Safe, High-throughput, Self-contained Irradiator

The Sterile Insect Technique (SIT) is an important pest management technique, however it relies on dangerous radioisotope-based gamma ray irradiators. In order to further the proliferation of the technique and reduce security concerns, non-radioisotope irradiators must be developed. While X-ray tube irradiators have been developed, they cannot produce energies above 1 MeV. A ~3 MeV irradiator is required to match the penetration of Co-60 and provide higher throughput. In response to this problem, RadiaBeam Systems will design an inexpensive, compact 3 MeV linac to act as the radiation source for a safe, self-contained irradiator for SIT and other applications. We plan to use X-band RF power to reduce size, an innovative split-linac approach to reduce cost, a novel X-ray conversion target geometry to spread the beam out on the target, widening the resulting X-ray beam and reducing the thermal load on the target, and select an uninterruptible power supply to allow for operation in environments with unstable electrical power. In Phase I, we carried out Monte-Carlo simulations to design the X-ray target and the shielding, as well as to optimize the delivered dose distribution. Beam dynamics studies of the linac were carried out to demonstrate that the required beam current is feasible and the detailed 3D RF design was generated. The split structure was fully engineered to a high level of readiness for manufacturing. The rest of the system was designed, models generated, and important components selected to estimate size, weight and cost. In Phase II, the linac-based irradiator system will be built and tested. The goal of the project is to build a prototype that can be smoothly transitioned to a commercial product. After Phase II, we plan to test the irradiator at the IAEA Insect Pest Control Laboratory. The output of this project will be a safe, compact, high-throughput irradiator that can be used for insect, blood, cannabis and research irradiation. Approximately 5,000 devices containing 55,000 high-activity radionuclide sources are in use in the United States today. Linacs would be a feasible replacement for many of these sources, and thus it may have a wide-ranging potential to reduce the use of radioisotopes increase our nation’s nuclear security.