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Furuta, Takuya

ANS RPSD 2018; 20th Topical Meeting of the Radiation Protection and Shielding Division of ANS (CD-ROM), 5 Pages, 2018/08

Recently we introduced a function in PHITS to treat tetrahedral-mesh geometry. Tetrahedral-mesh geometry is a structure composed of combination of tetrahedrons and able to construct complex objects. Tetrahedral-mesh objects can be obtained by converting polygon data using mesh generation software such as TetGen. We also implemented a function in PHITS to export tally results into the format of the three-dimensional visualization software ParaView. TetGen is able to convert the polygon data into ParaView format. Together with these tools, three-dimensional analysis can be realized for PHITS simulation using a polygon objects.

Furuta, Takuya

no journal, ,

It was difficult to construct complex three-dimensional (3D) geometries with original version of PHITS because 3D geometries in PHITS are defined by combinations of objects enclosed by simple surfaces planes, spheres, cylinders and so on. Useful software to construct 3D geometries interactively exists on the market and there are many requests from users to use such softwares in PHITS. We thus introduce a function to treat tetrahedral-mesh geometries, which is a type of polygon-mesh geometries, in PHITS. Being one of the simplest, the tetrahedral-mesh geometry is sufficiently flexible to construct complex geometries. Designing with CAD software is also possible with format conversions. In addition, we have introduced a function to create decomposition maps of tetrahedral-mesh objects at the initial process so that the computational time for transport process can be reduced. Owing to this function, transport calculation in tetrahedral-mesh geometry can be as fast as that for the geometry in voxel-mesh with the same number of meshes.

Furuta, Takuya

no journal, ,

It was difficult to construct complex three-dimensional (3D) geometries with original version of PHITS because 3D geometries in PHITS are defined by combinations of objects enclosed by simple surfaces planes, spheres, cylinders and so on. There are many requests from users to have a function which enables to import general polygon geometries into PHITS. We thus introduce a function to treat tetrahedral-mesh geometries, which is a type of polygon-mesh geometries, in PHITS. Being one of the simplest, the tetrahedral-mesh geometry is sufficiently flexible to construct complex geometries. It is also compatible with other polygon-mesh geometries by format conversions. In addition, we have developed an algorithm to reduce computational time required by the transport process in tetrahedral geometries. Owing to this algorithm, transport calculation in tetrahedral-mesh geometry can be as fast as that for the geometry in voxel-mesh with the same number of meshes.

Sato, Kaoru; Furuta, Takuya; Takahashi, Fumiaki

no journal, ,

We previously constructed average adult Japanese voxel phantoms (male: JM-103, female: JF-103) and others with various body sizes for application to dose assessment against persons with Japanese physiques. Generally, voxel phantom is not practical tool for dose assessment under various posture conditions, because of long construction term and difficulty of organ deformation. Thus, we are now constructing adult Japanese polygon male (JPM) and female (JPF) phantoms by modifying JM-103 and JF-103. In construction of JPM and JPF, the following processing were performed: (1) extraction of organ surface from JM-103 and JF-103, (2) smoothing organ surface, (3) adjustment of mass, shape and location, (4) multilayering of constructed polygon. Masses of most organs in JPM or JPF agreed with adult Japanese averages within 5%. In future, we will develop the limb operation technique for JPM and JPF. JPM and JPF with the new technique will be used for dose assessment against persons with various postures.