Transport and cooling of singly-charged noble gas ion beams

The transport and cooling of noble gas singly-charged ion beams by means of a Radio Frequency Quadrupole Cooler Buncher (RFQCB) have been studied at the LIMBE low energy beam line of the GANIL facility. Ions as light as $^{4}He^+$ have been cooled and stored before their extraction in bunches using $H_2$ as buffer gas. Bunches characteristics have been studied as a function of the parameters of the device. Sizeable transmissions of up to 10 $$ have been obtained. A detailed study of the lifetime of ions inside the buncher has been performed giving an estimate of the charge exchange cross-section. Results of a microscopic Monte-Carlo transport code show reasonable agreement with experimental data.Comment: 13 figure

Direct 1+ →\rightarrow N+ conversion of stable alkali ions using an electron cyclotron resonance ion source

International audienceThe production of radioactive ions using the Isotope Separation On-Line method gives rise, in most cases, to singly charged ions. In order to perform experiments with postaccelerated radioactive ion beams, these ions have to be multicharged. We describe here a new compact design for a charge breeder that will be coupled to the production target of SPIRAL1 at GANIL. We present recent results obtained offline with stable alkali ions Na, K, Rb, and Cs on the SIRa test bench. Particularly, 1+ to N+ conversion efficiencies and conversion times are presented. Several points have been identified for the improvements of the present performances

NanoNaKe : production of alkali ion beams for SPIRAL1/GANIL

International audienceThe SPIRAL1 facility is delivering radioactive ion beams at GANIL since 2001. However, the present operation is limited to gaseous elements (noble gases, oxygen, nitrogen...). The aim of the NanoNaKe project is to enlarge the available radioactive beams to alkali elements (especially Na and K) by using a new Target-Ion Source system for SPIRAL1. In this setup, a 1+ surface ionization ion source is directly coupled to the present Nanogan3 ECRIS which is used as a charge breeder. The advantage of such a compact geometry is that only minor modifications of the SPIRAL1 production cave are needed. The first part of the system (target-surface ionization ion source: MonoNaKe) has already been tested and validated online in 2007 for the production of different isotopes of Li+, Na+ and K+ [1]. Furthermore, a first demonstration of the principle of coupling Mononake to Nanogan3 was experimentally obtained with 47K5+ ions [2]. In order to increase the performances of Nanonake, the charge breeding of 1+ ions into the ECRIS has been successfully tested off-line using different stable alkali ions (Na+, K+, Rb+ and Cs+) on the SIRA test-bench. Significantly improved charge breeding efficiencies have been measured and some limitations in the performances of the present device have also been identified. An upgraded version of the setup will be tested on-line on SIRA in May 2009 for the production of multicharged radioactive alkali ions. Depending on the results of this experiment, a Target-Ion Source using Nanonake could possibly be installed on SPIRAL1 before 2012 for a physics experiment. A complete description of the setup as well as off-line and on-line results will be presented

Development of a surface ionization source for the SPIRAL 2 project

International audienceDevelopment of new radioactive beams, and thus of new target ion sources TISs for isotope-separator-on-line production systems are in progress at GANIL for the SPIRAL 2 project. The efficiency and time response measurements of each step in the production process are crucial to predict and maximize the available yields, in particular, for short lived isotopes. This paper presents a method for measuring these quantities that makes use of a stable alkali chopped beam of controlled intensity. This method was applied to surface ionization source test for high efficiency. Results of recent experiments are presented that include ionization efficiency measurements for Cs, Rb, K, Na, and Li with a graphite and rhenium ionizer and dwell time of these alkalis on graphite. The results enabled to design a first surface ionization source prototype which will be installed in the SPIRAL 2 TIS

Characterization of the Surface Ionization Source dedicated to radioactive alkali ion production in the frame of the SPIRAL 2 project

