JEOL SXES Soft X-ray Emission Spectrometer

[JonF]

I had a private message about the quantitative analysis of Li by EPMA-SXES and other SXES queries in general, and I thought I'd copy out the bulk of my reply here. All of the below is my interpretation of things based on my own experience, so read in to this what you will! I'm happy to be corrected by any stray physicists out there.
For the sake of clarity, I'd also say that I'm actually a fan of the SXES, but they aren't drop in replacements for WDS - they're another complementary detector alongside WDS and EDS that can provide a bit more information. To fully appreciate what the JS50XL, JS200N and JS300N gratings can tell you, you'll need to wander down the rabbit hole of "where do X-ray emissions come from and why do the peaks look the way they do?".   

Regarding Li determination:
Quantitatively analysing Li by EPMA is a bit of a non-starter. It breaks one of the golden rules of microanalysis in that the Li Ka intensity varies as a function of not just concentration but also the form that it is in i.e. the Li Ka emission from Li metal and Li2O is not directly proportional to the concentration of Li in each phase (matrix corrections aside). Hovington et al have a paper on this that covers the basics (https://doi.org/10.1002/sca.21302), and in particular figure 2 (note the 1/5th scaling of the Li Ka in Li metal relative to the other Li phases).
To make matters worse, aside from the concentration =/= intensity, the peak shift and the peak shape changes, the Li is also readily beam damaged, forming Li metal (and so the Li Ka becomes more obvious during a course of analysis as the sample becomes damaged!). And then there's interference: for natural materials, the Fe Mz (M2,3-M4,5) is right in the way of Li Ka! A (very) high order reflection of the C Ka is knocking about down there too, which isn't helpful if you need to carbon coat your non-conductive samples (which will also effectively hinder the Li Ka making it out of the sample).

Qualitatively determining presence/absence and phase of Li might be possible depending on the phase that it is in - sometimes the Li just refuses to generate an X-ray. To see Li though, you'll need the JS50XL grating, which is only available on the SXES-LR along with the JS200N grating. The SXES-ER comes with the JS300N and JS2000 gratings. I've been told that the gratings aren't compatible between the -LR and -ER (I'd quite like the JS2000 grating myself!).

Regarding the slow CCD speed, it is definitely a bit of a hindrance, but these light elements (rather low energy transitions) just aren't favourable for X-ray emission, so the slow CCD speed is actually not as bad as it sounds: you need to count for 100s if not 1000s of seconds by WDS to get good counting statistics if you want to quantify. If you're looking for multiple light element/low energy emissions, then measuring for a few seconds to get all of them and the backgrounds isn't too bad. You can also measure using the WDS and EDS during this time, so there's two hyperspectral datacubes (EDS and SXES) plus the WDS maps for a single pass.   
The slow CCD speed would also not be a problem for point analysis, however the software doesn't support automated acquisition of a series of points, so you'll be manually driving around and clicking "go" for each point - but at least the WDS are free to move around and measure as normal.

Regarding regular calibration: the SXES is quite stable relative to WDS as it is insensitive to barometric pressure and relative humidity fluctuations (i.e. why we need to keep re-standardising the GFPC - the sealed Xe detectors are much more stable). Well, at least as far as I've seen, anyway. That doesn't mean it doesn't need calibrating though! The energy axis is quite stable, but the intensity axis is quite sensitive to CCD temperature and the crud that will inevitably stick to the -70C CCD and absorb low energy X-rays (the cryo-pumping problem!).

Regarding cleaning of the SXES CCD: there's no window or anything between the sample and the CCD surface. It is the CCD itself that will become contaminated. The only way that you can clean this up is to turn the cooling off and allow it to warm up and hope everything that was on the CCD boils away in the vacuum. -70C shouldn't be cold enough to significantly capture water vapour under the chamber vacuum, but you shouldn't have the CCD cold during sample exchanges. If the crud on the CCD doesn't boil away, then it'll be an engineer visit to clean it up.
The time before the contamination builds up to the point where the SXES can't "see" will be variable depending on how often its used and how dirty the system is (and what the users try and put in there!). You can monitor the cleanliness of the system using your regular standards: the absorption by the muck layer will become apparent if you look at the intensity ratios between e.g. Al La and O Ka[3] over time (might not bee the best choice as the O Ka will get strongly absorbed as well!). 

[Ben Buse]

It looks like a similar spectrometer is now produced by eden instruments WDSX-300
https://eden-instruments.com/en/microanalyse/wdsx-300/
and looked at in this paper
https://www.epj-conferences.org/articles/epjconf/abs/2026/05/epjconf_emas2025_01017/epjconf_emas2025_01017.html
which is also here https://www.nanooptics-berlin.com/reflection-zone-plates
Looks interesting, are eden instruments selling it on behalf of nano optics berlin?

[JonF]

It looks like a similar spectrometer is now produced by eden instruments WDSX-300
https://eden-instruments.com/en/microanalyse/wdsx-300/
and looked at in this paper
https://www.epj-conferences.org/articles/epjconf/abs/2026/05/epjconf_emas2025_01017/epjconf_emas2025_01017.html
which is also here https://www.nanooptics-berlin.com/reflection-zone-plates
Looks interesting, are eden instruments selling it on behalf of nano optics berlin?

I might be wrong, but this looks like the same setup that the folks in Sorbonne University are using on their SX100. For example Jonnard et al 2026,  Hassebi et al 2024a, and Hassebi et al 2024b.

