Public defense of the doctoral dissertation will be held on June 9th 2007 at 12 o'clock in auditorium D101 of the Department of Physical Sciences of the University of Helsinki, Finland.
VTT's MultiTrans programme enables modelling of radiation transport in arbitrary 3D geometry. The computational geometry is generated directly from a CAD-model, which makes it possible to use modern design tools. The computational grid is tree-structured and self-adaptive at the material boundaries, where the mesh automatically becomes the finest. With this method, even a complicated geometry can be represented in fine detail without an excessive number of grid points compared to equidistant mesh.
The tree-structure makes it possible to always find a coarser representation for the problem. This enables the use of multigrid method in iterative solution of the transport equation: the problem can be quickly solved on a much coarser grid, and this solution can then be used as an initial guess for the solution on finer grids. Multigrid method accelerates the iterative solution significantly. In addition, the tree structure leads to a smaller number of grid points, which also makes the iterative solution faster. To VTT's knowledge, this is the first application of the tree-multigrid technique to the radiation transport modelling.
The MultiTrans programme has been tested for different radiotherapy, such as boron neutron capture therapy (BNCT) given at VTT's nuclear research reactor, and for reactor physics applications. So far, the MultiTrans programme has been in use only at VTT.
When high accuracy is required, the simplified spherical harmonics approximation of the radiation transport used in MultiTrans has, in some cases, turned out to be problematic. More accurate methods will be studied further.
Press Office | alfa
Data analysis optimizes cyber-physical systems in telecommunications and building automation
18.01.2017 | Fraunhofer-Institut für Algorithmen und Wissenschaftliches Rechnen SCAI
Brain-Computer Interface: What if computers could intuitively understand us
18.01.2017 | Technische Universität Berlin
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Materials Sciences
18.01.2017 | Information Technology
18.01.2017 | Ecology, The Environment and Conservation