Bunch Extension Monitor for LINAC of SPIRAL2 facility

WEPC20International audienceMeasurements of the bunch longitudinal shape of beam particles are crucial for optimization and control of the LINAC beam parameters and maximization of its integrated luminosity. The non-interceptive bunch extension monitor for LINAC of SPIRAL2 facility is being developed at GANIL. The five bunch extension monitors are to be installed on the entrance of LINAC between superconducting cavities. The principle of monitor operation is based on registration of x-rays induced by ions of accelerator beam and emitted from thin tungsten wire. The monitor consists of two parts: system for wire insertion and positioning and x-ray detector based on microchannel plates. The prototype of detector has been developed and was tested using protons and heavy ions beams

Comprendre les protocoles d\u27échange à travers deux exemples : Z39-50 et OAI-PMH

Cette fiche pratique présente les protocoles d\u27échange de données Z39-50 et OAI-PMH. Elle aborde leurs avantages, usages et limites respectifs

Beam profile and beam time structure monitors for the extracted beams from the GANIL cyclotrons

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A new low intensity beam profiler for SPIRAL2

WEPF14International audienceIn the framework of SPIRAL 2 ion beams, several beam profile monitors are presently being developed at GANIL. One of them is a low-intensity beam-profile monitor that works as a secondary electron detector. This Emission-Foil Monitor (EFM) will be used in the radioactive beam lines of SPIRAL2 and in the experimental rooms of this new facility. The ions produce secondary electrons when they are stopped in an aluminium emissive foil. The electrons are then accelerated using an electric field and guided using a magnetic field to a double-stage microchannel plate (MCP). A 2D pixellated pad plane placed below the MCP is used to collect the signals. The magnetic field created by permanent magnets in a closed magnetic circuit configuration permits the beam-profile reconstruction to be achieved with a good resolution. The EFM can visualize beam-profile intensities between only a few pps to as much as 109 pps and with energies as low as several keV. This profiler has been under development since 2009 and is currently manufactured. Recent results of this monitor are presented in this article

Injector Diagnostics Overview of SPIRAL2 Accelerator

International audienceThe SPIRAL2 project is based on a multi-beam driver in order to allow both ISOL and low-energy in-flight techniques to produce Radioactive Ion beams (RIB). A superconducting light/heavy-ion linac capable of accelerating 5 mA deuterons up to 40 MeV and 1 mA ions up to 14.5 MeV/u is used to bombard both thick and thin targets. These beams could be used for the production of intense RIB by several reaction mechanisms (fusion, fission, transfer, etc.). The post acceleration of RIB in the SPIRAL2 project is assured by the existing CIME cyclotron. SPIRAL2 beams, both before and after acceleration, can be used in the present experimental area of GANIL. The construction phase of SPIRAL2 is being started since the 1st of July 2005. An injector design overview is presented with diagnostics used to tune and qualify beams

SPIRAL 2 injector diagnostics

International audienceThe future SPIRAL2 facility will be composed of a multi-beam driver accelerator (5 mA/40 MeV deuterons, 5 mA /14.5 MeV/u heavy ions) and a dedicated building for the production of radioactive ion beams (RIBs). RIBs will be accelerated by the existing cyclotron CIME for the post acceleration and sent to GANIL's experimental areas. The injector constituted by an ion source a deuteron/proton source a L.E.B.T. and a M.E.B.T. lines and a room temperature R.F.Q. will produces, transports and accelerates beams up to an energy of 0.75 MeV/u. An Intermediate Test Bench (B.T.I.) is being built to commission the SPIRAL2 injector through the first rebuncher of the M.E.B.T. line in a first step and the last rebuncher in a second step. The B.T.I. is designed to perform a wide variety of measurements and functions and to go more deeply in the understanding of the behaviour of diagnostics under high average intensity beam operations. A superconducting LINAC equipped with two types of cavity will allow reaching 20 MeV/u for deuterons beam. This paper describes injector diagnostic developments and gives information about the current status

Kinship Structure and Political Authority: The Middle East and Central Asia

This is an offprint version of the article published in Comparative Studies in Society and History 28:334-55, made available by permission of the publisher. The version made available in Digital Common was supplied by the author.Publisher's Versiontru

Altération de la physiologie des poissons exposés à des hydrocarbures aromatiques polycycliques (HAP) : comportement et reproduction

