Determination of Incident Beam Energy at End of Beam Line on a GE PETtrace Cyclotron
Benjamin Bender, Colbin Erdahl, David Dick
Department of Radiology, University of Iowa Hospitals & Clinics
Poster
No conflicts to declare.
Introduction: Competing nuclear reactions sometimes dictate that the beam energy incident on the target should be lower than the nominal beam energy of medical cyclotrons (i.e. Sc-44 at 11 MeV to reduce Sc-43 and Sc-44m; Ga-68 at 14 MeV to reduce Ga-66 and Ga-67). To ensure proper degrader thickness, it is important to precisely know the incident energy so as to minimize competing nuclear reactions while maximizing the energy available for desired nuclear reactions. Solid targets at the University of Iowa are at the end of the GE PETtrace beam line. While we believe there to be minimal energy loss down the beam line, we decided to measure the beam energy at the end of the beam line before designing our solid targets.
Methods: The GE paper burn target was modified with a new back flange that accepts foil stacks to determine the beam incident energy using the technique previously published by Gagnon (Appl Radiat Isot. 2011). Foil measurements were made using both 0.875 mm and 1.0 mm aluminum spacers.
Results: The beam energy at the end of the PETtrace beam line was measured to be 15.8 MeV.
Conclusion: The beam energy at the end of the PETtrace beam line was successfully measured, allowing for optimization of target design when a lower incident energy is needed.