arXiv subjects

M. Nolte

Publications and source records attributed to M. Nolte.

3 recordsLinked to original sources

arXiv2015

Intermediate Mass Fragment Emission in ${^{32}}$S +${^{51}}$V, ${^{109}}$Ag, and ${^{238}}$U Collisions at E~=~31.6~MeV~A

Intermediate mass fragment emission for reactions of $^{32}\text{S} +\,^{51}\text{V},\,^{109}$Ag, and $^{238}\text{U}$ has been studied. Double differential cross sections were analysed in terms of the generalised moving source model yielding charge distributions. Isotope ratios show strong fragment mass dependencies. The data were successfully reproduced by the coalescence model as well as by statistical multifragmentation model calculations. Quantum molecular dynamics model calculations were not so successful.

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arXiv2008

Correlations of projectile like fragments in heavy ion reactions at Fermi energy

Correlations between pairs of projectile-like fragments, emitted by the system ${^{16}O}+{^{197}Au}$ at the laboratory bombarding energy of 515 MeV, have been studied under two stipulated conditions: (1) at least one member of the pair is emitted at an angle less than the grazing angle for the system, (2) both the members of the pair are emitted at angles larger than the grazing angle. A surprisingly large difference, by more than an order of magnitude, is found between the correlations for the two cases. This observation could be explained on the basis of a simple semi-classical break up model. Further analysis of the variation of the charge correlation function with the difference in the nuclear charges of the correlated pair showed trends which are consistent with an "inelastic break up process", in which the projectile breaks up at the radius of contact, in such a way that, one fragment (preferably the lighter) is emitted to one side within the grazing angle, while the other orbits around the target nucleus for a while and emerges on the other side, at a negative scattering angle, much like in a deep inelastic scattering.

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arXiv2006

Well-Balanced Schemes for the Initial Boundary Value Problem for 1D Scaler Conservation Laws

We consider well-balanced schemes for the following 1D scalar conservation law with source term: d_t u + d_x f(u) + z'(x) b(u) = 0. More precisely, we are interested in the numerical approximation of the initial boundary value problem for this equation. While our main concern is a convergence result, we also have to extend Otto's notion of entropy solutions to conservation laws with a source term. To obtain uniqueness, we show that a generalization, the so-called entropy process solution, is unique and coincides with the entropy solution. If the initial and boundary data are essentially bounded, we can establish convergence to the entropy solution. Showing that the numerical solutions are bounded we can extract a weak*-convergent subsequence. Identifying its limit as an entropy process solution requires some effort as we cannot use Kruzkov-type entropy pairs here. We restrict ourselves to the Engquist-Osher flux and identify the numerical entropy flux for an arbitrary entropy pair. By the uniqueness result, the scheme then approximates the entropy solution and a result by Vovelle then guarantees that the convergence is strong in L^p for finite p.

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