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Over the last few years, the accelerator community requested the development of improved negative hydrogen ion sources. For spallation sources, like SNS or ESS, pulsed high intensity H− ion beams of a few tens of milliamperes, with a duty cycle close to 10%, are required. New facilities like CERN also ask for high performance negative ion beams. Since CEA undertook an electron cyclotron resonance (ECR)-based ion source programme, a European network devoted to high performance negative ion source development has been created.In this group, several laboratories developing 2.45 GHz ECR sources follow different approaches to increase the extracted ion current. At Saclay, with a solenoidal magnetic structure based on coils, close to 3 mA H− ion beam is now extracted in pulsed mode (2 ms/100 ms). A metallic biased grid separates the plasma bulk from the H− ion production zone and significantly improves the H− extracted current. At Ecole Polytechnique, the source Camembert III operates in continuous wave and pulsed modes. Photodetachment measurements in continuous wave mode show considerable H− ion density (109–1010 cm−3), whether the primary electrons are provided by filaments or small ECR modules inserted into the plasma chamber. Similarities and differences between the ECR-driven and the filamented source are discussed. Representative experimental results from the sources of the two laboratories as well as future plans are reported here.

Based on the experience of the SILHI electron cyclotron resonance (ECR) ion source for the IPHI accelerator, which produces routinely 100-120 mA H(+) beam, the CEA-Saclay is in charge of the design and realization of the 140 mA cw deuteron source for the IFMIF project (International Fusion Materials Irradiation Facility). IFMIF is an accelerator-based neutron irradiation facility consisting of two accelerators of 125 mA D(+) beam at 40 MeV that hit in parallel a lithium target. IFMIF utilizes the deuteron-lithium (d-Li) neutron, producing a reaction to simulate the 14 MeV neutron environment in deuterium-tritium (D-T) fusion reactors. In the framework of the IFMIF EVEDA phase (Engineering Validation and Engineering Design Activities), we are studying a cw ECR ion source with a new extraction system to allow high current extraction while keeping a low divergence as well as a small emittance. Starting from SILHI five-electrode system with H(+) ions, the extracted beam characteristics as well as electric field conditions are compared with the cases of four- and three-electrode extraction systems. Experimental results made on the SILHI source with H(+) ions are briefly discussed. Extensive experimental results on the new source test bench BETSI are expected as soon as the design and fabrication of a dedicated extraction system with a new set of electrodes will be finished.

The high-intensity light ion source (SILHI) is designed to be a prototype source for high power linear accelerators. The goal is to produce a 100 mA proton or a 140 mA deuteron ion beams at 95 keV with rms normalized emittance lower than 0.2 π mm mrad. A 108 mA total beam (J=215 mA/cm2) was extracted in April 1997 (85% H+, 12% H2+, and 3% H3+ fractions) with two electron cyclotron resonance (ECR) zones located at both plasma chamber extremities simultaneously. First beam measurements indicate a 0.17 π mm mrad rms normalized emittance for a 80 mA proton beam at 80 keV. In these conditions, a 96% availability was obtained during an 8 h working day. An intermediate electrode is placed in the accelerator gap to minimize emittance distortions as shown by simulations. Beam analysis were made as a function of the intermediate electrode voltage, the gas flow, the magnetic field, and the 2.45 GHz rf power. First rf plasma coupling observations indicated that the magnetron was too highly coupled with the load (plasma chamber). By adding a second circulator and locking the oscillator with an external signal, this dependence was decreased. Measurements then clearly show that the output spectrum is completely independent of the load phasing. All these results will be presented.

At CEA‐Saclay, in 2003, the new 2.45 GHz ECR source, based on pure volume H− ion production, showed a dramatic increase of the H− extracted ion beam. In fact, since the rectangular plasma chamber is separated in two different parts by a stainless steel grid, the extracted H− current rose from few μA to 1.5 mA. Of course the grid position and its potential with respect to the plasma chamber were optimised. Ceramic plates allow increasing the electron density and lead to an improvement of the negative ion production. Plasma characterization by using Langmuir probes and positive charge analysis are also presented. The last results are reported and discussed. This work is part of the High Performance Negative Ion Sources (HPNIS) program and supported by the European Union under contract HPRI‐CT‐2001‐50021.

The high intensity light ion source (SILHI) is the electron cyclotron resonance (ECR) source constructed and tested at CEA-Saclay. The first aim is to produce up to 100 mA cw proton beams at 95 keV for the proton injection high intensity (IPHI) beams [5 MeV radio frequency quadrupole (RFQ) and 10 MeV drift tube linac (DTL)]. This prototype is developed by a CEA–CNRS-IN2P3 collaboration for applications such as accelerator driven systems for nuclear waste transmutation, production of radioactive ion beams or secondary particles. SILHI is also used to study the production of deuteron and H− beams for the International Fusion Material Irradiation Facility and European spallation source projects, respectively. The present status of SILHI and the experiments planned for the near future in both cw and pulsed modes are presented in this article. 80 mA cw proton beams are now currently produced at 95 keV with a high availability (∼1 spark/day). The proton fraction is around 90% and the typical r–r′ rms normalized...