TORAY-GA

TORAY-GA was installed in Transp in Decenber, 2003. It is a ray tracing code that is used for modeling heating and current drive during ECRH in tokamaks. TORAY-GA computes contributions to electron cyclotron heating (ECH) and current-drive (ECCD) sources. The version in TRANSP includes the Y.R. Lin-Liu adjoint formulation with collisionality correction factors that reduce the trapped electron fraction. Other revisions include improving the power integration along the arc length, the addition of an aspect ratio dependence in the J/P current drive efficiency, and an improved evaluation of the poloidal angle used to calculate the local value of the major radius.

Input parameters

In addition to the input parameters common to all EC modules, TORAY accepts the following inputs variables

NPROFTOR
number of TORAY zones, default is 41.
NDAMPECH (j=1:nantech)
damping model, default is 2.
NRAYECH (j=1:nantech)
Number of rays, default is 30.
BHALFECH (j=1:nantech)
divergence angle (degrees) defined as the half angle at half power for a given gaussian profile. The default is 1.7.
BSRATECH (j=1:nantech)
Aspect ratio of the beam; default is 1.0, corresponding to a circular beam.
EFFECH (j=1:nantech)
effective current drive efficiency correction applied to the output current; the default is 1.0.

Important: by default, TORAY-GA uses a template stored in the TRANSP repository. However, users can have their own template and select different options for the model used for current drive and for heating, as well as different dispersion relations.
To use a different template, download the TORAY template, copy it somewhere locally and provide the path to this file in the TRANSP namelist, EC section, as follows:
TORAY_TEMPLATE='the path to your template'
When TRDAT runs, it will process this template and use it, instead of the default template.

If in doubt, run TRDAT and you will notice that a new file has been created in your local directory where you are running TRDAT. This is a copy of teh default template for TORAY. Modify it as needed and set the path to this file.

Project sponsored by the Office of Fusion Energy Sciences of the US DOE