Sterile Insect X-ray Irradiator

The “sterile insect technique” has been successfully applied for several decades to controlor eradicate insect pests that threaten agricultural crops or human health in the U.S. and around the world. Pest insects are carefully bred at industrial-scale facilities, with the pupae irradiated with just enough dose to render the insects sterile but otherwise healthy when they are grown and released into the environment. They then mate with others of their species but produce no offspring, causing the pest population to decline and in some cases vanish. The problem is that most of the irradiators forthis technique are based on radioactive Cesium-137 or Cobalt-60, both of which could be used by terrorists in a radiological attack. Most of these irradiators are in remote locations, where providingthe necessary security for the isotopes imposes a high administrative and cost burden, thereby limiting the application of the technique. Of the 66 facilities currently in operation, 11 are in the U.S, but most are in less developed countries, including 16 in Africa. Available alternative technologies have been found wanting, including electron beam systems that cannot achieve the required dose uniformity without very high-energy sources that need massive radiation shielding, or point-source x-ray tubes, that cannot provide the required throughput. Stellarray is develoiping a Sterile Insect Technique X-ray Irradiator based on its proprietary flat panel x-ray sources. These efficiently deliver highly uniform x-ray flux over a broad area, with sustained operation at high power levels for high throughput. The Stellarray Irradiator will use pairs of these panels above and below a conveyor belt transporting the pupae through a self-shieldedirradiation chamber, in a system resembling an airport baggage scanner. The system will be modular and scalable to any size insect control operation. It will be designed to use power from any source, including stand-alone generators. Doses can easily be varied for use with any pest species. The Stellarray system will fit seamlessly into the process flow of these industrial-scale operations, and will save the operators several process steps. The Stellarray x-ray panels have been developed for blood irradiators and research irradiators. This Phase II will adapt these sources for a systemthat canoperate continuously at high dose rates. The project will also test a new source concept using grazing incidence electron beams, which if successful, will offer further efficiency increases and thus lower system power requirements. The immediate benefit of this technology will be an alternative to radioactive isotopes that present a security hazard, Cesium-137 because it has a long half-life and is made as a dispersible powder, and Cobalt-60 because it is so prevalent. Further applications will include medical product sterilization, where Cobalt-60 is common. By reducing the security burden to operators, the technology will ease the expansion of the sterile insect technique, which can save billions of dollars of agricultural production and thousands of lives in a way that is ecologically sound (no chemical pesticides) and environmentally benign (no added species).