Quantitative XRDat synchrotron resolution

A synchrotron is a particle accelerator built to produce X-rays. Electrons circulate in a storage ring hundreds of metres around, and each bend of their path sends out a beam of X-rays into an measurement station, a beamline. There are a few dozen such facilities in the world, national or international, and none of them fits in a laboratory. We do not own one and we do not build one. We prepare the samples, book beamtime and measure with our beamline partners, who operate at these facilities. We do the analysis.

You send ground samples. We prepare them, measure them at the beamline with our partners and quantify the mineralogy on Mintti, our own analysis system. Every sample comes back as a phase table with the evidence behind it, and the campaign as a written interpretation connected to the question you asked, reviewed together with you.

Four things decide the quality of a diffraction pattern: how bright the beam is, how it passes through the sample, how the sample is presented, and how it was ground. At a synchrotron all four are on our side. The beam is orders of magnitude brighter than a laboratory tube, so the pattern is collected in seconds with a signal-to-noise ratio a laboratory cannot reach. The X-rays are hard enough to pass through the sample, so the pattern is measured in transmission and every grain in the aliquot contributes, not only the surface. The holder is kept in motion during measurement, which averages out preferred orientation, the platy-mineral problem that skews laboratory results. And grinding matters: in our Luolamäki validation set, ball-milled samples fitted with about half the spread in fit quality of mortar-ground ones.

Synchrotron radiation is orders of magnitude brighter than a laboratory source, with angular resolution that separates peaks a diffractometer blurs together. Minor, poorly crystalline and overlapping phases become identifiable and quantifiable. Samples are kept in motion during measurement, which suppresses preferred orientation.

Mintti is our own analysis system. Automated phase identification is possible because synchrotron data is precise enough to tell phases apart. Where the data alone cannot decide, Mintti applies mineralogy and geology: which minerals are viable and likely in the region, which occur together. Every decision is logged as evidence, whether it came from the automation, from an analyst's adjustment, from an A/B test or from a hypothesis run across the whole set. Quantification is by Rietveld refinement, fast enough for thousands of samples in hours through parallel computing, optimised algorithms and the right hardware, including high-end GPUs. An expert mineralogist reviews every result before it goes out.

Quantification is by full Rietveld refinement on Mintti. Phase identification is deterministic and auditable: each assignment is supported by pattern fit, paragenetic viability and regional mineral likelihood, not by an analyst's preference, and the reasoning is logged. We back-calculate the chemistry from the mineralogy so you can compare it with your assays. Our validation on about 350 drill-core samples from a lithium pegmatite deposit, checked against published assays, is being published as its own page.

At the beamline the marginal cost of one more sample is seconds of beamtime. Setup and scheduling dominate small batches, so the per-sample price falls sharply with campaign size. A project of 50 samples costs 5,000 €, which is 100 € per sample. A project of 250 samples costs 10,000 €, which is 40 € per sample. Above 250 samples the price per sample keeps falling and is quoted per project. The more of the programme is measured, the less each sample costs, which is what makes measuring every pulp practical instead of a selection, and the decisions that follow are made on measured mineralogy instead of a few samples and chemistry. Sets below 50 samples and trial batches are priced case by case, so you can compare against your current laboratory before committing a programme.