scuff-cas2d is a command-line utility
very similar to
but with the difference that it computes Casimir interactions
among quasi-2D objects instead of compact 3D objects.
(A quasi-2D object is an object of infinite extent in one spatial
dimension, which we take to be the z dimension, and constant
cross section in the transverse (xy) dimensions.)
Actually, scuff-cas2d is not really part
of the scuff-em suite, but
more of a standalone code that is bundled together with the
scuff-em distribution because of its
similarity to scuff-cas3d. The main
distinction is that, instead of using
RWG basis functions
to describe surface currents,
scuff-cas2d uses a different type
of basis function, which I call ``two-dimensional rooftop'' (TDRT)
functions. (See Chapter 7 of
my PhD thesis
for more info on TDRT functions and the implementation of
This means that scuff-cas2d -- in
contrast to scuff-cas3d and all other
codes in the scuff-em suite -- does not
use the scuff-em core library or the
.scuffgeo file format for
scuff-em geometries. Instead,
for quasi-2D geometries there is a slightly different file
format and a slightly different procedure for generating meshed
geometries. These details are discussed in the tutorial and in
the reference sections below.
computes Casimir energies and forces per unit length
for a collection of quasi-2D objects, at various
displacements and rotations of the objects.
The basic flow of a scuff-cas2d run goes
something like this:
You create a 2D mesh file for each distinct object in your
geometry. (scuff-cas2d doesn't do the
meshing for you; you use external software like
COMSOL for that.)
You create a simple text file that lists all the objects in your
geometry and specifies their frequency-dependent material properties.
(As noted above, the format of this file is similar, but not identical,
to that of the usual
.scuffgeo files used to define
three-dimensional scuff-em geometries).
You create a second simple text file containing a list of
transformations to be applied to the geometry, where
each transformation is a series of displacements and rotations
applied to one or more of the objects in your geometry.
You run scuff-cas2d with appropriate
command-line options to compute Casimir energies and forces
per unit length for your geometry under each of the
transformations you described.
Finally, you interpret the variety of output files that
scuff-cas2d emits. In general the
one you will care most about is the
which simply lists the computed energy and force
per unit length at each of the transformations you specified.
The documentation for scuff-cas2d is divided into the