5,677 research outputs found
A mapping approach to synchronization in the "Zajfman trap". II: the observed bunch
We extend a recently introduced mapping model, which explains the bunching
phenomenon in an ion beam resonator for two ions [Geyer, Tannor, J. Phys. B 37
(2004) 73], to describe the dynamics of the whole ion bunch. We calculate the
time delay of the ions from a model of the bunch geometry and find that the
bunch takes on a spherical form at the turning points in the electrostatic
mirrors. From this condition we derive how the observed bunch length depends on
the experimental parameters. We give an interpretation of the criteria for the
existence of the bunch, which were derived from the experimental observations
by Pedersen et al [Pedersen etal, Phys. Rev. A 65 042704].Comment: 25 pages, 6 figures; added new section 5 and clarified text;
submitted to J. Phys.
The basic cohomology of the twisted N=16, D=2 super Maxwell theory
We consider a recently proposed two-dimensional Abelian model for a Hodge
theory, which is neither a Witten type nor a Schwarz type topological theory.
It is argued that this model is not a good candidate for a Hodge theory since,
on-shell, the BRST Laplacian vanishes. We show, that this model allows for a
natural extension such that the resulting topological theory is of Witten type
and can be identified with the twisted N=16, D=2 super Maxwell theory.
Furthermore, the underlying basic cohomology preserves the Hodge-type structure
and, on-shell, the BRST Laplacian does not vanish.Comment: 9 pages, Latex; new Section 4 showing the invariants added; 2
references and relating remarks adde
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