Density propagation and triggering of ELMs following pellet injection in DIII-D Plasmas

New observations have been made on DIII-D of pellet ablation striations from high field side (HFS) and low field side (LFS) injected D2 and H2 pellets leading to density pulses with soliton like structure propagating along field lines in both directions from the ablation location.  Previously, density pulses observed to be propagating along field lines from HFS injected pellets were in plasmas with q95 = 6.  Now pulses have also been observed from HFS and LFS pellets at lower more ITER like q95 = 3.6.  Despite the ExB drift of pellet mass in the major radius direction and the triggering of ELMs, there are some cases of LFS injected pellets showing this field line  propagation effect.  The summary of density pulses and triggering of ELMs observed thus far are presented along with a comparison with the dynamics of density propagation predicted using the Pellet Relaxation Lagrangian code.  Implications for refining pellet deposition fueling models and the triggering of ELMs in large burning plasmas are discussed.