TRANSP

TRANSP^[1] is a computer code used to analyze the results of plasma experiments, typically related to fusion energy, performed with a Tokamak device. TRANSP is developed and maintained at the Princeton Plasma Physics Laboratory (PPPL) at Princeton University. TRANSP continues to be extended and is presently widely used worldwide.^[2]

TRANSP uses Fortran, C/C++, Java, Python, Perl, Bash and C shell scripts. It supports OpenMP, OpenMPI, and OpenACC. It is stored on GitHub. It uses Monte Carlo methods with message passing interface (MPI) processing for computing kinetic properties of fast ions, such as neutral beam injected ions and fusion alpha particles. ^[3] The properties include the distributions of density and energy of these ions. It incorporates an electromagnetic wave solver for computing effects of ion cyclotron plasma heating. Some modules are MPI and some are GPU (graphics processing unit) compatible. TRANSP can run on an arbitrary number of parallel processors.

TRANSP was the first integrated code used for studying phenomena within the plasma boundary of tokamak discharges. It integrates complex interactions among diverse physical processes. It is used to compute properties which cannot be measured directly, such as the radial transport of plasma species, energy, toroidal momentum, and angular momentum. It computes the effects of actuators used to heat and fuel the plasma. It simulates parameters that can be compared with measurements to verify the accuracy and credibility of the digital model.

TRANSP has been used to predict results of future experiments. One early example is a prediction of fusion reaction rates expected from the deuterium-tritium experiments in Tokamak Fusion Test Reactor (TFTR) at PPPL.^[4]