Hand-held X-rays for crystallography on the hoof

X-ray diffraction is moving out of the laboratory and into the field with a handheld device that quickly establishes the mineral content and quantity of samples being analysed.

The 1.5kg device, which is being developed by Dr Graeme Hansford from Leicester University’s Space Research Centre (SRC) and Bruker Elemental, is expected to represent ‘an evolution’ in current handheld X-ray fluorescence (XRF) instruments.

Dr Hansford explained that such systems posses many capabilities, such as determining the presence of toxic elements in children’s toys and plastics, or for metal analysis.

X-ray diffraction (XRD) occurs when the atomic planes of a crystal cause an incident beam of X-rays to interfere with one another as they leave the crystal.

XRD built into a handheld device will differentiate between minerals that have the same chemical formula, an important factor when used in a mining context.

Dr Hansford added that the entire process would take between one and two minutes and that the sample would not require any special preparation.

The next stage of the project will focus on developing and testing the methodology using samples which are representative of real-world problems encountered in mining, such as determining the relative amounts of iron oxide minerals in ore samples.

In the second part of the project, a prototype handheld device will be developed at the SRC in conjunction with Bruker.

Dr Hansford said that relatively minor changes will be required in order to introduce this new capability, which will be incorporated into a device combining XRF along with XRD. According to Leicester University, hardware requirements of the technique are very similar to existing handheld XRF devices.

‘The key change is  a change in geometry,’ said Dr Hansford. ‘These instruments have an X-ray source and a detector plus the associated electronics and, at the moment, they are side by side in a configuration where the incident beam onto the sample…is something like 40 to 50 degrees. We need to bring that angle much lower down to less than 20 degrees.’

‘In other words, we need to bring the source and the detector much closer together within the instrument. That’s were the challenge will lie so it’ll need some redesign work of the head of the instrument and it may need some changes to…the X-ray source. There’ll be some changes to the design of the source in order to enable that change in configuration.’

This project is supported with an award from the Science and Technology Facilities Council’s Innovations Partnerships Scheme.