ISOL MYRRHA: An application of the MYRRHA accelerator for nuclear physics

In order to explore new research opportunities offered by the MYRRHA proton accelerator, a preparatory feasibility study was initiated within the framework of the 'Belgian Research Initiative on eXotic nuclei' (BriX) network. This study investigates unique possibilities for fundamental research using high intensity proton beams. One of the possible interesting approaches for fundamental research using the 600 MeV proton accelerator is the installation an Isotope Separator On-Line (ISOL) system to produce intense low-energy radioactive ion beams (RIB) available for experiments requiring very long beam times. From technical point of view this so-called ISOL MYRRHA project will follow closely the RIB production schemes that are developed and successfully used at the ISOLDE-CERN (Switzerland) and TRIUMF (Canada) facilities. ISOL MYRRHA will be equipped with simplified and ruggedized target-ion source systems, including laser ionization sources, that allow the use of a selection of target materials that can withstand the proton beam power. By using a part (between 100 - 200 μA) of the 600 MeV proton beam this new facility will produce a wide spectrum of intense and pure radioactive ion beams at energies around 50 keV. The rationale behind the choice for simplified and ruggedized target-ion source systems is that the facility should deliver RIB for experiments needing very long beam times up to a few months. The long beam times will be available for high-precision experiments, experiments hunting for extremely weak signals or experiments with an inherently low efficiency. In this sense ISOL MYRRHA will be complementary to other existing or planned facilities. Different physics cases are currently under investigation. The prospects with ISOL MYRRHA will be discussed and a limited number of possible physics cases will be presented. The latter might include detailed decay studies of exotic nuclei, weak interaction studies through precise nuclear β decay experiments in ion traps, laser spectroscopy studies of interest to atomic physics as well as implantation and detection of specific radioactive probes in different host materials, a topic of interest to solid state physics and applications in nanotechnology. (author)