Developing radiation-resistant electronics

Researchers at the University of Arkansas have received funding from the US Navy to develop technology that will prevent electronics from shutting down when in space or in high-radiation environments on Earth.

Although communication devices have advanced considerably in recent years, the latest communications technology doesn’t have adequate radiation resistance for use in space or other high-radiation environments. With this in mind, Morgan Ware and Jeff Dix, assistant professors of electrical engineering, each received $40,000 for six months with a one-year option period for $160,000 from the Naval Surface Warfare Center Crane Division to develop radiation-resistant electronic components, in order to fill the gap between what’s currently available on the commercial market and what’s needed to support state-of-the-art electronic components for the military.

Ware and his team will work to develop components that can operate continuously while exposed to high levels of radiation found in nuclear reactors, or as the result of a nuclear explosion. His team will focus on enhancing a power transistor, known as a high-electron-mobility transistor, made of gallium nitride — a widely used semiconductor for making efficient and compact power systems.

Usually, transistors control the flow of electricity by switching on or off, but when exposed to high-energy gamma rays from nuclear reactions the device can lose its ability to switch, creating large amounts of excess free charges which could cause the transistor to overheat. The answer to this issue, Ware said, is to trap those extra charges in something called a quantum well — a thin layer of charge-confining materials within the power device.

“We want to use this quantum well to trap and remove extra charges, which are unwanted and created as a direct result of the interaction with the radiation,” Ware said.

Radiation-tolerant devices resulting from Ware’s research will allow power subsystems to operate during exposure to radiation that would normally result in system failure. Once the devices are ready, Ware and his team will send them to the scientists at the Naval Surface Warfare Center Crane Division to perform radiation testing.

Dix will meanwhile work with Professor Alan Mantooth to harden electronics that will be used in space, creating components that can better resist damage caused by ionising radiation. This occurs from ionised particles from the Sun or other celestial objects, which can impact the electronics and cause harmful events like a spike in voltage that could destroy parts of the devices.

Dix’s team will thus create integrated circuit designs to extend the lifetime of electronics in space applications, such as satellites, and high-radiation environments on Earth, such as inside nuclear reactors. The team will design two components — an amplifier and a comparator — which will operate near a sensor and allow devices to analyse signals, which will then digitally process the information for the user to view.

The researchers will use radiation-hardened design techniques focused on two types of exposure: total-dose and single-event radiation. The total dose is the amount of radiation a component can absorb over a certain amount of time, while single-event radiation protection protects electronics from one instance of ionised particles hitting the system and damaging the component.

Dix said enhancing radiation resistance in electronics can make space operations more efficient, stating, “Putting technology that lasts longer into space is more economical and a more operationally effective way to do things. We’re working to create a design that will keep working even after several generations of commercial technology have become obsolete.”

Please follow us and share on Twitter and Facebook. You can also subscribe for FREE to our weekly newsletter and bimonthly magazine.