TF Ripple Loss of Alpha Particles in TFTR DT Experiments
Authors: M. H. Redi, R. V. Budny, D. S. Darrow, A. C. Janos, D. C. McCune, S. S. Medley, J. Schivell,S. D. Scott, R. B. White, M. C. Zarnstorff, S. J. Zweben and the TFTR group
Quantitative evaluation of TF ripple loss of DT alpha particles is a central issue for reactor design because of potentially severe first wall heat load problems. DT experiments on TFTR [1] allow experimental measurements to be compared to modelling of the underlying alpha physics, with code validation an important goal. Modelling of TF ripple loss of alphas in TFTR now includes neoclassical calculations of alpha losses arising from first orbit loss, stochastic ripple diffusion, ripple trapping and collisional effects. Recent Hamiltonian coordinate guiding center code (ORBIT) [2] simulations for TFTR have shown that collisions enhance the stochastic TF ripple losses at TFTR [3]. A faster way to simulate experiment has been developed which uses a simple stochastic domain model for TF ripple loss within the TRANSP analysis code [4].