Newbury & Ritchie, high-accuracy SEM/SDD-EDS (PMC4555346) · NIST DTSA-II · HyperSpy EDS user guide · SEM-EDS spectral overlaps & deconvolution · EDS deconvolution of overlapping peaks (M&M 2023) · PyMCA
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@ronnie-guymon

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@claude I am really interested in learning about how to create standards for EDS. If I were to create my own standards for a novel powder, that has been 3d printed via LPBF, how would I go about that? Use information based on what professionals do

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claude Bot commented Jul 23, 2026

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Todo

  • Research how professional labs make/source microanalysis standards (EPMA/EDS practice)
  • Outline a practical workflow for creating standards from a novel LPBF powder/printed material
  • Validate links and post answer

Short answer

An EDS "standard" is just a flat-polished, microscopically homogeneous piece of material whose composition is known from an independent (non-EDS) technique. Professionals rarely make a standard shaped like the unknown — you would not use loose powder or as-built LPBF material as the standard itself, because as-built LPBF violates all three requirements (porosity, Mg evaporation loss, sub-µm Si segregation). Instead the professional route is: (1) use purchased pure-element standards for the k-ratio protocol, and (2) if you want a matrix-matched check standard from your novel alloy, consolidate it into dense homogeneous bulk (remelt or HIP + homogenization anneal), have its bulk composition certified by ICP-OES, then qualify its micro-homogeneity yourself with a statistical grid of analyses.

1. What makes something a "standard" (professional criteria)

From EPMA practice (the discipline EDS quantification inherits from):

2. First: you may not need to make anything

For AlSi10Mg-type chemistry, the Newbury–Ritchie protocol needs only pure-element or simple compound standards: pure Al, pure Si, pure Mg, pure Fe, etc. Pure-element spectra also serve as the fitting references for the Mg/Al overlap discussed earlier. These are bought as polished multi-material mounts from Astimex, Geller MicroAnalytical (ISO-17025, NIST/NPL-traceable), or SPI; free/loaner options include NIST SRM glasses, Smithsonian microbeam standards, and USGS reference materials (directory at FIGMAS; a university probe lab's block, e.g. UW–Madison's, shows what a working set looks like). One standard block (~$1–3k) + DTSA-II gets you the documented ±3%-relative accuracy tier (Standard Bundles in DTSA-II). A custom standard from your own alloy is then a validation/QC material, not a prerequisite.

3. Making a custom standard from your novel powder — the professional workflow

Step 0 — decide what material state to certify. The powder and the printed part have different compositions: Mg (boiling point 1091 °C) measurably evaporates in the LPBF melt pool, so parts run Mg-lean relative to feedstock (micropore/post-treatment study noting Mg/Cu loss and Si enrichment). If your goal is checking printed-part analyses, certify material made from a printed coupon; certify the powder separately (by ICP) if you want to track feedstock→part drift — that drift is itself a CALIBER-relevant measurement.

Step 1 — consolidate to dense, homogeneous bulk. Loose powder can't be a standard (particle geometry breaks the flat-surface assumption), and as-built LPBF material has gas/keyhole porosity and a sub-µm cellular Si network — heterogeneous right at the ~1 µm interaction-volume scale. Two professional routes:

  • Remelt route (how custom alloy standards are classically made): arc- or induction-melt a few grams of the powder, remelt ~5× with flipping to mix, then homogenization-anneal below solidus to erase microsegregation (custom alloy fabrication practice). For AlSi10Mg note the Al–Si eutectic: fully single-phase is impossible, but a long anneal coarsens/equilibrates the two phases so a defocused-beam or large-area average is stable — same situation as many accepted two-phase standards.
  • From-the-print route: take a high-density printed block, HIP or hot-isostatic-press + solution anneal to close pores and homogenize. More representative of your actual process; slightly more residual risk of inhomogeneity.

Step 2 — independent bulk certification. Send pieces of the same billet to a commercial or university lab for ICP-OES after acid digestion (metals) and combustion/inert-gas-fusion analysis for O/N/C if relevant (alloy chemistry analysis; technique comparison for commercial alloys). Ideally two labs or two techniques (ICP + XRF) — agreement is your certification; NIST-grade CRMs go further with round-robins, overkill for an in-house working standard.

Step 3 — mount, polish, coat. Standard metallographic prep: flat polish to ≤1 µm finish, no etching, clean, carbon-coat identically to your unknowns (NIST prep guidance).

Step 4 — qualify micro-homogeneity statistically. This is the step amateurs skip and professionals don't: run a grid (e.g. 10×10 points across the mount, plus several fields at different depths of a sectioned piece) at high counts, and require the observed relative standard deviation of each element's intensity to approach the counting-statistics limit — excess scatter = heterogeneity, and the number of points sets how small a heterogeneity you can rule out (EPMA homogeneity-testing methodology). You can do this entirely with your own EDS + the exported spectra.

Step 5 — document and maintain. Record certified values + uncertainties, prep/coating details, and the homogeneity data; store desiccated; re-polish/re-coat and spot-check periodically. Load the spectra into DTSA-II as a standard bundle so quantification picks them up automatically (Standard Bundles paper).

4. How the pieces fit for CALIBER

  • Primary standards: purchased pure Al, Si, Mg, Fe mounts → k-ratios in DTSA-II (±3–5% relative on majors).
  • Secondary / matrix-matched standard: your certified, consolidated AlSi10Mg billet → measured as a "known unknown" every session to catch drift, geometry errors, and dead-time miscalibration; also the honest test of the Mg-next-to-Al deconvolution accuracy discussed above.
  • Powder itself: characterized by ICP for feedstock certification, and by EDS only qualitatively (mounted/sectioned particles) — powder EDS is never quantitative-grade because of geometry.

Cost/effort reality check: purchased block ≈ order-and-go; custom billet ≈ one melt/HIP run + ~$100–300 of commercial ICP + an afternoon of homogeneity mapping. That combination is essentially what a professional microprobe lab would set up for a new alloy system.

Sources: Homogeneity testing of microanalytical reference materials (Talanta) · ISO 14595 CRMs for EPMA · NIST sample prep for EPMA · Standards-Based Quantification in DTSA-II, Part I · NIST Standard Bundles for DTSA-II · NIST DTSA-II · Astimex · Geller MicroAnalytical · FIGMAS standards directory · UW–Madison standards block · Mg loss / porosity in LPBF AlSi10Mg · Alloy chemistry techniques comparison · SGS alloy chemistry analysis
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@ronnie-guymon

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@claude help me understand step 4 better. When you say 10x10 points across the mount, would that mean methodically analyzing 100 different points while I'm at the microscope? Like focusing on 100 different points and collecting data from each of them?

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claude Bot commented Jul 24, 2026

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Todo

  • Explain what a "10×10 grid" homogeneity test actually looks like in practice
  • Cover how professionals automate it (batch points vs. maps) and the time involved

Short answer

Conceptually yes — it's 100 separate spectrum acquisitions at 100 locations. But in practice, no, you don't sit there manually focusing and clicking 100 times. You focus once, define the grid, and let the software drive the stage/beam unattended. It's roughly an hour of hands-off acquisition, and there's an even lazier route: just collect maps and slice them into "points" afterward in software.

What one "point" actually is

A point analysis means the beam is parked at a stationary spot (or rastered over a tiny box) while the detector accumulates a spectrum for a fixed live time — say 30–60 s at moderate dead time, enough for a few hundred thousand counts. No per-point focusing is involved: the mount is flat-polished and the stage stays at one working distance, so focus set once at the start holds across the whole grid. (This is exactly why the flat-polish requirement in step 3 matters — it's what makes the grid comparable point-to-point.)

How the 100 points actually get collected

Three ways, in decreasing order of effort:

  1. Manual — move stage, click, wait, repeat ×100. Possible, tedious, nobody does it this way.
  2. Automated point grid — TEAM (like all vendor EDS packages) has batch/multi-point acquisition: you define a grid of points or fields over the mount, set the live time per point, and walk away. The software steps the stage/beam and saves a spectrum per point. 100 points × 30 s live time ≈ 50–70 min of unattended run time.
  3. Maps as points (the modern shortcut) — a spectrum-image map is already thousands of point spectra. Acquire a few .spd map cubes at different locations on the mount, then offline in HyperSpy rebin each cube into, say, a 10×10 block of summed sub-region spectra. You get your 100 "points" (at whatever effective pixel size you choose) from data you'd be collecting anyway, and you can re-slice at different length scales to test homogeneity at 1 µm vs. 10 µm vs. 100 µm — which a fixed point grid can't do.

