A CAD service for fusion physics codes

There is an increased need for coupling machine descriptions to various fusion physics codes. We present a computer aided design (CAD) service library that interfaces geometrical data requested by fusion physics codes in completely programmatic way for use in scientific workflow engines. Fusion codes can request CAD geometrical data at different levels of details (LOD) and control major assembly parameters. This service can be part of the scientific workflow that delivers meshing of the CAD model and/or variation of the parameters. In this paper we present re-engineering of the ITER tokamak using an open source CAD kernel providing standalone library of services. Modelling of the machine is done with several LOD, starting from the rough one and building/replacing with more detailed models by adding more details and features. Such CAD modelling of the machine with LODs delivers flexibility and data provenance records for the complete CAD to physics codes workflow chain.