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The Electron Cyclotron Resonance Ion Sources (ECRISs) development is strictly related to the availability of new diagnostic tools, as the existing ones are not adequate to such compact machines and to their plasma characteristics. Microwave interferometry is a non-invasive method for plasma diagnostics and represents the best candidate for plasma density measurement in hostile environment. Interferometry in ECRISs is a challenging task mainly due to their compact size. The typical density of ECR plasmas is in the range 10(11)-10(13) cm(-3) and it needs a probing beam wavelength of the order of few centimetres, comparable to the chamber radius. The paper describes the design of a microwave interferometer developed at the LNS-INFN laboratories based on the so-called "frequency sweep" method to filter out the multipath contribution in the detected signals. The measurement technique and the preliminary results (calibration) obtained during the experimental tests will be presented.

The characteristics of the ideal injector for high power proton accelerators have been studied in the last two years with the TRIPS ion source built at INFN-LNS, Catania and now installed at INFN-LNL, Legnaro. The beam production must obey to the request of high brightness, stability and reliability. The new Versatile Ion Source (VIS) is a permanent magnet version of the TRIPS source with a simpler extraction system and mechanics. Its design permits to operate at 80 kV without a bulky high voltage platform, in order to produce multi-mA beams of protons and H2+. The description of the source design and the expected performances will be presented.

Over the past two years, INFN-LNS has undertaken to improve the source reliability for high-power proton accelerators. A full set of magnetic field measurements has been carried out to define a different design of the TRIPS magnetic system, based on permanent magnets, in order to increase the reliability of the source devoted to the ADS. The OPERA-3D package was used to design the new magnetic system as a combination of three rings of NdFeB magnets and soft iron in between. The description of the magnetic measurements and the comparison with the simulations are presented, along with the design of a new version of the source, called PM-TRIPS. Finally the new low-energy beam transfer line (LEBT) will be described, with particular regard to the improvement of accelerator availability, which can be obtained with the installation of two PM-TRIPS sources or more on a switching magnet.

During the last years big effort was devoted to increase the electrostatic deflectors’ reliability; this provided a better comprehension of the most significant effects concerning their working conditions. Deflectors were checked during the normal operation of the K800 Superconducting Cyclotron (CS) at LNS, at the operating pressure of 1 10-6mbar and a magnetic field of 3.5 T, the maximum cathodes voltage was – 60kV (120 kV/cm). The maximum extracted beam power was, up to now, 100 W; it is foreseen to extract up to 500 W. In this contribution we present the study, the tests and the design of a new water cooled electrostatic deflector. Particular effort was applied to optimise the beam extraction efficiency, the thermal dissipation, and the mechanical stability. In particularly we implemented new insulators, new anodised aluminium cathodes, new Ta septum, new voltage and water feedthroughs and a more efficient cooling system. All these improvements were performed to increase the mean time between failure and the beam current stability.

The TRASCO intense proton source (TRIPS) has been installed at INFN-LNS in May 2000 and is now operational. The paper describes the design of the source along with the first results obtained and the next developments. The source has been able to deliver more than 20 mA of protons from a 5 mm hole at 65 kV extraction voltage, largely above the minimum requested current density. The optimisation of the source is under way, with special care to the reliability and satisfactory results have been achieved.