Novel Proton Alignment Aid for Isotope Production

Accelerator produced radioisotopes are used every day for medical imaging techniques such as positron emission tomography PET). Importantly, research into the development of new isotopes suitable for this technique has expanded the biological characteristics which can be studied using this non-invasive method. This technique relies on robust production of these isotopes for the expansion of this exciting work. Isotopes can be produced via the irradiation of solid, liquid or gas targets with charged particle accelerators. Beam alignment is crucial to obtaining optimized yields fromthese targets. While commercially available collimators may provide some information on the X,Y alignment of the beam, the angle and beam trajectory along the target is just as important. The ideal detector system for this application would be modular, smalland radiation resistant, sensing the neutrons produced by these p,n reactions. Advances in the growth of high quality Chemical Vapor Deposition CVD) diamond have created high purity diamond and an opportunity for the application of this material in practical detectors. Diamond is a semiconductor with a large band gap 5.45 eV) which allows production of detectors with very low leakage currents. The high electron and hole mobility in the diamond material provides very fast signal response with very short rise times and total pulse widths. The large lattice displacement energy for atoms and small cross section give diamond excellent radiation tolerance. In Phase 1 we will develop diamond detectors for collecting neutron emission data from the exterior of target holders attached to the beam pipe. The use of a diamond detector-based modular, flexible system will show the feasibility of this concept for use by all types of targets in all types of isotope production facilities. Detectors placed in a variety of locations collecting flux and energy data will provide beam steering and target yield information guiding cyclotron operations. A modular detector system, placed outside the beam pipe and providing beam position and target yield information, would allow improved radioisotope production at many facilities. Its small size and flexible design would improve operations independent of target type allowing local engineers to optimize target design for their specific operational needs. Improved cyclotron operations will speed the development of new radioisotopes for medical imaging.