The reason the grid is spread "across the mount" (and ideally on a sectioned face too) is to sample different length scales: point-to-point scatter within a field catches µm-scale segregation, field-to-field scatter across millimeters catches macrosegregation from the melt/anneal.

What you do with the 100 spectra

For each element, extract the peak intensity from every spectrum and compute the observed relative standard deviation across the 100 values. Compare it to the counting-statistics limit (≈ 1/√N for N peak counts): if the observed scatter matches what Poisson statistics alone predicts, the material is homogeneous at your measurement precision; excess scatter = real compositional variation. More counts per point makes the test more sensitive — with ~10⁶ counts per point you can detect inhomogeneity below ~1% relative. This is the statistical protocol in the microanalytical reference-material homogeneity paper from the earlier reply, and the whole computation can be done from exported .msa/.spd files in Python — no vendor software needed.

Bottom line: it's one focusing session plus an hour of automated acquisition (or a couple of maps you slice up afterward), followed by a straightforward statistics pass on the exported spectra — not 100 manual point-and-shoot measurements.

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@claude I have a meeting with Mike today to get trained for EDS using their EDAX system. I want to use eXSpy. What data should I ask to collect in order to use eXSpy, and what other questions should I ask that would help in developing a process to accurately characterize Mg wt%?

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claude Bot commented Jul 27, 2026

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Todo

  • Review prior thread context (export formats, Mg/Al overlap, standards workflow)
  • Compile the data checklist for eXSpy compatibility
  • Compile training-session questions targeting accurate Mg wt%
  • Post answer with validated links

Short answer

For eXSpy you want three things out of the session: (1) the .spd + .spc + .ipr map trio exported with the same base name into the same folder, (2) point spectra as .msa, and (3) pure-element reference spectra (Mg, Al, Si) if the lab has a standards block — acquired under the exact same conditions as your unknowns. The questions to ask Mike fall into four buckets: detector/DAQ settings, calibration & standards, beam current & geometry, and export/automation logistics. Details below, ordered so you can use it as a meeting checklist.

1. Data to ask to collect (the eXSpy checklist)

What Format Why
Spectrum-image map .spd + .spc + .ipr, same base name, same folder The raw per-pixel MCA counts; RosettaSciIO reads it natively and auto-picks up calibration from the companions
Point spectra .msa (EMSA) Vendor-neutral; loads in eXSpy and bridges to DTSA-II for standards-based quant later
Pure-element spectra .msa, high counts (≥10⁶) Fitting references for the Mg/Al overlap and k-ratio standards — the single most valuable extra ask if the lab owns pure Mg/Al/Si mounts
SE/BSE reference image + stage coordinates TIFF + notes Provenance for where each spectrum came from

Metadata to verify is present in the exports (open the .msa header in a text editor at the microscope — it's plain ASCII):

  • Beam energy (kV), live time, real time (→ dead time)
  • Process/amp time setting used
  • Energy calibration: eV/channel and offset
  • Detector geometry: take-off angle, or elevation + azimuth
  • Pixel size / field width (in the .ipr)
  • Beam current if measurable — TEAM usually does not record this; write it down manually if there's a Faraday cup (eXSpy's ζ-factor quantification needs beam_current and real_time; anything missing can be patched in later with set_microscope_parameters(), but only if you wrote it down)

Same-day sanity check (do this before leaving or that evening — catching a broken export while you still have scope access is the whole point):

import hyperspy.api as hs
s = hs.load("map.spd")   # auto-finds map.spc / map.ipr
print(s.metadata)        # verify beam_energy, live_time, elevation/azimuth
s.set_elements(["Al", "Si", "Mg", "Fe"])

2. Questions to ask Mike, aimed at accurate Mg wt%

Detector & DAQ (these map directly onto docs/eds_daq.md):

  • What is the detector's resolution (FWHM at Mn Kα), model, and window type?
  • What process-time options does TEAM expose, and which is the highest-resolution one? (Longest process time narrows the Al Kα tail under Mg Kα — the key knob for your overlap.)
  • What dead-time range does he recommend, and where is pile-up rejection configured? (You want ~20–30% and longer acquisitions, not high throughput.)
  • Can you run at low kV (5–10 kV) for better peak-to-background on Mg Kα, or is there a practical floor?

Calibration & standards (the accuracy questions):

  • How often is the energy calibration checked, against what, and can you verify it at the start of each session?
  • Does the facility own a standards block — pure Mg, Al, Si mounts? May you acquire high-count spectra from them? If not, would they order one (~$1–3k, e.g. Astimex/Geller)?
  • Is there a Faraday cup / picoammeter to measure beam current, and how stable is the current over ~1 h? (Standards-based k-ratios assume the same dose on standard and unknown.)

Geometry & sample prep:

  • What working distance gives the nominal take-off angle, and what is the take-off angle? (Quant corrections are sensitive to it.)
  • Is a carbon coater available, and is coating thickness reproducible? (Standards and unknowns must be coated identically.)
  • Confirm the holder sits at 0° tilt unless told otherwise.

Export & automation logistics:

  • Which software version — TEAM or APEX? (APEX exports HDF5, even friendlier to eXSpy.)
  • Can you export and transfer files yourself (USB/network share), and do exports include the .spc/.ipr companions by default?
  • Does TEAM support batch/multi-point acquisition or multi-field maps, and are unattended runs allowed? (This is what makes the 10×10 homogeneity grid from the standards discussion an hour of walk-away time instead of a day of clicking.)

3. Suggested first-session acquisition plan

  1. Energy-calibration check spectrum (whatever reference Mike uses).
  2. Pure-element Mg, Al, Si spectra — longest process time, ~20–30% dead time, ≥10⁶ counts each (30–60 s live time is usually plenty at moderate current).
  3. Two or three high-count point spectra on your AlSi10Mg sample at the same settings.
  4. One map cube (.spd trio) of a representative region.
  5. Export everything, note beam current / working distance / coating by hand, and run the eXSpy load test above the same day.

That single session gives you everything needed to prototype the full offline pipeline: model-fit the Mg/Al region in eXSpy using the pure-element peak positions, and later feed the same .msa files into DTSA-II for standards-based wt% at the ±5–10% relative tier discussed earlier.

Sources: RosettaSciIO EDAX format docs · eXSpy EDS user guide · NIST DTSA-II · Newbury & Ritchie 2015 (PMC4555346)

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@ronnie-guymon

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@claude Our time was limited during the training yesterday, but I found that we can export the .msa file and the TIFF file (I can take notes for the parameters that aren't recorded). The counts can be saved as a .xls or .csv file, I didn't see anything that is .spd, .spc, or .ipr. I can ask Mike about that in an email. If amp time is the same as processing time, 7.68 is the longest amp time that was available. We can do 5 or 10 kV, From what I understand we want the overvoltage to be at least double the energy of the K-alpha line, and since Si has the largest K-alpha line of about 1.74, 5kV should be enough. He said there wasn't really a downside to using more overvoltage than needed. He recommended a dead time of around .30, and that is done by increasing or decreasing the beam current. Energy calibration is done weekly. There is point analysis where I think Team does multiple point analysis, but we only had half the normal time to get through our training so I'll have to talk to him another time to figure that out.

