RPI wins radiation model grant

Researchers at Rensselaer Polytechnic Institute have received a $1m grant from the US Department of Defense to model how different metals are affected by neutron irradiation.

Researchers at Rensselaer Polytechnic Institute (RPI) have received a $1m (£0.6m) grant from the US Department of Defense (DoD) to model how different metals are affected by neutron irradiation.

The three-year study, awarded by the DoD’s Defense Threat Reduction Agency (DTRA) and led by Suvranu De, associate professor in the Department of Mechanical, Aerospace and Nuclear Engineering at RPI, could lead to more effective, more predictable performance of electronic shielding materials in satellites and structural components in submarines and nuclear reactors.

‘We’re looking very carefully at how the mechanical properties of metals change over time when exposed to radiation. This should allow us to accurately predict the expected lifespan of these metals and then design better devices,’ De said.

De and his team will build complex computational models to simulate the irradiation of different metals at the atomic level and then scale them up to see how the phenomena at the atomic level impact the overall mechanical properties of the material and device.

Starting at the nanoscale and employing quantum mechanics, the model will look at the cause and effect of atomic events that last mere picoseconds. That nanoscale model will inform a microscale model, which measures events in microseconds and nanoseconds. Similarly, the microscale model will feed into a larger model, which in turn will feed into the fourth, life-size model that measures the irradiation of metals in terms of seconds, days and years.

The trick, De said, is developing code that allows the different models to speak the same language and correctly share information, in order to create the larger, self-consistent, multiscale model.

‘Using quantum mechanics, we can predict what happens when a single neutron knocks out a few atoms from where they’re supposed to be and then trace that chain reaction from the atomic scale to the microscale, mesoscale and finally to the macroscale to see how that leads to the eventual mechanical failure of the device,’ De said.

‘We hope this research will lead to the design of self-healing metals that can withstand radiation for long periods of time without endangering their structural integrity or mechanical properties.’

Rensselaer professor Suvranu De has received a $1m (£0.6m) grant from the DTRA to create a multiscale model that simulates how different metals are affected by neutron irradiation. The model will simulate how irradiation impacts metals at the atomic level, but will also scale up to illustrate how the atomic-level changes create chain reactions that can affect the overall integrity and mechanical properties of the metal. Credit: Rensselaer/Suvranu De