Real-time, remote detection of radioactive material using a high-power millimeter/THz wave vacuum device

We present the first experimental demonstration of the remote-detection of a concealed radioactive material using a high-power millimetre-wave vacuum device, a gyrotron. A 95 GHz, 30 kW pulsed gyrotron was used for detecting a 0.64 mCi
⁶⁰
Co radioactive material via plasma breakdown. We observed the obvious difference in the measured plasma formation delay time in the presence of radioactive material compared to without the radioactive material. The plasma breakdown threshold electric field was measured with the radioactive material and compared to without it. The presented experimental results support a strong detection capability of the concealed radioactive material using the invisible electromagnetic wave source, a highpower vacuum device.