***************************************************************
**
**  SOFT X-RAY DIAGNOSTIC
**  
***************************************************************
**
**  softxry="enabled" means that the diagnostic will be utilized.
**            Electron-ion and electron-electron collisions are
**            included, as described in the report CompX-02-2000.
**            Ions are treated as single species of charge Zeff,
**            density n_e.
**            X-ray spectra are added to the .nc file at the first
**            and last steps.
**          "ncdf_all" same as "enabled" except spectra for all
**            time steps is stored in the netCDF file (rather than
*             just the first and last time steps).
**          "e-ion", is a non-physical diagnostic mode which
**                   includes only e-ion collisons (no e-e).
**           default: softxry="disabled"
**
**  A right-hand cartesian x,y,z-coordinate system is assumed,
**  with the z-axis along the symmetry axis of the toroidal
**  device.
**
**  Toroidal geometry with circular or non-circular flux surfaces 
**  is assumed (depending on eqmod namelist variable).
**  The detector is assumed to be located outside the plama,
**    and without loss of generality, to be in the x-z 
**    plane (y=0.).
**  Detector location is specified by either
**    (a) rd(1:nv),thetd(1:nv): minor radius (cm) 
**                   measured from the magnetic 
**                   axis, and poloidal angle (degs) measured 
**                   from the x-axis in right-hand
**                   sense about the negative y-axis
**                   (defaults: rd(*)=100., thetd(*)=0.).
**       or, if the first elements of either of the following 
**       two inputs is .ne.0., use:
**    (b) x_sxr(1:nv),z_sxr(1:nv): the x,z-location (cm) of the detector.
**                   (defaults: x_sxr(:)=0., z_sxr(:)=0.)
**
**  nv=number of viewing cords.
**          Must be .le. nva (in param.h).
**
**  Detector viewing coords are specified by two angles,
**    (in the manner of the GENRAY and TORAY ray tracing codes):
**    thet1(1:nv)=polar angle measured from the z-axis (degs).
**                (90. deg is horizontal).  default: 90.
**    thet2(1:nv)=toroidal angle of the viewing coord, measured 
**          from the x-z plane (y=0.) in right-hand-sense with 
**          respect to the z-axis direction (degs).
**          (0. is in +R major radius dirn, 
**           180. is in -R major radius direction.)  default: 180.
**    We have detector direction vector x,y,z-components:
**          detec_x=sin(thet1)*cos(thet2)
**          detec_y=sin(thet1)*sin(thet2)
**          detec_z=cos(thet1)
**          
**  nen=number of energies at which spectral values calculated,
**          for each sightline.
**          Must be .le. nena (presently set to 30, in param.h).
**  enmin,enmax=minimum,maximum energy in the 
**              calculated spectra(keV). (defaults: 5., 50.)
**  msxr is the order of the highest polynomial used in the Legendre
**     expansion for computing SXR spectra 
**     (default value: msxr=mx in aindflt.f).
**     (Prior to 3/31/2011, msxr could not be greater than mx,
**      else reset to mx. Now, this restriction removed.  BH)
**     Values of .ge.8 are recommended.
**
**  fds= specifies the step size along the viewing cord, as a 
**     fraction of the average radial width of each radial bin 
**     (0.2 is a reasonable value).
**
***************************************************************