Nanocrystals could be key to low-cost radiation detectors

The proof-of-concept study, described in the Journal of Applied Physics, suggests that nanocrystals – nanoparticles clustered together to mimic the densely-packed crystals traditionally used in scintillation devices – may one day yield radiation detectors that are easy and inexpensive to manufacture, can be produced quickly in large quantities, are less fragile, and capture most of the X-ray and gamma ray energies needed to identify radioactive isotopes.

Earlier studies have shown that when X-rays or gamma rays strike these miniature, non-crystalline scintillators, some atoms within them are raised to a higher energy level.

These atoms de-excite and give off their energy as optical photons in the visible and near-visible regions of the electromagnetic spectrum.

The photons can be converted to electrical pulses, which, in turn, can be measured to quantify the X-ray and gamma radiation detected and help locate its source.

In the latest experiment, the researchers suspended nanoparticles of lanthanum halide and cerium tribromide (loaded in 5 per cent and 25 per cent concentrations) in oleic acid to create nanocomposite scintillators with sizes between 2-5 nanometres.