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The space charge compensation process is important in order to transport ion beams with high perveance from the source to the RFQ. In particular, not fully compensated beams may develop halo and emittance growth at the entrance of the RFQ. The signal of incomplete compensation is the presence of a significant residual potential (in the range of 5% or 10% of the uncompensated potential). In order to investigate these phenomena, we performed CPU-time-demanding simulations with selfconsistent programs from which we could extract the information about the space charge and the potential along the transfer line (consisting of three drift spaces and two solenoid), especially at the entrance and at the exit of the solenoids, with a typical D+ beam current of 135 mA, a 0:25 mm mrad rms normalized emittance at a 100 keV input energy. We also compared the results with the FGA (four grid analyzer) measurements performed at the prototype accelerator of the IFMIF/EVEDA stage. Simulations were parallelized through message passing interface python compiled code, via the PIC codeWARP. Particularly we compare the results obtained in the rz (cylindrical symmetry) and in the 3d xyz implementations, to verify whether the former approach (much faster) is accurate enough. [ABSTRACT FROM AUTHOR]

After installation of Mo liners in the source NIO1 (Negative Ion Optimization phase 1), hydrogen plasmas in a continuous regime operation (much longer than one hour) are routinely maintained, with more than 1 kW rf power and 0.5 Pa pressure, allowing a systematic investigation of pure H- volume effect, which requests a much lower acceleration voltage Vs ≅ 12 kV than future Cs operations at Vs ≅ 60 kV . A new extraction grid EG was installed (replacing some eroded insulators) and preliminary beam images are compared to old EG ones, discussing effects of different deflection field strength and need of intermediate values. Large improvements in beam diagnostics and the effect of installation of a cryogenic pump are also reported. [ABSTRACT FROM AUTHOR]

SPES (Selective Production of Exotic Species) is an INFN project to develop a Radioactive Ion Beam (RIB) facility as an intermediate step toward EURISOL. The SPES project is part of the INFN Road Map for the Nuclear Physics development in Italy and is supported by the whole Italian Nuclear Physics community and mainly by LNL and LNS the INFN National Laboratories of Nuclear Physics in Legnaro and Catania. The Laboratori Nazionali di Legnaro (LNL) was chosen as the site for the facility construction due to the presence of the PIAVE-ALPI accelerator complex, which will be used as re-accelerator for the RIBs. The SPES project is based on the ISOL method with an UCx Direct Target and makes use of a proton driver of at least 40 MeV energy and 200 microA current. Neutron-rich radioactive beams will be produced by Uranium fission at an expected fission rate in the target in the order of 1013 fissions per second. The key feature of SPES is to provide high intensity and high-quality beams of neutron rich nuclei to perform forefront research in nuclear structure, reaction dynamics and interdisciplinary fields like medical, biological and material sciences. The exotic isotopes will be re-accelerated by the ALPI superconducting linac at energies up to 10 AMeV for masses in the region of A = 130 amu with an expected rate on target of 109 pps. [ABSTRACT FROM AUTHOR]