Alastair Lough
In May this year myself, Prof. Maeve Lohan and Dr. Oliver Moore from the University of Leeds travelled to Diamond light source UK in Didcot. Diamond light source is the UK’s national synchrotron facility. Many people will be familiar with the large hadron collider which accelerates protons around two rings in opposite directions in order to collide the protons together to study physics. Diamond is a smaller facility the large hadron collider and instead of accelerating two separate beams of protons around a ring in opposite directions at diamond electrons are accelerated in one direction at speeds close to the speed of light. When electrons are accelerated to this speed light 10 billion times brighter than the sun is given off and this synchrotron light is directed off into many different laboratories called beam lines. Each beam line contains a different type of microscope to deliver a range of measurements in order to study everything from the structure of viruses to new battery technology and ancient artefacts.
Our experiments were conducted on the i08 beamline which is one of the main beam lines used for environmental science. The i08 beamline is one of three scanning transmission microscopy beam lines in the world. This allows areas of a sample several micrometres in size to be scanned by the nanometre scale x-ray beam in rows and columns to create a grid. The sample grid is scanned multiple times at a range of x-ray energies. The absorption of the x-rays at different energies tells us about the composition (chemical speciation) of the sample. Repeatedly scanning the sample area creates something called a stack which gives highly spatially resolved speciation of a particle.