by Doug McCune, PPPL
This module implements the Kadomtsev Sawtooth Mixing Model and the
Porcelli Sawtooth Mixing Model for axisymmetric tokamaks in general
geometry. The module is initialized by calls to "kdsaw_pre_init" and
to "kdsaw_init", the former specifying the mixing model selection, and
the latter providing a grid, the iota(bar) (1/q) profile, and zone volumes;
kdsaw_init computes the Kadomtsev or Porcelli mapping and stores it in the
module's internal memory. Subsequent calls are used to extract specific
information about the sawtooth mixing. The grid passed to kdsaw_init is
specified in normalized square-root-toroidal-flux, a coordinate which
functions in a way strictly analogous to the minor radial coordinate "r"
in Kadomtsev's original paper, but is suitable for general geometry. The
grid is given explicitly and need not be evenly spaced. The current profile
is expressed as (1/q), and the zone volumes (in any suitable units) are
used to adjust the mapping such that a change in a particle or energy
density profile according to the ideal Kadomtsev mapping volume integrates
to precisely zero: typically, a peaked density profile is flattened, with
the density reduced in the center and raised at the edge of the mixing
region. A user-adjustable current profile remapping is also provided.
Both REAL and REAL*8 interfaces are provided to all routines in the module.
 Sov. J. Plasma Phys. Vol. 1 No. 5 Sept. Oct. 1975, p. 389.
 Porcelli et al., Plasma Physics & Controlled Fusion 38 (1996) p. 2163, (See section 4).