International audienceDevelopments of new radioactive beams and thus of new target-ion-sources (TIS) for isotopeseparator- on-line (ISOL) production systems are in progress at GANIL for the SPIRAL 2 project. Measurements of the time response and of the efficiency of each step of the production process are crucial to predict the available yields, in particular for short lived isotopes. This paper presents a method that uses a chopped beam of stable alkali of controlled intensity. This method was applied on SISTHE (Source à Ionisation de Surface de Test à Haute Efficacité). During the tests, the ionization efficiency is extracted from the ratio between the flux emerging from the TIS and the flux implanted in the TIS. Time responses are obtained using the ion gun in pulsed mode. Results of recent experiments are presented that include: ionization efficiency measurements for Cs, Rb, K, Na and Li in a graphite and rhenium ionizer, sticking time of these alkalis on graphite and the time response of the ionizer tube. The results enabled to design a first SIS prototype which will be installed in the SPIRAL 2 TIS. It is expected to be ready for testing by the end of October 09

MULTIGAN®: A new multicharged ion source based on axisymetric magnetic structure

Original publication available at http://www.jacow.orgInternational audienceThe regular ECR ion sources, allowing the production of multicharged ions, have openings only at their two ends. Based on the MONO1000 ECRIS [1] concept and experience, a new multicharged ECR ion source has been designed with a large opened space in the middle of the source enabling a direct contact with the ECR plasma. This source will combine the advantages of the axisymetric magnetic structures made only of permanent magnets with a high operating frequency. The magnetic structure calculations as the mechanical design and stress will be described in details. An estimation of the electronic energy distribution has been calculated using the TrapCad code [2] and thus the performances of the source have been deduced. A rough calculation of the beam extraction and formation has also been calculated taking into account of the several fields (magnetic and electric) surrounding the extraction system. The ion source presented in this paper is a prototype which shall validate the magnetic concept and which shall confirm the expected performances. The next step will be the design of an optimized ECRIS according to its future applications

Latest developments at GANIL for stable and radioactive ion beam production

International audienceIn the frame of the SPIRAL II Système de Production d'Ions Radioactifs Accélérés en Ligne Partie II project, several developments of stable and radioactive ion production systems have been started up. In parallel, GANIL has the ambition to preserve the existing stable and radioactive beams and also to increase its range by offering new ones. In order to identify the best directions for this development, a new group called GANISOL has been formed. Its preliminary conclusions and the latest developments at GANIL are presented

Caracterisation en bande large du canal radio-mobile en milieu urbain

CNRS RP 256 (20) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

GISELE: A resonant ionization laser ion source for the production of radioactive ions at GANIL

International audienceSPIRAL2 is the new project under construction at GANIL to produce radioactive ion beams and in particular neutron rich ion beams. For the past 10 yr SPIRAL1 at GANIL has been delivering accelerated radioactive ion beams of gases. Both facilities now need to extend the range of radioactive ion beams produced to condensable elements. For that purpose, a resonant ionization laser ion source, funded by the French Research National Agency, is under development at GANIL, in collaboration with IPN Orsay, University of Mainz Germany and TRIUMF, Vancouver Canada . A description of this project called GISELE GANIL Ion Source using Electron Laser Excitation is presented

Development of a surface ionization source for the production of radioactive alkali ions in SPIRAL

International audienceIn the framework of the production of radioactive alkali ion beams by the isotope separator on-line (ISOL) method in SPIRAL, a surface ionization source has been developed at GANIL to produce singly-charged ions of Li, Na and K. This new source has been designed to work in the hostile environment found at SPIRAL whilst having a long lifetime. This new system of production has two ohmic heating components: the first for the target oven and the second for the ionizer. The latter, being in carbon, offers high reliability and competitive ionisation efficiency. This new surface ionization source has been tested on line using a 48Ca primary beam at 60,3A MeV with an intensity of 0,14 pµA. The ionization efficiencies obtained for Li, Na and K are significantly better than the theoretical values calculated using the known Langmuir surface ionisation equation. Moreover, the design of the ion source avoids the cavity effects reported by Kirchner. The enhanced efficiency can be understood by considering a particular effect related to the polarization of the ionizer. This feature is shown to be extremely important also for short-lived isotopes. In the future, this source will be associated with the multicharged electron-cyclotron-resonance (ECR) ion source NANOGAN III for production of multicharged alkali ions in SPIRAL. The preliminary tests of the setup for the production of multicharged alkali ions will also be presented in this contribution