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claude Bot commented Jul 28, 2026

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Todo

  • Review training notes against prior thread guidance
  • Check overvoltage rule, kV choice, amp time, dead-time advice
  • Clarify the .msa vs .spd export situation + questions for Mike
  • Post answer with validated links

Short answer

Good session — most of what you learned is right, and .msa + TIFF + your own notes is genuinely enough to start the eXSpy/DTSA-II point-spectrum workflow. Two corrections worth making before your next session: the overvoltage rule uses the ionization edge energy, not the Kα line energy (5 kV still passes, just barely more comfortably than the line-energy math suggests), and "no downside to more overvoltage" is not right for your problem — for accurate Mg wt% at low energies, 5 kV is actively better than 10. The one real gap in 5–10 kV operation is Fe, whose K line can't be usefully excited below ~15 kV. Details point by point:

1. Amp time = process time — yes, use 7.68 µs

They're the same knob (EDAX calls it amp time). 7.68 µs is the longest option on EDAX pulse processors, i.e. the best energy resolution setting — exactly what you want for pulling the small Mg Kα out from under the Al Kα tail. The trade-off is a low throughput ceiling: at 7.68 µs you'll hit 30% dead time at a fairly modest beam current. That's fine — you're choosing resolution over speed deliberately. Just compensate with longer live time per spectrum (aim for ≥10⁶ total counts on quant spectra).

2. Overvoltage — the rule, corrected, and the real downsides

  • The criterion is overvoltage U = E₀ / E_c ≥ ~2, where E_c is the critical ionization (absorption-edge) energy, not the emission-line energy. For Si that's 1.839 keV (vs. Kα at 1.740), so 5 kV gives U ≈ 2.7 for Si, ≈ 3.2 for Al (edge 1.560), ≈ 3.8 for Mg (edge 1.303). 5 kV comfortably excites all three — Mike's bottom line holds, the reasoning just needs the edge energies.
  • "No downside to more overvoltage" is where I'd push back. Higher kV: (1) grows the interaction volume roughly as E₀^1.7 — at 10 kV you're averaging over several times the depth/volume of 5 kV, which matters if you ever care about the cellular Si network or small features; (2) generates X-rays deeper, so the soft Mg/Al/Si K lines suffer more self-absorption, inflating the absorption correction and its uncertainty in quantification; (3) degrades peak-to-background for low-energy lines. Low-beam-energy analysis is a recognized strategy for exactly your situation — see Newbury & Ritchie's NIST review of electron-excited EDS microanalysis. For the Mg-in-Al accuracy goal, prefer 5 kV.
  • The Fe catch: Fe Kα is 6.40 keV (edge 7.11 keV). At 5 kV it's not excited at all; at 10 kV, U = 1.4 — excited so weakly it's near-useless for quant. At 5 kV, Fe only appears via its Lα line at 0.705 keV, which is a poor line for quantification. If Fe content matters for your AlSi10Mg characterization, ask whether kV settings above 10 are available (15–20 kV is the normal Fe Kα regime) and plan a two-condition protocol: 5 kV spectra for accurate Mg/Al/Si, plus a higher-kV spectrum of the same spot for Fe and any other transition metals. If the instrument truly tops out at 10 kV for your sessions, note that Fe numbers from it will be semiquantitative at best.

3. Dead time ~30% via beam current — agreed, with two notes

0.30 (30%) matches the 20–30% guidance from earlier in this thread; adjusting it via beam current is standard. Two additions: (1) since long amp time caps throughput, expect the current that gives 30% DT to be low — that's fine; (2) for standards-based k-ratios later, the beam current must be the same (or measured) between standard and unknown — so once you find a current that gives ~30% DT, log it (or the spot-size/aperture settings that produced it) and reuse it, and ask whether there's a Faraday cup to actually measure it.

4. Exports: what you found is enough — and where the .spd trio hides

  • .msa is the workhorse. It loads directly into eXSpy (hs.load("spec.msa")) and into DTSA-II, and its plain-text header carries live time, real time, kV, and (usually) take-off angle — open one in a text editor and verify those fields are populated; hand-note anything missing (beam current, working distance, coating).
  • .csv/.xls counts are redundant with .msa (same numbers, no metadata) — fine as a backup, not needed otherwise.
  • You didn't see .spd/.spc/.ipr because those only exist in mapping mode. They're the spectrum-image (map) files, not point-spectrum exports, and in TEAM they typically live in the project data directory on disk rather than behind an obvious "export" button (RosettaSciIO EDAX docs cover reading them). Suggested email questions for Mike:
    1. "When we collect an EDS map/spectrum image, can I get the raw .spd (with its .spc and .ipr companions) — either via an export option or by copying from the TEAM project folder?"
    2. "Does our TEAM version support batch/automated multi-point acquisition, and can runs go unattended?" (This is what turns the 100-point homogeneity grid into an hour of walk-away time.)
    3. "Is there a Faraday cup/picoammeter to measure beam current?"
  • Meanwhile you're not blocked: everything discussed so far — pure-element references, high-count point spectra, DTSA-II standards-based quant at the ±5–10% relative tier, and homogeneity statistics — runs entirely on .msa point spectra. The .spd cube only becomes necessary when you want per-pixel elemental maps in eXSpy.

5. Weekly energy calibration — fine, with a session-start habit

Weekly is a reasonable cadence. Still worth a 30-second sanity check each session: acquire a quick spectrum from anything with known lines (your Al alloy works — Al Kα should sit at 1.487 keV) and confirm peak centroids land within a few eV. At 5 kV with the Mg/Al deconvolution, a small calibration drift shifts fitted peak positions and quietly biases the fit, so this cheap check protects your most sensitive measurement.

Suggested settings card for your next session

Parameter Setting
kV 5 kV for Mg/Al/Si quant (ask about ≥15 kV for Fe)
Amp/process time 7.68 µs
Dead time ~30%, via beam current; log the current/aperture used
Live time Enough for ≥10⁶ counts (start ~60–100 s, check counts)
Per spectrum Export .msa; note WD, tilt (0°), current, coating

--- · Branch

@ronnie-guymon

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@claude is there a way to strip the Al peak at all using eXSpy? What eXSpy parameters or other options are there to get a good Mg qunatification? show me a eXSpy script of what you would do to find the Mg wt%. I don't have any real data for you rn, but I can get some during an EDS session to give later to try out that script.

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claude Bot commented Jul 28, 2026

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Todo

  • Verify eXSpy API for peak stripping (model fitting, component subtraction) against current docs
  • Compile the parameters/options that matter for Mg quantification in eXSpy
  • Write a ready-to-run eXSpy script for Mg wt% (works on .msa point spectra)
  • Post answer with validated links

Short answer

Yes — in eXSpy you "strip" the Al peak by fitting a model (one Gaussian per X-ray line + background) and subtracting the fitted Al components from the spectrum. But the important subtlety: the stripped spectrum is for your eyes; the Mg number comes from the fit itself. Once the model is fit, get_lines_intensity() already gives you the Mg Kα intensity with the Al tail's contribution separated out — subtracting first and then integrating would just add noise. One honest limitation I verified in the docs: eXSpy's built-in quantification() method (Cliff-Lorimer etc.) exists only on the TEM signal class, not EDS_SEM — so for bulk SEM samples, eXSpy's job ends at overlap-corrected intensities and k-ratios, and the k-ratio → wt% matrix correction (ZAF/φ(ρz)) happens in DTSA-II. The script below does everything up to the k-ratio and prints a first-order wt% estimate.

1. How "stripping" works in eXSpy

m = s.create_model() builds a Gaussian per line plus a background polynomial. After fitting, m.as_signal(component_list=[...]) regenerates a spectrum from only the components you name — so s - m.as_signal(component_list=al_components) is the Al-stripped spectrum (model docs). Kβ lines are included automatically as sub-lines with weights tied to Kα, so Al Kβ (1.557 keV) gets stripped along with Al Kα.

2. What actually buys you Mg accuracy in eXSpy

  • Model everything that emits in the fit window — Mg, Al, and Si. An unmodeled Si Kα tail (1.74 keV) biases the background under Al, which biases Mg.
  • Restrict the fit range (m.set_signal_range(0.9, 2.5)) so the low-energy noise floor and empty high-energy channels don't distort the background polynomial.
  • m.fit_background() then refit — it refines the background using only line-free channels.
  • Keep line energies/widths fixed (the default). Only if you have a very-high-count spectrum, refine detector resolution with m.calibrate_energy_axis(calibrate='resolution') — with weekly energy calibration on the scope, don't free per-line energies on a small Mg peak; the fit will happily "walk" a small peak to compensate for other errors.
  • Check the residual (m.plot(plot_components=True)) — a wavy residual between 1.2–1.5 keV means the overlap isn't cleanly fit and the Mg number isn't trustworthy yet.
  • Metadata completeness: kV and live time ride along in the .msa header; take-off angle and beam current come from your notebook via set_microscope_parameters() (eXSpy EDS guide).
  • Acquisition side (recap from last time): 5 kV, 7.68 µs amp time, ~30% dead time, ≥10⁶ counts, and — critical for the k-ratio — the same beam current on sample and pure-Mg standard, or measured values for both.

