In this paper we analyze the combined envelope-centroid dynamics of magnetically focused high-intensity charged beams surrounded by conducting walls. Similar to the case where conducting walls are absent, it is shown that the envelope and centroid dynamics decouple from each other. Mismatched envelopes still decay into equilibrium with simultaneous emittance growth, but the centroid keeps oscillating with no appreciable energy loss. Some estimates are performed to analytically obtain characteristics of halo formation seen in the full simulations.

Resonant active-to-active (νa → νa), as well as active-to-sterile (νa → νs) neutrino (ν) oscillations can take place during the core bounce of a supernova collapse. Besides, over this phase, weak magnetism increases antineutrino (ν) mean free paths, and thus its luminosity. Because the oscillation feeds mass-energy into the target ν species, the large mass-squared difference between species (νa → νs) implies a huge amount of energy to be given off as gravitational waves (L GWs ∼ 10 49 erg s −1 ), due to anisotropic but coherent ν flow over the oscillation length. This asymmetric ν-flux is driven by both the spin-magnetic and the universal spin-rotation coupling. The novel contribution of this paper stems from 1) the new computation of the anisotropy parameter α ∼ 0.1 − 0.01, and 2) the use of the tight constraints from neutrino experiments as SNO and KamLAND, and the cosmic probe WMAP, to compute the gravitational-wave emission during neutrino oscillations in supernovae core collapse and bounce. We show that the mass of the sterile neutrino νs that can be resonantly produced during the flavor conversions makes it a good candidate for dark matter as suggested by Fuller et al. (2003). The new spacetime strain thus estimated is still several orders of magnitude larger than those from ν difussion (convection and cooling) or quadrupole moments of neutron star matter. This new feature turns these bursts the more promissing supernova gravitational-wave signal that may be detected by observatories as LIGO, VIRGO, etc., for distances far out to the VIRGO cluster of galaxies.

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