2,540 research outputs found
Modification of surface energy in nuclear multifragmentation
Within the statistical multifragmentation model we study modifications of the
surface and symmetry energy of primary fragments in the freeze-out volume. The
ALADIN experimental data on multifragmentation obtained in reactions induced by
high-energy projectiles with different neutron richness are analyzed. We have
extracted the isospin dependence of the surface energy coefficient at different
degrees of fragmentation. We conclude that the surface energy of hot fragments
produced in multifragmentation reactions differs from the values extracted for
isolated nuclei at low excitation. At high fragment multiplicity, it becomes
nearly independent of the neutron content of the fragments.Comment: 11 pages with 13 figure
Control of the woolly apple aphid (Erisoma lanigerum Hausm.) by releasing earwigs (Forficula auricularia L.) and support oil applications - an interim report of first year results
The woolly apple aphid (Erisoma lanigerum Hausm.) has been recognised for some years as
a serious pest in organic fruit growing where they may cause severe economic damage due
to a lack of control strategies. Based on preliminary results a new project has been started in
2007 testing combinations of releasing earwigs and oil applications in order to develop an onfarm
control strategy. In this paper we present preliminary results of the first year of the
project´s field trials. They showed good efficacies for applying oil preparations by brush. The
efficacy of releasing earwigs depended on the infestation intensity
Mechanisms for Direct Breakup Reactions
We review some simple mechanisms of breakup in nuclear reactions. We mention
the spectator breakup, which is described in the post-form DWBA. The relation
to other formulations is also indicated. An especially important mechanism is
Coulomb dissociation. It is a distinct advantage that the perturbation due to
the electric field of the nucleus is exactly known. Therefore firm conclusions
can be drawn from such measurements. Some new applications of Coulomb
dissociation for nuclear astrophysics are discussed.Comment: 17 pages, 5 figures, to appear in the proceedings of the RCNP-TMU
Symposium on Spins in Nuclear and Hadronic Reactions, October 16-18 199
State-Dependent Optical Lattices for the Strontium Optical Qubit
We demonstrate state-dependent optical lattices for the Sr optical qubit at
the tune-out wavelength for its ground state. We tightly trap excited state
atoms while suppressing the effect of the lattice on ground state atoms by more
than four orders of magnitude. This highly independent control over the qubit
states removes inelastic excited state collisions as the main obstacle for
quantum simulation and computation schemes based on the Sr optical qubit. Our
results also reveal large discrepancies in the atomic data used to calibrate
the largest systematic effect of Sr optical lattice clocks.Comment: 6 pages, 4 figures + 6 pages supplemental materia
Local formation of nitrogen-vacancy centers in diamond by swift heavy ions
We exposed nitrogen-implanted diamonds to beams of swift uranium and gold
ions (~1 GeV) and find that these irradiations lead directly to the formation
of nitrogen vacancy (NV) centers, without thermal annealing. We compare the
photoluminescence intensities of swift heavy ion activated NV- centers to those
formed by irradiation with low-energy electrons and by thermal annealing. NV-
yields from irradiations with swift heavy ions are 0.1 of yields from low
energy electrons and 0.02 of yields from thermal annealing. We discuss possible
mechanisms of NV-center formation by swift heavy ions such as electronic
excitations and thermal spikes. While forming NV centers with low efficiency,
swift heavy ions enable the formation of three dimensional NV- assemblies over
relatively large distances of tens of micrometers. Further, our results show
that NV-center formation is a local probe of (partial) lattice damage
relaxation induced by electronic excitations from swift heavy ions in diamond.Comment: to be published in Journal of Applied Physic
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