Cargo scanning using either radiographic imaging or active interrogation for Special Nuclear Material (SNM) requires high energy and high intensity x-rays. A controlled source of such x-rays is an electron linear accelerator (linac) equipped with a metal x-ray conversion target. Existing pulsed copper accelerators have relatively low average current, which limit the quality of x-ray images and SNM detection sensitivity. Furthermore, interrogation systems based on copper accelerators typically weigh several tons, have a large footprint, and consume hundreds of kilowatts of electric power. As a result, these machines require a large, fixed site to operate. To overcome these limitations, Niowave is developing a compact, portable, high-efficiency, 10 kW niobium superconducting electron linac.

Our 10 MeV, 10 kW, superconducting, continuous wave linac operates at 4 K, requiring cryogenics. The accelerator will be cooled with insulated liquid nitrogen and helium dewars, so no on-site refrigeration system is required. The entire system can be powered by a compact portable generator. A liquid-metal x-ray converter, capable of dissipating hundreds of kilowatts needed for high-powered linacs, creates the x-ray flux necessary for cargo scanning. A collimator to limit the interrogating x-ray angles will be placed after the converter. Finally, the whole setup will be properly shielded to protect the operators. The system will have a small footprint and could be placed in a small truck.