Compact Ion Cyclotron for Nuclear Security Applications

The mission of the Office of Defense Nuclear Nonproliferation Research and Development Division at DOE is to develop effective and transportable systems for nuclear security. Present cargo inspection systems exploit the broad bremsstrahlung spectrum from a 6-10 MeV, pulsed, low-duty cycle electron accelerator which in the presence of significant backgrounds presents difficulties in image and material identification, making unambiguous detection of special nuclear materials extremely challenging. An alternative approach is to use ions which can excite nuclear states either directly, or through generation of secondary high-energy signature gammas produced from nuclear interactions in a target. In response to this problem, we propose to design a compact sector isocyclotron 1.25 meters in radius, with dual, high-gradient, 0.2 MV cavities to accelerate multi-ion species up to 15 MeV/u with large orbit separation for low-loss extraction without lossy foil stripping. Innovations in injection, a solid-state tandem system or RFQ, will be introduced to replace the high-loss central region, a critical design condition for high-current ion beams. In Phase I, the conceptual design of the cyclotron will be carried out, including beam dynamics optimization, 3D magnetic design, injection and extraction, and RF systems design. In Phase II, the full engineering design of the cyclotron prototype will be performed for fabrication and, if budget permits, the manufacture of a prototype magnet or RF cavity.The strategic goal of Phases I and II of this project is develop a turnkey compact accelerator that would make cyclotron the standard tool for National Security Application devices worldwide. Non-security applications of the cyclotron include medical isotope production (alpha emitters and theranostic radiopharmaceuticals), ion radiobiology, as well as laboratory-scale material science research and instrumentation development.