I think the RZP is from Nano Optics Berlin and is what JEOL refer to as their gratings (JS50XL, JS200N, JS300N, JS2000 and whatever the new low energy one is called), which they themselves buy in from a third party.
The Eden Instruments detector uses a GreatEyes CCD (website) and I guess they've built the enclosure to bolt the bits together and written the software. I know the folks in CSIRO have replaced their JEOL-supplied CCD with one from Princeton (a Sophia), according to this work and also written their own software. 

[Ben Buse]

Is there any publications giving the resolution for the different gratings on SXES. I.e. resolution at different energies.

I found this

"The soft X-ray emission spectrometer (SXES) provided by JEOL covers an energy range of 50 eV to 2.3 keV. Its energy resolution is better than 0.3 eV at 73 eV of Al L-emission, and better than 5.0 eV at 704 eV of Fe Lα-emission." on JEOL website https://www.jeol.com/words/semterms/20170527.212359.php#gsc.tab=0

Thanks

Ben

[Probeman]

Is there any publications giving the resolution for the different gratings on SXES. I.e. resolution at different energies.

I asked Grok: "Are there any publications giving the resolution for the different gratings on JEOL SXES spectrometers. I.e. resolution at different energies?"

and it replied:

"Yes, there are several publications and technical resources that discuss the energy resolutions for various gratings used in JEOL Soft X-ray Emission Spectrometers (SXES). These often focus on low-energy regions for light elements, with resolutions typically evaluated using the Fermi edge of emission lines like Al-L (~73 eV). Resolutions improve (i.e., delta E decreases) with higher-order reflections but at the cost of intensity. Below, I summarize key findings from relevant sources, grouped by grating where specified. Note that JEOL SXES models (e.g., standard vs. extended range like SXES-ER) may use different grating configurations, and resolutions can vary slightly based on setup (e.g., CCD offset or photon-counting mode).

Common Gratings and Resolutions
JEOL SXES systems commonly use varied line spacing (VLS) gratings optimized for soft X-rays. Key gratings include:

JS50XL (laminar type, ~1200 lines/mm groove density at center, energy range: 50–170 eV 1st order, extendable to ~700 eV with higher orders):
Resolution: Better than 0.2 eV (actual) at Al-L emission (~72–73 eV) on Al metal, with a guaranteed spec of 0.3 eV (evaluated via Fermi edge sharpness).

At lower energies (e.g., Li-K ~55 eV), resolutions around 0.1–0.2 eV have been reported in optimized setups.

JS200N (laminar type, energy range: 70–210 eV 1st order, extendable to ~700 eV with higher orders):
Resolution: ~0.1–0.2 eV at Al-L emission (~72–73 eV) on Al metal (e.g., 0.105 eV measured between 75% and 25% of Fermi edge peak height).

For C-Kα (~280 eV, often measured in 2nd or higher order): Resolution improves with order (e.g., 2nd order offers optimal balance of ~0.2–0.5 eV resolution and signal-to-noise), but 1st order is coarser.

JS300N (used in extended-range models like SXES-ER/EP, similar to JS200N but optimized for light elements/soft X-rays):
Energy range: Broad low-energy focus (below C-Kα in 1st order; specifics not always detailed, but overlaps with JS200N).
Resolution: Comparable to JS200N (~0.2 eV at low energies), with potential for WDS-like performance in light element analysis.

JS2000 (~2400 lines/mm groove density, used in some SEM configurations for wider coverage):
Energy range: 350–2300 eV (covers Kα from N to P).
Resolution: Comparable to wavelength-dispersive spectrometers (WDS); better than TAP crystals across most of the range (~5–10 eV) but coarser than PET at high energies (~2000+ eV, up to ~20–30 eV). In photon-counting mode, resolutions as fine as 0.08 eV have been achieved at Al-L.

General System Resolutions at Higher Energies
For energies beyond the primary grating ranges (e.g., using higher-order reflections):

Better than 5.0 eV at Fe-Lα emission (~704 eV).
~8 eV FWHM at Fe-K (~6400 eV, in comparison contexts, though SXES is primarily for soft X-rays).
Some configurations cover up to 3800 eV (1st order) with multiple gratings, achieving ~0.2 eV at low ends but degrading to 10–20 eV at higher ends.

Key Publications and Resources
Here are primary sources with these details (many are open-access or abstracts; full texts may require access):

Takahashi et al. (2016): "Development of soft X-ray emission spectrometer for EPMA/SEM and its application" (IOP Conference Series: Materials Science and Engineering). Detailed specs on JS50XL and JS200N gratings, resolutions, and applications to light elements.

MacRae et al. (2026): "Development and application of soft X-ray spectroscopy and cathodoluminescence to minerals" (EPJ Web of Conferences). Focuses on JS200N usage, with measured resolutions like 0.105 eV at Al-L and order-dependent improvements for C-Kα.

JEOL Glossary Entry (2017): Provides system-level resolutions at specific lines (e.g., <0.3 eV at 73 eV, <5.0 eV at 704 eV).

JEOL Application Notes and Brochures: E.g., "Chemical State Analyses by Soft X-ray Emission Spectroscopy" details multi-grating setups (up to four gratings) and resolutions like 0.08–0.2 eV at Al-L. Product pages often cite 0.3 eV guaranteed at Al-L.

CSIRO-Related Resources: Discussions in forums reference CSIRO presentations comparing JS2000 resolution to WDS crystals across energies. The CSIRO SXES Database includes example spectra from JEOL 8530F with gratings like 50XL, showing practical resolutions in mineral analysis.

For more precise data on a specific grating or energy, JEOL's handbooks (e.g., "Handbook of Soft X-ray Emission Spectra") or direct contact with JEOL may provide spectra and resolution curves. If you have a particular model or energy range in mind, I can refine the search."

[Ben Buse]

That's great, thanks, much appreciated