Progress With a New Radioisotope Production Facility and Construction of Radioactive Beam Facility at iThemba LABS

With the termination of the neutron and proton therapy programs at iThemba LABS, the use of the Separated Sector Cyclotron (SSC) has now shifted to nuclear physics research with both stable and radioactive ion beams, as well as biomedical research. A dedicated isotope production facility with a commercial 70 MeV H-minus cyclotron has been approved and both the cyclotron and isotope production target stations will be housed in the vaults that were previously used for the therapy programs. The status of this new facility will be reported. In the future the SSC will mostly be used for nuclear physics research, as well as the production of isotopes that cannot be produced with the 70 MeV H-minus cyclotron. At present the production of the α-emitting radionuclide Astatine (211At) with a 28 MeV alpha beam is being investigated. Progress with the construction of a facility for production of radioactive beams will be discussed. There will also be reports on development work on the ECR ion sources and progress with implementation of an EPICS control system. DEDICATED 70 MeV CYCLOTRON FOR ISOTOPE PRODUCTION The initial idea to simultaneously produce radioisotopes and radioactive ion beams with a dedicated 70 MeV Hminus cyclotron was discarded due to a number of reasons as explained in [1]. A feasibility study has shown that a very cost effective, dedicated isotope production facility can be constructed at iThemba LABS by making use of the existing infrastructure, which became available when iThemba LABS discontinued proton and neutron therapy. The layout of the proposed facility is shown in Fig. 1. There will be two isotope production vaults (Fig. 1, vaults A and B) with two bombardment stations in each. The 70 MeV H-minus cyclotron will be housed in a separate vault (Fig. 1, vault C) located between the two isotope production vaults. The irradiated targets will be transported via a rail transport system, through new labyrinths that will be connected to existing labyrinths, to the existing hot cells. Detailed FLUKA calculations have been done for the different vaults and labyrinths to ensure that all the radiation safety requirements will be met. With a dedicated isotope production facility available, the bulk production of isotopes with the SSC will end. In future the SSC will then mainly be used for nuclear physics research and the development of new radioisotopes that cannot be produced with the dedicated isotope production facility, such as the alpha emitter 211At. Following approval of the project by the Board of the National Research Foundation, a contract for the manufacturing, delivery and installation of the 70 MeV cyclotron and associated beamlines has recently been signed after an open tender process. The 70 MeV H-minus cyclotron is capable of delivering two 375 μA beams simultaneously from two extraction ports placed 180 degrees apart. The consulting engineers for the design, development and construction of the required infrastructure have also been appointed. The infrastructure of the 70 MeV project will be completely separated from the infrastructure of the existing SSC facility to ensure that the new facility can operate independently from the SSC facility. The time schedule for completion of this project is 3 years. The cyclotron and beamlines will be delivered within 2 years after contract signature. During this time, the infrastructure and the modifications to the 3 vaults will be completed and the 4 target stations will be designed, built and installed. Commissioning of the new equipment will take place during the third year. ISOTOPE PRODUCTION TARGET STATIONS The current plan is to build four new target stations that will receive beam from the 70 MeV cyclotron. They will be similar in design to the existing horizontal-beam target station (HBTS or Elephant) at iThemba LABS, but with thicker local radiation shields and several other smaller modifications and improvements. These target stations will be identical in all respects except for the aperture of the entrance collimator, which can have different sizes on different stations. During bombardment, a target will be completely surrounded by a composite radiation shield, consisting of an inner iron layer, a borated paraffin wax middle layer and a lead outer layer. This local shielding will reduce the neutron flux into the vault by about three orders of magnitude and reduce the thickness of the concrete shielding required for the vault significantly. More details on the station design can be found in [2]. Target transfer between a station and an electric rail transport system will be facilitated by a robot arm. All target handing, including the connection of cooling water, will be done by remote control. 22nd Int. Conf. on Cyclotrons and their Applications Cyclotrons2019, Cape Town, South Africa JACoW Publishing ISBN: 978-3-95450-205-9 doi:10.18429/JACoW-Cyclotrons2019-MOB02 05 Cyclotron Applications MOB02 17 Co nt en tf ro m th is w or k m ay be us ed un de rt he te rm so ft he CC BY 3. 0 lic en ce (© 20 19 ). A ny di str ib ut io n of th is w or k m us tm ai nt ai n at tri bu tio n to th e au th or (s ), tit le of th e w or k, pu bl ish er ,a nd D O I