New exotic beams from the SPIRAL 1 upgrade

Abstract

Since 2001, the SPIRAL 1 facility has been one of the pioneering facilities in ISOL techniques for reaccelerating radioactive ion beams: the fragmentation of the heavy ion beams of GANIL on graphite targets and subsequent ionization in the Nanogan ECR ion source has permitted to deliver beams of gaseous elements (He, N, O, F, Ne, Ar, Kr) to numerous experiments. Thanks to the CIME cyclotron, energies up to 20 AMeV could be obtained. In 2014, the facility was stopped to undertake a major upgrade, with the aim to extend the production capabilities of SPIRAL 1 to a number of new elements. This upgrade, which is presently under commissioning, consists in the integration of an ECR booster in the SPIRAL 1 beam line to charge breed the beam of different 1+ sources. A FEBIAD source (the so-called VADIS from ISOLDE) was chosen to be the future workhorse for producing many metallic ion beams. This source was coupled to the SPIRAL 1 graphite targets and tested on-line with different beams at GANIL. The charge breeder is an upgraded version of the Phoenix booster which was previously tested in ISOLDE. It was lately commissioned at LPSC and more recently in the SPIRAL 1 beam lines with stable beams. The upgrade additionally permits the use of other target material than graphite. In particular, the use of fragmentation targets will permit to produce higher intensities than from projectile fragmentation, and thin targets of high Z will be used for producing beams by fusion-evaporation. The performances of the aforementioned ingredients of the upgrade (targets, 1+ source and charge breeder) have been and are still being optimized in the frame of different European projects (EMILIE, ENSAR and ENSAR2). The upgraded SPIRAL 1 facility will provide soon its first new beams for physics and further beam development are undertaken to prepare for the next AGATA campaign. The results obtained during the on-line commissioning period permit to evaluate intensities for new beams from the upgraded facility.

The General Purpose Ion Buncher: A radiofrequency quadrupole cooler-buncher for DESIR at SPIRAL2

“…the GPIB, the effect on the emittance is small when the number of ions is increased (a few %) as can also be seen in table 3. It can nonetheless be seen for the simulations with 10 4 particles as the uncertainty is then only 0.4%.…”

“…As pictured in Fig. 1, the DESIR hall [1,2] will receive beams from the upgraded SPIRAL1 [3] installation, from the low-energy branch of the new Super Separator Spectrometer (S 3 ) [4] also part of SPIRAL2 and from a production building that could be constructed on a longer timescale. All these beams are ISOL-like, being extracted either from a target-ion source system or from a gas catcher.…”

Anomalous Ionization Regime in a Forced Electron Beam Induced Arc Discharge Ion Source for Singly Charged Radioactive Ion Beam Production

“…The principle figure of merit for radioactive ion sources is the ionization efficiency and while the ISAC-FEBIAD (Fig. 1) shows offline 40 Ar + efficiencies <1 %, values from 10 % to 25 % [7,8] are within reach. With the goal of addressing this, a combined numerical and experimental campaign has been undertaken to identify the underlying processes that improve the FEBIAD's performance.…”

Extraction of diffusion coefficients from the study of Rb release in different carbon catchers

“…Graphite sheet of 200 µm was initially considered as a good candidate for the catcher for technical reasons of resistivity, heat resistance, ease of use, which facilitate the R&D of the TISS, and also for physico-chemical reasons related to its porosity and to the short sticking time of Rb on graphite [5] at the working temperature required for the TISS (~1400°C). Despite mechanical features less adapted to its use in the TULIP TISS design, rigid graphite of 1 µm grains used to design graphite targets of the current FEBIAD and Nanogan TISS at GANIL [6] was also selected for comparison. Two types of carbon nanotubes were also considered owing to their microstructure, i.e.…”