Comparison of the charge state distributions of electron cyclotron resonance ion sources working in high B mode at different frequencies

The behavior of the two superconducting electron cyclotron resonance ion sources of Michigan State University-National Superconducting Cyclotron Laboratory and of INFN-Laboratori Nazionali del Sud, operating respectively at 6.4 and 14 GHz is compared in this note. The charge state distributions present a similar shape, when both the sources are optimized for the production of high charge state ions. The beam intensity is roughly proportional to the square of the frequency which may be explained by the difference in plasma density

Study of charge state enhancement by means of the coupling of a Laser Ion Source to the ECR ion source SERSE

The possibility to produce intense ion beams from solid elements, by using a pulsed Laser ion source as the first stage of the superconducting ECR ion source SERSE is discussed in the following. The Laser ion source may be used to produce negative or positive ions and electrons that are injected into the plasma of SERSE. The design of the experimental setup and the study of the extraction of ions from a target by means of Nd:Yag laser irradiation are briefly described. This Laser ion source will be located in the plasma chamber of the source SERSE, in presence of its magnetic field. A simple evaluation of the charge state enhancement inside the ECR plasma is also presented in the following

Introduction to RISC-KIT: Resilience-increasing strategies for coasts

Recent and historic low-frequency, high-impact events have demonstrated the flood risks faced by exposed coastal areas in Europe and beyond. These coastal zone risks are likely to increase in the future which requires a re-evaluation of coastal disaster risk reduction (DRR) strategies and a new mix of PMP (prevention, e.g., dike protection; mitigation, e.g., limiting construction in flood-prone areas and eco-system based solutions; and preparedness, e.g., Early Warning Systems, EWS) measures. In response to these challenges, the RISC-KIT project has delivered a set of open-source and openaccess methods, tools and management approaches to reduce risk and increase resilience to lowfrequency, high-impact hydro-meteorological events in the coastal zone (the “RISC-toolKIT”). These products enhance forecasting, prediction and early warning capabilities, improve the assessment of long-term coastal risk and optimise the mix of PMP-measures. In this paper an introduction is provided to the objectives, products, applications and lessonslearned of the RISC-KIT project, which are the subjects of this Special Issue. Subsequent papers provide details on the tools and their application on 10 case study sites in Europe

RISC-KIT: resilience-increasing strategies for coasts

High-impact storm events have demonstrated the vulnerability of coastal zones in Europe and beyond. These impacts are likely to increase due to predicted climate change and ongoing coastal development. In order to reduce impacts, disaster risk reduction (DRR) measures need to be taken, which prevent or mitigate the effects of storm events. To drive the DRR agenda, the UNISDR formulated the Sendai Framework for Action, and the EU has issued the Floods Directive. However, neither is specific about the methods to be used to develop actionable DRR measures in the coastal zone. Therefore, there is a need to develop methods, tools and approaches which make it possible to: identify and prioritize the coastal zones which are most at risk through a Coastal Risk Assessment Framework, and to evaluate the effectiveness of DRR options for these coastal areas, using an Early Warning/Decision Support System, which can be used both in the planning and event-phase. This paper gives an overview of the products and results obtained in the FP7-funded project RISC-KIT, which aims to develop and apply a set of tools with which highly-vulnerable coastal areas (so-called “hotspots”) can be identified

