High power conical-shaped Niobium targets for reliable [18F-] production and lower [18O] water consumption: High power conical-shaped Niobium targets for reliable [18F-] production and lower [18O] water consumption

Introduction In order to address the increasing demand for Fluorine-18 and the rising cost per mL of 18O enriched water, IBA developed improvements to their 18F- production systems. For this new design we started from scratch, with the main objectives of reducing the required enriched water volume and improving the cooling of the insert. A better cooling allows increasing the target current and thus the produced activity. Finally, we aimed to reduce the number of parts and improve the design of auxiliary components. Material and Methods Six Niobium conical inserts with different target chamber volumes were machined and tested. Only 4 of these were selected to create the new range of IBA 18F− targets shown in TABLE 1. The new Niobium target inserts have a complex shape with drilled channels on the outside of the chamber and a deep channel next to the beam strike area (FIG. 1, green circle) to ensure efficient cooling. The 18O water inlet lines are now directly inserted in the Niobium body (FIG. 1, blue circle) to improve 18F- quality (no more contact with small o-rings). In operation, a 35µm Havar® target window is used. All tests were performed using IBA Cyclone® 18 cyclotron. The targets were filled with different volumes of enriched 18O water (enrichment > 92 %) and irradiated with 18 MeV protons on target with beam currents up to 145 μA for 30 to 150 minutes, while the internal pressure rise of the target was recorded. For each target, a pressure-current curve was plotted and an optimum balance between target water fill volume, pressure and current has been determined, which maximises available activity after two hours, in each case. Results and Conclusion Radionuclidic impurities were measured and more than 100 FDG syntheses on various synthesizers confirmed the effectiveness of the new design. Increasing the current up to 145µA in Conical 16, the production reached 18 Ci in 2 hours, single beam, with a target pressure under 43 bar. Today, the use of these new targets for daily commercial production is increasing within the IBA Cyclone® installed base

DESIGN OF IBA CYCLONE® 30XP CYCLOTRON MAGNET

IBA is currently developing an evolution of its famous Cyclone® 30 cyclotron. The Cyclone® 30XP cyclotron will be a multi-particle, multiport cyclotron capable of accelerating alpha particles up to 30 MeV (electrostatic extraction), deuteron (D-) beams between 7.5 and 15 MeV and proton (H-) beams between 15 and 30 MeV (stripping extraction). The magnet system has been updated with improved versions of IBA Cyclone 18/9 and Cyclone 70 features. At first, coil dimensions have been updated in order to raise the free space in the median plane to allow mounting a retractable electrostatic deflector system for the extraction of the alpha particle beam. Gradient corrector pole extensions, have been added to ease the alpha beam extraction. Finally, compensation for relativistic effects between H- (q/m=1/1) and D-/alpha (q/m=1/2) beams is made by the use of movable iron inserts located in two valleys, as is done in IBA Cyclone® 18/9 cyclotrons. These modifications could have an adverse effect on the flutter. In addition, the second harmonic induced by the movable iron inserts drives the machine in the 2.νr=2 resonance close to the extraction. As a consequence, modifications on the pole sectors and chamfers have been made in order to improve the flutter and eliminate harmful resonance up to extracted energies. After the presentation of the magnet features, some results on beam extraction are also discussed.IMP;Chinese Academy of Science

DESIGN OF IBA CYCLONE®11 CYCLOTRON MAGNET

The development of a new Cyclone®11 11MeV Hcyclotron is in progress at IBA. Such machine is designed for the production of radionuclides for nuclear medicine. This cyclotron is based on the existing Cyclone®10 that has been boosted to more than 11 MeV with as minor as possible change to the Cyclone®10 geometry. At first, the magnetic field has been raised by a small reduction of the valley depth. Additionally, the main coil current has been increased. Pole edge milling has been used to obtain the isochronous magnetic field shape. Beam optics in the magnet is excellent. Extraction is ensured by means of stripper foils mounted on carousels located at different azimuths allowing installation up to eight targets and dual beam extraction.IMP;Chinese Academy of Science

High power conical-shaped Niobium targets for reliable [18F-] production and lower [18O] water consumption: High power conical-shaped Niobium targets for reliable [18F-] production and lower [18O] water consumption

Introduction In order to address the increasing demand for Fluorine-18 and the rising cost per mL of 18O enriched water, IBA developed improvements to their 18F- production systems. For this new design we started from scratch, with the main objectives of reducing the required enriched water volume and improving the cooling of the insert. A better cooling allows increasing the target current and thus the produced activity. Finally, we aimed to reduce the number of parts and improve the design of auxiliary components. Material and Methods Six Niobium conical inserts with different target chamber volumes were machined and tested. Only 4 of these were selected to create the new range of IBA 18F− targets shown in TABLE 1. The new Niobium target inserts have a complex shape with drilled channels on the outside of the chamber and a deep channel next to the beam strike area (FIG. 1, green circle) to ensure efficient cooling. The 18O water inlet lines are now directly inserted in the Niobium body (FIG. 1, blue circle) to improve 18F- quality (no more contact with small o-rings). In operation, a 35µm Havar® target window is used. All tests were performed using IBA Cyclone® 18 cyclotron. The targets were filled with different volumes of enriched 18O water (enrichment > 92 %) and irradiated with 18 MeV protons on target with beam currents up to 145 μA for 30 to 150 minutes, while the internal pressure rise of the target was recorded. For each target, a pressure-current curve was plotted and an optimum balance between target water fill volume, pressure and current has been determined, which maximises available activity after two hours, in each case. Results and Conclusion Radionuclidic impurities were measured and more than 100 FDG syntheses on various synthesizers confirmed the effectiveness of the new design. Increasing the current up to 145µA in Conical 16, the production reached 18 Ci in 2 hours, single beam, with a target pressure under 43 bar. Today, the use of these new targets for daily commercial production is increasing within the IBA Cyclone® installed base

UPGRADE OF IBA CYCLONE® 3 CYCLOTRON

Some specific applications of 15O2 need a stand alone production machine to avoid disrupting the hospital main PET cyclotron. Due to recent renewal in interest, IBA has decided to improve the design of its Cyclone® 3 which accelerates D+ ions to energy of more than 3 MeV and which was originally developed for this purpose. The main improvement relates to the magnetic structure. In the existing design the vertical focusing is obtained by four straight pole-sectors that are mounted on the circular base of the pole. In the new design these are replaced by three spiralled pole sectors. This modification changes the rotational symmetry from four to three and improves the vertical focusing properties of the machine. Also the main coil and the return yoke were slightly modified. This allowed increasing the extraction energy by about 10 % from 3.3 MeV to 3.6 MeV. This new design will improve the transmission in the cyclotron and will result in an extraction efficiency of more than 80% using an electrostatic deflector. For the prototype the goal is to obtain an extracted current of 50 μA. This value should rise to 70 μA for subsequent machines, representing a doubling of the existing performance. In the paper, results of magnetic field optimization and extraction calculations are presented.IMP;Chinese Academy of Science

Production and Purification of Tc-99m Pertechnetate from Mo-100 Targets Irradiated in a Nirta Solid Target Station on an IBA Cyclone (R) 18 Cyclotron

Direct production of the highly utilized radioisotope 99mTc is a practical approach to self-sufficiency of supply. A TRIUMF-led consortium developed Mo-100 coating technology to manufacture high current targets and demonstrated the routine production and purification of 99mTc. The aim of this work is to implement these processes on an IBA Nirta target station and Synthera® Extension automated synthesis units