Ravindran, M. M.

Paper	Title	Page
THPL024	Computational Strategies in Optimizing a Real-Time Grad-Shafranov PDE Solver using High-Level Graphical Programming and COTS Technology	180
	L. Giannone, R. Fischer, K. Lackner MPI/IPP, Garching M. D. Cerna, J. Nagle, M. M. Ravindran, Q. Ruan, D. Schmidt, A. Veeramani, A. Vrancic, L. Wenzel National Instruments, Austin P. J. McCarthy National University of Ireland, University College Cork
	Big physics control experiments require enormous computational power to solve large problems with demanding real-time constraints. Sensors are acquired in real-time to feed mathematical routines, which then generate control outputs to real-world processes. The underlying mathematics can be sophisticated, as even non-linear PDEs have to be solved thousands of times per second. Is low-level coding of highly specialized hardware required to meet the challenge? We report on an alternative approach based on LabVIEW that addresses demanding plasma shape control in tokamaks. A variety of input signals (magnetic coils, X-ray sensors) are combined and a constrained non-linear Grad-Shafranov PDE is solved to calculate the magnetic equilibrium in under 0.5 ms with low jitter. The off-the-shelf n-core hardware and graphical software architecture is described with a strong emphasis on the seamless interplay between development system and real-time target deployment. Numerous mathematical challenges were addressed and several generally-applicable numerical and mathematical strategies proved critical to the timing goals. Several benchmarks illustrate what can be achieved with this approach.
	Poster