TEDDI: Tomographic Energy Dispersive Diffractive Imaging

X-rays have revolutionised our understanding of the micro and macro world.  TEDDI is a revolutionary new X-ray technique that holds the promise of becoming a main-stream analysis and characterisation tool for a wide range of applications by using the principles of X-ray tomography, X-ray diffraction and X-ray fluorescence.

The TEDDI process allows the user to obtain X-ray diffraction data from a sample, enabling analysis of the samples internal structure.  The process has a wide range of applications including analysis of pathological tissues, security, non-destructive testing of engineering parts and archaeology.

To produce an entirely new imaging concept with numerous applications in science, engineering and processing technologies. To achieve this goal, this project sought to:

• manufacture high aspect ratio X-ray collimators coupled with the creation of inexpensive and scaleable X-ray detectors to greatly increase the spatial resolution of TEDDI and data collection rates.
• build a high aspect ratio X-ray collimator and design a robust manufacturing route for the rapid creation of X-ray collimators using high fluence (J/cm ) short wavelength lasers.
• couple the X-ray collimators with new inexpensive X-ray detectors to allow rapid (seconds) non-destructive characterisation of a test piece.

The first X-ray collimator employed a patent pending alignment and drilling process. The collimator holes were laser drilled using a nanosecond pulse duration DPSS (Diode Pumped Solid State) laser operating at 355nm. Testing of the collimator has revealed collimation of the X-rays through the array, but also revealed a misalignment of some of the holes within each of the discrete tungsten drilled plates. The next version will use a more robust version of the alignment and drilling procedure and will employ a DPSS femtosecond laser to enhance the laser drilled hole quality.

The fast and reconfigurable manufacture of a high aspect ratio X-ray collimator with a DPSS nanosecond pulse duration laser has been demonstrated with the creation of the version 1 collimator. A new concept for collimator production has been developed and will be realised in the near future.

This EPSRC funded research collaboration was undertaken between 2003 and 2005 with Spectra Physics UK Ltd, RAL, Culham Lab, Daresbury Lab, The University of Manchester and Birbeck College.