Two-dimensional/three-dimensional simulations for the optimization of an-electron-beam-generated-plasma-based-type ion source

International audienceTo fulfill the need of a plasma ion source for SPIRAL-2 and EURISOL, capable of producing radioactive ion beams under strong radiation, the first prototype of the IRENA (Ionization by Radial Electrons Neat Adaptation) ion source has been designed. For designing an optimized prototype based on the first one, the influence of the geometrical parameters on the electron trajectories is investigated by means of two-dimensional/three-dimensional (3D) simulations. Due to the strong space charge effect in this kind of ion source, 3D simulations help particularly to better estimate effects on ion confinement and extraction. Simulation constructions will be presented and results discusse

Status of ionization by radial electron neat adaptation ion source research and development for SPIRAL2 and EURISOL-DS

International audienceTo take up the challenging issue of supplying a plasma ion source able to produce radioactive beams under extreme SPIRAL2 and EURISOL irradiation conditions, a research and development program has been initiated to work out ionization by radial electron neat adaptation (IRENA) ion source. Based on the electron beam generated plasma concept, the ion source is specifically adapted for thick target exploitation under intense irradiation. A validation prototype has been designed, constructed, and tested. First results obtained will be presented and commented. IRENA potential will be discussed, particularly in the framework of multimegawatt EURISOL

Investigation on Ion Source Parameters

The EURISOL multi-mega-watt target station requires dedicated radioactive ion sources. Notably, they must be capable of operating under extremely hard radiations and with a larger fission target producing over 1014 fissions/s. The realisation of next-generation ion sources suitable for such operating conditions needs exhaustive studies and developments. In order to take up such a challenge, a review on radioactive ion sources was achieved and the investigation on ion source parameters was in particular focused on a plasma ion source through a R&D program

Contribution to ion source developments for SPIRAL-2 and EURISOL

International audienceNext generation facilities such as those designed in SPIRAL-2 and EURISOL projects require dedicated radioactive ion sources. Indeed, the ion source must be capable of operating under the very strong radiation generated by the primary beam in the production target. In the framework of the SPIRAL-2 design study, realistic and efficient solutions have been studied to face these unprecedented irradiation constraints. The considered options will be described and argued. In particular, considering forced electron beam induced are discharge-type ion sources, the reasons to start the development of a new prototype, the ionization by radial electron neat adaptation (IRENA) ion source, will be presented. The IRENA ion source is based on the electron beam generated plasma ion source. The design of the first prototype will be presented and discussed

ICIS05 CONFERENCE

Contribution to Ion Source Developments for SPIRAL-2 and EURISO

An off-line method to characterize the fission product release from uranium carbide-target prototypes developed for SPIRAL2 project

International audienceIn the context of radioactive ion beams, fission targets, often based on uranium compounds, have been used for more than 50 years at isotope separator on line facilities. The development of several projects of second generation facilities aiming at intensities two or three orders of magnitude higher than today puts an emphasis on the properties of the uranium fission targets. A study, driven by Institut de Physique Nucléaire d'Orsay (IPNO), has been started within the SPIRAL2 project to try and fully understand the behavior of these targets. In this paper, we have focused on five uranium carbide based targets. We present an off-line method to characterize their fission product release and the results are examined in conjunction with physical characteristics of each material such as the microstructure, the porosity and the chemical composition

RIB production by photofission in the framework of the ALTO project: first experimental measurements and Monte-Carlo simulations

à paraîtreInternational audienceThe ALTO facility (Accélérateur Linéaire auprès du Tandem d’Orsay) has been built and is now under commissioning. The facility is intended for the production of low energy neutron-rich ion-beams by ISOL technique. This will open new perspectives in the study of nuclei very far from the valley of stability. Neutron-rich nuclei are produced by photofission in a thick uranium carbide target (UCx) using a 10 μA, 50 MeV electron beam. The target is the same as that already had been used on the previous deuteron based fission ISOL setup (PARRNE [F. Clapier et al., Phys. Rev. ST-AB (1998) 013501.]). The intended nominal fission rate is about 1011 fissions/s. We have studied the adequacy of a thick carbide uranium target to produce neutron-rich nuclei by photofission by means of Monte-Carlo simulations. We present the production rates in the target and after extraction and mass separation steps. The results from Monte-Carlo simulations are compared to experimental data either with the ALTO facility (in the first step of commissioning, i.e. 100 nA of the electron beam current intensity), or with fast-neutron-induced fission generated from a 26 MeV deuteron beam. The results obtained support the suitability of FLUKA simulation code used to describe all the photofission process with an electron beam energy of 50 MeV. (Elsevier

Ucxc_x target developments for the ALTO and the SPIRAL 2 projects

The ALTO project (Accélérateur Linéaire auprès du Tandem d'Orsay) will provide an electron beam available at IPN Orsay at the end of 2005. The maximum energy will be 50 MeV with a maximum average intensity of 10 $\mu$A. It will be used for photofission in U$C_x$ targets. With the same target as that already used on the PARRNE set up it will be possible using ALTO to induce up to $10^11$ fissions/s instead of $10^9$ previously obtained with the 26 MeV/1 $\mu$A deuteron beam. Several ion sources will be adapted on the set up: ISOLDE FEBIAD type, surface ionization, laser,.... Moreover the electron beam could be used for other applications. Calculation about fission, energy deposition and dose rate will be presented, as well as the target-ion source adaptation on the PARRNE facility. For the SPIRAL 2 project planned at GANIL for 2008, the fission of $^{238}$U in uranium carbide target will be induced by a neutron flow created by bombarding a carbon converter with a 40 MeV high intensity deuteron beam. The target has been designed to reach more than $10^13$ fissions/s with a good release time. Calculation and technical considerations used to optimize the target design are detailed. One of main difficulties for this target is to maintain it at high temperature (more than 2000 °C) during 3 months. A tantalum oven has been studied and a prototype is under test at IPN Orsay. Some R&D studies on a high density target are in progress in collaboration with PNPI Gatchina and INFN Legnaro

Production of Mass-Separated Fission Fragment Beams at ALTO

International audienceYields of neutron-rich isotopes produced by the photofission were measured at the ISOL ALTO facility. The identification was achieved by a combined measurement of beta and gamma-rays. Production rates for Xe, Kr, Sn, In and I isotopes are presented here. In parallel, empirical estimations for the yields based on the PARRNe experimental data and the results provided by a very recent FLUKA simulation are presented