Characterization of the Fast Ion Stopping Cyclotron for NSCL/FRIB

The Facility for Rare Isotope Beams (FRIB) will be a 600 million dollar national user facility operated by Michigan State University providing facility users with intense rare-isotope beams for a wide variety of applications. Converting intense low-energy ion beams from fast ion beams into low-energy beams by employing gas stopping is critical for FRIB science with stopped and reaccelerated rare isotope beams. A high efficiency for the gas stopping at high beam rates is required and the gas-stopping cyclotron is a strong candidate for this purpose. The cyclotron magnet is soon to be commissioned, and the implementation of gas-stopping cyclotron is only a few years out. Current simulation capabilities are severely limited, however, leaving many questions about the optimization and improvement of the device uncertain. We will provide particle-in-cell Monte Carlo simulation support, using the particle-in-cell code VORPAL, for characterizing the gas stopping cyclotron and the design of future devices. VORPAL will be used to explore the limitations of the device by simultaneous simulation of ionization, space-charge effects, and other loss mechanisms while the isotope beam is being stopped and extracted. VORPAL will also be used to simulate experimental observables to be verified against FRIB operations and tests. Commercial Applications and Other Benefits: The project will improve VORPAL and extend its capabilities, allowing VORPAL to expand into new markets. This proposal also builds collaboration with Michigan State University (MSU) experts who are responsible for delivering the cyclotron to FRIB and potentially new collaborations with the ion beams community.