FIRST BEAM FROM THE TRASCO INTENSE PROTON SOURCE (TRIPS) AT INFN-LNS

Abstract The TRASCO intense proton source (TRIPS) has been installed at INFN-LNS THE SOURCE DESIGN The TRASCO Project is a R&D program which goal is the design of an Accelerator Driving System (ADS) for nuclear waste transmutation. The high current cw proton linear accelerator will drive a subcritical system to transmutate nuclear wastes. [1] The accelerator design is shared between different INFN laboratories and the LNS is in charge of the source design and construction. The proton source TRIPS is a high intensity microwave source, which goal is the injection of a minimum proton current of 35 mA in the following RFQ [2], with a rms normalized emittance lower than 0.2π⋅mm⋅mrad for an operating voltage of 80 kV. With respect to other sources for high intensity applications, some new features have been added, according to our experience with the high-intensity source SILHI • the microwave matching system has been improved; • a system to move the coils on-line has been realized; • the extraction system has been optimised with the aim to increase the source availability and reliability, in order to meet the requirement of a driver for an ADS system. The final design of TRIPS is shown in 2 The gaps, the voltage and the extraction holes have been designed in order to reduce the length of the extraction zone (where the beam is uncompensated) and to reduce the aperture-lens effect. Rms normalized emittance below 0.2π mm mrad (including the beam halo) have been calculated EXPERIMENTAL RESULTS CONCLUSION AND FUTURE DEVELOPMENTS In table 1 the status of the source is compared with the requirements of the TRASCO project. The requested reliability at 80 kV is not yet achieved, but the source performance are already good in terms of beam intensity, reproducibility and stability. The innovative solutions presented above have confirmed their validity. We are confident that in a few months a more significant reliability test at 80 3 kV (over two weeks) can be done. As this goal will be accomplished, the emittance measurements can be done with a similar emittance measuring device as the one described in ACKNOWLEDGEMENT

Application of Ferroelectric Cathodes to Enhance the Ion Yield in the Caesar Source at LNS

With increasing RF power the electron concentration in the plasma of ECR ion sources is decreasing in comparison to the ion concentration, so that the plasma is charging up positively. Direct injection of electrons into the ECR plasma can increase the electron charge density and the ion current yield. We have used ferroelectric cathodes to inject electrons into the Argon plasma of the CAESAR ion source at INFN-LNS (Catania, Italy). The cathode was placed at about 10 cm from the hot plasma and a bipolar high voltage pulse of 1.6 kV was used to trigger the electron emission. No additional acceleration has been provided. The use of the ferroelectric cathode leads to an increase of about 30% of the Ar8+ intensity, which has been monitored during the test. In addition, magneto-hydrodynamic instabilities in the ECR source were damped during and after electron injection

Installation of ECR2 at LNS and Preliminary tests

The source ECR2 has been built in 1998 by Pantechnik, according to the design suggested by LNS Ion Source Group. This design entails some improvements with respect to a standard CAPRICE-type source: a) the magnetic field (up to 1.6 T axial, 1.1 T radial) allows to operate the source at 14 GHz in High B mode and at 18 GHz; b) two frequency heating can be used; c) an aluminum made plasma chamber is used in place of the stainless steel one. The main features of ECR2 along with a review of the preliminary tests will be outlined. Typical currents for fully stripped nitrogen are about 25 emA; for the heaviest ions, 1 emA of Kr28+ and 10 emA of Ta27+ have been measured. The installation at LNS has been completed recently and the details will be given

Production of intense highly charged ion beams with SERSE

The source SERSE is operational at LNS since June 1998 and many improvements have been carried out in this period. The frequency has been increased from 14.5 GHz to 18 GHz and the use of two frequency heating has given positive results. Metallic ion production has been tested by means of a high temperature oven and the preliminary results are described. Tests of magnetic field scaling and frequency scaling have confirmed the results of previous tests with SC-ECRIS at lower frequency and seems to suggest that the upgrading of the source to higher frequency may be considered

Expansion of tungsten ions emitted from laser-produced plasma in axial magnetic and electric fields

The experimental results of the investigations on the influence of external magnetic and electric fields on the characteristics of a tungsten ion stream emitted from a plasma produced by the Nd:glass laser (1 J, 1 ns) performed at IPPLM, Warsaw are presented. A negatively biased target up to −15 kV and a magnetic field up to 0.45 T were used in the experiment. A set of ion collectors and an electrostatic cylindrical ion energy analyzer located at small angles with respect to the laser beam axis and at large distances from the target were applied for ion measurements. The effect of an external magnetic field is essential to plasma expansion, but the effect of the retarding potential of the target is very weak in our experimental conditions. The aim of the studies was to prove the possibility of the optimization of ion beam parameters from laser-produced plasma for the particular application as a laser ion source coupled with the electron cyclotron resonance ion source for particle accelerators