3. The script

Works on point spectra (.msa) — the sample plus pure-element standards acquired under identical conditions:

import hyperspy.api as hs

# ---------- Part A: fit the sample and strip the Al peaks ----------
s = hs.load("sample_AlSi10Mg.msa", signal_type="EDS_SEM")

# kV and live_time usually come from the .msa header — patch gaps from your notes
s.set_microscope_parameters(
    beam_energy=5.0,        # kV (only needed if absent from header)
    elevation_angle=35.0,   # take-off angle — ask Mike for the real value
    azimuth_angle=0.0,
)

s.add_elements(["Mg", "Al", "Si"])   # everything that emits in the fit window
s.add_lines()                        # selects Ka lines; Kb handled as tied sub-lines

m = s.create_model()                 # one Gaussian per line + background
m.set_signal_range(0.9, 2.5)         # keV — the Mg/Al/Si region
m.fit()
m.fit_background()                   # refine background on line-free channels
m.fit()
m.plot(plot_components=True)         # inspect fit + residual before trusting anything

# The "strip": subtract the fitted Al components (Al_Ka + Al_Kb) from the data
al_components = [c for c in m if c.name.startswith("Al")]
s_stripped = s - m.as_signal(component_list=al_components,
                             out_of_range_to_nan=False)
s_stripped.plot()                    # Mg Ka now sits on the bare background

# Overlap-corrected Mg intensity — comes from the FIT, not the stripped spectrum
i_mg = m.get_lines_intensity(["Mg_Ka"])[0].data

# ---------- Part B: k-ratio against a pure Mg standard ----------
std = hs.load("pure_Mg.msa", signal_type="EDS_SEM")
std.add_elements(["Mg"])
std.add_lines()
ms = std.create_model()
ms.set_signal_range(0.9, 2.5)
ms.fit()
ms.fit_background()
ms.fit()
i_mg_std = ms.get_lines_intensity(["Mg_Ka"])[0].data

# Dose normalization: counts / (live time × beam current).
# Live time is in the .msa header; beam current is from your notebook —
# if it was identical for sample and standard, it cancels out.
lt_s   = s.metadata.Acquisition_instrument.SEM.Detector.EDS.live_time
lt_std = std.metadata.Acquisition_instrument.SEM.Detector.EDS.live_time
ib_s = ib_std = 1.0                  # nA — fill in measured values if they differ

k_mg = (i_mg / (lt_s * ib_s)) / (i_mg_std / (lt_std * ib_std))
print(f"Mg k-ratio: {float(k_mg):.4f}")
print(f"Mg wt% (first-order, no matrix correction): {float(k_mg) * 100:.2f}")

4. From k-ratio to real wt%

k × 100 is only the zeroth approximation. For Mg in an Al matrix it's biased in both directions at once: Al Kα (1.487 keV) sits above the Mg K edge (1.303 keV), so it secondarily fluoresces Mg (reads high), while Mg Kα generated at depth is absorbed on the way out (reads low). The ZAF/φ(ρz) correction that untangles this is exactly what DTSA-II does: feed it the same .msa files (sample + standards) and quantify there — that's the ±5–10% relative tier for minor elements. At 5 kV the corrections are smaller than at 20 kV (shallower generation depth), which is another reason low kV was the right call.

So the division of labor stands: eXSpy = fitting, stripping, maps, k-ratios; DTSA-II = the wt% number you'd defend. The script's printed k-ratio is also your session-to-session QC metric — on a homogeneous sample it should reproduce to within counting statistics.

5. When you have data

Bring back: the AlSi10Mg .msa, pure Mg/Al/Si .msa (≥10⁶ counts each, same kV/amp time/current), and your noted take-off angle + beam current. Share them here and I'll commit this as a runnable script in the repo, tune the fit window/background order against the real spectra, and check the residuals with you.

Sources: eXSpy EDS user guide · eXSpy signals API (EDSSEMSpectrum vs EDSTEMSpectrum) · HyperSpy model fitting guide · NIST DTSA-II · Newbury & Ritchie 2015 (PMC4555346)

--- · Branch

@ronnie-guymon

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@claude I'm pretty sure I get k-ratios from team as well, I'm going to want to get the Team-generated k ratios and compare them to expsy's. Eventually, I will want to be able to get all the data/info I get from Team from either exspy or another open source method so it can be used in CALIBER. If I'm understanding right, the info (such as k-ratio, etc) generated from exspy is what will be used to do the wt% analysis in DTSA-II? From a CALIBER standpoint, I would mess around with the exspy script, changing parameters in order to get what I needed for a reliable wt% from DTSA-II? How would I know once I have the most optimal parameters before moving over the DTSA-II? If there is no way, then this could potentially be part of the feedback loop

@claude

claude Bot commented Jul 28, 2026

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Todo

  • Clarify the eXSpy → DTSA-II handoff (spectra vs. k-ratios — correct the mental model where needed)
  • Explain what to expect when comparing TEAM k-ratios vs. eXSpy k-ratios
  • Answer "how do I know parameters are optimal before DTSA-II" (validation criteria)
  • Tie into the CALIBER feedback loop; validate links

Short answer

Your mental model is close, but one correction changes the workflow: you don't feed eXSpy's k-ratios into DTSA-II. DTSA-II takes the raw .msa spectra (unknown + standards) and computes its own k-ratios internally via MLLS fitting, then applies the matrix correction — so the defendable wt% path never depends on the eXSpy fit at all. eXSpy's k-ratios are an independent parallel computation, and that's their value: a third voice in a TEAM-vs-eXSpy-vs-DTSA-II cross-check, plus the per-pixel mapping engine DTSA-II doesn't provide. And yes — there is a concrete way to know your eXSpy parameters are good before touching DTSA-II (four tests below, none requiring you to know the true composition), and the one test that does require truth (recovery on a known standard) is exactly the metric that should drive the CALIBER feedback loop.

1. The corrected pipeline

Route A (the wt% you'd defend):
  .msa spectra (sample + standards) ──→ DTSA-II ──→ its own MLLS fit ──→ k-ratio ──→ ZAF/φ(ρz) ──→ wt%

Route B (maps + cross-validation):
  .msa / .spd ──→ eXSpy fit ──→ k-ratios ──→ compare vs. TEAM & DTSA-II
                                        └──→ (optional) matrix-correct via DTSA-II scripting or CalcZAF

So "mess with the eXSpy script until DTSA-II gives a reliable wt%" isn't quite the coupling — the two fits are independent. What you tune the eXSpy script for is (a) agreement with DTSA-II's k-ratios on the same spectra, and (b) the map/automation work DTSA-II can't do. If you do want an all-open-source k-ratio→wt% path without DTSA-II's GUI: DTSA-II is fully scriptable in Jython (headless — it can sit inside a CALIBER pipeline as a batch step), and CalcZAF (MIT-licensed, John Donovan's EPMA utility) converts k-ratios to compositions with a choice of φ(ρz) models. Between eXSpy (Python), DTSA-II scripting, and CalcZAF, everything TEAM produces is reproducible open-source — TEAM ends up being only the acquisition/export front-end, which is the CALIBER end-state you described.

2. Comparing TEAM's k-ratios to eXSpy's — do it, with one caveat

The caveat: TEAM's eZAF (standardless) "k-ratios" are computed against factory-stored theoretical reference intensities, while your eXSpy k-ratio is against a pure-element spectrum you measured that session at the same current. Those are different denominators, so expect a systematic offset between the two — that alone doesn't mean either fit is wrong. What should agree tightly is: relative trends across samples, reproducibility scatter, and (if TEAM offers a standards-based quant mode using your measured standards) the k-ratios themselves. The genuinely apples-to-apples comparison is eXSpy vs. DTSA-II on the identical .msa files — same data, same standards, two independent fitting engines. A three-way k-ratio table (TEAM / eXSpy / DTSA-II, with counting-statistics error bars) is a natural first CALIBER artifact: any disagreement beyond √N is a real finding about fit models or live-time/current normalization, not noise.

