NEW DEVELOPMENTS ON PREPARATION OF COOLED AND BUNCHED RADIOACTIVE ION BEAMS AT ISOL-FACILITIES: THE ISCOOL PROJECT AND THE ROTATING WALL COOLINGSummary: Last years have become very productive for the research, construction and development of new facilities devoted to the production of beams with exotic radioisotopes (Radioactive Ion Beams, RIB). These beams are later used for experiments in fields like nuclear physics, atomic physics, astrophysics or medicine, among others. Within this kind of facilities, the ISOL facilities stand out. They are based on the on-line separation of radioactive isotopes produced in nuclear reactions between a target and a high-energy proton beam. The ISOL method was the pioneer for these facilities and it has kept up to now the leadership of RIB facilities. The main reason is ISOLDE, an ISOL facility located at CERN, the largest accelerator complex in the world, where this doctoral thesis has been carried out. The first innovation which is described is the design of an ion trap for the cooling and bunching of RIB's for ISOLDE, the so-called ISCOOL (ISOLDE COOLer). It is an Radio Frequency Quadrupole ion Cooler and Buncher (RFQCB), device based on the Paul traps. In these traps, the ions are confined in the three dimensions by electric fields. The ions are confined on the transverse plane with the pseudopotential well created by the Radio Frequency Quadrupole (RFQ) and focused on the longitudinal axis. At the same time, a gas (normally helium) fills the chamber with a pressure between 10-3 and 10-2 mbar. The collisions between the atoms or molecules of the gas and the ions. In addition, to drive the ions to the extraction of the RFQCB, an axial electric field is created by segmented electrodes. Different voltages are applied to these electrodes in order to choose the shape of the field. The shape can be chosen to create a potential well close to the extraction from the RFQCB in which the ions are accumulated and extracted as bunches, by the fast-switch of the voltages applied to the axial electrodes. The new ISCOOL will be installed as a permanent device of the ISOLDE beam lines. It will improve the performance of most of the existing experiments and will become the first general purpose RFQCB, not only applied to a single experiment. This thesis represents an original description of the engineering and physics design of the RFQCB and its systems. The main innovations in the injection, cooling and bunching are detailed. A theoretical and practical study of the differential pumping problem in the vacuum system is discussed. The electronics system is simplified because the DC is applied individually to the axial electrodes without combining it with the RF as in old devices, and it makes it more reliable for a continuous operation in a big facility. To enhance the reliability, it is not less important the control system, which incorporates the robust design to this kind of research devices with the use of industrial Programmable Logic Controllers (PLC's) as core of the design. In addition to all the results of the design phase, the thesis presents the successful construction and assembly of hte RFQCB and all the systems discussed in the design phase. Finally, as a second innovation, the results obtained during the analysis of a new method for cooling in Penning traps are analyzed. Penning trpas are ion traps which combine magnetic and electric fields for the three-dimensional confinement of the ions, and mainly used for the precise mass measurements. The new method, the rotating wall cooling, was proposed as an improvement of the accumulation and cooling at these traps when the space charge effects are important. The thesis presents the results obtained at the Penning trap REXTRAP, used for the preparation, at the post-accelerator REX-ISOLDE at ISOLDE, of the low-energy beam from ISOLDE. The performance of the present and new cooling methods at the trap are compared, focusing the study in the 8 cooling 2af and extraction of high-intensity beams
