Improvements to Siemens eclipse PET cyclotron penning ion source
The Siemens Eclipse (RDS111) cyclotron utilizes an internal Penning Ion Gauge (PIG) ion source to provide the negative hydrogen ions for this 11 MeV PET cyclotron. Siemens worked with D-Pace Inc. to optimize the ion source current and transmission through the cyclotron to the radioisotope targets. The goal was to increase the target current from 120µA (dual 60µA) to 150µA (dual 75µA) and to increase the time between ion source rebuilds from 120 hours to more than 300 hours. Over 80 experiments were conducted including tests on ion sources with modified cathode, anode, and puller lens geometries and materials, hydrogen gas flow configurations, and a biased plasma lens design. Cesium was introduced to the source which alone increased the beam current on target by over 20%. These short-term tests are being followed up with longer duration field testing.