Maia Mapper Capabilities

Count-rates and throughput
Maia Mapper achieves count-rates on typical ore samples up to 5 million counts per second, which enables very short “dwell” times per pixel in a scan. The high rates come from a combination of a high intensity X-ray source, high efficiency polycapillary focussing element and the large solid-angle of the Maia detector array. Fortunately, the Maia detector can handle over 20 million counts per second, shared between its 384 detectors, so this is easy for it. Hence, even at 5 million counts per second Maia loses less than 5% of X-ay events to dead-time and shows little pileup in the X-ray spectra.
High count rates enable sufficient counting statistics to be achieved in each pixel spectrum in just a few milliseconds, which enables scans over tens of millions of positions on a sample in a few hours to produce incredibly detailed images of between 10 and 60 megapixels. These images are “hyperspectral” containing planes of data for up to 30 chemical elements separated efficiently using our Dynamic Analysis algorithm.

Chemical images utilizing Dynamic Analysis
XRF spectra from geological samples can be complex. Deconvoluting spectra with complex overlaps between numerous chemical elements is always technically demanding. For Maia mapper this is more challenging given that we have up to 60 million spectra acquired for a single core scan. Our solution is to use an algorithm called “Dynamic Analysis”, developed at CSIRO initially for PIXE analysis, that reduces the deconvolution problem to a fast matrix transformation, which can even be performed inside the Maia detector’s processor as data are accumulated, so that we see element images in real-time.

Microanalysis at “intermediate spatial scales”
Maia Mapper scans core samples up to 500 mm long and 80 mm wide, with a pixel size of 30 microns. Providing detailed hyperspectral XRF images over this spatial scale fills a gap between classical microanalysis imaging over a few millimetres and drill hole logging at the metre scale. In a workflow where samples are selected from a drilling program, Maia Mapper and CSIRO geochemists can provide a detailed analysis of chemical and mineralogical associations and metal deportment at 30 micron spatial resolution over decimetre scales.

Finding the “needles in a stack”
Often locating the tell-tale indicators of geological processes or the distribution of precious metals in ore at low gram per tonne levels is like searching for needles in a haystack. Fortunately, the sensitivity and throughput of Maia Mapper allows thousands of these rare phases to be located in each core, even at low bulk concentrations, enough to decipher the detailed deportment of metals and the story behind the formation of the ore.