Precision measurement of the half-life and the decay branches of 62Ga

In an experiment performed at the Accelerator Laboratory of the University of Jyvaskyla, the beta-decay half-life of 62Ga has been studied with high precision using the IGISOL technique. A half-life of T1/2 = 116.09(17)ms was measured. Using beta-gamma coincidences, the gamma intensity of the 954keV transition and an upper limit of the beta-decay feeding of the 0+_2 state have been extracted. The present experimental results are compared to previous measurements and their impact on our understanding of the weak interaction is discussed.Comment: 7 pages, 7 figures, submitted to EPJ

Development of methods for the preparation of radiopure ⁸²Se sources for the SuperNEMO neutrinoless double-beta decay experiment

A radiochemical method for producing 82Se sources with an ultra-low level of contamination of natural radionuclides (40K, decay products of 232Th and 238U) has been developed based on cation-exchange chromatographic purification with reverse removal of impurities. It includes chromatographic separation (purification), reduction, conditioning (which includes decantation, centrifugation, washing, grinding, and drying), and 82Se foil production. The conditioning stage, during which highly dispersed elemental selenium is obtained by the reduction of purified selenious acid (H2SeO3) with sulfur dioxide (SO2) represents the crucial step in the preparation of radiopure 82Se samples. The natural selenium (600 g) was first produced in this procedure in order to refine the method. The technique developed was then used to produce 2.5 kg of radiopure enriched selenium (82Se). The produced 82Se samples were wrapped in polyethylene (12 μm thick) and radionuclides present in the sample were analyzed with the BiPo-3 detector. The radiopurity of the plastic materials (chromatographic column material and polypropylene chemical vessels), which were used at all stages, was determined by instrumental neutron activation analysis. The radiopurity of the 82Se foils was checked by measurements with the BiPo-3 spectrometer, which confirmed the high purity of the final product. The measured contamination level for 208Tl was 8-54 μBq/kg, and for 214Bi the detection limit of 600 μBq/kg has been reached.</p

Calorimeter development for the SuperNEMO double beta decay experiment

SuperNEMO is a double-β decay experiment, which will employ the successful tracker–calorimeter technique used in the recently completed NEMO-3 experiment. SuperNEMO will implement 100 kg of double-β decay isotope, reaching a sensitivity to the neutrinoless double-β decay (0νββ) half-life of the order of 1026 yr, corresponding to a Majorana neutrino mass of 50–100 meV. One of the main goals and challenges of the SuperNEMO detector development programme has been to reach a calorimeter energy resolution, ΔE∕E, around 3%∕E(MeV) σ, or 7%∕E(MeV) FWHM (full width at half maximum), using a calorimeter composed of large volume plastic scintillator blocks coupled to photomultiplier tubes. We describe the R&D programme and the final design of the SuperNEMO calorimeter that has met this challenging goal

DroneSCAT : Système actif hyper-fréquences porté par drone

International audienc

Système actif hyper-fréquences porté par drone

Dans le cadre d’activités cal-val pour des missions d’observation de la Terre et pour l’étude des zones désertiques (paléo-hydrologie), nous développons un système actif hyper-fréquences en bandes C (5-6 GHz) et P(1-2 GHz) porté par drone. L’objectif est de pouvoir acquérir rapidement des profils de rétrodiffusion, type géoradar mais calibrés en amplitude, pour caractériser la réponse hyper-fréquences de surfaces naturelles. Deux prototypes ont été développés, basés sur un VNA commercial compact et des antennes cornet, et embarqués sur des porteurs DJI (M200 pour la bande C et M600 pour la bande L). Nous présenterons les premiers résultats obtenus sur des sites naturels en Aquitaine, ainsi qu’une comparaison avec des données géo-radar

Système actif hyper-fréquences porté par drone

National audienceDans le cadre d’activités cal-val pour des missions d’observation de la Terre et pour l’étude des zones désertiques (paléo-hydrologie), nous développons un système actif hyper-fréquences en bandes C (5-6 GHz) et P(1-2 GHz) porté par drone. L’objectif est de pouvoir acquérir rapidement des profils de rétrodiffusion, type géoradar mais calibrés en amplitude, pour caractériser la réponse hyper-fréquences de surfaces naturelles. Deux prototypes ont été développés, basés sur un VNA commercial compact et des antennes cornet, et embarqués sur des porteurs DJI (M200 pour la bande C et M600 pour la bande L). Nous présenterons les premiers résultats obtenus sur des sites naturels en Aquitaine, ainsi qu’une comparaison avec des données géo-radar

Technical description of the CENBG nanobeam line

Commune avec INSTRU et MECA (CENBG)International audienceTwo years ago, the CENBG has commissioned the AIFIRA (Application Interdisciplinaire des Faisceaux d'Ions en Aquitaine) facility for the development of an interdisciplinary research program based on a 3.5 MV SingletronTM accelerator (HVEE, The Netherlands). In addition to the existing beam lines, this facility is being equipped with a high demagnification focused beam line allowing the focusing of protons, deuterons and alpha particles down to a sub-micrometer resolution. This so-called ‘‘nanobeam line”, based on a long working distance doublet–triplet of Oxford Microbeams Ltd., OM-50TM quadrupoles, is at its final stage of development. The chosen layout of the beam line has been computed in details using the GEANT4 simulation toolkit. In the simulations, experimental measurements of the beam emittance at the entrance slits have been used to obtain more realistic beam distributions and intensities along the full beam line. According to these simulations, a beam resolution of about 300 nm in high current mode and below 100 nm in STIM mode is expected. The components of the beam line have been mounted at the 0 output of the SingletronTM switching magnet and the fine alignment will be performed using the ion beam in the coming weeks. In the present paper, all the major components of the CENBG nanobeam line are described in details

SPIRAL2/DESIR high resolution mass separator

DESIR is the low-energy part of the SPIRAL2 ISOL facility under construction at GANIL. DESIR includes a high-resolution mass separator (HRS) with a designed resolving power m=Dm of 31,000 for a 1 p-mmmrad beam emittance, obtained using a high-intensity beam cooling device. The proposed design consists of two 90-degree magnetic dipoles, complemented by electrostatic quadrupoles, sextupoles, and a multipole, arranged in a symmetric configuration to minimize aberrations. A detailed description of the design and results of extensive simulations are given