Experiments at the National Institute of Science and Technology (NIST) have demonstrated the feasibility of a new method for detecting nuclear materials that avoids the need to handle samples. The method could potentially be used for screening cargo at ports and borders or for detecting nuclear weapons in the field.

The method, called X-ray fluorescence (XRF) imaging, works by bombarding a sample with X-rays and then measuring the characteristic X-rays that are emitted by the sample's atoms. The energy of these characteristic X-rays is unique for each element, so by measuring the energy of the X-rays emitted by a sample, it is possible to identify the elements present in the sample.

In the NIST experiments, a beam of X-rays was directed at a sample of nuclear material. The characteristic X-rays emitted by the sample were detected by a spectrometer, which measured their energy. The results showed that XRF imaging could be used to identify nuclear materials, even when they were hidden inside other objects.

The NIST experiments represent a proof of concept for XRF imaging as a method for detecting nuclear materials. More research is needed to develop a practical system that could be used in real-world applications. However, the results of these experiments suggest that XRF imaging has the potential to be a valuable tool for detecting nuclear materials, and thus improve security and safeguard public health.