Ultra-portable Multi-Energy X-ray Source using Novel RF Technology

Low-MeV x-ray sources that are compact, man-portable and easily deployed in the field are very desirable for security and inspection as well as for non-destructive testing. These energies are well suited to penetrate most objects of interest for these applications. However, in some cases lower energies are more desirable where the objects may be less dense and or made of lower atomic number material since lower energies result in improved image contrast. This could further allow image subtraction and improved object identification. The ability for the x-ray source to be able to generate multiple energies especially within a single unit makes it a very attractive option. Existing systems are either bulky, have low-x-ray yield and are mostly produced overseas, or use radioactive sources with single energy output. Our proposed system will overcome all of these issues. In Phase I of this proposal, we investigated the feasibility of developing a variable energy linear accelerator system based on TibaRay technology. We simulated and performed early prototyping of a linac-based source that will produce at least 2.6 MeV with the possibility of generating lower energies, with a dose rate >5 R/min at 1 m and have a total system weight that is < 90 lbs. Our company, TibaRay Inc. is actively developing RF components including linacs for use in our novel medical accelerator application. These are based on recent technology developed at SLAC and improved at TibaRay. This involves new approaches to designing highly efficient resonant cavities and for manufacturing them. The proposed linac was designed based on this concept of distributed coupling source with our new addition of calculations to account for beam loading. It will operate at X-band frequencies that area a standard for medical and industrial applications as well as for large research accelerators. It will be powered by a commercial RF source with the electrical power being provided by a power modulator based on a concept developed at TibaRay. This modulator uses the concept of distributed Marx capacitor bank where lower voltage boards are stacked up as per requirement to generate the high voltage. In Phase II we plan to build and test the complete x-ray system (variable energy linac, modulator, low-level RF system, cooling system, beam-monitoring system, control system, interlock and safety system and mechanical assembly). We will calibrate the variable energy performance and benchmark the measurements against simulated output. We will build two iterations of the system and optimize the performance. If approved, at the end of Phase II we will produce one complete 2.6 MeV, variable energy x-ray imaging source. We will develop the plan for the production and sale of these devices.