3. How you know the eXSpy parameters are converged (before DTSA-II)

You can't optimize against the unknown's true Mg content — you don't know it. But four tests need no ground truth:

  1. Residual structure: after fitting, m.plot(plot_components=True) — the residual across 1.0–1.8 keV should be structureless noise. A wavy residual under the Mg/Al region means model error, and no parameter is "optimal" yet.
  2. Perturbation stability: nudge the nuisance choices — fit window ±0.2 keV, background order, Si included/excluded — and re-fit. The Mg k-ratio should move by less than its counting-statistics uncertainty. If fit choices move the answer more than √N does, the fit isn't converged; if they don't, further fiddling is noise-chasing.
  3. Poisson-limited reproducibility: acquire ~5–10 repeat spectra on one spot/area; the relative scatter of the fitted Mg k-ratio should approach 1/√(Mg peak counts). Excess scatter points at instrument drift or fit instability. (Same statistic as the homogeneity test from earlier in this thread — same code, different question.)
  4. Recovery on simulated truth: DTSA-II can Monte-Carlo-simulate spectra of exactly known composition at your kV and detector parameters. Fit those with your eXSpy script and check you recover the truth. This is a free way to debug fit parameters with zero scope time.

The fifth test needs truth and is the decisive one: run a known material (a purchased certified standard, or later your certified in-house billet) through the full chain — eXSpy fit → DTSA-II wt% — and check recovery within the expected tier (±5–10% relative for minor elements). Pass tests 1–3 and the eXSpy side is done: any remaining wt% error lives in acquisition, standards, or the matrix correction — not in the fit.

4. Yes — this is the feedback loop

What you've described is exactly a closed loop, and the "no way to know" worry dissolves once the loop's metric is named:

acquisition params (kV, amp time, dead time, live time, current)
  + fit params (window, background, elements)
        │
        ▼
  k-ratios + σ (eXSpy ∥ DTSA-II ∥ TEAM)
        │
        ▼
  wt% (DTSA-II / CalcZAF)
        │
        ▼
  score: recovery error on knowns  +  (observed scatter ÷ Poisson limit)
        │
        └──→ adjust params, repeat

Every box except TEAM is scriptable Python/Jython, so the whole loop can run unattended on exported files — which is precisely why getting raw .msa/.spd out of TEAM early was worth the effort. The score in the last box is the objective function: perfect = knowns recovered within tier and scatter at the Poisson floor. That's a well-posed optimization target for CALIBER rather than a judgment call.

Sources: NIST DTSA-II · CalcZAF (open-source, MIT) · eXSpy EDS user guide · Standards-Based Quantification in DTSA-II · Newbury & Ritchie 2015 (PMC4555346)

--- · Branch

@ronnie-guymon

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@claude so does exspy not use ZAF correction at all, just the raw k-ratio? And DTSA-II does, so it gives a more accurate wt%? Or is calcZAF the only one that uses those corrections? And if I understand correctly, exspy is more for compositional mapping while DTSA-II gives me a more accurate weight%?

@claude

claude Bot commented Jul 28, 2026

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Todo

  • Clarify which tools apply ZAF/φ(ρz) matrix corrections (eXSpy vs. DTSA-II vs. CalcZAF)
  • Confirm/refine the "eXSpy for mapping, DTSA-II for accurate wt%" mental model

Short answer

Almost exactly right, with one refinement. For bulk SEM samples: eXSpy applies no matrix correction — it stops at fitted intensities and k-ratios. DTSA-II applies the full φ(ρz)/ZAF correction, which is why its wt% is the accurate one. CalcZAF is not the only corrector — it's an alternative to DTSA-II's correction step, useful if you already have k-ratios and just want them converted to wt%. And yes: eXSpy = fitting + mapping engine, DTSA-II = the defendable wt%.

1. What each tool actually does

Step eXSpy DTSA-II CalcZAF
Peak fitting / overlap separation ✅ (Gaussian model fit) ✅ (MLLS vs. measured standards) ❌ (takes k-ratios as input)
k-ratio computation ✅ (you do it, as in the script) ✅ (internal)
Matrix correction (ZAF/φ(ρz)) for bulk samples ✅ (XPP φ(ρz) and others) ✅ (choice of ~10 φ(ρz) models)
wt% output for bulk SEM raw k-ratio only (first-order)
Per-pixel maps

One clarification on eXSpy so the docs don't confuse you later: eXSpy does have a quantification() method, but only on its TEM signal class, and those methods (Cliff-Lorimer, ζ-factor, cross-section) are thin-specimen approximations — they assume the sample is so thin that absorption and fluorescence are negligible, which is the opposite of your bulk polished mount. That's why the earlier script hands off at the k-ratio: for bulk SEM there is simply no ZAF implementation inside eXSpy to call (eXSpy EDS guide — note the quantification section lives under the TEM workflow).

2. Why DTSA-II's wt% is more accurate

Two independent reasons, and it's worth keeping them separate:

  1. It applies the matrix correction. The raw k-ratio ignores that Mg Kα generated at depth gets absorbed by the Al matrix on the way out (reads low) and that Al Kα secondarily fluoresces Mg (reads high). The φ(ρz)/ZAF correction models exactly these effects. Skipping it isn't a small error — for soft lines like Mg Kα in Al it can be tens of percent relative.
  2. It fits against measured standards (MLLS with your pure-element spectra), which is the fitting protocol behind the ±5–10% relative accuracy tier.

So "DTSA-II is more accurate" is true, but not because of some proprietary magic — it's because it performs both steps of the physics that a raw k-ratio omits.

3. Where CalcZAF fits

CalcZAF does only the last step: k-ratio in → matrix correction → wt% out. It exists so you can bring your own k-ratios (e.g. from your eXSpy fit) and still get a properly corrected composition without re-fitting in DTSA-II. That makes it the piece that would let a fully eXSpy-based pipeline produce corrected wt% — including, in principle, per-pixel: eXSpy k-ratio maps → CalcZAF (or scripted DTSA-II) correction → wt% maps. DTSA-II and CalcZAF use the same class of φ(ρz) models, so they're alternatives for the correction step, not a hierarchy.

4. So your mental model, refined

  • eXSpy = spectral fitting, Al-peak stripping, k-ratios, and anything spatial (maps, PCA/NMF phase unmixing). Its k-ratios are physics-uncorrected by design.
  • DTSA-II = the complete point-spectrum quant chain (its own fit + matrix correction + uncertainty) → the wt% you'd put in a paper.
  • CalcZAF = a standalone matrix-correction calculator — the bridge if you ever want corrected wt% from eXSpy's k-ratios without going through DTSA-II's fitting.

Practical consequence for CALIBER: the three-way comparison from the last reply stays as planned (TEAM vs. eXSpy vs. DTSA-II k-ratios), and when you eventually want wt% maps rather than point values, the route is eXSpy per-pixel k-ratios + a scripted correction (CalcZAF or headless DTSA-II/Jython) — that combination reproduces everything TEAM does, open-source.

Sources: eXSpy EDS user guide · NIST DTSA-II · Standards-Based Quantification in DTSA-II · CalcZAF · Newbury & Ritchie 2015 (PMC4555346)


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@ronnie-guymon

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I need to get some raw data to try out DTSA-II and eXSpy/CalcZAF. @gage-erickson is there a time this week when you could come? I was thinking Thursday around 12:00 or 1:00.

@gage-erickson

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I am available Wednesday. Would a time tomorrow work?

