Transport modeling of Alcator C-Mod H-mode Magnetic Field Scan

The GACODE transport modeling suite is used to predict core temperature and density profiles

for a set of Alcator C-Mod H-mode discharges with on-axis magnetic fields varying from 2.7 to

7.8 Tesla, in order to assess the fidelity of these tools as a function of magnetic field strength.

Assessing their fidelity at high field is particularly important given recent interest in compact

fusion devices. The GACODE tools include NEO (a multi-species drift-kinetic solver that

calculates neoclassical transport), TGLF (a quasilinear gyro-Landau-fluid model which predicts

turbulent transport), and the TGYRO transport solver which utilizes both TGLF and NEO to

predict steady state temperature and density profiles for a given equilibrium and external heating

and current drive sources (taken from TRANSP runs in these cases). Established metrics will be

used to quantify the fidelity of the models as a function of magnetic field strength and TGLF

saturation rules. Uncertainties in both heating source calculations and profiles will be included.

Additional physics studies such as impact of magnetic fluctuations will be included as time

permits.