Micro-Spectroscopy

XRF And Confocal Microscopy

The microprobe beamline at 25-ID-D is optimized for XRF mapping and micro-spectroscopy, including several state-of-the-art fluorescence detectors. Capabilities include chemical mapping with rapid variable focus from 0.5 to 10 microns using unique Be lenses.

Example XRF spectrum from a sample containing the elements listed. By plotting the signal strength of one element over a 2D sample area, an element specific picture can be produced like those below for As in plant tissue.

Some of the detectors available for XRF mapping

Imaging on Resonance

Incident energy held at maximum for an atomic species allows speciation maps.
𝜇-XRF measured at each relevant incident energy (multiple maps required).
Shown above for As speciation in gold dust ferns after As(V) uptake.
Some As(V) is converted to As(III), and is concentrated in pinnule and stipe.

EXAFS study of Nb3Sn superconductors

Nb3Sn proposed for future accelerator upgrades, but needs improved properties.
Doping can offer improvement, but optimization needs better understanding.
Ti, Ta, and Hf dopants studied.
Determined Ta dopant increased antisite disorder with beneficial results.
Hf formed HfO2 nanoparticle pinning sites.

Beryllium Focusing Lenses

The beam spot-size can be adjusted quickly and easily through the use of a series of Be lenses contained in a chamber like the one shown. This method has proven to be both reliable and repeatable.