@ronnie-guymon

ronnie-guymon commented Aug 12, 2026

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Sadly I won't be able to today, are you free at all next week? I'm free all day the 19th-21st (Wed-Fri)

@ronnie-guymon

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@claude I think I will just do eXSpy for the elemental per-pixel map of the sample, and DTSA-II for the sample wt%. It seems like that is more accurate and less complicated that using CalcZAF. Is that right? Is there any reason I should use CalcZAF over DSTA-II? From Edison scientific, find what the best use case is for each of these three and their strengths, weaknesses, and computing/other costs

@claude

claude Bot commented Aug 12, 2026

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Todo

  • Answer the direct question (eXSpy maps + DTSA-II wt%, when CalcZAF matters)
  • Install edison-client and submit an Edison Scientific deep-research task (LITERATURE_HIGH job b81eeb1f)
  • Wait for the Edison task and fetch results (completed in ~28 min)
  • Commit Edison artifacts to the branch (commit 5505f54)
  • Post the synthesized answer

Short answer

Yes — your plan is right, and the Edison Scientific literature review independently landed on the same split: eXSpy for per-pixel elemental maps, DTSA-II for the bulk-sample wt%. CalcZAF is not a competitor to DTSA-II for your main workflow; it's a specialized add-on you'd only reach for in three specific situations (below). For getting a defendable Mg wt% number from point spectra, DTSA-II alone is both more accurate and simpler — it does peak fitting + matrix correction in one validated package, whereas CalcZAF does only the correction step and would force you to supply k-ratios from somewhere else.

The full Edison report (with citations and the raw research trajectory) is committed to the branch: answer.md, plus references.txt, contexts.json, and task_full.json.

When CalcZAF would beat DTSA-II (the only three reasons)

  1. Model-sensitivity / uncertainty checks. DTSA-II uses a single default matrix-correction model (XPP, Pouchou & Pichoir). CalcZAF lets you run the same k-ratios through many φ(ρz)/ZAF models (PAP, XPP, PROZA, Armstrong/CITZAF…) and multiple mass-absorption-coefficient databases, so the spread across models becomes an uncertainty estimate. Relevant to you: Donovan notes the Mg Kα MAC differs by several percent between databases, which propagates to roughly 1% variation in results — a real, checkable term in your Mg error budget.
  2. Correcting k-ratios that were measured elsewhere. CalcZAF takes bare k-ratios as input. If you ever want per-pixel wt% maps (not just intensity/k-ratio maps), the route is eXSpy per-pixel k-ratios → batch matrix correction — and CalcZAF (or scripted Jython DTSA-II) is that correction engine, since eXSpy has no bulk-sample ZAF at all.
  3. Cross-checking DTSA-II itself. Running your DTSA-II k-ratios through CalcZAF's models is a cheap independent audit of the correction step — a natural CALIBER cross-validation artifact alongside the TEAM/eXSpy/DTSA-II k-ratio comparison already planned.

None of these are needed for your first goal (accurate point-spectrum Mg wt%), so skipping CalcZAF for now is the right call. Note its practical downsides from the review: Windows-only, GUI-centric with limited batch capability, and it does no peak fitting — it can never stand alone.

Edison's tool-by-tool comparison

eXSpy/HyperSpy NIST DTSA-II CalcZAF
Best use case Spectrum-image datacube processing: per-pixel fitting, PCA/NMF denoising, phase unmixing, maps Standards-based bulk SEM-EDS wt% via MLLS peak fitting + XPP φ(ρz) correction Standalone k-ratio → composition conversion; comparing multiple φ(ρz) models on the same data
Strengths Native Python/NumPy; best automation and ecosystem integration; the natural datacube environment Best published accuracy of the three: at 5 keV, >98% of 263 measurements within ±5% relative deviation, 82% within ±2% (Newbury & Ritchie 2024); MLLS fitting handles the Mg/Al overlap with residual-spectrum QC; analytical-total sanity check Multi-model + multi-MAC-database comparison for uncertainty estimation; accepts external k-ratios; very light computationally
Weaknesses No bulk-sample ZAF/φ(ρz) at all; no published bulk-SEM accuracy benchmark (its validation is in thin-specimen TEM contexts) Jython scripting is clunkier than native Python; single default correction model; per-pixel quant mapping is count-hungry (~1000+ counts/pixel) and slow No peak fitting or spectrum processing — must be paired with another tool; least scriptable
Costs Free, cross-platform; needs Python environment upkeep; RAM-heavy on big cubes Free (NIST), cross-platform Java; moderate-to-steep learning curve (standards archive, k-ratio protocol) Free/open source; Windows-only; low compute; learning curve centered on matrix-correction theory

Two findings worth highlighting for your Mg problem specifically: the review confirms DTSA-II's ±5% relative tier covers minor constituents like your 0.3–0.5 wt% Mg (Newbury & Ritchie 2019/2024), and it flags the MAC-database sensitivity of Mg Kα as the one place a CalcZAF cross-check adds information DTSA-II won't give you.

Bottom line for your workflow

Proceed exactly as you planned: eXSpy for the .spd datacube → per-pixel maps and phase unmixing; DTSA-II for point-spectrum Mg wt% against your pure-element standards. Park CalcZAF as a future step for (a) wt% maps and (b) an uncertainty/audit pass on the matrix correction — both nice-to-haves for CALIBER's feedback loop, neither needed to get your first accurate Mg number.

Key commands run:

pip install edison-client   # v0.16.1, installed cleanly
# submitted LITERATURE_HIGH task b81eeb1f-741e-475a-92d0-5349f057ec0a; polled every 4 min → success in ~28 min
git commit 5505f54          # Edison artifacts committed to outputs/edison_eds_tools_comparison/

Sources (from the Edison report): Newbury & Ritchie 2024, low-beam-energy EDS accuracy · Newbury & Ritchie 2019, EDS at 50 · Goldstein et al., SEM/EDS k-ratio procedure · Goldstein et al., Compositional Mapping · Rickerby 1995, φ(ρz) model comparison · Korolyuk et al. 2009, correction-model accuracy

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Co-authored-by: Ronnie Guymon <244881888+ronnie-guymon@users.noreply.github.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
@gage-erickson

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I can do Wednesday the 19th

@ronnie-guymon

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We have an EDS session scheduled for Wednesday the 19th at 11:30am, after which we will spend time using claude and getting familiar with the software.

@ronnie-guymon

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@claude what are all the files of raw data I should try and get from my EDS session from team so I can use eXSpy, calZAF, and DTSA-II

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claude Bot commented Aug 19, 2026

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Todo

  • Compile the per-tool raw-data requirements (eXSpy, DTSA-II, CalcZAF) from the established workflow
  • Turn it into a session export checklist with the TEAM-specific caveats found in training

Short answer

Three file families cover all three programs: .msa point spectra (the workhorse — feeds both eXSpy and DTSA-II), the .spd + .spc + .ipr map trio (eXSpy maps only), and TIFF reference images + your handwritten metadata notes. CalcZAF needs no spectral files at all — it takes k-ratios (plain text you'll produce later from the eXSpy/DTSA-II fits), so nothing extra to export for it beyond the metadata that the correction step needs (kV, take-off angle). The .csv/.xls count exports are a redundant backup of the .msa — grab them if it's one click, skip otherwise.

Session export checklist (in priority order)

# What Files Used by
1 High-count point spectra of your AlSi10Mg sample (≥10⁶ counts, 5 kV, 7.68 µs amp time, ~30% DT) .msa per point eXSpy fit, DTSA-II quant
2 Pure-element standard spectra — Mg, Al, Si — same kV, amp time, and beam current as the sample, ≥10⁶ counts each .msa per standard DTSA-II k-ratios, eXSpy fit references
3 Energy-calibration check spectrum (any known material, start of session) .msa QC for all downstream fitting
4 Spectrum-image map of a representative region (if you do mapping) .spd + .spc + .iprsame base name, same folder eXSpy per-pixel maps
5 SE/BSE image of each analyzed region, with stage coordinates noted TIFF provenance
6 Counts backup (optional) .csv/.xls none (redundant with .msa)
7 Higher-kV (≥15 kV) spectrum of the same spots if Fe matters — Fe Kα isn't usefully excited at 5–10 kV .msa DTSA-II (Fe quant)

The notebook is a "file" too

TEAM doesn't record everything the quant chain needs. Write down, per acquisition:

  • Beam current (or at least the spot-size/aperture settings that produced ~30% DT) — required for k-ratio dose normalization if it differs between sample and standards
  • Working distance / take-off angle — DTSA-II and CalcZAF both need the take-off angle for the matrix correction
  • Tilt (confirm 0°) and coating (type/thickness, same on standards and unknowns)
  • Amp time, kV, and dead time as displayed (these should also be in the .msa header — your notes are the cross-check)

TEAM-specific gotchas (from your training session)

  • You won't see .spd/.spc/.ipr in the export menu — they only exist after a mapping/spectrum-image acquisition, and typically live in the TEAM project data directory on disk rather than behind an export button. Ask Mike to show you the project folder path, or email him beforehand so you can copy the trio during the session (RosettaSciIO reads them natively).
  • Open one .msa in a text editor at the microscope (it's plain ASCII) and verify the header carries live time, real time, kV, and take-off angle. Anything missing goes in the notebook and gets patched in eXSpy later via set_microscope_parameters().
  • Same base name, same folder for the map trio — downstream tools auto-find the .spc/.ipr companions; separated files load uncalibrated.
  • Before leaving (or same evening), run the 30-second sanity check: hs.load("spectrum.msa", signal_type="EDS_SEM") and hs.load("map.spd"), then print(s.metadata). Catching a broken export while you still have scope access is the whole point.

