Well, from the console I see that your quality is quite good! min = 0.7. The wavy appearance could be due to the fact that each one of the 500 splits has no curve entitity to be associated with. ICEM is simply projecting the edges of each split to the nearest surface, causing the non-smooth appearence of the shell elements. However, if you still want to fix the appearance (and perhaps gain a bit of quality) you can:
1) Introduce a few circles (curve entities) along the helix, starting at one of the ends, perhaps 4 or 5. Associate with the corresponding edges and see if the mesh appearance improves.
2) If so, then you can do the same for the other 495 circles. Perhaps you want to draw the circles in an external CAD software and then import the .tin file to the actual project.

Also, at least visually it looks like each split is equally spaced. Is that the case? And the number of nodes along the helix is equal for each split?