Layer shape development

[daveweisberg]

Summary:

A new layer shape has been added named rectangle_ellipse. This is a simple version of the double_ellipse shape in which the inboard ellipses have radius = 0, and are therefor right angles instead of curves.

In addition to this new shape, the vertical_clearance calculation has been modified so that vertical_clearance is equal to the inboard clearance (instead of an average of the inboard and outboard clearances). This is a more efficient use of vertical space.

Example:

The FPP case with rectangle_ellipse blanket, shield, and vacuum vessel looks like this:

Unfinished work:

The optimize_outline function in cx_actor.jl is not correctly adjusting the height of the TF shape princeton_D_scaled to avoid overlaps with interior layers. As a temporary work-around, the TF coil has been removed from the layers that are optimized by optimize_outline. An example of the problem is shown here:

Ideally, the height of the princeton_D_scaled TF shape would be optimized to avoid any overlaps, and to conform to the requested vertical_clearance. But for now, excluding the TF layer from this results in a non-optimized TF shape that seems to be ok for this case.