Who consumes what (so nothing gets over-collected)

  • eXSpy: .msa (point fitting, Al-peak stripping, k-ratios) + .spd trio (per-pixel maps). Docs: eXSpy EDS guide.
  • DTSA-II: .msa only — sample + pure-element standards; it does its own MLLS fit and φ(ρz) correction internally (NIST DTSA-II).
  • CalcZAF: k-ratios you compute later, entered as text/.dat — no microscope export needed; just make sure kV and take-off angle are recorded (CalcZAF).

Bottom line for today at 11:30: come home with the calibration-check .msa, sample .msas, pure Mg/Al/Si .msas at matched conditions, one .spd/.spc/.ipr map trio if mapping is attempted, TIFFs, and a filled-in notebook. That set feeds every tool in the pipeline — and if the standards block isn't available, everything else still lets you prototype the eXSpy fit while you sort out standards later.

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@ronnie-guymon

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@claude how big should the .msa files be that will be exported and used for everything?

voltage of 5kv (over double the energy of SI kalpha), 3.2 nA beam current, dead time of 28-29, Input CPS of ~21500, amp time 7.68, working distance of 10.1, mag of 6120x

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claude Bot commented Aug 19, 2026

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Claude finished @ronnie-guymon's task in 1m 5s —— View job


Todo

  • Answer the .msa file-size question given the stated acquisition parameters
  • Convert "big enough" into concrete live-time / count targets at 21,500 input CPS

Short answer

The file size of an .msa is essentially fixed and tiny — roughly 30–200 KB each — because it's plain ASCII with one line per MCA channel (~4096 channels) plus a header. Acquiring longer does not make the file meaningfully bigger; it only makes the numbers on each line larger. So don't judge a spectrum by its file size — judge it by total counts, which is set by live time. Your settings look right (5 kV, 7.68 µs, 28–29% DT matches everything planned in this thread); the only knob left is how long you count.

The number that actually matters: counts → live time

At your input rate of ~21,500 CPS:

Target Live time needed Real (wall-clock) time at ~28.5% DT
10⁶ counts (minimum quant grade) ≈ 47 s ≈ 65 s
2×10⁶ counts (comfortable) ≈ 93 s ≈ 130 s
4×10⁶ counts (small-Mg-peak insurance) ≈ 186 s ≈ 260 s

(Stored counts ≈ input CPS × live time; real time ≈ live time ÷ (1 − dead-time fraction).)

Practical recipe for today:

  • Pure-element standards (Mg, Al, Si): 100 s live time each → ~2×10⁶ counts. More than enough; the peaks are huge on pure elements.
  • AlSi10Mg sample spectra: go longer — 150–200 s live time. Total counts aren't the limiter for you; Mg-peak counts are. At ~0.3–0.5 wt% Mg, only a small fraction of the 10⁶+ counts land in the Mg Kα peak, and your Mg precision goes as 1/√(Mg peak counts) — doubling the live time is the cheapest accuracy you'll buy all day.
  • Energy-calibration check spectrum: 30 s is fine.

Two sanity checks while you're at the scope:

  1. After the first sample acquisition, look at the reported total counts (or integrate the spectrum) and confirm it's ≥10⁶ — if TEAM displays counts in the ROI, glance at the Mg Kα region too; you'd like at least a few thousand counts there.
  2. If an exported .msa comes out at, say, 40–150 KB, that's normal and healthy. If one is only a few KB, the export probably wrote a truncated/summary file — re-export.

For contrast: the .spd map cube is the only large export (MBs–GBs depending on pixels × channels). Everything .msa from the whole session will fit in a few MB total.

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@ronnie-guymon

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@claude I'm trying to figure out how to export the files we need, how do I even navigate there? it is kinda confusing to navigate and the microscopy advisors are not currrently here

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claude Bot commented Aug 19, 2026

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Claude finished @ronnie-guymon's task in 2m 58s —— View job


Todo

  • Research EDAX TEAM UI navigation for exporting spectra (.msa/.csv) and map data (.spd/.spc/.ipr)
  • Post step-by-step export navigation guide (plus the .msa file-size answer from your earlier question)

Short answer

TEAM's mental model is the key to not getting lost: everything you collect is auto-saved into the project tree (the "Project Content" tab on the side of the window), and all exporting is done by double-clicking an item in that tree to display it, then using small icons that only appear when you hover over the displayed spectrum/image. There is no central "File → Export" menu — that's why it feels unnavigable. Below is the click-path for each file type, based on a detailed university operating guide for TEAM (UF Tescan MIRA3 + EDAX TEAM procedure).

1. Point spectra (.msa and .csv)

  1. Collect the spectrum ("Spectrum Only" or "Point Analysis" from the top menu bar). In Point Analysis mode, spectra save to the project automatically; in Spectrum Only mode, click the disk icon on the left side of the spectrum window → "Send to Project".
  2. To get files out: with the spectrum displayed, click the same disk icon → "Send to Folder" — this writes the image + spreadsheet (csv/xls) versions to your designated export folder.
  3. For the .msa specifically (the one that matters for eXSpy/DTSA-II): right-click directly on the displayed spectrum and look for Export → EMSA/MSA in the context menu — right-click-on-the-spectrum is the historic EDAX path for MSA export and is easy to miss because nothing on screen hints at it. You confirmed in training that .msa export exists on your system, so it's one of these two spots (disk icon options or right-click menu).
  4. To re-open something you collected earlier in the session: double-click it in the project tree (double-clicking a Point Analysis area shows the SEM image with all analysis spots; double-clicking an individual spot shows that spot's spectrum).

2. Reference images (TIFF)

Double-click the analysis area in the project tree so the SEM image displays, then hover over the image → click the folder icon (top-left corner of the image). That saves the image (with analysis spots/regions marked) to your designated folder.

3. Where "Send to Folder" actually puts things

Exports go to your designated user folder, set when your TEAM user/project was created — not somewhere you choose per-export. If you don't know where it points, don't hunt through menus: after exporting one spectrum, open Windows File Explorer on the TEAM PC and search the C: and D: drives for files modified in the last hour (sort by "Date modified"), or just search *.msa. Wherever that file landed is your export folder for everything else.

4. The map trio (.spd / .spc / .ipr)

These are not behind any export button — they're written into TEAM's project data directory on disk when you collect a map (RosettaSciIO EDAX docs). The reliable way to find them without an advisor:

  1. Collect a map ("Mapping" → "Image Area" → "Collect Map" → let it finish → "Finish" to save it to the project).
  2. In Windows File Explorer, search the whole PC for *.spd and sort by Date modified — today's map will be at the top. Its .spc and .ipr companions are in the same folder with the same base name.
  3. Copy all three together (same folder, same base name) to your USB stick. If you can't find a .spd, the map may have been collected without full spectral data — collect with a "Quality" setting that stores the full spectrum per pixel, or grab whatever map export the folder icon gives you and we'll sort out the cube later.

5. End-of-session checklist (5 minutes before you leave)

  • Copy the entire designated export folder to USB.
  • File Explorer search: *.msa, *.spd, *.spc, *.ipr sorted by today's date — copy anything the export folder missed.
  • Open one .msa in Notepad on the scope PC: it should be plain text with header lines (#LIVETIME, #BEAMKV, etc.) followed by two columns of numbers. If it looks like that, eXSpy and DTSA-II will read it.
  • Photograph/note: beam current (3.2 nA), WD (10.1 mm), kV, amp time, dead time, magnification per acquisition — you already have this habit, keep it up.