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants (POPs) which are found in complex mixtures in the environment including aquatic ecosystems. They adsorb on particles, accumulate in sediment and in the first link of the food web. The aim of this study was to measure long term effects of PAHs contamination on a vertebrate model : the zebrafish. In a first study, embryos were exposed on natural sediment spiked with 3 individual PAH (phenanthrene, pyrene and benzo[a]pyrene) during the first four days of their development. In a second study, to evaluate the consequences of long-term chronic exposure to PAHs, zebrafish were exposed, from their first meal (5 days post fertilisation) until they became reproducing adults, to diets spiked with three PAHs fractions at environmentally relevant concentrations (0.3X, 1X and 3X; with the 1X concentration being in the range of 4.6-6.7 μg.g-1 for total quantified PAHs). The fractions used were representative of PAHs of pyrolytic (PY) origin or of two different oils of differing compositions (a heavy fuel (HO) and a light crude oil (LO)). Long term effects on growth, survival, reproduction and behavior were evaluated at different ages. Effects were observed at molecule, tissue, organ and individual scales. In general, for contaminated fish, growth was reduced, larval survival decreased in HO, and reproduction was strongly impaired at hormonal, tissue and phenotypic levels, and behavioral responses were lethargic or hyperactive depending on fractions and stages. Sediment exposure still revealed visible effects when fish were 6 month old. These results hereby showed significant late effects, especially in behavioral responses after an early exposure, including in larvae issued from contaminated fish. In spiked diets contaminated fish, we observed a gradation of effects. Combining all functions, we established of hierarchy in toxicity in the studied fractions: PY < LO ≈ HO. Finally, our results gathered at a multiscale from molecule, to tissue and individuals, indicate that PAH mixtures of different compositions, representative of situations encountered in the wild, can promote lethal and sublethal effects which are likely to be detrimental for fish survival and recruitment into future generations.Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants organiques persistants qui sont présents en mélange complexe dans l’environnement et notamment dans les milieux aquatiques. Ils s’adsorbent sur les particules en suspension, s’accumulent dans les sédiments et dans les premiers maillons de la chaîne trophique. L’objectif de cette étude était de mesurer les effets à long terme d’une contamination par des HAP chez un modèle de vertébrés : le poisson zèbre. Dans un premier temps, des embryons ont été exposés pendant les 4 premiers jours de leur développement sur du sédiment naturel enrobé de 3 HAP individuel (phénanthrène, pyrène et benzo[a]pyrène) puis transférés et élevés en eau propre. Dans un deuxième temps, des poissons ont été exposés par voie alimentaire tout au long du cycle de vie et dès le premier repas à 3 fractions de HAP à doses environnementales enrobées sur les aliments : une fraction pyrolytique (PY) extraite d’un sédiment échantillonné dans la Seine et deux fractions pétrogéniques (un fuel lourd (HO) provenant de l’Erika et un pétrole brut type Arabian light (LO)). Les effets à long terme sur la croissance, la survie, la reproduction et le comportement ont été évalués à différents âges. Ces effets ont pu être observés à plusieurs échelles, i.e. de la molécule, aux tissus et organes puis à l’échelle de l’individu. Globalement, chez les poissons contaminés, la croissance est ralentie, la survie larvaire diminuée chez les HO, la fonction reproduction est altérée fortement à la fois au niveau hormonal, tissulaire et phénotypique ainsi que les réponses comportementales léthargiques ou hyper-réactives selon les cas. L’exposition par voie sédimentaire a révélé des effets visibles lorsque les individus atteignaient 6 mois soulignant l’existence d’effets tardifs, notamment sur les réponses comportementales, d’une exposition très précoce y compris chez la descendance. Quant à l’exposition par voie alimentaire, elle a montré une gradation des effets. Toutes fonctions confondues, les résultats obtenus permettent d'établir une hiérarchie dans la toxicité des fractions étudiées : PY < LO ≈ HO. L'approche multi-échelle utilisée dans ce travail a permis, en partant d'informations acquises au niveau moléculaire, tissulaire et individuel, d'aboutir à une compréhension intégrée des conséquences qu'une exposition à des HAP peut avoir sur l'aptitude à la survie des poissons dans leur milieu naturel ainsi qu'à leur capacité à participer au renouvellement des générations futures