Gemma: Development of a two-dimensional neutron transport code with the method of characteristics

This work describes the development of Gemma code, a next generation neutron transport solver capable of employing accurate solution methods with the ability to incorporating the latest computing techniques and providing a flexible developmental environment. The Gemma code is a 2D method of characteristics solver, which was written completely in the D programming language. In doing so, flexibility is provided on two fronts, for the end user and future developers. Users interact with the code through an input text file where the geometry, materials and calculation parameters are specified with input cards. This approach eliminates the need for leaning any programming language and any errors found are presented clearly.