Your earlier question: how big should the .msa files be?

Small — roughly 50–200 KB each. An .msa is plain ASCII: a few dozen header lines plus one line per energy channel (typically 2048–4096 channels). So don't judge acquisition quality by file size; every .msa is about the same size regardless of counts. Quality is the total counts number in TEAM (or the #LIVETIME × your ~15,000 output cps). At your settings (21,500 input cps, ~29% dead time → roughly 15,000 stored cps), you need about 70 s of live time to reach the 10⁶-count target per quant spectrum. The only big files today will be the .spd map cubes (tens to hundreds of MB) — make sure the USB stick has a few GB free.

Sources: UF EDS-with-EDAX-TEAM operating procedure · RosettaSciIO EDAX format docs · EDAX Genesis utilities manual (MSA export heritage)

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@ronnie-guymon

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We also noticed a large amount of what we think is charging, like a crazy amount compared to what we had previously seen. It was like a box made of dark lines was carved around the area we were sampling, I assumed it was from charging by scanning multiple times over an area with a high beam current over light elements. We will upload an image of that here too. @claude any ideas of what could be causing it?

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claude Bot commented Aug 19, 2026

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Claude finished @ronnie-guymon's task in 1m 21s —— View job


Todo

  • Diagnose the dark box artifact around the scanned area (charging vs. contamination vs. beam damage)
  • Validate reference links and post answer

Short answer

Almost certainly not charging — that dark box "carved" around the scanned area is the classic signature of electron-beam-induced carbon contamination (hydrocarbon deposition). The beam cracks residual hydrocarbons on the surface and in the chamber into amorphous carbon wherever it dwells, so the rastered rectangle gets a carbon layer — and the edges of the scanned region grow the thickest deposit, because hydrocarbons migrate along the surface toward the irradiated zone and get cracked right at the border before they can diffuse in. That's why it looks like a box made of dark lines outlining your map area, rather than a uniformly dark patch. This edge-amplified frame is well documented (EBICD study — edge thicker than center via surface diffusion; NIST quantification & mitigation paper, M&M 2023).

Why it's this and not charging

  • Your sample is conductive. AlSi10Mg is a metal; on a properly grounded metal mount, charging is essentially impossible. Charging artifacts also look different: shifting bright/dark patches, image drift/tearing, contrast that changes with scan speed — not a permanent, sharply bounded rectangle that stays put when you zoom out.
  • The mark is persistent. Charging dissipates when the beam moves away; a contamination frame is a physical carbon deposit that remains visible (and would still be there next session).
  • Your conditions maximize it. Everything you dialed in for good EDS also maximizes contamination growth and visibility: high beam current (3.2 nA), long dwell (repeated maps/long live times over the same area), and low kV (5 kV), which is extremely surface-sensitive — a few nm of carbon that would be invisible at 20 kV shows up as strong dark contrast at 5 kV because carbon's secondary-electron yield is low.
  • Quick confirmation when you upload the image: if the outline is darkest at the perimeter with a fainter interior, and multiple overlapping scan rectangles each left their own frame, it's contamination.

Where the hydrocarbons come from

  1. The sample itself — residual polishing lubricants, solvent films, fingerprint oils, ultrasonic-bath residue.
  2. Mounting materials — carbon tape, carbon/silver paint, and epoxy outgas hydrocarbons profusely; tape anywhere near the analysis area is a common culprit.
  3. The chamber — pump oil (if not dry-pumped), previous users' samples, vacuum grease.

Why it matters for your Mg quantification (not just cosmetics)

The carbon layer grows during acquisition on exactly the spot you're quantifying, and at 5 kV your analysis lines are soft: Mg Kα (1.25 keV) and Al Kα (1.49 keV) are measurably absorbed by even a thin carbon film, and the beam loses energy passing through it. Practically: the Mg signal slowly drops during a long acquisition, the C Kα peak grows, and the k-ratio gets biased low — worst for the longest acquisitions, which are precisely your high-count quant spectra. A growing C peak between the start and end of a long acquisition is your tell-tale diagnostic.

What to do about it

  • Clean the sample properly: ultrasonicate in fresh isopropanol (or acetone followed by IPA), dry with clean dry air/N₂, then handle only with gloves/tweezers. This is the single biggest lever.
  • Ask if the SEM has a plasma cleaner (in-chamber or benchtop) — a few minutes of plasma cleaning before analysis is the standard professional fix (NIST mitigation paper). Also ask about a liquid-nitrogen cold trap / anti-contamination device.
  • Minimize mounting adhesives near the analysis surface; a mechanical clamp or a small dab of silver paint far from the region beats a bed of carbon tape.
  • Don't pre-dwell on the quant spot: focus and stigmate on a sacrificial area adjacent to where you'll analyze, then move to a fresh spot for the actual acquisition.
  • "Beam shower" trick if contamination is bad: scan a large area at low magnification for a few minutes first — this polymerizes/pins the mobile hydrocarbons over a wide region so less migrates into your analysis area afterwards.
  • Let the chamber pump longer after loading, especially with epoxy-mounted samples.
  • For CALIBER bookkeeping: log the C Kα peak intensity at the start vs. end of each long acquisition — it's a free, quantitative contamination QC metric that lives in the same .msa files you're already exporting.

One caveat to keep honest: if the image shows bright streaking, sample drift, or contrast that flickered while scanning, some genuine charging could be stacked on top (e.g. if the part sits on oxide or the mount path to ground is poor through tape). Upload the image and I can say which signatures are present — but a stable dark box outline around the scan area is contamination, not charge.

Sources: Electron-beam-induced carbon deposition — edge-enhanced growth via surface diffusion (ScienceDirect) · Electron-Beam-Induced Carbon Contamination: Quantification and Mitigation (Microscopy & Microanalysis, NIST) · Mitigating e-beam-induced hydrocarbon deposition (JVST B)
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@ronnie-guymon

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@claude that makes sense. I think the biggest thing we will make sure to do is to not increase the beam current or zoom in on our spot until right as we are about to do our analysis and mapping, but we can always look into more extreme methods if that starts to cause too much carbon deposition. I'm pretty sure the last part of our polishing SOP already includes the ultrasonic IPA cleaning.

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claude Bot commented Aug 19, 2026

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Todo

  • Review the trigger comment (plan confirmation — no code changes requested)
  • Reply with assessment of the mitigation plan

Assessment

Your plan is sound, and having ultrasonic IPA as the last polishing step already removes the biggest hydrocarbon source. Three refinements to make it work in practice:

  1. You still have to focus and stigmate somewhere at high mag before analyzing — that's unavoidable dwell. The trick is to do it on a sacrificial spot: pick a region a few tens of µm away from your intended analysis area, zoom in there, set focus/stigmation/current, then translate the stage to the fresh spot and start acquiring immediately. "Don't zoom in until right before analysis" only helps if the zoomed-in setup happens off-target.

  2. Delaying the exposure doesn't eliminate deposition during the acquisition itself. Your quant spectra are 100–200 s of continuous dwell and maps are longer — carbon grows on the spot the whole time regardless of how clean your approach was. So keep the free QC check from before: compare the C Kα peak at the start vs. end of each long acquisition (or between the first and last of a set of repeat spectra on one spot). If it's flat, your current approach is sufficient and no "extreme methods" are needed; if it climbs, that's the trigger to ask about plasma cleaning or try the low-mag beam shower first.

  3. One caveat on the IPA step: it only helps if the bath solvent is fresh and the sample isn't re-contaminated afterward — mounting with carbon tape near the analysis surface, or bare-finger handling, reintroduces hydrocarbons after the cleanest polish. Worth a quick look at what the SOP says about handling/mounting after the ultrasonic step.

Net: your two levers (clean sample + minimal pre-dwell) are the standard first-line defense and are probably enough for a conductive metal at your currents. The C Kα start/end comparison tells you objectively whether to escalate — and it comes free out of the .msa files you're already exporting.

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@ronnie-guymon

ronnie-guymon commented Aug 19, 2026

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Here's the image of the carbon deposition visible as rectangles on the sample where we were zoomed in to around 6000-7000x with 3.2 nA

AlSi10Mg SEM Image of burning

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