6,311 research outputs found
Direction for the Future - Successive Acceleration of Positive and Negative Ions Applied to Space Propulsion
Electrical space thrusters show important advantages for applications in
outer space compared to chemical thrusters, as they allow a longer mission
lifetime with lower weight and propellant consumption. Mature technologies on
the market today accelerate positive ions to generate thrust. The ion beam is
neutralized by electrons downstream, and this need for an additional
neutralization system has some drawbacks related to stability, lifetime and
total weight and power consumption. Many new concepts, to get rid of the
neutralizer, have been proposed, and the PEGASES ion-ion thruster is one of
them. This new thruster concept aims at accelerating both positive and negative
ions to generate thrust, such that additional neutralization is redundant. This
chapter gives an overview of the concept of electric propulsion and the state
of the development of this new ion-ion thruster.Comment: 10 pages, contribution to the CAS-CERN Accelerator School: Ion
Sources, Senec, Slovakia, 29 May - 8 June 2012, edited by R. Bailey. appears
in CERN Yellow Report CERN-2013-007, pp.575-58
Status Report on GANIL
International audienceThe performance of GANIL are in constant progress and some special equipments are now installed which give a great operation flexibility. Moreover we now routinely accelerate ions from an external ECR source. We first report on these two aspects. Then we will shortly describe two of our main experimental equipments namely the 'SPEG' spectrometer and the ''LISE'' beam line both used in particular for exotic beam production and analysis. We will conclude, mentionning the funded GANIL improvements :'2.5' transformation and ''SME'' beam line
The Baum-Connes Conjecture via Localisation of Categories
We redefine the Baum-Connes assembly map using simplicial approximation in
the equivariant Kasparov category. This new interpretation is ideal for
studying functorial properties and gives analogues of the assembly maps for all
equivariant homology theories, not just for the K-theory of the crossed
product. We extend many of the known techniques for proving the Baum-Connes
conjecture to this more general setting
Collisionless heating in capacitive discharges enhanced by dual-frequency excitation
We discuss collisionless electron heating in capacitive discharges excited by a combination of two disparate frequencies. By developing an analytical model, we find, contrary to expectation, that the net heating in this case is much larger than the sum of the effects occurring when the two frequencies act separately. This prediction is substantiated by kinetic simulations, which are also in excellent general quantitative agreement with the model for discharge parameters that are typical of recent experiments
Application to the SPIRAL project at GANIL of a new kind of large acceptance mass separator
International audienc
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