Real-Time Monitoring Method for Irradiated Materials

The new method relies on optical probes, which use multiple sets of laser beams. Image courtesy of MIT.

Massachusetts Institute of Technology (MIT) (Cambridge, Massachusetts) researchers developed a new method to enable the continuous monitoring of materials exposed to high radiation. The researchers believe this method could eliminate the need for preventive replacement by allowing materials to remain in place longer.

According to the team, findings show their technique, known as transient grating spectroscopy (TGS), can be performed quickly and with high sensitivity. Traditional practices requiring samples to be extracted and tested in outside devices can be time-consuming and expensive, the researchers explain, and they also do not provide information on how damage occurs over time.

However, this method works without requiring any physical contact between the monitoring device and metals. Instead, it relies on optical probes, which use one set of laser beams to stimulate surface vibrations, and others to probe the properties of those vibrations by using the interference patterns of the beams. Those properties can reveal details of both the surface properties and bulk material.

“Our whole goal was to monitor how materials evolve when exposed to radiation, but do it in a way that’s online,” explains Michael Short, an MIT assistant professor and researcher helping lead the project.

The new approach can also show changes in the thermal and mechanical properties that affect the material’s response to temperature surges or vibration. “What we’re working toward is a real-time diagnostic system that works under radiation conditions,” Short says.

Compared to existing methods, which use multiple samples exposed over long periods, Short says the technique can provide “more data from one sample, in one experiment, in about 1% of the time.” 

Source: MIT,