Description de trois espèces nouvelles de Chaetabraeus (s. str.) associées aux latrines du Daman des rochers en Afrique du Sud et notes sur l'écologie des espèces du genre (Coleoptera, Histeridae)

Chaetabraeus (s. str.) tuberculatus n. sp. et C. (s. str.) francoisi n. sp. sont deux espèces très particulières décrites d’Afrique du Sud. Ces deux espèces sont les seuls Chaetabraeus (s. str.) connus possèdant un tubercule à chaque angle antérieur de leur pronotum. Avec Chaetabraeus (s. str.) johnstoni n. sp., ce sont les premiers Histeridae signalés des latrines du Daman des rochers (Procavia capensis). Des données écologiques concernant les espèces du genre Chaetabraeus (s. str.) sont rassemblées

Contribution à l'étude des coléoptères de Guyane : tome 11

Des récoltes récentes et intensives en Guyane et au Suriname permettent de compléter les connaissances faunistiques sur les Histeridae. 225 espèces ou sous-espèces, distribuées en 7 sous-familles et 64 genres, sont signalées, dont 12 nouvelles pour ce département d'outre-mer. La présence de 11 espèces reste cependant à confirmer. 112 espèces sont citées du Suriname. Des trois localités ayant fourni le plus de matériel, Saül possède la plus forte diversité spécifique, avec 43 espèces en propre. Les taxons suivants sont décrits dans la sous-famille des Haeteriinae : Alleneterius dalensi n. gen. n. sp., Aristomorphoides guyanensis n. gen. n. sp., Convivister guyanensis n. sp., Enicosoma poirieri n. sp., Opadosister guyanensis n. sp., Troglosternus horridus n. sp. Un lectotype est désigné pour Enicosoma vespertinum Lewis, 1904, accompagné de sa redescription

Overview of JET results

Since the last IAEA conference, the scientific programme of JET has focused on the qualification of the integrated operating scenarios for ITER and on physics issues essential for the consolidation of design choices and the efficient exploitation of ITER. Particular attention has been given to the characterization of the edge plasma, pedestal energy and edge localized modes (ELMs), and their impact on plasma facing components (PFCs). Various ELM mitigation techniques have been assessed for all ITER operating scenarios using active methods such as resonant magnetic field perturbation, rapid variation of the radial field and pellet pacing. In particular, the amplitude and frequency of type I ELMs have been actively controlled over a wide parameter range (q95 = 3-4.8, βN ≥ 3.0) by adjusting the amplitude of the n = 1 external perturbation field induced by error field correction coils. The study of disruption induced heat loads on PFCs has taken advantage of a new wide-angle viewing infrared system and a fast bolometer to provide a detailed account of time, localization and form of the energy deposition. Specific ITER-relevant studies have used the unique JET capability of varying the toroidal field (TF) ripple from its normal low value δBT = 0.08% up to δBT = 1% to study the effect of TF ripple on high confinement-mode plasmas. The results suggest that δBT < 0.5% is required on ITER to maintain adequate confinement to allow QDT = 10 at full field. Physics issues of direct relevance to ITER include heat and toroidal momentum transport, with experiments using power modulation to decouple power input and torque to achieve first experimental evidence of inward momentum pinch in JET and determine the threshold for ion temperature gradient driven modes. Within the longer term JET programme in support of ITER, activities aiming at the modification of the JET first wall and divertor and the upgrade of the neutral beam and plasma control systems are being conducted. The procurement of all components will be completed by 2009 with the shutdown for the installation of the beryllium wall and tungsten divertor extending from summer 2009 to summer 2010

Study of fast-ion transport induced by fishbones on JET

The impact of fishbone oscillations onto a confined fast-ion population is simulated for a JET plasma and benchmarked against experiment quantitatively with the help of neutron rate measurements. The transient drops in volume integrated neutron emission are found to be mainly caused by the spatial redistribution of the (neutral beam injected) fast-ion population confined in the plasma rather than by fast-ion loss. The simulations yield a quadratic dependence of the neutron drop on the fishbone amplitude. It is found that the simulations are able to correctly reproduce the magnitude of the experimentally observed drop in volume integrated neutron emission to within a factor 2. Furthermore, frequency chirping is found to be important. Omitting the fishbone frequency chirp in the simulations reduces the magnitude of the neutron rate drop (and hence fast-ion redistribution) to about half its original value

Non-resonant magnetic braking on JET and TEXTOR

The non-resonant magnetic braking effect induced by a non-axisymmetric magnetic perturbation is investigated on JET and TEXTOR. The collisionality dependence of the torque induced by the n = 1, where n is the toroidal mode number, magnetic perturbation generated by the error field correction coils on JET is observed. The observed torque is located mainly in the plasma core (normalized radius