Robust, low-cost micro-linac as a replacement for Ir-192 radiography sources

To improve public security and prevent the diversion of radioactive material for Radiation Dispersion Devices (or so-called dirty bombs), The US government is planning to dramatically reduce the amount of radioactive material in use. Ir-192 is the most common isotope used for radiography and poses a high risk of being diverted since it must constantly be replenished, and is found in small, portable devices that nevertheless contain dangerous amounts of material. The existing options for electronic replacement of such sources is too complicated and expensive to address the market need. RadiaBeam will develop an inexpensive, energy-tunable, portable linac consisting of a robust, easy-to-manufacture, smooth-walled dielectric structure having a cylindrical aperture and tapered outer diameter to allow effective capture of a tens of keV electron beam injected from an inexpensive electron gun and acceleration to a final energy up to 1 MeV. The structure and couplers do not require time consuming tuning due to the absence of cells and the high group velocity. The bremsstrahlung X-rays produced by the ~1 MeV electron beam on a high-Z converter at the end of the linac will match the penetration and dose rate of a typical 300 Ci Ir-192 source. Commercial Applications and Other Benefits: The intended application of the technology is as a replacement for radioisotopes in high-energy field radiography. These devices are critical for finding defects in oil and gas pipelines, bridges, buildings etc. Apart from having a large market, there is also a critical public safety need to replace these sources with safer alternatives.