NASA reports that it is now looking into the use of gallium-nitride, for space applications. Gallium nitride (GaN) is a material that is widely used in LEDs, laser diodes, and is set to be widely adopted in numerous power electronics applications, due to its efficiency compared to silicon. In fact, the material can handle ten times the electrical current of silicon. Most importantly for space applications, GaN can tolerate high levels of radiation and a wide temperature range. The material is also good at detecting energetic particles.
With NASA funding, engineer Jean-Marie Lauenstein and scientist Elizabeth MacDonald are developing Gallium-Nitride High Electron Mobility Transistors, or GaN HEMTs to study how Earth’s magnetosphere interacts with its ionosphere. Also, Stanley Hunter and Georgia de Nolfo, are looking into the material’s use for a solid-state neutron detector that could be useful for both science and homeland security.
One of the primary aspects of the NASA research into GaN will be testing its tolerance to radiation which would be useful in a harsh space environment. “The team’s research on radiation tolerance helps us understand how to fly these accelerators in the harsh space environment over the mission’s lifetime,” MacDonald said.
According to Lauenstein, these findings will also serve other scientific endeavors. “We need a path forward for this technology,” she said, “This opens the door for others to incorporate this technology into their missions.”
Hunter and de Nolfo’s neutron detector design concept would position a gallium-nitride crystal inside an instrument. As neutrons enter the GaN crystal, they scatter off gallium and nitrogen atoms, thereby exciting other atoms. These excited atoms then produce a flash of light that reveals the position of the neutron that started the reaction. The design envision would also employ silicon photomultipliers attached to the crystal that convert the flash of light into an electrical pulse that sensors could analyze.